pmc02313352915ChestChestChest0012-36921931-3543394909741198531010.1016/j.chest.2024.10.033HHSPA2033733ArticlePatterns and Differences in Lung Cancer Treatment — United States, 2015–2020KavaChristine M.PhD12SiegelDavid A.MD2QinJinScD2SabatinoSusan A.MD2WilsonRedaMPH2WuManxiaMD2Epidemic Intelligence Service, Centers for Disease Control and Prevention, Atlanta, GADivision of Cancer Prevention and Control, National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention, Atlanta, GACorresponding author: Christine M. Kava, PhD, MA, Division of Cancer Prevention and Control, Centers for Disease Control and Prevention, 4770 Buford Hwy NE, Atlanta, GA 30341. tqz1@cdc.gov.1411202442025261020241142025167412181231Background:

Treatment for lung cancer can improve prognosis, but 5-year survival remains low at 26%. An examination of treatment using data with higher population coverage, and among a broader number of treatment modalities and individual characteristics, would provide greater insight into differences in lung cancer treatment.

Research Question:

Among adults diagnosed with lung cancer, how does reported receipt of lung cancer treatment differ by sociodemographic characteristics?

Study Design and Methods:

We used 2015–2020 National Program of Cancer Registry data covering 89% of the US population to describe first-course treatment among persons ages ≥20 years diagnosed with lung and bronchus cancer. We performed multivariable logistic regression to examine associations between sociodemographic characteristics and treatment received.

Results:

Among 1,068,155 people diagnosed with lung cancer, 22% received surgery, 41% received chemotherapy, 40% received radiation, 13% received immunotherapy, and 75% received at least one of the four treatments. People who were ages ≥45 years (odds ratio [OR] range=0.08–0.67); American Indian or Alaska Native (OR=0.82; 95% CI: 0.77–0.87), Black (OR=0.82; 95% CI: 0.81–0.84), or Hispanic (OR=0.80; 95% CI: 0.78–0.82); resided in a non-metropolitan county (OR=0.98; 0.96–0.99); resided in the bottom 25% (OR=0.80; 95% CI: 0.78–0.81) and middle 50% (OR=0.87; 95% CI: 0.86–0.88) of counties by economic status (considers unemployment rate, per capita market income, and poverty rate); and in the West US census region (OR=0.95; 95% CI: 0.94–0.97) had significantly lower odds of receiving at least one of the four treatments.

Interpretation:

Chemotherapy and radiation were the most common types of first-course treatment reported. Receipt of at least one of the four treatments examined was lower among several groups, including certain racial and ethnic groups and those residing in counties with lower economic status. Future studies might further identify and intervene upon factors underlying differences.

disparitiesdrug therapylung cancerNational Program of Cancer Registriestherapeutics

Between 2014–2020, lung cancer had a five-year relative survival of 28%.1,2 Standard treatments for lung cancer include surgery, chemotherapy, radiation, and immunotherapy. Treatment varies according to several factors, including histology (e.g., non-small cell vs. small cell lung cancer) and stage.3,4 Treatment can improve lung cancer survival and reduce mortality,5-7 especially when diagnosed at earlier stages of disease.8

Previous studies have reported differences in lung cancer treatment by sociodemographic characteristics and have primarily focused on surgery, chemotherapy, and radiation. Studies using Surveillance, Epidemiology, and End Results (SEER) cancer registry data,9 which covered approximately 35% of the US population in 2018,10 have found lower treatment rates among people who are male, Black or African American, who have lower levels of socioeconomic status, and in rural vs. urban counties.11-14 An examination of data with higher population coverage, and among a broader number of treatment modalities and sociodemographic characteristics, would provide additional insight into differences in lung cancer treatment.

This study describes first-course lung cancer treatment patterns between 2015–2020 by sociodemographic characteristics. Our study used data available on lung cancer treatment from the Centers for Disease Control and Prevention’s (CDC’s) National Program of Cancer Registries (NPCR).15 This study examined receipt of surgery, chemotherapy, and radiation, as reported by cancer registries. We also examined reported receipt of immunotherapeutic (biologic response modifiers) agents, defined as biological or chemical agents that modify the immune system or body’s response to tumor cells to fight cancer.16 Immunotherapy is a relatively new and promising approach to treating lung cancer.17,18 To date, there is limited information on the prevalence of this treatment among persons with lung cancer.

Study Design and MethodsData and Sample

Our population-based study used data from NPCR,19 a national surveillance system that captures information on newly diagnosed cancer cases in the United States. NPCR collects cancer registry data in 46 states, District of Columbia, and three US territories.15 Institutional Review Board approval was exempted under the Common Rule (45 CFR §46) because we used de-identified data.

Cancer is diagnosed in multiple settings, including hospitals and cancer treatment centers.20 Information about the cancer diagnosis, including first-course treatment, is recorded in the patient’s medical chart.20 A local cancer registrar identifies the cancer case through different notification systems, reviews the patient’s medical chart, and records information into a local registry database.20 Local registry data are reported to central cancer registries, where the data are reviewed, consolidated, and sent to CDC annually.20 The North American Association of Central Cancer Registries21 provides standards on how to collect and code cancer registry data.

Our dataset included adults diagnosed with lung and bronchus [lung] cancer between 2015–2020. We defined lung cancer using a predefined SEER site recode variable based on International Classification of Diseases for Oncology, Third Edition (ICD-O-3) site codes C340–C349.22,23 We restricted our analysis to 41 states and District of Columbia, which cover 89% of the US population (Figure 1).

Data from five central cancer registries were excluded: two registries (Indiana and Nevada) did not meet data quality standards for all years between 2015–2020; two registries (Kansas and Minnesota) did not have available county-level data needed to calculate county economic status; and one registry (Virginia) had a coding issue affecting the quality of data for county economic status. We further restricted our analysis to adults ages ≥20 years at diagnosis. We included malignant cases only and excluded cases identified by death certificate or autopsy only. We also excluded data reported from non-hospital settings due to low level of completeness.

Measures

Our primary outcomes were first-course treatment, defined as the first cancer-directed treatment(s) administered to the person.24 First-course treatment ends when the treatment plan is completed; in the event of disease progression, recurrence, or treatment failure; or after one year of the date of diagnosis if there is no documented treatment plan.25 We examined whether individuals were reported to have received surgery, chemotherapy, radiation, immunotherapy, and at least one of the four treatments (1=yes vs. 0=no) as the first course of treatment. Immunotherapy was defined as immunotherapeutic (biologic response modifiers) agents, including targeted therapies that evoke an immune response.16 People whose treatment was coded as “unknown” in the database were recoded to missing for our analysis. For each treatment, among people reported as not receiving treatment, we examined the reason recorded for this decision.

We included information on the following characteristics: age at diagnosis (20–44, 45–54, 55–64, 65–74, 75–84, and ≥85 years), sex (female and male), reported race and ethnicity (non-Hispanic [NH] American Indian and Alaska Native [AI/AN], NH Asian and Pacific Islander [Asian/PI], NH Black [Black], NH White [White], and Hispanic), county classification (metropolitan and non-metropolitan), county economic status (bottom 25%, middle 50%, and top 25%), and US Census region (Northeast, Midwest, South, and West). County economic status was defined for 2018 by the Appalachian Regional Commission26 and considers three-year average unemployment rate, per capita market income, and poverty rate. We defined county classification based on the 2013 National Center for Health Statistics Urban-Rural Classification Scheme for Counties.27

We also included information on cancer histology, summary stage at diagnosis (localized, regional, and distant), and year of diagnosis (2015–2020). Similar to previous papers,28 histology groups were defined using ICD-O-3 codes. Non–small cell carcinomas included adenocarcinoma (8140–8239; 8250–8384; 8440–8490; 8550–8551; 8570–8574; 8576), squamous cell carcinoma (8050–8084), and other histology (8000–8040; 8046–8049; 8085–8139; 8240–8249; 8385–8439; 8491–8549; 8552–8569; 8575; 8577–9992). Small–cell carcinoma was defined by codes 8041–8045.

Between 2015–2020, NPCR collected information on cigarette smoking [smoking] status (currently smoked, formerly smoked, and never smoked) in 10 states.29,30 We examined smoking status in eight states meeting NCPR data quality standards: Alaska, California, Colorado, Florida, Idaho, Louisiana, New Hampshire, and Texas.

Data Analysis

Analyses were conducted in R Studio 4.1.0.32 We produced descriptive statistics for all variables and conducted bivariate analyses to examine each treatment received (surgery, chemotherapy, radiation, immunotherapy, at least one of the four treatments) by sociodemographic and cancer characteristics. We ran five separate logistic regression models—one for each treatment outcome—to predict odds of receipt of treatment. We imputed missing data (m = 20 imputations, where m = the number of complete datasets in which missing values were generated for) using the aregImpute function from the Hmisc package33 in R. We included all candidate predictors and the four individual treatment outcomes in the multiple imputation process.

Each regression model included age at diagnosis, sex, race and ethnicity, county classification, county economic status, US census region, histology, stage at diagnosis, and year of diagnosis. From the regression models, we estimated adjusted average predicted probabilities of receiving treatment. We conducted subgroup analyses—with smoking status included as a covariate—in the eight states listed above. As a sensitivity analysis, we also restricted our analysis to people diagnosed with first primary tumors only.

Results

Our analytic sample comprised 1,068,155 individual diagnoses. The percentage of people that were reported to have received surgery, chemotherapy, radiation, or immunotherapy was 22%, 41%, 40%, and 13%, respectively (Table 1). Three-fourths of people (75%) were reported to have received at least one of the four treatments. Conversely, treatment was not reported for 25% of people. Not being planned as part of first-course treatment was the primary reason (range: 84–98%) for reported non-receipt recorded for each treatment (e-Table 1).

The largest proportions of people were 65–74 years old at diagnosis (36%), male (51%), and White (81%). Eighty-seven percent of people were diagnosed with non-small cell carcinoma and 13% were diagnosed with small cell carcinoma. Of the eight states where smoking status was collected, 80% (n=240,848) of people had available data on this measure. Of these people, 51% formerly smoked, 33% currently smoked, and 16% had never smoked.

The largest differences in reported receipt of treatment were observed by age at diagnosis, histology, and stage at diagnosis (Table 2). The largest variations in receipt of treatment were generally observed for surgery. For example, 26% of people residing in the top 25% of counties by economic status were reported to have received surgery, compared to 17% residing in a county in the bottom 25%.

People ages ≥45 years (vs. ages 20-44) had generally lower odds of reported treatment (Table 3). Females vs. males had higher odds of surgery and lower odds of chemotherapy, radiation, and immunotherapy. People reported as AI/AN vs. White had lower odds of surgery, chemotherapy, and immunotherapy; there was not a statistically significant difference for radiation. People reported as Asian/PI vs. White had higher odds of surgery and chemotherapy and lower odds of radiation and immunotherapy. People reported as Black vs. White had lower odds of surgery, chemotherapy, and immunotherapy; no statistically significant difference was observed for radiation. People reported as Hispanic vs. White had higher odds of surgery and lower odds of radiation and immunotherapy; there was not a statistically significance difference for chemotherapy.

People residing in non-metropolitan vs. metropolitan counties had lower odds of surgery and higher odds of chemotherapy, radiation, and immunotherapy. People in the Northeast and Midwest vs. South had higher odds of reported receipt of all four treatments. People in the West vs. South had higher odds of surgery and lower odds of chemotherapy, radiation, and immunotherapy. People residing in counties in the bottom 25% and middle 50% vs. top 25% by economic status had lower odds of surgery, chemotherapy, and immunotherapy, and higher odds of radiation.

People with small cell carcinoma and squamous cell carcinoma vs. adenocarcinoma had lower odds of surgery and immunotherapy, and higher odds of chemotherapy and radiation. People with other histology types had lower odds of reported receipt of all four treatments. People diagnosed at the localized and regional vs. distant stage had higher odds of surgery and lower odds of immunotherapy. People diagnosed at the localized stage had lower odds of chemotherapy and radiation, while people diagnosed at the regional stage had higher odds of reported receipt of these treatments. By year of diagnosis, people diagnosed in 2016 or later vs. 2015 had lower odds of surgery and generally higher odds of radiation and immunotherapy. Odds of chemotherapy were lower for years 2017 and later; there was no statistically significant difference in receipt of chemotherapy between 2016 vs. 2015.

When modeling odds of reported receipt of at least one of the four treatments, people who were older; reported as being AI/AN, Black, or Hispanic; resided in non-metropolitan counties; resided in the bottom 25% and middle 50% of counties by economic status; resided in the West US census region; diagnosed with small cell carcinoma, squamous cell carcinoma, or other histology; and diagnosed in 2017 and 2020 had lower odds of treatment. In contrast, people who were female; Asian/PI; resided in the Northeast and Midwest US census regions; and diagnosed at the localized and regional stages had higher odds of treatment. There were no statistically significant differences in receipt of treatment between 2016, 2018, and 2019 vs. 2015.

The largest differences in the mean predicted probability of receiving at least one of the four treatments were observed by age at diagnosis (0.90 for 20–44 years vs. 0.48 for ≥85 years), histology (0.81 for adenocarcinoma vs. 0.62 for other histology), and stage at diagnosis (0.84 for localized vs. 0.64 for distant) (e-Table 2).

In our analysis among the eight states that included smoking status as a covariate (Table 4), people who currently and formerly smoked vs. never smoked had lower odds of surgery and higher odds of radiation and immunotherapy. People who currently vs. never smoked had lower odds of chemotherapy and at least one of the four treatments. People who formerly smoked had higher odds of receiving at least one of the four treatments; we did not find a statistically significant difference for receipt of chemotherapy between people who formerly vs. never smoked. Our findings for treatment between models with and without smoking status included were generally similar. Our findings were also generally comparable when restricting our main analyses to people with first primary tumors only (n=791,665) (e-Table 3).

Discussion

We used 2015–2020 NPCR data to describe patterns in first-course treatment for lung cancer and examine differences in treatment. Reported receipt of at least one treatment was lower among several groups, including males; people reported as AI/AN, Black, or Hispanic; and people residing in counties designated as non-metropolitan and with lower economic status. Our findings align with previous studies that have found similar differences in lung cancer treatment by sex, race and ethnicity, socioeconomic status, and rural vs. urban status.11-14

As noted earlier, lower treatment proportions have been observed among people who are male, Black or African American, who have lower levels of socioeconomic status, and who live in rural vs. urban counties.11-14 Possible reasons that these differences exist include inequitable receipt of guideline-concordant treatment due to unequal healthcare access,34,35 presence of co-morbidities,36 and individual preferences for treatment.37 For example, Harrison et al.34 highlight lower rates of curative-intent surgery for early-stage lung cancer and lower receipt of guideline-concordant treatment among Black vs. White individuals. The authors describe multiple factors, including unequal healthcare access as noted above, and mistrust of the healthcare system among Black individuals due to historical mistreatment and discrimination,38,39 that could explain these differences.34

Interventions that identify and address underlying causes leading to a lower percentage of people treated for lung cancer among specific populations may improve differences in treatment. For example, the Accountability for Cancer Care through Undoing Racism and Equity (ACCURE) study tested an intervention to improve cancer treatment quality and completion among people with early-stage lung cancer and breast cancer.40 The intervention included a real-time registry system that triggered warnings for missed appointments and treatment delays, feedback to clinical care teams on cancer treatment completion by race, and nurse navigation.40 The authors found a significant reduction in Black-White differences in treatment completion in the intervention vs. control group.40 Continued efforts like ACCURE to improve treatment differences may reduce the burden of lung cancer among groups most impacted by this disease.

The most common treatments in our study were chemotherapy (41%), radiation (40%), and surgery (22%). Ahmed et al.11 found comparable treatment rates for surgery (22%) and radiation (43%), while Williams et al.12 found that 16% and 25% of SEER and Veterans Administration patients did not receive any treatment, respectively. Reported receipt of chemotherapy was lower in our study compared to prior reports,41 though differences in dataset composition (e.g., age, stage at diagnosis, histology, year of diagnosis and treatment, treatments examined) across studies makes it harder to compare findings.

Immunotherapy was the least reported treatment (13%). In a scoping review of target and immunotherapies for lung cancer, the reported incidence of use of immunotherapy as a second-line treatment for non-small cell lung cancer ranged from 10% to 50%.42 The authors highlight differences in study period as one reason for the large variation in use.42 Data reporting for cancer treatment also has limitations; for example, oral therapies are less likely to be captured in cancer registry data.43 Given this, use of immunotherapy is likely to be higher than what is reported here.

We also observed a large increase in odds of immunotherapy from 2015 to 2020, which is consistent with advancements in treatment over time. The first immunotherapy treatment for lung cancer (nivolumab) was approved by the Federal Drug Administration in 2015,44 and several treatments have been approved since. Future studies that examine the prevalence of immunotherapy treatment among people with lung cancer could provide further insight into its use. Stratifying receipt of treatment by characteristics like sex, histology, and year of diagnosis combined could additionally inform our understanding of treatment patterns.

In our subgroup analysis, people with a history of smoking had lower odds of surgery. A 2018 survey among thoracic surgeons revealed that 40% required individuals to quit smoking before lung resection45; this finding could explain why we found lower rates of surgery among people who currently smoked. Current National Comprehensive Cancer Network guidelines for treating non-small cell lung cancer recommend that people who actively smoke receive counseling and cessation support, and that people should not be denied surgery solely on the basis of smoking status.3 Further, postoperative mortality and major morbidity after lung resection has been found similar between people who currently vs. formerly smoke.46

Limitations

Our analysis including smoking status was conducted among a subset of cases in eight states and may lack representation from all groups; the results from this subgroup analysis should be interpreted with caution. The COVID-19 pandemic led to disruptions in multiple health services, including lung cancer treatment.47,48 Odds of receiving treatment for lung cancer in 2020 may not be as comparable to other years. We examined the odds of each reported treatment separately, limiting our ability to understand how correlations between treatment types may have impacted their receipt.

The NPCR captures information on first-course treatment only, so we were unable to estimate the percentage of people who reportedly received any treatment during their illness. Relatedly, we were not able to compare or distinguish between different types of immunotherapeutic agents received. Combined with issues of under-reporting of treatment modalities, the true prevalence of treatment may be higher than what we found in our study. NPCR does not collect data on contextual factors that might influence receipt of treatment, including individual-level (vs. county-level) socioeconomic status, health insurance coverage, comorbidities, and perceived barriers to treatment. Data were also unavailable for date of treatment, limiting our ability to understand how the time from diagnosis to initiation of treatment may have impacted receipt of treatment.

It is possible that race and ethnicity were misclassified for some individuals due to lack of self-report data on these characteristics in medical records. To overcome this limitation, NPCR uses identification algorithms to increase reporting accuracy for Asian/PI and Hispanic persons, as well as several methods to improve estimates among AI/AN populations.49 Cases with unknown stage at diagnosis were coded as missing and excluded from our analysis. While we coded unknown in this manner to obtain consistency across our measures and estimates, it is possible that their exclusion could have impacted our findings for receipt of treatment.

Lastly, analyses using big datasets like NPCR may find small effects that are statistically significant50 but not necessarily clinically relevant. To address this limitation, we estimated adjusted average predicted probabilities to aid in the interpretation and understanding of our results. Future research seeking to reduce disparities could help to further quantify meaningful differences in treatment outcomes.

Interpretation

This study used NPCR data covering 89% of the population to understand differences in receipt of lung cancer treatment. Reported receipt of at least one treatment was lower among certain racial and ethnic groups and those residing in counties with lower economic status. Our study provides support for the use of cancer registry data to track patterns in lung cancer treatment and has implications for intervention efforts to reduce differences. Based on our findings, interventions might focus on identifying and addressing underlying causes (e.g., unequal healthcare access) that lead to a lower percentage of people being treated for lung cancer among specific populations.

Supplementary MaterialAcknowledgements

We would like to thank Trevor Thompson for guidance on the data analysis. We would like to thank members of the CDC’s Division of Cancer Prevention and Control Internal Data Users Group for their contributions to the study. Lastly, we would like to acknowledge the state central cancer registries who support data collection for the National Program of Cancer Registries (NPCR).

The first author (Christine M. Kava [CMK]) takes responsibility for all content of the manuscript, including data and analysis. All authors made substantial contributions to study conception and design. CMK led data analysis, interpretation, and manuscript writing. All authors critically reviewed the manuscript for important intellectual content and approved the final version for publication. All authors agree to be accountable for all aspects of the work, including ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

This work was supported in part under US Centers for Disease Control and Prevention (CDC) cooperative agreements of the NPCR (U58/DP000792). These data were provided by central cancer registries participating in the NPCR and submitted to CDC in the 2022 data submission. The NPCR Internal Quality Control Data dataset includes diagnosis years 1995–2020. The findings and conclusions are those of the authors and do not necessarily represent the official position of the CDC.

Conflict of Interest statement: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Notification of Prior Publication/Presentation: This work was previously presented at the American Society of Preventive Oncology 47th Annual Meeting in San Diego, CA (March 12-14, 2023) as a poster presentation.

AbbreviationsACCURE

Accountability for Cancer Care through Undoing Racism and Equity

AI/AN

American Indian and Alaska Native

Asian/PI

Asian and Pacific Islander

CDC

Centers for Disease Control and Prevention

ICD-O-3

International Classification of Diseases for Oncology, Third Edition

NH

Non-Hispanic

NPCR

National Program of Cancer Registries

SEER

Surveillance, Epidemiology, and End Results Program

ReferencesU.S. Cancer Statistics Working Group. U.S. Cancer Statistics Data Visualizations Tool. Released in June 2024. U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Cancer Institute; https://www.cdc.gov/cancer/datavizU.S. Cancer Statistics Working Group. Data from: U.S. Cancer Statistics Data Visualizations Tool, based on 2022 submission data (1999-2020). Released in June 2023.National Comprehensive Cancer Network (NCCN). NCCN Guidelines: Non-small cell lung cancer. National Comprehensive Cancer Network; Accessed December 5, 2023. https://www.nccn.org/guidelines/guidelines-detail?category=1&id=1450National Comprehensive Cancer Network (NCCN). NCCN Guidelines: Small cell lung cancer. National Comprehensive Cancer Network; Accessed December 5, 2023. https://www.nccn.org/guidelines/guidelines-detail?category=1&id=1462HowladerN, ForjazG, MooradianMJ, The effect of advances in lung-cancer treatment on population mortality. N Engl J Med. Aug 13 2020;383(7):640–649. doi:10.1056/NEJMoa191662332786189 CaprarioLC, KentDM, StraussGM. Effects of chemotherapy on survival of elderly patients with small-cell lung cancer: Analysis of the SEER-medicare database. J Thorac Oncol. Oct 2013;8(10):1272–81. doi:10.1097/JTO.0b013e3182a007ba24457238 HuangCY, JuDT, ChangCF, Muralidhar ReddyP, VelmuruganBK. A review on the effects of current chemotherapy drugs and natural agents in treating non-small cell lung cancer. Biomedicine (Taipei). Dec 2017;7(4):23. doi:10.1051/bmdcn/201707042329130448 SchabathMB, CoteML. Cancer progress and priorities: Lung cancer. Cancer Epidemiol Biomarkers Prev. Oct 2019;28(10):1563–1579. doi:10.1158/1055-9965.EPI-19-022131575553 National Cancer Institute. Surveillence, Epidemiology, and End Results program. Accessed March 7, 2023. https://seer.cancer.gov/about/EnewoldL, ParsonsH, ZhaoL, Updated overview of the SEER-Medicare data: Enhanced content and applications. J Natl Cancer Inst Monogr. May 1 2020;2020(55):3–13. doi:10.1093/jncimonographs/lgz02932412076 AhmedZ, KujtanL, KennedyKF, DavisJR, SubramanianJ. Disparities in the management of patients with stage I small cell lung carcinoma (SCLC): A Surveillance, Epidemiology and End Results (SEER) analysis. Clin Lung Cancer. Sep 2017;18(5):e315–e325. doi:10.1016/j.cllc.2017.03.00328438510 WilliamsCD, AlpertN, ReddingTSIV, Racial differences in treatment and survival among veterans and non-veterans with stage I NSCLC: An evaluation of Veterans Affairs and SEER-Medicare populations. Cancer Epidemiol Biomarkers Prev. Jan 2020;29(1):112–118. doi:10.1158/1055-9965.EPI-19-024531624076 AtkinsGT, KimT, MunsonJ. Residence in rural areas of the United States and lung cancer mortality: Disease incidence, treatment disparities, and stage-specific survival. Ann Am Thorac Soc. Mar 2017;14(3):403–411. doi:10.1513/AnnalsATS.201606-469OC28118039 ForrestLF, AdamsJ, WarehamH, RubinG, WhiteM. Socioeconomic inequalities in lung cancer treatment: Systematic review and meta-analysis. PLoS Med. 2013;10(2):e1001376. doi:10.1371/journal.pmed.100137623393428 Centers for Disease Control and Prevention. National Program of Cancer Registries. Accessed March 5, 2024. https://www.cdc.gov/cancer/npcrNorth American Association of Central Cancer Registries. Data standards and data dictionary, Version 22. Accessed October 23, 2023. https://apps.naaccr.org/data-dictionary/data-dictionary/version=22/chapter-view/BrahmerJR, GovindanR, AndersRA, The Society for Immunotherapy of Cancer consensus statement on immunotherapy for the treatment of non-small cell lung cancer (NSCLC). J Immunother Cancer. Jul 17 2018;6(1):75. doi:10.1186/s40425-018-0382-230012210 BarrowsED, BlackburnMJ, LiuSV. Evolving role of immunotherapy in small cell lung cancer. Semin Cancer Biol. Nov 2022;86(Pt 3):868–874. doi:10.1016/j.semcancer.2022.02.02135192928 National Program of Cancer Registries. Data from: SEER*Stat database: NPCR and SEER Incidence — QC file — 1995–2020. Released June 2022, based on the 2021 data submission.Centers for Disease Control and Prevention. How cancer registries work. Division of Cancer Prevention and Control, Centers for Disease Control and Prevention; Accessed October 24, 2023. https://www.cdc.gov/national-program-cancer-registries/about/how-cancer-registries-work.htmlNorth American Association of Central Cancer Registries. Home page. Accessed October 24, 2023. https://www.naaccr.org/FritzA, PercyC, JackA, International Classification of Diseases for Oncology. 3rd ed. World Health Organization; 2000.National Cancer Institute Surveillance Epidemiology and End Results Program. Site recode ICD-O-3/WHO 2008 definition. National Cancer Institute, National Institutes of Health, U.S. Department of Health and Human Services; Accessed December 5, 2023. https://seer.cancer.gov/siterecode/icdo3_dwhoheme/National Cancer Institute. Cancer treatment. Accessed January 11, 2023. https://www.training.seer.cancer.gov/treatment/AdamoM, GrovesC, DickieL, RuhlJ. SEER Program Coding and Staging Manual 2023. Bethesda, MD: National Cancer Institute, U.S. Department of Health and Human Services, National Institutes of Health; September 2022.Appalachian Regional Commission. County economic status and distressed areas in the Appalachian Region, fiscal year 2011. Accessed January 9, 2023. https://www.arc.gov/distressed-designation-and-county-economic-status-classification-system/IngramDD, FrancoSJ. NCHS Urban-Rural Classification Scheme for Counties. Vital Health Stat 2. Jan 2012;(154):1–65.SiegelDA, FedewaSA, HenleySJ, PollackLA, JemalA. Proportion of never smokers among men and women with lung cancer in 7 US states. JAMA Oncol. Feb 1 2021;7(2):302–304. doi:10.1001/jamaoncol.2020.636233270100 SiegelDA, HenleySJ, WikeJM, Capture of tobacco use among population-based registries: Findings from 10 National Program of Cancer Registries states. Cancer. Jun 1 2018;124(11):2381–2389. doi:10.1002/cncr.3132629579317 ChenVW, EhemanCR, JohnsonCJ, Enhancing cancer registry data for comparative effectiveness research (CER) project: Overview and methodology. J Registry Manag. Fall 2014;41(3):103–12.25419602 SAS software. Version 9.4. SAS Institute Inc. Cary, NC; 2023.RStudio: Integrated development for R. RStudio, PBC, Boston, MA; 2024. http://www.rstudio.com/HarrelFrank E.Jr. Hmisc: Harrell Miscellaneous. R package version 5.1.3. 2024. https://cran.r-project.org/package=rmsHarrisonS, JuddJ, ChinS, RaginC. Disparities in lung cancer treatment. Curr Oncol Rep. Feb 2022;24(2):241–248. doi:10.1007/s11912-022-01193-435080738 BlomEF, Ten HaafK, ArenbergDA, de KoningHJ. Disparities in receiving guideline-concordant treatment for lung cancer in the United States. Ann Am Thorac Soc. Feb 2020;17(2):186–194. doi:10.1513/AnnalsATS.201901-094OC31672025 SarfatiD, KoczwaraB, JacksonC. The impact of comorbidity on cancer and its treatment. CA Cancer J Clin. Jul 2016;66(4):337–50. doi:10.3322/caac.2134226891458 MehtaRS, LenznerD, ArgirisA. Race and health disparities in patient refusal of surgery for early-stage non-small cell lung cancer: A SEER cohort study. Ann Surg Oncol. Mar 2012;19(3):722–7. doi:10.1245/s10434-011-2087-321947698 KennedyBR, MathisCC, WoodsAK. African Americans and their distrust of the health care system: Healthcare for diverse populations. J Cult Divers. 2007;14(2)LinJJ, MhangoG, WallMM, Cultural factors associated with racial disparities in lung cancer care. Ann Am Thorac Soc. May 2014;11(4):489–95. doi:10.1513/AnnalsATS.201402-055OC24701981 CykertS, EngE, ManningMA, A multi-faceted intervention aimed at Black-White disparities in the treatment of early stage cancers: The ACCURE pragmatic quality improvement trial. J Natl Med Assoc. Oct 2020;112(5):468–477. doi:10.1016/j.jnma.2019.03.00130928088 National Cancer Institute. Cancer trends progress report, July 2021. National Cancer Institute, National Institutes of Health, Department of Health and Human Services; https://progressreport.cancer.gov/SpiniA, HyeraciG, BartoliniC, Real-world utilization of target- and immunotherapies for lung cancer: A scoping review of studies based on routinely collected electronic healthcare data. Int J Environ Res Public Health. Jul 19 2021;18(14)doi:10.3390/ijerph18147679BradleyCJ, LiangR, JasemJ, LindroothRC, SabikLM, PerraillonMC. Cancer treatment data in central cancer registries: When are supplemental data needed? Cancer Inform. 2022;21:11769351221112457. doi:10.1177/11769351221112457National Cancer Institute. FDA approves first immunotherapy treatment for lung cancer. Accessed October 24, 2023. https://www.cancer.gov/news-events/cancer-currents-blog/2015/fda-opdivoMarrufoAS, KozowerBD, TancrediDJ, Thoracic surgeons' beliefs and practices on smoking cessation before lung resection. Ann Thorac Surg. May 2019;107(5):1494–1499. doi:10.1016/j.athoracsur.2018.11.05530586576 DelmanAM, TurnerKM, WimaK, Offering lung resection to current smokers: An opportunity for more equitable care. J Thorac Cardiovasc Surg. Aug 2022;164(2):400–408 e1. doi:10.1016/j.jtcvs.2021.09.06234802749 FujitaK, ItoT, SaitoZ, KanaiO, NakataniK, MioT. Impact of COVID-19 pandemic on lung cancer treatment scheduling. Thorac Cancer. Oct 2020;11(10):2983–2986. doi:10.1111/1759-7714.1361532790028 BakhribahH, ZeitouniM, DaghistaniRA, Implications of COVID-19 pandemic on lung cancer management: A multidisciplinary perspective. Crit Rev Oncol Hematol. Dec 2020;156:103120. doi:10.1016/j.critrevonc.2020.10312033099232 Centers for Disease Control and Prevention. Interpreting race and ethnicity in cancer data. Accessed February 9, 2023. https://www.cdc.gov/united-states-cancer-statistics/technical-notes/interpreting-race-ethnicity.htmlKhalilzadehJ, TasciADA. Large sample size, significance level, and the effect size: Solutions to perils of using big data for academic research. Tourism Management. 2017;62:89–96. doi:10.1016/j.tourman.2017.03.026

Study Inclusion Flow Chart, National Program of Cancer Registries

Characteristics of Lung Cancer Cases, National Program of Cancer Registries, 41 states and District of Columbia, United States, 2015–2020, n=1,068,155

VariableNo.%
First-course treatment (% received)a
  Surgery233,49022.11
  Chemotherapy423,86440.94
  Radiation414,18839.51
  Immunotherapy138,21013.10
  At least one of the four treatments768,73575.15
  None of the four treatments254,16924.85
Age at diagnosis (years)
  20–4411,7141.10
  45–5463,3745.93
  55–64249,97023.40
  65–74384,08235.96
  75–84278,33426.06
  ≥8580,6817.55
Sex
  Female521,83548.85
  Male546,32051.15
Race and ethnicity
  NH American Indian or Alaska Native6,5930.62
  NH Asian or Pacific Islander30,4742.86
  NH Black117,02910.99
  NH White858,42780.62
  Hispanic, all races52,3014.91
County classificationb
  Metropolitan869,32381.41
  Non-metropolitan198,46218.59
County economic statusc
  Bottom 25%125,94911.80
  Middle 50%648,60360.74
  Top 25%293,20627.46
US Census region
  Northeast221,18820.71
  Midwest213,59520.00
  South456,37642.73
  West176,99616.57
Smoking statusd
  Currently smoked80,20333.30
  Formerly smoked122,27550.77
  Never smoked38,37015.93
Histologye
  Adenocarcinoma484,47045.36
  Small cell carcinoma135,07312.65
  Squamous cell carcinoma237,96322.28
  Other210,64919.72
Stage
  Localized284,49627.62
  Regional245,85923.87
  Distant499,51548.50
Year of diagnosis
  2015187,76717.58
  2016188,09817.61
  2017190,64517.85
  2018189,07317.70
  2019187,30817.54
  2020125,26411.73

Abbreviations: NH, non-Hispanic.

The number and percentage missing data for surgery was 12,226 (1.14%); 32,799 (3.07%) for chemotherapy; 19,738 (1.85%) for radiation, and 13,519 (1.27%) for immunotherapy.

Defined based on the 2013 National Center for Health Statistics Urban-Rural Classification Scheme for Counties.

Defined for 2018 by the Appalachian Regional Commission and considers three-year average unemployment rate, per capita market income, and poverty rate.

Reported for a subset of cases in eight states (n=240,848): Alaska, California, Colorado, Florida, Idaho, Louisiana, New Hampshire, and Texas.

Histology groups were defined using International Classification of Diseases for Oncology, Third Edition site codes: adenocarcinoma (8140–8239; 8250–8384; 8440–8490; 8550–8551; 8570–8574; 8576), small cell carcinoma (8041–8045), squamous cell carcinoma (8050–8084), and other histology (8000–8040; 8046–8049; 8085–8139; 8240–8249; 8385–8439; 8491–8549; 8552–8569; 8575; 8577–9992).

Number and Percentage of People Diagnosed with Lung Cancer Reported to have Received Treatment, National Program of Cancer Registries, 41 states and District of Columbia, 2015–2020, n=1,068,155

VariableSurgeryChemotherapyRadiationImmunotherapyAt least one of thefour treatments
No.%No.%No.%No.%No.%
Age at diagnosis (years)
  20–443,85533.326,60858.264,43938.612,11818.3410,03488.66
  45–5415,23624.3036,90360.0528,84246.2911,33718.1052,42985.60
  55–6460,19924.33126,09752.02106,40343.3440,14016.25197,57682.02
  65–7497,64525.71161,02643.26149,43939.6250,15613.22291,85579.10
  75–8452,15718.9783,10730.82100,97236.9929,29510.67183,19569.24
  ≥854,3985.5310,12312.9424,09330.515,1646.5033,64644.33
Sex
  Female126,94224.59200,74039.60197,16738.4564,09412.43380,88176.08
  Male106,54819.75223,12442.22217,02140.5274,11613.75387,85474.26
Race and ethnicity
  NH American Indian or Alaska Native1,15517.692,66341.602,69741.6881412.514,59272.42
  NH Asian or Pacific Islander8,03726.5513,64046.129,33831.053,81512.6422,48177.06
  NH Black20,71017.9047,90242.3847,00140.9215,61713.5181,87173.29
  NH White190,99722.50338,47640.60338,38640.14111,63213.17623,06075.67
  Hispanic, all races11,78022.9520,05240.4415,74730.985,91011.4934,50170.12
County classificationa
  Metropolitan196,36822.82342,05840.54331,92438.84112,14513.05627,46975.29
  Non-metropolitan37,03518.9981,70242.7182,14142.4425,99313.32141,01274.55
County economic statusb
  Bottom 25%21,32517.2350,70841.8350,76041.3115,39512.4286,51272.06
  Middle 50%137,55821.45257,88841.04252,58739.6782,95012.95463,85174.69
  Top 25%74,51725.65115,16040.35110,70238.3739,79413.73218,10077.50
US Census region
  Northeast60,59927.4887,84140.4685,20938.8730,06413.70168,35078.64
  Midwest44,82121.2090,69043.3894,69144.9830,84914.61162,76978.84
  South89,16519.91180,71941.44172,31838.8656,78212.67315,72073.07
  West38,90522.0964,61437.3361,97035.3620,51511.66121,89671.58
Histologyc
  Adenocarcinoma143,61029.87188,38940.01177,25937.1377,47016.16374,77180.87
  Small cell carcinoma4,8163.5993,86771.1058,98544.3515,82211.82101,74777.14
  Squamous cell carcinoma54,25223.0393,65040.62111,63847.7629,57412.58180,75579.42
  Other30,81214.9947,95823.7466,30632.4615,3447.44111,46255.73
Stage
  Localized135,67048.1529,06510.44101,85436.354,9691.76239,50685.94
  Regional80,29532.87141,27759.22116,87148.2626,77911.00199,87283.71
  Distant15,4483.11246,93350.88189,98938.58105,08521.26318,74367.33
Year of diagnosis
  201540,41821.8078,90943.5972,13439.186,7613.63135,17174.30
  201641,50922.3377,20742.4273,52039.7810,0155.37136,55075.13
  201741,86122.2073,21339.6774,24639.5419,01910.10136,15274.90
  201841,87522.3974,10940.2274,74840.1732,67117.52136,86075.86
  201941,69222.5072,93039.9873,06439.7641,49922.50135,99176.13
  202026,13521.1147,49639.2146,47638.1128,24523.0088,01174.33
Smoking statusd
  Currently smoked13,20816.8031,13241.1528,57936.819,09611.5951,62868.55
  Formerly smoked27,22722.6245,93739.3543,10236.1815,16912.6484,95973.58
  Never smoked9,86826.2013,71837.569,51925.503,92410.4025,11169.33

Abbreviations: NH, non-Hispanic.

Defined based on the 2013 National Center for Health Statistics Urban-Rural Classification Scheme for Counties.

Defined by the Appalachian Regional Commission and considers three-year average unemployment rate, per capita market income, and poverty rate.

Histology groups were defined using International Classification of Diseases for Oncology, Third Edition site codes: adenocarcinoma (8140–8239; 8250–8384; 8440–8490; 8550–8551; 8570–8574; 8576), small cell carcinoma (8041–8045), squamous cell carcinoma (8050–8084), and other histology (8000–8040; 8046–8049; 8085–8139; 8240–8249; 8385–8439; 8491–8549; 8552–8569; 8575; 8577–9992).

Reported for a subset of cases in eight states (n=240,848): Alaska, California, Colorado, Florida, Idaho, Louisiana, New Hampshire, and Texas.

Odds of Reported Receipt of Lung Cancer Treatment, National Program of Cancer Registries, 41 states and District of Columbia, 2015–2020, n=1,068,155a

VariableModel 1:SurgeryModel 2:ChemotherapyModel 3:RadiationModel 4:ImmunotherapyModel 5:At least one of thefour treatments
OR (95 CI%)OR (95 CI%)OR (95 CI%)OR (95 CI%)OR (95 CI%)
Age at diagnosis (years) (ref: 20–44)
  45–54 0.52 (0.49–0.55) 0.84 (0.80–0.88) 1.23 (1.18–1.28) 0.97 (0.92–1.03) 0.67 (0.62–0.71)
  55–64 0.42 (0.40–0.44) 0.61 (0.59–0.64) 1.04 (1.00–1.09) 0.84 (0.80–0.89) 0.47 (0.44–0.50)
  65–74 0.37 (0.35–0.39) 0.45 (0.43–0.47) 0.89 (0.86–0.92) 0.72 (0.68–0.76) 0.36 (0.34–0.38)
  75–84 0.20 (0.19–0.22) 0.26 (0.25–0.27) 0.81 (0.78–0.84) 0.54 (0.52–0.57) 0.20 (0.19–0.22)
  ≥85 0.05 (0.05–0.05) 0.08 (0.08–0.09) 0.65 (0.63–0.68) 0.29 (0.28–0.31) 0.08 (0.07–0.08)
Sex (ref: Male)
  Female 1.16 (1.15–1.17) 0.96 (0.95–0.97) 0.95 (0.94–0.96) 0.95 (0.93–0.96) 1.04 (1.03–1.05)
Race and ethnicity (ref: NH White)
  NH American Indian or Alaska Native 0.76 (0.71–0.82) 0.89 (0.84–0.94) 1.01 (0.96–1.06) 0.90 (0.83–0.98) 0.82 (0.77–0.87)
  NH Asian or Pacific Islander 1.31 (1.26–1.35) 1.32 (1.29–1.36) 0.75 (0.73–0.77) 0.69 (0.66–0.72) 1.09 (1.06–1.13)
  NH Black 0.70 (0.69–0.71) 0.93 (0.92–0.95) 1.01 (1.00–1.02) 0.86 (0.84–0.88) 0.82 (0.81–0.84)
  Hispanic, all races 1.13 (1.10–1.16) 0.98 (0.96–1.00) 0.72 (0.70–0.73) 0.72 (0.70–0.75) 0.80 (0.78–0.82)
County classificationb (ref: Metropolitan)
  Non-metropolitan 0.89 (0.87–0.90) 1.02 (1.00–1.03) 1.06 (1.05–1.07) 1.02 (1.00–1.04) 0.98 (0.96–0.99)
County economic statusc (ref: Top 25%)
  Bottom 25% 0.75 (0.74–0.77) 0.87 (0.86–0.89) 1.04 (1.03–1.06) 0.81 (0.79–0.83) 0.80 (0.78–0.81)
  Middle 50% 0.86 (0.85–0.87) 0.93 (0.92–0.94) 1.02 (1.01–1.03) 0.89 (0.88–0.90) 0.87 (0.86–0.88)
US Census region (ref: South)
  Northeast 1.41 (1.39–1.43) 1.06 (1.04–1.07) 1.07 (1.05–1.08) 1.14 (1.12–1.16) 1.33 (1.32–1.35)
  Midwest 1.02 (1.01–1.04) 1.10 (1.09–1.12) 1.28 (1.27–1.30) 1.21 (1.19–1.23) 1.35 (1.33–1.37)
  West 1.07 (1.06–1.09) 0.90 (0.88–0.91) 0.96 (0.94–0.97) 0.93 (0.92–0.95) 0.95 (0.94–0.97)
Histologyd (ref: Adenocarcinoma)
  Small cell carcinoma 0.11 (0.11–0.11) 2.66 (2.63–2.70) 1.27 (1.26–1.29) 0.43 (0.42–0.43) 0.94 (0.93–0.95)
  Squamous cell carcinoma 0.50 (0.49–0.50) 1.05 (1.04–1.07) 1.48 (1.46–1.50) 0.88 (0.87–0.90) 0.84 (0.82–0.85)
  Other 0.36 (0.36–0.37) 0.46 (0.45–0.46) 0.84 (0.83–0.85) 0.40 (0.39–0.40) 0.31 (0.31–0.31)
Stage at diagnosis (ref: Distant)
  Localized 33.22 (32.60–33.84) 0.13 (0.12–0.13) 0.95 (0.94–0.96) 0.05 (0.05–0.05) 3.53 (3.49–3.58)
  Regional 18.01 (17.67–18.35) 1.42 (1.41–1.44) 1.40 (1.39–1.42) 0.38 (0.38–0.39) 2.42 (2.39–2.45)
Year of diagnosis (ref: 2015)
  2016 0.90 (0.88–0.91) 1.01 (1.00–1.03) 1.03 (1.02–1.04) 1.64 (1.59–1.69) 1.01 (0.99–1.02)
  2017 0.84 (0.82–0.85) 0.90 (0.89–0.92) 1.02 (1.01–1.04) 3.47 (3.37–3.57) 0.97 (0.95–0.98)
  2018 0.82 (0.80–0.83) 0.95 (0.93–0.96) 1.05 (1.04–1.07) 7.14 (6.95–7.34) 0.99 (0.98–1.01)
  2019 0.82 (0.80–0.84) 0.93 (0.92–0.95) 1.04 (1.02–1.05) 10.27 (9.99–10.55) 1.01 (1.00–1.03)
  2020 0.75 (0.73–0.76) 0.86 (0.85–0.88) 0.96 (0.95–0.98) 10.30 (10.01–10.60) 0.89 (0.88–0.91)

Abbreviations: CI, confidence interval; NH, non-Hispanic; OR, odds ratio.

Boldface indicates statistical significance (p<0.05).

Total sample size; people missing data on the outcome of interest in each model were excluded from analyses.

Defined based on the 2013 National Center for Health Statistics Urban-Rural Classification Scheme for Counties.

Defined by the Appalachian Regional Commission and considers three-year average unemployment rate, per capita market income, and poverty rate.

Histology groups were defined using International Classification of Diseases for Oncology, Third Edition site codes: adenocarcinoma (8140–8239; 8250–8384; 8440–8490; 8550–8551; 8570–8574; 8576), small cell carcinoma (8041–8045), squamous cell carcinoma (8050–8084), and other histology (8000–8040; 8046–8049; 8085–8139; 8240–8249; 8385–8439; 8491–8549; 8552–8569; 8575; 8577–9992).

Odds of Reported Receipt of Lung Cancer Treatment with Smoking Status, National Program of Cancer Registries, 8 States, 2015–2020, n=240,848a

VariableModel 1:SurgeryModel 2:ChemotherapyModel 3:RadiationModel 4:ImmunotherapyModel 5:At least one of thefour treatments
OR (95 CI%)OR (95 CI%)OR (95 CI%)OR (95 CI%)OR (95 CI%)
Age at diagnosis (years) (ref: 20–44)
  45–54 0.64 (0.58–0.71) 0.87 (0.80–0.94) 1.06 (0.98–1.15)0.92 (0.83–1.03) 0.68 (0.61–0.75)
  55–64 0.52 (0.48–0.57) 0.65 (0.60–0.70) 0.91 (0.84–0.98) 0.80 (0.72–0.89) 0.49 (0.44–0.54)
  65–74 0.46 (0.42–0.50) 0.49 (0.45–0.53) 0.78 (0.72–0.84) 0.70 (0.63–0.77) 0.39 (0.36–0.43)
  75–84 0.25 (0.23–0.27) 0.28 (0.26–0.30) 0.72 (0.67–0.78) 0.53 (0.48–0.59) 0.23 (0.20–0.25)
  ≥85 0.06 (0.05–0.06) 0.09 (0.08–0.10) 0.63 (0.58–0.68) 0.33 (0.29–0.37) 0.09 (0.08–0.10)
Sex (ref: Male)
  Female 1.15 (1.13–1.18) 0.97 (0.95–0.99) 0.97 (0.95–0.98) 0.97 (0.94–0.99) 1.05 (1.03–1.07)
Race and ethnicity (ref: NH White)
  NH American Indian or Alaska Native 0.80 (0.69–0.94) 0.81 (0.72–0.91) 1.15 (1.04–1.28) 0.85 (0.71–1.02) 0.87 (0.78–0.98)
  NH Asian or Pacific Islander1.03 (0.98–1.08) 1.20 (1.16–1.25) 0.94 (0.91–0.97) 0.77 (0.73–0.82) 1.09 (1.05–1.13)
  NH Black 0.63 (0.60–0.65) 0.91 (0.89–0.94) 1.02 (0.99–1.05) 0.81 (0.77–0.84) 0.80 (0.78–0.82)
  Hispanic, all races 1.07 (1.04–1.11) 0.94 (0.91–0.96) 0.78 (0.76–0.80) 0.75 (0.72–0.79) 0.83 (0.81–0.85)
County classificationb (ref: Metropolitan)
  Non-metropolitan 0.89 (0.86–0.93) 0.95 (0.92–0.98) 1.07 (1.04–1.10) 0.96 (0.92–1.00) 0.96 (0.93–0.99)
County economic statusc (ref: Top 25%)
  Bottom 25% 0.77 (0.73–0.80) 0.94 (0.91–0.97) 1.01 (0.98–1.04) 0.86 (0.81–0.90) 0.80 (0.78–0.83)
  Middle 50% 0.92 (0.90–0.95) 0.98 (0.96–1.00) 0.95 (0.93–0.97) 0.91 (0.88–0.93) 0.88 (0.86–0.90)
Histologyd (ref: Adenocarcinoma)
  Small cell carcinoma 0.12 (0.11–0.13) 2.29 (2.23–2.36) 1.15 (1.12–1.18) 0.44 (0.42–0.46) 0.93 (0.90–0.96)
  Squamous cell carcinoma 0.52 (0.50–0.53) 1.06 (1.03–1.08) 1.35 (1.33–1.38) 0.87 (0.84–0.89) 0.81 (0.79–0.83)
  Other 0.40 (0.38–0.41) 0.45 (0.44–0.47) 0.73 (0.71–0.74) 0.37 (0.35–0.38) 0.32 (0.32–0.33)
Stage at diagnosis (ref: Distant)
  Localized 32.58 (31.46–33.74) 0.14 (0.13–0.14) 0.98 (0.96–1.00) 0.06 (0.06–0.07) 3.01 (2.94–3.08)
  Regional 18.32 (17.68–18.99) 1.29 (1.26–1.32) 1.34 (1.32–1.37) 0.40 (0.39–0.41) 2.29 (2.23–2.34)
Year of diagnosis (ref: 2015)
  2016 0.91 (0.88–0.95) 1.05 (1.02–1.08) 1.02 (1.00–1.05) 1.60 (1.50–1.70) 1.01 (0.98–1.04)
  2017 0.85 (0.82–0.88) 0.90 (0.88–0.93) 1.00 (0.98–1.03) 3.00 (2.84–3.18) 0.93 (0.90–0.96)
  2018 0.83 (0.80–0.86) 0.96 (0.93–0.98) 1.01 (0.98–1.03) 5.85 (5.54–6.17) 0.96 (0.93–0.99)
  2019 0.87 (0.84–0.90) 0.95 (0.93–0.98) 0.99 (0.97–1.02) 8.10 (7.69–8.54) 0.98 (0.95–1.01)
  2020 0.79 (0.75–0.82) 0.86 (0.83–0.89) 0.89 (0.86–0.91) 7.91 (7.48–8.36) 0.82 (0.79–0.85)
Smoking status (ref: Never smoked)
  Currently smoked 0.51 (0.49–0.53) 0.73 (0.71–0.75) 1.41 (1.37–1.45) 1.10 (1.05–1.15) 0.75 (0.73–0.78)
  Formerly smoked 0.77 (0.74–0.79) 1.00 (0.97–1.03) 1.45 (1.41–1.48) 1.37 (1.31–1.42) 1.13 (1.10–1.16)

Abbreviations: CI, confidence interval; NH, non-Hispanic; OR, odds ratio.

Boldface indicates statistical significance (p<0.05).

Total sample size of people with smoking status available in eight states; people missing data on the outcome of interest in each model were excluded from analyses. US census region excluded as a covariate in the models due to collinearity given the limited number of states included.

Defined based on the 2013 National Center for Health Statistics Urban-Rural Classification Scheme for Counties.

Defined by the Appalachian Regional Commission and considers three-year average unemployment rate, per capita market income, and poverty rate.

Histology groups were defined using International Classification of Diseases for Oncology, Third Edition site codes: adenocarcinoma (8140–8239; 8250–8384; 8440–8490; 8550–8551; 8570–8574; 8576), small cell carcinoma (8041–8045), squamous cell carcinoma (8050–8084), and other histology (8000–8040; 8046–8049; 8085–8139; 8240–8249; 8385–8439; 8491–8549; 8552–8569; 8575; 8577–9992).

Take-Home PointsStudy Question:

Among adults diagnosed with lung cancer, how does reported receipt of lung cancer treatment differ by sociodemographic characteristics?

Results:

Reported receipt of at least one of four treatments (surgery, chemotherapy, radiation, and immunotherapy) was lower among several groups, including males; people reported as American Indian or Alaska Native, Black, and Hispanic; and people residing in counties designated as non-metropolitan and lower economic status.

Interpretation:

Our study provides support for the use of cancer registry data to track patterns in lung cancer treatment and has implications for intervention efforts to reduce differences in reported receipt of lung cancer treatment.