Breast cancer is the most common cancer in women, claiming more than 40,000 lives in 2011 alone (1). Of the 232,340 women diagnosed with incident invasive breast cancer in 2013, 42% were aged 65 or older (2).

Although breast cancer is amenable to screening, one-third of breast cancer diagnoses are for regional-stage or distant-stage disease (2), and these patients have a poor prognosis. Numerous initiatives have been developed to increase screening rates by improving outreach and reducing barriers to mammography. One such initiative is the National Breast and Cervical Cancer Early Detection Program (BCCP) of the Centers for Disease Control and Prevention, implemented in 1990 (3). Targeting low-income uninsured women, the BCCP in Ohio provides clinical breast examinations and diagnostic mammography to women aged 40 to 64 and screening mammography to women aged 50 to 64. Outreach efforts have focused not only on one-time mammography use but also on repeat use.

Evaluations of the BCCP have focused mostly on outcomes in women younger than 64 (4–7). However, the benefits of having participated in the BCCP may extend well beyond the years in which a woman is eligible for BCCP services as she becomes age-eligible for and transitions to Medicare. First, past screening behavior (8) is strongly associated with use of subsequent mammography, possibly because of habit and reassurance (9). Second, participation in the BCCP might impart greater knowledge of the benefits of breast cancer screening (10). Third, and just as important, participating in the BCCP might provide women the opportunity to connect and develop a continuity of care relationship with primary care providers. This factor is strongly and positively associated with screening mammography (11,12) and reduced breast cancer mortality (13), especially given the role of primary care providers in preventing treatment delays (14). Additional factors contributing to better survival in women with screening-detected breast cancer are breast cancer diagnosis at earlier stages of the disease and the fact that screening-detected tumors tend to be slower-growing than those detected otherwise (15). This survival advantage in screening-detected breast cancer patients over other breast cancer patients persists even after adjusting for tumor characteristics (15,16).

The objective of this study was to compare screening and cancer-related outcomes between 2 groups of Medicare beneficiaries: former BCCP participants and their low-income non-BCCP counterparts. We hypothesized that among Medicare beneficiaries with breast cancer, former BCCP participants would be more likely than their low-income non-BCCP counterparts to be diagnosed with cancer after screening, rather than after diagnostic (or no) mammogram, and more likely to have better treatment and survival outcomes.

We used linked records from the Ohio Cancer Incidence Surveillance System (OCISS), the state’s BCCP data, Medicare enrollment and claims files, the US Census, and death certificate files. This study was approved by the Case Western Reserve University institutional review board (IRB); by the IRB of the Ohio Department of Health, which maintains the OCISS, BCCP, and death certificate files; and by the Centers for Medicare and Medicaid Services (CMS).

Our study population had 93 BCCP and 420 low-income non-BCCP women. Of the BCCP women, 57 (61%) were repeat participants. The BCCP group and non-BCCP group differed significantly in their sociodemographic distribution and place of residence (Table 1). The percentage of women aged 70 to 74 was significantly higher among non-BCCP women than among BCCP women (58.1% vs 30.1%). In addition, we found a lower percentage of African American women in the BCCP group (19.4% vs 39.8%); a lower percentage of women residing in areas of low educational attainment (small numbers and percentages masked in accordance with Centers for Medicare and Medicaid Services’ privacy rules); a lower percentage residing in MUA or MUP regions (66.7% vs 88.6%); and a lower percentage of women with 1 or more comorbid conditions (66.7% vs. 75.7%).

The percentage of women undergoing screening mammography in the year before cancer diagnosis was 51.6% in the BCCP group and 38.8% in the low-income non-BCCP group (P = .02). However, the proportion of women diagnosed with regional-stage or distant-stage disease was similar in the 2 groups (31.2% vs 32.1%), and it was lowest among repeat BCCP users (24.6%). Receipt of standard treatment was lower in the BCCP group than in the low-income non-BCCP group (72.7% vs 78.4%) and lowest among one-time BCCP users (61.8%). None of these differences were significant. Similarly, neither all-cause survival (log-rank χ² = 1.2; P = .27) nor cancer survival (log-rank χ² = 1.7; P = .19) differed significantly between the 2 groups.

Adjusting for potential confounders and propensity scores, we found that the BCCP group was significantly more likely than the low-income non-BCCP group to have had screening mammography (adjusted odds ratio [AOR], 1.77; 95% confidence interval [CI], 1.01–3.09) (Table 2). No significant differences were detected in any other outcomes (Table 2 and Table 3).

The sensitivity analysis by income level yielded 1 noteworthy difference: when we compared outcomes between BCCP women and non-BCCP women residing in census block groups with MHI-CB in the lowest 5th percentile, we found no significant difference in the likelihood to have had screening mammography (AOR, 1.23; 95% CI, 0.63–2.40); however, this may have been due to a small sample size. In contrast, when comparing outcomes between BCCP women and non-BCCP women residing in census block groups with incomes in the lowest 15th percentile, BCCP women were nearly twice as likely to have undergone screening mammography (AOR, 1.90; 95% CI, 1.16–3.12).

This study compared breast cancer outcomes between Medicare beneficiaries with a history of participation in the BCCP and their low-income non-BCCP counterparts. The findings indicated that compared with low-income non-BCCP Medicare beneficiaries, former BCCP women were significantly more likely to have undergone screening mammography before cancer diagnosis. The results pertaining to breast cancer outcomes were mixed, although none of the differences were significant.

To our knowledge, this is the first study to document the lasting effects of participation in the BCCP among women who become age-eligible and transitioned to Medicare. The differentials in the outcomes of interest, or lack thereof, provide a glimpse of what we might observe after the implementation of the Affordable Care Act (ACA), when many uninsured women receive insurance coverage. Nonetheless, to a great extent, these findings, especially the greater likelihood of former BCCP participants to undergo screening mammography, reflect important differences in health care–seeking behaviors between former BCCP participants and their low-income non-BCCP counterparts. However, reasons why better screening did not translate into early-stage diagnosis and receipt of standard treatment remain to be explored.

Our study has several limitations. First, the lack of significant differences probably resulted from a small sample size, especially for BCCP participants, despite pooling nearly 10 years of data. In a follow-up study, it would be interesting to expand the study population by including data from multiple states. Second, low-income women in our comparison group were identified on the basis of MHI-CB rather than at the individual level; however, such measures have been deemed adequate to evaluate socioeconomic inequalities (25). Furthermore, our criterion for defining low-income women (those residing in census block groups with an MHI-CB in the lowest 10th percentile) was somewhat arbitrary, although consistent with a previous study (24). To address this limitation, we conducted sensitivity analyses by identifying comparison groups at 2 income thresholds — one with MHI-CB at the lowest 5th percentile and the other with MHI-CB at the lowest 15th percentile — and we found some differences in screening mammography. We also noted some differences in cancer stage at diagnosis, although these differences were not significant. Third, because this study was not randomized, there may have been selection bias due to inherent differences between former BCCP women and non-BCCP women. We addressed this limitation with the propensity score approach in our analysis.

Despite these weaknesses, our study informs the discussion on the contribution of the BCCP to the improvement of breast cancer outcomes in low-income women, especially in the context of Medicaid expansion and the implementation of the ACA. While the new policies will likely improve access to care, it will be important to determine whether, through an organized rather than an opportunistic approach to screening (26,27), the BCCP may offer a venue to improve breast and cervical cancer screening above and beyond the improvements that might be achieved with the implementation of Medicaid expansion and the ACA alone, especially given low reimbursement rates and providers’ reluctance to serve Medicaid patients. Indeed, while an organized approach to screening relies on policy and an adequate call-recall system, the opportunistic approach will depend on individual-related and provider-related factors, such as knowledge and behavior. Future studies weighing the benefits of Medicaid expansion and the ACA versus the benefits of the BCCP need to account for these factors.