24658879

PMC4045012

Purpose

There are limited data regarding breast cancer subtypes among Hispanic women. The current study assessed the distribution and prognosis of molecular subtypes defined by joint expression of the hormone receptors (HR; estrogen and progesterone) and human epidermal growth factor receptor 2 (HER2).

Methods

Using California Cancer Registry data, we identified Hispanic women diagnosed with invasive breast cancer from 2005–2010. Breast cancer subtypes were defined as HR+/HER2−, HR+/HER2+, HR−/HER2+, and HR−/HER2− (triple negative). We estimated breast cancer subtype frequencies and used polytomous logistic regression, Kaplan Meier survival plots and Cox regression to examine differences in relation to demographic and clinical characteristics.

Results

Among 16,380 Hispanic women with breast cancer, HR+/HER− subtype was most common (63%), followed by triple negative (16%), HR+/HER2+ (14%) and HR−/HER2+ (8%). Women in lower SES neighborhoods had greater risk of triple negative and HR−/HER2+ subtypes relative to HR+/HER2− (p<0.05). Hispanic women with triple negative and HR−/HER2+ tumors experienced poorer survival than those with HR+/HER− tumors. Breast cancer-specific mortality increased with decreasing SES, relative to the highest SES quintile, from HR=1.38 for quintile 4 to HR=1.76 for quintile 1 (lowest SES level).

Conclusion

Our findings indicate that Hispanic women residing in low SES neighborhoods had significantly increased risk of developing and dying from HR− than HR+ breast cancers. Similar patterns of subtype frequency and prognosis among California Hispanic women and studies of other racial/ethnic groups underscore the need to better understand the impact of SES on risk factor exposures that increase the risk of breast cancer subtypes with poor prognosis.

CDC Public Access

HHSN261201000034C/PHS HHS/United States
HHSN261201000140C/CA/NCI NIH HHS/United States
HHSN261201000035C/CA/NCI NIH HHS/United States
HHSN261201000035C/PHS HHS/United States
U58 DP000807/DP/NCCDPHP CDC HHS/United States
Z99 CA999999/Intramural NIH HHS/United States
HHSN261201000035I/CA/NCI NIH HHS/United States
HHSN261201000034C/CA/NCI NIH HHS/United States
HHSN261201000140C/PHS HHS/United States