1. Impact of molecular subtype and race on HR+, HER2− breast cancer survival
- Author
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Ann Tezak, Tuya Pal, Yuwei Zhu, Wei Zheng, Anne Weidner, Jaleesa Moore, Xiao-Ou Shu, Ingrid A. Mayer, Sonya Reid, Xuefeng Wang, Sydney Cadiz, Diane N. Haddad, and Brian S. Mautz
- Subjects
Oncology ,Cancer Research ,medicine.medical_specialty ,Receptor, ErbB-2 ,Population ,Breast Neoplasms ,Article ,Breast cancer ,Internal medicine ,Ethnicity ,Humans ,Medicine ,Stage (cooking) ,skin and connective tissue diseases ,education ,Survival analysis ,Proportional Hazards Models ,Black women ,education.field_of_study ,business.industry ,Mortality rate ,Hazard ratio ,Luminal a ,medicine.disease ,Black or African American ,Female ,Receptors, Progesterone ,business - Abstract
PURPOSE: There is an urgent need to understand the biological factors contributing to the racial survival disparity among women with hormone receptor-positive (HR+), HER2− breast cancer. In this study, we examined the impact of PAM50 subtype on 10-year mortality rate in women with HR+, HER2− breast cancer by race. METHODS: Women with localized, HR+, HER2− breast cancer diagnosed between 2002 to 2012 from two population-based cohorts were evaluated. Archival tumors were obtained and classified by PAM50 into four molecular subtypes (i.e., luminal A, luminal B, HER2-enriched, and basal-like). The molecular subtypes within HR+, HER2− breast cancers and corresponding 10-year mortality rate were compared between Black and Non-Hispanic White (NHW) women using Cox proportional hazard ratios and survival analysis, adjusting for covariates. RESULTS: In this study, 318 women with localized, HR+, HER2− breast cancer were included—227 Black (71%) and 91 NHW (29%). Young Black women (age≤50) had the highest proportion of HR+,non-luminal A tumors (47%), compared to young NHW (10%), older Black women (31%), and older NHW (30%). Overall, women with HR+,non-luminal A subtypes had a higher 10-year mortality rate compared to HR+, luminal A subtypes after adjustment for age, stage and income (HR 4.21 for Blacks, 95% CI=1.74–10.18 and HR 3.44 for NHW, 95% CI=1.31–9.03). Among HR+, non-luminal A subtypes there was however no significant racial difference in 10-yr mortality observed (Black vs. NHW: HR 1.23, 95% CI=0.58–2.58). CONCLUSION: Molecular subtype classification highlights racial disparities in PAM50 subtype distribution among women with HR+, HER2− breast cancer. Among women with HR+, HER2− breast cancer, racial survival disparities are ameliorated after adjusting for molecular subtype.
- Published
- 2021