Race-based mortality as determined by intrinsic breast tumor subtype and p53 status.

Abstract

e12519 Background: Race-based mortality differences have been reported for intrinsic breast tumor subtypes. p53 status has recently emerged as a marker of worse prognosis among African-American (AA) women with breast cancer; however, the impact of p53 status on mortality by specific subtype is not clear. Methods: Multivariable (age, stage and race adjusted) stratified (subtype and p53) analyses with proportional hazards regression models [hazard ratios (HR), 95% confidence intervals (CIs)] for all-cause mortality, in a cohort of 331 AA and 203 non-AA women (115 Hispanic, 88 non-Hispanic white) of lower socioeconomic status, consecutively treated for breast cancer at an urban hospital, with 60.4 months median follow-up, and known intrinsic subtype and p53 immunohistochemical status. Results: The Table shows the effect of p53 status and demonstrates increased mortality hazards across all subtype strata for AA women compared to non-AA. The largest change in hazards was observed for luminal A and HER2 subtype tumors with higher stage, but this pattern was also evident for lower stage tumors. Hazards of death were least increased across basal type tumors. Conclusions: Across each level of subtype, p53+ status increased the hazards of death in AA women with breast cancer. However, mortality hazards appeared most increased in women with luminal A and HER2 type tumors. [Table: see text]