Race and the Prognostic Influence of p53 in Women with Breast Cancer

Prior study suggests that p53 status behaves as an independent marker of prognosis in African American (AA) women with breast cancer. We investigate whether the influence of p53 is unique to AAs or is present in other race/ethnic groups, and how this compares with known prognostic factors. Cox regression models [hazard ratios (HRs), 95% confidence intervals (CIs)] were used to select and evaluate factors prognostic for all-cause mortality in 331 AA and 203 non-AA consecutively treated women. Statistically significant baseline prognostic factors were as follows. For AAs: stage [(III/I) HR 5.57; 95% CI 3.08-10.09], grade [(higher/low) HR 1.55; 95% CI 1.14-2.11], estrogen receptor (ER)/progesterone receptor (PR) status [(-/+) HR 2.01; 95% CI 1.38-2.93], triple negative (ER-, PR-, HER2-) subtype [(+/-) HR 1.95; 95% CI 1.33-2.85], and p53 status [(+/-) HR 1.69; 95% CI 1.10-2.58]. For non-AAs: stage [HR 11.93; 95% CI 2.80-50.84], grade [HR 1.61; 95% CI 0.96-2.71], and ER/PR status [HR 2.13; 95% CI 1.19-3.81]. There was a differential effect of race within p53 groups (P = 0.05) and in multivariate modeling p53-positive status remained an adverse prognostic factor in AAs only [HR 1.82; 95% CI 1.04-3.17]. Compared to non-AAs, 5-year unadjusted survival was worse for AAs overall (73.4% vs. 63.6%; P = 0.032), and also for AAs with p53-positive status (80.3% vs. 54.2%; P = 0.016), but not for AAs with p53-negative disease (68.4% vs. 67.9%; P = 0.81). Among women with breast cancer of different race/ethnicity, an adverse prognostic effect as a result of p53 positivity was only observed in AA women.