Purpose: To determine the influence of race on breast cancer treatment and on recurrence and breast cancer specific death.
Patients and methods: The study population consisted of 6,054 African-American or white women who were diagnosed with breast cancer and received at least one of the treatments including mastectomy or breast conservative surgery, radiation, adjuvant chemotherapy, neo-adjuvant chemotherapy, and adjuvant endocrine therapy at M.D. Anderson Cancer Center between June 1997 and February 2005. The clinical outcomes were disease-free survival and breast-cancer-specific survival. Logistic regression analysis was performed to investigate if race was associated with the selection of each primary treatment while adjusting for tumor characteristics at diagnosis. Cox proportional hazards model was used to determine the effect of race on recurrence-free survival and breast-cancer-specific survival controlling for tumor characteristics, presence of co-morbidity conditions and use of these treatments.
Results: The use of any primary treatment for breast cancer was not significantly different by race after adjusting for tumor characteristics and co-morbidity conditions. Although tumor characteristics at diagnosis explained the major differences in clinical outcomes, race remained an independent prognostic factor for breast-cancer-specific survival (P=0.002), and a marginally significant factor for disease-free survival (P=0.063) in multivariate analyses.
Conclusion: Equal treatment may not lead to equal clinical outcomes given similar tumor characteristics at diagnosis. To reduce racial differences in breast cancer recurrence and survival, it is important to have a better understanding of differences in tumor biology by race and to promote the use of early detection programs among African-American women.