Ethnicity related differences in the survival of young breast carcinoma patients.

Background: African-American women face an increased risk of early-onset breast carcinoma compared to white American women, and breast carcinoma has been reported to be particularly aggressive in premenopausal women.

Methods: Surveillance, Epidemiology, and End Results Program data were analyzed for 507 African-American and 1378 white patients from Detroit diagnosed with breast carcinoma under the age of 40 between 1990 and 1999.

Results: The proportion of in situ disease detected in African-American patients between 1995 and 1999 nearly doubled compared to the 1990-1994 interval (11.3% compared to 6.4%) but was consistently lower than the proportion of in situ disease seen in white patients for the same intervals (15.7% and 16.4% respectively). Evaluation of patients with invasive disease revealed that African-American patients had larger mean tumor size (3.4 cm versus 2.6 cm; P < 0.001), lower rates of localized disease (42.4% versus 52.1%; P < 0.001), higher rates of estrogen receptor negativity (61.9% versus 44.4%; P < 0.001), and higher proportions of medullary tumors (5.8% versus 3.3%; P = 0.021). Cox proportional hazards survival analysis adjusted for age, tumor size, nodal status, hormone receptor status, and histology showed higher mortality rates for African-American patients at all disease stages. Relative risk of death for African-American patients was 1.94 in patients with localized disease (95% confidence interval [CI], 1.23-3.05), 1.58 for regional disease (95% CI = 1.18-2.11), and 2.32 for distant disease (95% CI = 1.15-4.69).

Conclusions: These findings show that young African-American breast carcinoma patients face an increased mortality risk. Additional studies evaluating risk and treatment response in this subset of patients are warranted.