Purpose: The purpose of this study was to evaluate the prognostic significance of race in breast cancer patients treated with lumpectomy and radiation therapy.
Methods and materials: Between 1973 and 1997, 1614 patients were treated with lumpectomy and radiation therapy at our institution. All patient data, including race, age, stage, pathology, treatment, and outcome variables, were entered into a computerized database. One hundred and one women were identified as African American, and 1513 were identified as white. A small number (22) of patients of Asian, Hispanic, or other ethnic groups were eliminated from analysis. A detailed cosmetic analysis was performed on a selected subset of 20 African-American patients and 20 white patients from the database. The two groups were intentionally matched by age, follow-up, adjuvant therapy, and breast size and were asked to participate in a detailed cosmetic evaluation.
Results: As of September 2001, median follow-up was 14.5 years. African-American patients presented with an earlier age of onset than white patients (51.1 African-American patients vs 56.5 white). By age groups, 42.5% of African-American patients were older than 50 years, compared with 68.6% of white patients. African-American patients presented with larger tumors (mean pathological size, 1.87 cm in African-American patients vs 1.57 cm in white patients) and were more frequently estrogen receptor negative (51% estrogen receptor-negative African-American patients vs 37% estrogen receptor-negative white patients). However, nodal status was similar in the two populations (27% node-positive African-American patients vs 24% node-positive white patients). Given their younger age and estrogen receptor negativity, African-American patients were more likely to receive chemotherapy, whereas white patients were more likely to receive adjuvant tamoxifen. Despite the earlier age of onset and larger tumor size, there were no significant differences between the African-American and white populations with respect to overall survival (82% in the African-American population vs 79% in the white) or cause-specific survival at 10 years (88% in the African-American population vs 86% in the white). African-American patients had a significantly lower breast relapse-free rate at 10 years (81% in the African-American population vs 87% in the white). Although this may be in part related to the younger age in the African-American patients, a multivariate analysis including age, race, margin status, and treatment parameters revealed young age and African-American race to be significantly associated with local relapse. With respect to overall cosmetic outcome and all specific cosmetic measures (edema, fibrosis, and pigmentation), African-American patients fared more poorly than white patients. Overall cosmesis was good to excellent in 55% of African Americans, compared with 90% of whites.
Conclusions: Despite a younger age of onset and a larger tumor size, outcome in African-American patients was similar to that of white patients with respect to overall and cause-specific survival. The explanation for a slightly higher local relapse rate and poorer cosmetic result requires further investigation.