Outcomes in black patients with early breast cancer treated with breast conservation therapy.
BACKGROUND
The race-specific impact of prognostic variables for early breast cancer is unknown for black patients undergoing breast conservation.


METHODS
This was a retrospective study of 1,231 consecutive patients ≥40 years of age with Stage I-II invasive breast cancer treated with lumpectomy and radiation therapy at the University of Chicago Hospitals and affiliates between 1986 and 2004. Patients were classified as either black or nonblack. Cox proportional hazards regression was used to model the effects of known prognostic factors and interactions with race.


RESULTS
Median follow-up for surviving patients was 82 months. Thirty-four percent of patients were black, and 66% were nonblack (Caucasian, Hispanic, and Asian). Black patients had a poorer 10-year overall survival (64.6% vs. 80.8%; adjusted hazard ratio [HR], 1.59; 95% confidence interval [CI], 1.23-2.06) and 10-year disease-free survival (58.1% vs. 75.4%; HR 1.49; 95% CI, 1.18-1.89) compared with nonblack patients. Tumor sizes were similar between nonblack and black patients with mammographically detected tumors (1.29 cm vs. 1.20 cm, p = 0.20, respectively). Tumor size was significantly associated with overall survival (HR 1.48; 95% CI, 1.12-1.96) in black patients with mammographically detected tumors but not in nonblack patients (HR 1.09; 95% CI, 0.78-1.53), suggesting that survival in black patients depends more strongly on tumor size in this subgroup. Tests for race-size method of detection interactions were statistically significant for overall survival (p = 0.049), locoregional control (p = 0.036), and distant control (p = 0.032) and borderline significant for disease-free survival (p = 0.067).


CONCLUSIONS
Despite detection at comparable sizes, the prognostic effect of tumor size in patients with mammographically detected tumors is greater for black than in nonblack patients.
Nichols
Michael A
MA
Department of Radiation and Cellular Oncology, University of Chicago, Chicago, IL 60637, USA.
Mell
Loren K
LK
Hasselle
Michael D
MD
Karrison
Theodore G
TG
MacDermed
Dhara
D
Meriwether
Amber
A
Witt
Mary Ellyn
ME
Weichselbaum
Ralph R
RR
Chmura
Steven J
SJ
D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D044466:Asian People; D044383:Black People; D001943:Breast Neoplasms / Q000000981:diagnostic imaging / Q000208:ethnology* / Q000401:mortality / Q000473:pathology / Q000628:therapy*; D003131:Combined Modality Therapy / Q000379:methods; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006630:Hispanic or Latino; D006801:Humans; D008327:Mammography; D015412:Mastectomy, Segmental; D008875:Middle Aged; D016016:Proportional Hazards Models; D011878:Radiotherapy / Q000379:methods; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D013629:Tamoxifen / Q000627:therapeutic use; D016896:Treatment Outcome; D047368:Tumor Burden; D044465:White People
D018931:Antineoplastic Agents, Hormonal; D013629:Tamoxifen