Life Sciences | Medicine and Health Sciences
A possible explanation for the relatively poor survival from breast cancer among blacks is the much higher rate of the adverse Triple-Negative sub-type. In a study of 1372 patients, blacks had twice the risk of death compared to whites among those with advanced cancer whether or not tumors were Triple-Negative. More research is still warranted to determine why blacks with advanced, but not local, breast cancer have a consistently higher rate of death.
Emerging research suggests a substantially greater prevalence of the adverse triple-negative (TN) subtype (human epidermal growth factor receptor [HER]2−, estrogen receptor [ER]−, and progesterone receptor [PR])−) among black patients with breast cancer. No reports however have been generated from a statewide cancer registry.
Patients and Methods
The study consisted of all black patients (N = 643) and a random sample of white patients (n = 719) diagnosed with primary invasive breast cancer (2000–2003) listed in the National Cancer Institute–Surveillance Epidemiology and End Results (NCI-SEER) Connecticut Tumor Registry (CTR). HER2 status was obtained from pathology reports submitted to the registry. Remaining data were obtained from the registry database.
TN tumors were more prevalent in black compared with white patients (30.8% vs. 11.2%, respectively; P < .001.) There was a 2-fold greater frequency of ER− and PR− phenotypes among black patients, but HER2 status did not differ by race. Patients with lobular cancer were less likely to have TN breast cancer compared with patients with ductal tumors (odds ratio [OR] = 0.23; 95% confidence interval [CI], 0.10–0.58). Among patients with regional disease, black patients exhibited increased risk of death (relative risk [RR] = 2.71; 95% CI, 1.48–4.97) independent of TN status. No survival disparity was found among patients with local disease.
These registry-based data corroborate reports that TN breast cancer varies substantially by race and histologic subtype. A survival disparity among patients with advanced disease, but not local disease, casts some doubt on TN status as an explanation for differences.
More research is warranted to understand why black patients with advanced breast cancer may be at increased risk for death whether or not their tumors express the TN phenotype.
Swede, Helen; Gregorio, David I.; Tannenbaum, Susan H.; Brockmeyer, Jessica A.; Wilson, Lori L.; Pensa, Mellisa A.; Stevens, Richard G.; and Runowicz, Carolyn D., "Prevalence and Prognostic Role of Triple-Negative Breast Cancer by Race: A Surveillance Study" (2011). Articles - Research. 268.