Racial Differences in the Use and Outcome of Neoadjuvant Chemotherapy for Breast Cancer: Results From the National Cancer Data Base.

Abstract

To explore racial differences in the use and outcome of neoadjuvant chemotherapy for breast cancer. The National Cancer Data Base was queried to identify women with stage 1 to 3 breast cancer diagnosed in 2010 and 2011. Chemotherapy use and rate of pathologic complete response (pCR) was determined for various racial/ethnic groups. Of 278,815 patients with known race and ethnicity, 127,417 (46%) received chemotherapy, and of 121,446 where the timing of chemotherapy was known, 27,300 (23%) received neoadjuvant chemotherapy. Chemotherapy, and neoadjuvant chemotherapy in particular, was given more frequently to black, Hispanic, and Asian women than to white women (P < 0.001). This difference was largely explained by more advanced stage, higher grade tumors, and a greater proportion of triple-negative and human epidermal growth factor receptor 2 (HER2)-positive tumors in these women. Of 17,970 patients with known outcome, 5,944 (33%) had a pCR. No differences in response rate for estrogen receptor (ER)/progesterone receptor (PR)-positive tumors were found, but compared with white women, black but not Hispanic or Asian women had a lower rate of pCR for ER/PR-negative, HER2-positive (43% v 54%, P = 0.001) and triple-negative tumors (37% v 43%, P < 0.001). This difference persisted when adjusted for age, clinical T stage, clinical N stage, histology, grade, comorbidity index, facility type, geographic region, insurance status, and census-derived median income and education for the patient's zip code (odds ratio, 0.84; 95% CI, 0.77 to 0.93). Neoadjuvant chemotherapy is given more frequently to black, Hispanic, and Asian women than to white women. Black women have a lower likelihood of pCR for triple-negative and HER2-positive breast cancer. Whether this is due to biologic differences in chemosensitivity or to treatment or socioeconomic differences that could not be adjusted for is unknown.