Racial differences in the use and outcome of neoadjuvant chemotherapy for breast cancer: Results From the National Cancer Data Base

Abstract

Purpose: To explore racial differences in the use and outcome of neoadjuvant chemotherapy for breast cancer. Methods: 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. Results: 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 triplenegative 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). Conclusion: 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.