National Cancer Database Study Indicates Racial Differences in Neoadjuvant Chemotherapy Use in Women With Breast Cancer
In a study reported in the Journal of Clinical Oncology, Killelea et al found that chemotherapy, particularly neoadjuvant chemotherapy, was more frequently given to black, Hispanic, and Asian women vs white women with stage I to III breast cancer, with the difference largely attributable to more advanced stage, higher grade tumors, more triple-negative tumors, and more HER2-positive tumors in nonwhite women. Black women had a lower likelihood of pathologic complete response for hormone receptor–negative, HER2-positive disease, and triple-negative disease.
Study Details
The study involved National Cancer Database data from women diagnosed in 2010 and 2011. Of 278,815 patients with known race/ethnicity, 127,417 (46%) received chemotherapy; among 121,446 with known timing of chemotherapy, 27,300 (23%) received neoadjuvant chemotherapy. Among all patients, white women had higher rates of estrogen receptor/progesterone receptor–positive, HER2-negative disease, smaller tumor size, less nodal involvement, well-differentiated tumors, and older age at diagnosis compared with other groups.
Black women had the highest rates of triple-negative disease, and Hispanic women showed the highest proportion of patients aged ≤ 30 years. White women were more likely to have Medicare and to receive treatment from a comprehensive community cancer program. Black and Hispanic women were more likely to have no insurance or Medicaid and to have a low level of income and education. Asian women were more likely than other groups to have a high level of education and had the highest income levels.
Likelihood of Chemotherapy
In unadjusted analysis, odds ratios (ORs; significant unless otherwise noted) for receiving any chemotherapy vs white women were 1.90, 1.48, and 1.69 for black, Asian, and Hispanic women, respectively. In analysis adjusting for age, clinical T stage, clinical N stage, histology, grade, and molecular type, odds ratios vs white women were 1.05 for black women, 0.92 for Asian women, and 0.98 (nonsignificant) for Hispanic women. In analysis adjusting for these risk factors plus insurance, income education, comorbidity, facility type and region, odds ratios were 1.04 for black women, 1.01 for Asian women (nonsignificant), and 1.02 for Hispanic women (nonsignificant).
Likelihood of Neoadjuvant Therapy
In unadjusted analysis, odds ratios vs white women for receiving neoadjuvant chemotherapy were 1.47, 1.21, and 1.58 for black, Asian, and Hispanic women, respectively. In analysis adjusting for age, clinical T stage, clinical N stage, histology, grade, and molecular type, odds ratios were 1.12 for black women, 1.08 for Asian women, and 1.25 for Hispanic women. In analysis adjusting for these risk factors plus insurance, income education, comorbidity, facility type, and region, odds ratios were 1.12 for black women, 1.00 for Asian women (nonsignificant), and 1.20 for Hispanic women.
Likelihood of Pathologic Complete Response
In unadjusted analysis, odds ratios vs white women for achieving pathologic complete response were 0.94 for black women (nonsignificant), 1.02 for Asian women (nonsignificant), and 1.03 for Hispanic women (nonsignificant). In analysis adjusting for age, clinical T stage, clinical N stage, histology, grade, and molecular type, odds ratios were 0.84 for black women, 0.91 for Asian women (nonsignificant), and 0.98 for Hispanic women (nonsignificant). In analysis adjusting for these risk factors plus insurance, income education, comorbidity, facility type, and region, odds ratios were 0.84 for black women, 0.91 for Asian women (nonsignificant), and 1.00 for Hispanic women (nonsignificant).
No differences in pathologic complete response rates in estrogen receptor/progesterone receptor–positive tumors were found. Compared with white women, black but not Hispanic or Asian women had a lower rate of pathologic complete response for estrogen receptor/progesterone receptor–negative, HER2-positive (43% vs 54%, P = .001) and triple-negative tumors (37% vs 43%, P < .001).
The investigators concluded: “Neoadjuvant chemotherapy is given more frequently to black, Hispanic, and Asian women than to white women. Black women have a lower likelihood of pathologic complete response 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.”
Brigid K. Killelea, MD, of Yale University School of Medicine, New Haven, Connecticut, is the corresponding author of the Journal of Clinical Oncology article.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
