Racial Disparities in Chemotherapy Administration for Early-stage Breast Cancer: a Systematic Review and Meta-analysis

Purpose: We conducted a systematic review and meta-analysis to measure the extent to which race is associated with delayed initiation or receipt of inadequate chemotherapy among women with early-stage breast cancer.

Methods: We performed a systematic search of all articles published from January 1987 until June 2017 within four databases: PubMed/Medline, EMBASE, CINAHL, and Cochrane CENTRAL. Eligible studies were US-based and examined the influence of race on chemotherapy delays, cessation, or dose reductions among women with stage I, II, or III breast cancer. Data were pooled using a random effects model.

Results: A total of twelve studies were included in the quantitative analysis. Blacks were significantly more likely than whites to have delays to initiation of adjuvant therapy of 90 days or more (OR 1.41, 95% CI 1.06-1.87; X² = 31.05, p < 0.00001; I² = 90%). There was no significant association between race and chemotherapy dosing. Due to overlap between studies assessing the relationship between race and completion of chemotherapy, we conducted two separate analyses. Black patients were significantly more likely to discontinue chemotherapy, however, this was no longer statistically significant when larger numbers of patients with more advanced (stage III) breast cancer were included.

Conclusions: These results suggest that black breast cancer patients experience clinically relevant delays in the initiation of adjuvant chemotherapy more often than white patients, which may in part explain the increased mortality observed among black patients.