Racial Disparities in Pathologic Complete Response and Survival after Neoadjuvant Chemotherapy for Breast Cancer.

Background: Pathological complete response (pCR) is utilized as a surrogate for breast cancer outcomes in high-risk breast cancer patients. Racial disparities in pCR have been assessed by clinical trial data, the National Cancer Database, and single-center experiences; however, results vary by setting. This population study using the Surveillance Epidemiology, and End Results (SEER) program aims to assess differences in pCR rates between black and white women after neoadjuvant chemotherapy and assess survival by race and by pCR status.

Methods: This is a population-based cohort study utilizing SEER. Black and white women with nonmetastatic breast cancer diagnoses who received neoadjuvant chemotherapy between 2010 and 2018 were included.

Results: A total of 10,254 patients were analyzed. Black women had lower odds of pCR compared to white women (adjusted odds ratio 0.85, 95% confidence interval 0.76 - 0.95). With a median follow-up of 5.2 years, there was no difference in the adjusted risk of breast cancer-related or all-cause mortality between races when pCR was achieved. However, among patients who did not achieve pCR, blacks had higher breast cancer-related and all-cause mortality risk.

Conclusions: Utilizing real-world data, black women had lower odds of pCR than white women, and non-pCR black women had worse survival outcomes than non-pCR white women.

Impact: pCR alone can impact survival outcomes in black and white women. Outside of clinical trials racial disadvantages are clear. These findings highlight the need for interventions so that all patients receive optimal treatment to help mitigate breast cancer survival disparities.