Differences in breast tumor response to neoadjuvant chemotherapy by race – Is obesity the key?

Abstract

Introduction: Breast cancer treatment includes neoadjuvant chemotherapy offered to patients with aggressive subtypes and locally advanced breast cancer. Black women receive neoadjuvant chemotherapy more frequently as they present more advanced stage tumors and triple negative subtype. Non-Hispanic Black women have the greatest prevalence of obesity in most states. Patients with higher body mass index (BMI) have lower rates of chemotherapy response. Whether obesity is a confounding factor requires investigation.Methods: A retrospective cohort study of patients diagnosed with non-metastatic breast cancer who completed neoadjuvant chemotherapy and had surgery at The Ohio State University Comprehensive Cancer Center between January 1 2005 and December 31 2019, was conducted. Demographic characteristics were compared using Pearson’s chi-square test, or Wilcoxon rank-sum test. Logistic regression models were used to assess associations between pathologic response and age, race, BMI, menopausal status, and insurance status.Results: More Black women had high grade tumors, triple negative advanced stage disease, and higher BMI. Race and BMI were not significant predictors of poor pathologic complete response, however patients aged <40 years had higher odds of pathologic complete response.Discussion: Further exploration evaluating differences in pathologic response by BMI could lead to a better understanding of the association between obesity and treatment response.

Keywords

• Breast cancer
• neoadjuvant chemotherapy
• obesity
• racial disparities