The association of socioeconomic status with receipt of neoadjuvant chemotherapy

There are advantages to neoadjuvant chemotherapy in operable breast cancer, particularly for those with higher-risk cancers, but little is known about factors that are associated with the use of neoadjuvant chemotherapy outside of clinical trials. We examined whether use of neoadjuvant chemotherapy instead of adjuvant chemotherapy varies by nonclinical factors such as patient socioeconomic status or rural residence.

Women diagnosed with breast cancer in 2013-2014 at eight medical institutions were surveyed by mail regarding their experiences with breast cancer treatment, and this information was linked to hospital-based cancer registries. We examined the use of neoadjuvant chemotherapy among women with histologically confirmed invasive stage I-III breast cancer and used regression models to examine the association of socioeconomic status with chemotherapy timing. We also explored potential mechanisms for those differences.

Over 29% of the chemotherapy sample overall received neoadjuvant chemotherapy. Neoadjuvant receipt was lower for those with income < $100,000 (AOR 0.56, 95% CI 0.2-0.9) even with adjustment for other demographics, stage, and biomarker status, and findings for education and a variable for both lowest education and income < $100,000 were similar. Rural/urban residence was not associated with neoadjuvant receipt. Differences by income in perceptions of the importance of neoadjuvant chemotherapy advantages and disadvantages did not appear to explain the differences in use by income.

In a multicenter sample of breast cancer patients, lower income was strongly associated with less receipt of neoadjuvant chemotherapy. Since patients with lower socioeconomic status are more likely to present with later-stage disease, this pattern has the potential to contribute to breast cancer outcome disparities.