Neoadjuvant chemotherapy use trends among older women with breast cancer: 2010-2017

This study assessed chemotherapy use trends before (neoadjuvant chemotherapy [NAC]) or after surgery (adjuvant chemotherapy [AdC]) among older women with breast cancer and examined factors related to NAC receipt.

Women (> 65 years) diagnosed with stage I-III breast cancer during 2010-2017 who received NAC or AdC were identified from the Surveillance, Epidemiology, and End Results (SEER)-Medicare database. All patients were stratified into six strata based on subtype (hormone receptor-positive/human epidermal growth factor receptor 2-negative [HR + /HER2-], HER2 + , and triple-negative breast cancer [TNBC]) and stage (I-II and III). Cochran-Armitage tests were performed to test temporal trends of NAC use in each stratum. Multivariable logistic regression analyses were performed to identify factors (sociodemographic and clinical) related to NAC use.

Among included older (mean ± standard deviation: 72.3 ± 5.2 years) women (N = 8,495) with stage I-III breast cancer, NAC use increased from 11.7% (2010) to 32.6% (2017). Significant increases in NAC were found in all strata (p < .0001) with more substantial increases in HER2 + disease and TNBC compared to HR + /HER2- disease. Multivariable logistic regressions identified the youngest age category (66-69 years) and later stage as significant (p < 0.05) predictors of NAC receipt in most strata, in addition to diagnosis year.

Similar to the overall breast cancer population, NAC use increased among a population of older women. NAC was received by most patients with stage III HER2 + disease or TNBC in more recent years and was more common among younger elderly women and those in stage III.