Factors affecting the delivery of adjuvant/neoadjuvant chemotherapy in older women with breast cancer

Background: Recent studies suggest that older women derive similar benefits from adjuvant systemic chemotherapy (AST) as younger women. In older women, the ability to successfully complete chemotherapy may be complicated by other health conditions and performance status. We examined factors affecting the delivery of chemotherapy to older patients with breast cancer. Methods: Women age ≥ 65 treated with adjuvant/neoadjuvant chemotherapy at Roswell Park Cancer Institute were identified from the RPCI database from 7/1997 to 4/2010. Endpoints were delay, hospitalization, dose reduction, relative dose intensity (RDI) < 85%, and incomplete administration of chemotherapy. Data recorded included medical comorbidities and the use of anthracycline-based chemotherapy. The Pearson chi-squared, Wilcoxon rank sum, logistic regression, Kaplan-Meier, and log-rank tests were used to analyze outcomes. A 0.05 nominal significance level was used in all testing. Results: 204 older women received AST. Median follow-up was 50.2. months. Seventy percent received anthracycline-based AST. In multivariate analysis, older age was a predictor for early termination of chemotherapy and RDI < 85%. Hypertension was correlated with delay and hospitalization. A Charlson comorbidity index ≥ 1 and anthracycline-based chemotherapy regimens were associated with chemotherapy delays. The successful completion of chemotherapy and the delivery of a RDI ≥ 85% of planned chemotherapy were associated with improved survival (p = 0.01, and p < 0.01 respectively). Significant toxicity resulting in a change in therapy or schedule occurred in 45% of cases. Conclusion: Successful administration of planned chemotherapy to older women with breast cancer was associated with improved OS. However, delivery of chemotherapy was associated with increased toxicity and reduced tolerance. Models allowing physicians to better risk-stratify older patients with breast cancer are needed and under development.