Early discontinuation of chemotherapy in older adults with early breast cancer: results from the prospective multicenter HOPE study.

Abstract

Older adults with early-stage breast cancer (EBC) receiving neo/adjuvant chemotherapy frequently discontinue treatment early. However, the incidence, risk factors, and survival implications of early discontinuation remain poorly understood. This is a post-hoc analysis of 501 older adults (aged≥65) with EBC treated with neo/adjuvant chemotherapy from the Hurria Older PatiEnts (HOPE) Study. Prior to chemotherapy, we collected sociodemographic, clinical, and geriatric assessment characteristics. The primary outcome was early discontinuation (yes/no), defined as not completing all planned chemotherapy. We used multivariable logistic regression with stepwise selection to identify pretreatment risk factors and the Kaplan-Meier method to evaluate the impact of discontinuation on survival. Of 501 participants (median [range] age, 70 [65-86] years), 113 (23%) had early discontinuation. After multivariable analysis, ≥1 fall within 6 months (odds ratio [OR] = 2.06, 95% CI: 1.11-3.81, p = 0.02) and an activity of daily living score <85 (OR = 2.00, 95% CI: 1.26-3.18, p = 0.003) were identified as risk factors for early discontinuation. Participants with both risk factors were at highest risk (OR = 4.61, 95% CI: 2.18-9.79, p < 0.001). With a median follow up of 4.3 years, early discontinuation was not associated with worse overall or breast cancer-specific survival but was associated with higher non-breast cancer-specific mortality (Hazard Ratio = 2.94, 95% CI 1.22-7.07, p = 0.02). In this cohort of older adults with EBC, nearly one-quarter discontinued chemotherapy early. Early discontinuation was associated with increased non-cancer related mortality but not cancer-related mortality, emphasizing the importance of identifying high-risk older adults and optimizing treatment delivery.