Intensity and Toxicity of Systemic Treatment for Elderly Patients With Metastatic Breast Cancer

Kenneth L Kehl, The University of Texas School of Public Health

Abstract

Purpose: Despite recent therapeutic advances, the outcomes of elderly patients with cancer have not improved as much as those of younger patients. Our goal was to identify patterns of systemic therapy utilization and associated toxicities in elderly patients with metastatic breast cancer to inform clinical decision-making and research priorities in this population. Methods: We examined linked registry and claims data for elderly women with stage IV breast cancer newly diagnosed from 2007-2013 who were included in the SEER-Medicare database. Our primary outcomes of interest were 1) delivery of any systemic therapy (including hormonal therapy, cytotoxic therapy, and/or anti-HER2/neu-directed therapy), 2) delivery of any cytotoxic chemotherapy, and 3) hospitalization or death within 60 days of starting a new line of treatment containing cytotoxic chemotherapy. Results: We identified 2403 patients for analysis. Most patients (70%; 95% CI, 68%-72%) received systemic therapy by one year after diagnosis; this rate varied according to age, hormone receptor status, HER2/neu status, race/ethnicity, marital status, comorbidity, and prior skilled nursing facility stays (adjusted P all < 0.001). Only 41% of patients (95% CI, 39%-43%) received cytotoxic chemotherapy by four years after diagnosis. Given the availability of hormonal therapy, patients with hormone receptor-positive disease were more likely to receive any therapy (81%) than those with hormone receptor-negative disease (65%), but patients with hormone receptor-negative disease were more likely to receive any chemotherapy (60%) than those with hormone receptor-positive disease (41%). Age remained inversely associated with treatment even after adjustment for comorbidity score, hospitalization rates, and skilled nursing facility stays (P<0.001). Married patients were more likely than unmarried patients to receive any systemic therapy (78% vs 67%; adjusted P 0.002) or any chemotherapy (51% vs 37%; adjusted P 0.01). Initiation of a new line of cytotoxic therapy was associated with a 60-day hospitalization or death rate of 28%, without significant variation among the most common chemotherapy regimens. Conclusion: Among elderly patients with newly diagnosed metastatic breast cancer, a substantial proportion did not receive systemic therapy, and most did not receive cytotoxic chemotherapy. Many patients receive upfront hormonal therapy but do not receive chemotherapy before dying of breast cancer. Optimizing outcomes in this population in conjunction with patient preferences will require a multifaceted approach, including earlier diagnosis, improved access to more tolerable novel therapies, comorbidity care, and social support.

Subject Area

Oncology

Recommended Citation

Kehl, Kenneth L, "Intensity and Toxicity of Systemic Treatment for Elderly Patients With Metastatic Breast Cancer" (2017). Texas Medical Center Dissertations (via ProQuest). AAI10608406.
https://digitalcommons.library.tmc.edu/dissertations/AAI10608406

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