Differential Effects of Endocrine Therapy Type on Quality of Life in Older (≥70 Years) Women with Early-Stage Breast Cancer.

BACKGROUND

There is limited data on health-related quality of life (HRQoL) in older breast cancer (BC) patients. This study examines patient-reported outcomes (PROs) by type of endocrine therapy (ET) prescribed, aromatase inhibitors (AI), or tamoxifen (Tam) to estrogen receptor-positive BC patients aged ≥70 years.

METHODS

This retrospective review includes 1052 women diagnosed with early-stage BC from the REQUITE study database, who underwent breast conservation surgery (BCS), and received adjuvant breast radiation therapy (RT), and ET as the only systemic therapy. Among them, 201 women were aged ≥70 years. The PROs were assessed by using EORTC-QLQ-C30, BR23, and Multidimensional Fatigue Inventory measures obtained at baseline after BCS, post-RT, and at 1, 2, and 3 years follow-up. Statistical analysis involves mixed model analysis of variance and propensity score weights.

RESULTS

Among the 201 women, 131 received AI, and 70 received Tam. The overall mean age of this cohort is 75.3 years. Compared with Tam, AI-treated patients experience worse insomnia and general and physical fatigue. Tam-treated patients experienced more physical and cognitive functioning decline than the AI-treated patients. The Tam-treated patients also reported more mental fatigue and reduced sexual enjoyment compared to the AI-treated patients.

CONCLUSIONS

This study suggests a differential impact by type of ET on distinct HRQoL domains experienced by older postmenopausal women. Furthermore, larger prospective clinical trials are necessary to inform treatment decisions for older ER-positive BC patients, considering patient preferences and understanding trade-offs between disease outcomes and HRQoL.