Abstract P1-11-22: Aromatase inhibitors are significantly better tolerated by early stage breast cancer patients 75 or older and with significantly lower early discontinuation rate

Abstract

Abstract Introduction: Breast cancer is the most common cancer in women. In postmenopausal women with early stage estrogen receptor positive breast cancer, aromatase inhibitors (AI) are a common treatment option. AI's are reported to lead to a high early discontinuation rate in younger post-menopausal women due to poor tolerance. The most common side effects reported to lead to early discontinuation are arthralgia, hot flashes, fatigue, and night sweats. The reported tolerance to AI therapy in women age 75 or older is not well documented. Our study looks at women, ages 75 and older, diagnosed with early stage breast cancer who were placed on adjuvant AI therapy and focuses on tolerability, incidence of common side effects, rate of treatment changes, and on discontinuation rates. Objective: This study evaluates the tolerability, treatment side effects and the discontinuation rate of AI in women over the age of 75 with early stage breast cancer. Methods: Our study is a retrospective chart review of 58 patients' ages 75 to 95 with early stage breast cancer treated with adjuvant AI. Charts of patients were reviewed and duration of treatment, patient reported side effects, treatment changes, and discontinuation rate were recorded. Results: Data analysis showed that 36/55 (65.5%) of patients did not report significant side effects to AI. 6/55 (10.9%) patients required therapy changes due to side effects. 5/6 required one treatment change and 1/6 required multiple treatment changes. In 5/6 therapy was changed to another AI. Only 2/55 (3.6%) of patients discontinued therapy. In both patients who discontinued AI, therapy was discontinued due to medical complications unrelated to AI therapy. Average time to discontinuation was 11 months. The most common reported side effects were arthralgia 9/55 (16.4%), fatigue 3/55 (5.5%), hot flashes 4/55 (7.3%), rash 3/55 (5.5%) and hair thinning 3/55 (5.5%). The most common reported side effect which led to treatment change was arthralgia 4/6 (66.7%). With a median follow up time of 24 months, breast cancer specific mortality was 1/55 (1.8%). Reported Side Effects on AIn=55 patientsPatients who noted symptomsPatients who changed therapy due to symptomsFatigue30Arthralgia94Hot flashes40Rash31Vaginal dryness10Hair thinning31 Conclusion: Our study evaluated the tolerance of AI in older women diagnosed with early stage breast cancer. 36/55 (65.5%) of elderly patients reported no significant side effects suggesting that AI's are well tolerated in this population and the known side effects are significantly less common than previously reported in a younger cohort in whom arthralgia as well as vasomotor symptoms affect as many as 30% of women. This improved tolerance led to a significantly lower early discontinuation rate than previously reported in the younger cohort: discontinuation rate of 3.6% by 24 months in the 75 or older population versus 20% by 24 months in the younger cohort of post-menopausal women treated with AI. Reference: 1 Wagner, L.I., Zhao, F., Goss, P.E. et al. Breast Cancer Res Treat (2018) 169: 537. https://doi-org.proxy.library.stonybrook.edu/10.1007/s10549-018-4713-2 Citation Format: Chaudhry B, Baer L, Kudelka A, Cohen J, Stopeck AT. Aromatase inhibitors are significantly better tolerated by early stage breast cancer patients 75 or older and with significantly lower early discontinuation rate [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-11-22.