Abstract LB_B07: Probability of negative impact on adherence caused by the most frequent side effects of adjuvant endocrine therapy for premenopausal breast cancer in SOFT and TEXT Trials

Abstract

Abstract Background: Regardless of adjuvant chemotherapy, the addition of ovarian function suppression (OFS) to adjuvant endocrine therapy tamoxifen or exemestane in pre-menopausal women with estrogen receptor (ER)-positive breast cancer cause adverse events may affect adherence. Among the 22 targeted adverse events systematically reported in SOFT and TEXT trials, adverse events commonly experienced in exemestane–OFS group (32.3%) and tamoxifen–OFS group (31.0%), compared with tamoxifen alone group (24.6%). Side effects associated with endocrine therapy cause negative impact on adherence. Early discontinuation of endocrine therapy in 22.5%, 19.3%, and 23.7% of the tamoxifen, tamoxifen–OFS, and exemestane–OFS groups, respectively, in SOFT and TEXT trials. This report is intended to evaluate the possible contribution of the 8 most frequently studied side effects that have negative impact on adherence to hormone therapy in breast cancer. Methods: Calculating the probability of negative impact of most frequent endocrine therapy`s side effects (per SOFT-TEXT trials) on adherence per Leanne Fleming et al quantitative systematic review “The impact of medication side effects on adherence and persistence to hormone therapy in breast cancer survivors” Results: Musculoskeletal/joint pain had the most negative impact on the adherence in tamoxifen, tamoxifen–OFS, and exemestane–OFS groups (56%, 63% and 73%, respectively). Average of negative impact of tamoxifen, tamoxifen–OFS, and exemestane–OFS on adherence is 22%, 25% and 27%) Conclusions: The probability of adherence of using tamoxifen alone seems better than tamoxifen–OFS and exemestane–OFS. Citation Format: Tariq Hassan AL Qurayshah. Probability of negative impact on adherence caused by the most frequent side effects of adjuvant endocrine therapy for premenopausal breast cancer in SOFT and TEXT Trials [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr LB_B07.