Abstract PO3-01-08: Interaction of Prior Chemotherapy and Addition of Ovarian Function Suppression on Menopausal Symptoms in Tamoxifen-Treated Breast Cancer Patient: A prospective, Observational study

Abstract Background: Adjuvant endocrine therapy (AET) is commonly used for hormone receptor-positive breast cancer patients. Combining ovarian function suppression (OFS) with tamoxifen improves survival outcomes, but is associated with menopausal symptom-related issues and treatment discontinuation. This study aimed to compare menopausal symptoms between tamoxifen alone and tamoxifen plus OFS over 12 months and identify related factors. Methods: This prospective study included 209 premenopausal breast cancer patients on tamoxifen. Menopausal symptoms were assessed using the Menopausal Rating Scale (MRS) at baseline, 3, 6, and 12 months. Statistical analysis involved linear regression and generalized estimating equations. Results: Of the participants, 27.8% received tamoxifen plus OFS and were younger and more likely to be unmarried. The tamoxifen plus OFS group had lower baseline MRS scores, but higher scores at 6 and 12 months compared to tamoxifen alone. MRS scores increased significantly in both groups, plateauing at 6 months with tamoxifen alone and at 12 months with tamoxifen plus OFS. Factors associated with higher MRS scores at 6 months were baseline MRS scores and addition of OFS. Impact of OFS on MRS scores varied with prior chemotherapy status, being significant in patients without prior chemotherapy. Conclusion: Adding OFS to tamoxifen in premenopausal breast cancer patients was associated with a higher burden of menopausal symptoms compared to tamoxifen alone, particularly in patients who have not undergone prior chemotherapy. Therefore, careful consideration and decision-making regarding this issue are crucial in terms of both treatment outcomes and quality of life. Table 1. Baseline characteristics, Overall and According to adjuvant endocrine therapy, tamoxifen alone versus tamoxifen plus ovarian function suppression (OFS) Table 2. Multivariable linear regression about MRS scores from the baseline to 6 months, and with interaction between addition of OFS and prior chemotherapy effect Table 3. Interaction effect of additional OFS depending on prior chemotherapy; (a) without prior chemotherapy, (b) with prior chemotherapy Citation Format: Youngwon Lee, Jong Won Lee, Sae Byul Lee, Byung Ho Son, Hee Jeong Kim, Beom Seok Ko, Jisun Kim, Il-Yong Chung, Tae-Kyung Yoo. Interaction of Prior Chemotherapy and Addition of Ovarian Function Suppression on Menopausal Symptoms in Tamoxifen-Treated Breast Cancer Patient: A prospective, Observational study abstract. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-01-08.