Adding Ovarian Function Suppression to Tamoxifen Worsened Some Patient-Reported Outcomes in Premenopausal Women With Early Breast Cancer
Ribi et al reported in the Journal of Clinical Oncology that addition of ovarian function suppression to tamoxifen resulted in greater endocrine and sexual function symptoms among premenopausal patients with early breast cancer in the Suppression of Ovarian Function Trial (SOFT). The SOFT study showed that adding ovarian function suppression to tamoxifen did not significantly improve disease-free survival in the overall population but improved outcomes in the subgroup that received adjuvant chemotherapy and remained premenopausal.
Study Details
The current analysis included 1,722 of 2,045 premenopausal patients with hormone receptor–positive breast cancer randomized in the trial, in which chemotherapy use before enrollment was optional. Patients completed a quality-of-life instrument consisting of global and symptom indicators at baseline, every 6 months for 24 months, and annually during years 3 to 6.
Patient-Reported Outcomes
Patients receiving ovarian function suppression and tamoxifen were more affected by hot flushes at 6 and 24 months (both P < .0001), loss of sexual interest and sleep disturbance at 6 months (both P < .0001), and vaginal dryness up to 60 months (P < .01 at 6, 24, and 60 months). Among the 772 patients in the quality-of-life analysis who had not received prior chemotherapy, those receiving tamoxifen alone reported more vaginal discharge over 5 years.
Differences in treatment-specific symptoms were less pronounced at 6 moths among the 950 patients in the analysis who had received prior chemotherapy. Changes in global quality of life were small and similar in the two groups over 5 years.
The investigators concluded: “Overall, ovarian function suppression added to tamoxifen resulted in worse endocrine symptoms and sexual functioning during the first 2 years of treatment, with variable magnitudes of treatment differences. Short-term differences in symptom-specific quality of life, treatment burden, and coping effort between treatment groups were less pronounced for patients with prior chemotherapy, the cohort that benefited most from ovarian function suppression in terms of disease control.”
The SOFT study was supported by Pfizer, the International Breast Cancer Study Group (IBCSG), and the U.S. National Cancer Institute (NCI). The coordinating group of IBCSG was supported by the Frontier Science and Technology Research Foundation, the Swiss Group for Clinical Cancer Research, the NCI, Cancer Research Switzerland/Oncosuisse, and the Foundation for Clinical Cancer Research of Eastern Switzerland.
Karin Ribi, PhD, of the International Breast Cancer Study Group, Bern, Switzerland, is the corresponding author of the Journal of Clinical Oncology article.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
