Adjuvant Ovarian Suppression Versus Chemotherapy for Premenopausal, Hormone-responsive Breast Cancer: Quality of Life and Efficacy Tradeoffs

Abstract

Recent clinical trials suggest that adjuvant ovarian suppression may be an equally effective and less toxic alternative to systemic chemotherapy in premenopausal women with hormone-responsive breast cancer. We used a decision-analytic framework to evaluate tradeoffs between efficacy and quality of life in the choice between these treatments. We used a Markov state-transition model to simulate clinical practice in a cohort of 40-year-old premenopausal women with newly diagnosed, hormone-responsive early breast cancer. We assessed three adjuvant treatments: chemotherapy, surgical ovarian suppression, and medical ovarian suppression. Outcomes were recurrence-free, overall, and quality-adjusted survival. Quality-adjusted survival reflected effects of cancer, treatment-related side effects, and menopausal symptoms. Assuming equal efficacy, ovarian suppression was superior to chemotherapy when the relative utility of chemotherapy side effects compared with ovarian suppression side effects was less than 0.95. Results were sensitive to assumptions about the likelihood, duration and consequences of treatment-induced menopause. Treatment choice was affected by a 7% proportional increase in the efficacy of one therapy relative to the others, independent of other factors. If adjuvant chemotherapy and ovarian suppression have similar efficacy, then there may be a subgroup of women for whom quality-of-life considerations dominate the choice of treatment. However, small differences in the relative efficacy of these therapies have a substantial impact on treatment choice, regardless of side effects and menopausal transitions.