Costs and Benefits of Extended Endocrine Strategies for Premenopausal Breast Cancer.

Background: After completing 5 years of adjuvant tamoxifen, women with estrogen receptor (ER)-positive breast cancer benefit from 5 more years of endocrine therapy, either with tamoxifen or an aromatase inhibitor (AI). For premenopausal women, ovarian ablation (OA) would be required before starting an AI (OA/AI). According to the SOFT/TEXT studies, OA/AI improves 5-year disease-free survival compared with tamoxifen alone, suggesting that OA/AI could be superior to tamoxifen as extended endocrine therapy. The long-term costs and consequences of premature menopause from OA are unknown, but could be estimated through a cost-effectiveness analysis. Methods: A Markov chain Monte Carlo simulation model estimated the costs and benefits of 3 extended endocrine strategies in a hypothetical cohort of premenopausal women with ER-positive early breast cancer: (1) no further treatment; (2) tamoxifen for 5 years (extended tamoxifen); or (3) OA/AI for 5 years. Effectiveness was measured in years of life expectancy gain. Sensitivity analyses accounted for uncertainty surrounding various parameters. Monte Carlo simulation estimated the number of adverse events and deaths from each strategy in the US population over a 40-year period. Results: Extended tamoxifen yielded a higher average life expectancy gain than OA/AI (17.31 vs 17.06 years) at lower average cost ($3,550 vs $14,312). For 18,000 premenopausal ER-positive women, the simulation estimated 13,236, 12,557, and 11,338 deaths with no further treatment, extended tamoxifen, and OA/AI, respectively, but an additional 1,897 deaths from OA, for a total of 13,235 deaths associated with OA/AI. After 24.6 years of follow-up, more women are expected to die from OA/AI than extended tamoxifen. Conclusions: For premenopausal women with ER-positive cancer who have completed adjuvant tamoxifen, another 5 years of tamoxifen is the preferable extended endocrine strategy. The potential long-term health consequences of OA could affect overall survival when it precedes the use of an AI.

Long-term consequences of ovarian ablation for premenopausal breast cancer.

The TEXT and SOFT trials concluded that an aromatase inhibitor (AI) with ovarian ablation (OA) yields a higher 5-year disease-free survival than tamoxifen alone in premenopausal ER+ high-risk early breast cancer. However, the long-term health consequences and costs of OA, either by GnRH agonist or oophorectomy, have not been evaluated. The objective was to conduct a cost-effectiveness analysis comparing tamoxifen to OA with AI. Markov Monte Carlo simulation model estimated the costs and benefits of 3 endocrine strategies: (1) tamoxifen; (2) GnRH agonist with AI (GnRHa-AI); (3) bilateral salpingo-oophorectomy with AI (BSO-AI). Effectiveness was measured in life expectancy gain (years), and costs were averaged over a lifetime (USD 2015). Adverse events and deaths from each strategy were modeled in the United States population over a time horizon of 40 years. For women without prior chemotherapy (low-risk), tamoxifen alone was more effective (18.03 years) and less costly ($1566) than GnRHa-AI (17.66 years, $93,692) or BSO-AI (17.63 years, $25,892). For those with prior chemotherapy (high-risk), BSO-AI was more costly but more effective (16.78 years, $25,368) than tamoxifen alone (16.55 years, $1523) with an ICER of $102,290, while GnRHa-AI yielded an ICER of $443,376. The simulation estimated 787 and 577 deaths attributable to OA among 9320 high-risk women after BSO-AI and GnRHa-AI, respectively. There may be a role for ovarian ablation in premenopausal women with ER+ high-risk early breast cancer; however, this analysis raises concerns about the long-term health consequences of ovarian ablation and the potential effects on overall survival.