Delea, T.El-Ouagari, K.Karnon, J.Sofrygin, O.2008-08-202008-08-202008Breast Cancer Research and Treatment, 2008; 108(3):375-3870167-68061573-7217http://hdl.handle.net/2440/47478The original publication can be found at www.springerlink.comBackground In the primary core analysis of BIG 1–98, a randomized, double-blind trial comparing 5 years of initial adjuvant therapy with letrozole versus tamoxifen in postmenopausal women with hormone receptor-positive (HR+) early breast cancer, letrozole significantly improved disease-free survival by 19% and reduced the risk of breast cancer recurrence by 28% and distant recurrence by 27%. Methods A Markov model was used to estimate the incremental cost per quality-adjusted life year (QALY) gained with 5 years of initial adjuvant therapy with letrozole versus tamoxifen from a Canadian healthcare system perspective. Probabilities of recurrence and side effects for tamoxifen were based on published results of BIG 1–98 and other published population-based studies. Corresponding probabilities for letrozole were calculated by multiplying probabilities for tamoxifen by estimated relative risks for letrozole versus tamoxifen from BIG 1–98. Other probabilities, costs of breast-cancer care and treatment of side effects, and health-state utilities were obtained from published studies. Costs and QALYs were estimated over the lifetime of a cohort of postmenopausal women with HR+ early breast cancer, aged 60 years at initiation of therapy, and discounted at 5% annually. Results Compared with tamoxifen, letrozole yields an additional 0.368 life-years (12.453 vs. 12.086) and 0.343 QALYs (11.582 vs. 11.239). These benefits are obtained at an additional cost of $Can 8,110 ($Can 30,819 vs. $Can 22,709). Cost per QALY gained for letrozole versus tamoxifen is $Can 23,662 (95% CI $Can 15,667–$Can 52,014). Conclusion In postmenopausal women with HR+ early breast cancer, initial adjuvant treatment with letrozole is cost-effective from the Canadian healthcare system perspective.enAdjuvant therapyBreast cancerCost-effectivenessLetrozoleTamoxifenJournal article00200822942008082011501910.1007/s10549-007-9607-70002542344000072-s2.0-4114917916642245Karnon, J. [0000-0003-3220-2099]