Objective: Practice patterns vary across Canada with respect to indications for surgical staging and adjuvant radiotherapy in early endometrial cancer. We evaluated the cost-effectiveness of two common strategies for managing early endometrial cancer as part of an Ontario population-based study.
Methods: A decision-analytic model (DATA 4.5) was developed for Stage I and II endometrioid-type cancer using empiric data from Ontario. On the basis of preoperative biopsy grade, one of two surgical procedures was selected: (1) hysterectomy and bilateral salpingo-oophorectomy (HBSO) or (2) surgical staging (HBSO and pelvic +/- para-aortic lymphadenectomy). Adjuvant radiotherapy (RT) was administered according to final grade and stage. After HBSO, pelvic RT was indicated for Grades 1 and 2 if Stage IC, IIA with > 50% myometrial invasion (MI), or IIB, and for Grade 3 if Stage IB, IC, IIA, or IIB. After staging, pelvic RT was indicated for Grades 1 and 2 if Stage IIB, and for Grade 3 if Stage IC, IIA with > 50% MI, or IIB. Main outcome measures were quality-adjusted life-years (QALY) and incremental cost-effectiveness ratios (ICER). Sensitivity analyses were used to evaluate uncertainty around various parameters.
Results: The most cost-effective (dominant) strategies were determined for each preoperative grade. For Grade 1, HBSO strongly dominated surgical staging. For Grade 2, neither strategy was dominant; surgical staging had an ICER of $5216 per QALY. For Grade 3, surgical staging strongly dominated HBSO. These results were stable over a wide range of estimates for costs and utilities (i.e., patient preferences for a particular health state).
Conclusion: The most cost-effective treatment strategies for early endometrial cancer in Ontario differ according to preoperative grade.