Three Lymphadenectomy Strategies in Low-Risk Endometrial Carcinoma: A Cost-effectiveness Analysis

There has been an ongoing debate on the optimal approach to lymph node dissection in women with endometrial cancer. Traditionally, routine lymph node dissection has been considered to be the standard of care for surgical management of endometrial cancer. Some trials, however, have shown that routine lymph node dissection provides no survival advantage (especially for low-risk disease) and increases surgical morbidity without any appreciable diagnostic benefit. Sentinel lymph node (SLN) mapping using a selective lymph node dissection approach has been proposed as an alternative strategy. Previous costeffectiveness studies comparing routine and selective lymph node dissection have had conflicting results, and no studies have examined the cost-effectiveness of an SLN algorithm compared with other management strategies. The aim of this study was to evaluate the cost-utility of 3 lymphadenectomy strategies in the management of women with low-risk endometrial carcinoma. Low-risk endometrial carcinoma was defined on preoperative endometrial biopsy as clinical stage 1 disease with grade 1 to 2 endometrioid histology. Three lymphadenectomy strategies were compared using a decision analysis model in women undergoing minimally invasive surgery for low-risk endometrial carcinoma: one strategy was routine lymphadenectomy in all patients; the second was selective lymphadenectomy based on intraoperative frozen-section criteria; the third was SLN mapping. Estimated cost and outcomes were obtained from Medicare reimbursement rates and published literature. Cost categories included hospital, physician, operating room, pathology, and lymphedema treatment. Effectiveness was defined as 3-year disease-specific survival, adjusting for the effect of lower extremity lymphedema (utility = 0.8) on quality of life. The different strategies were compared in a cost-utility analysis - a cost-effectiveness analysis accounting for cost, survival, and quality of life. To assess the robustness of the results, multiple deterministic sensitivity analyses were performed, adjusting for different parameters. Routine lymphadenectomy in the base-case scenario had a cost of $18,041 per patient and an effectiveness of 2.79 qualityadjusted life-years (QALYs), whereas selective lymphadenectomy had a cost of $17,036 per patient and an effectiveness of 2.81 QALYs. Sentinel lymph node mapping had a cost of $16,401 and an effectiveness of 2.87 QALYs. Given the difference of $1005 and 0.02 QALYs, selective lymphadenectomy was both less costly and more effective than routine lymphadenectomy, making it a more dominant strategy. However, SLN mapping (with the lowest cost and highest effectiveness) dominated the other strategies and was the most cost-effective approach. In multiple sensitivity analyses, varying the rates of lymphedema and lymphadenectomy, surgical approach (open or minimally invasive), lymphedema utility, and costs showed the robustness of these findings. An estimated 40,000 women undergo surgery for low-risk endometrial carcinoma each year in the United States. If all these women underwent routine lymph node dissection, selective lymph node dissection, and SLN mapping, the total annual lymphedema treatment costs would be $722 million, $681 million, and $656 million, respectively. In this cost-utility analysis, selective lymph node dissection is more cost-effective than routine lymph node dissection in patients undergoing surgery for low-risk endometrial carcinoma. Further studies are needed to assess the cost and effectiveness of different lymph node dissection strategies.