Salpingo-oophorectomy or surveillance for ovarian endometrioma in asymptomatic premenopausal women?: a cost-effectiveness analysis

Abstract

The lifetime risk of ovarian cancer is 1.9% among women with endometriosis compared to 1.3% among the general population. When an asymptomatic endometrioma is incidentally discovered on imaging, gynecologists must weigh procedural complications and surgical menopause against future ovarian pathology or cancer. We aimed to determine if performing unilateral salpingo-oophorectomy (USO) is a cost-effective strategy for prevention of death compared to surveillance for asymptomatic endometriomas. We created a cost-effectiveness model using TreeAge Pro with a lifetime time horizon. Our hypothetical cohort included premenopausal patients with two ovaries who do not desire fertility. Those diagnosed with asymptomatic endometrioma underwent USO or surveillance (ultrasound 6-12 weeks after diagnosis, then annually). Our primary effectiveness outcome was mortality, including death from ovarian cancer or surgery and all-cause mortality related to surgical menopause (+/- hormone replacement therapy). We modeled the probabilities of surgical complications, occult malignancy, development of contralateral adnexal pathology, surgical menopause, use of hormone replacement therapy, and development of ovarian cancer. Costs included surgical procedures, complications, ultrasound surveillance, hormone therapy, and treatment of ovarian cancer, with information gathered from Medicare reimbursement data and published literature. Cost-effectiveness was determined using the incremental cost-effectiveness ratio (ICER) of Δ costs / Δ deaths with a willingness to pay (WTP) of $11.6 million as the value of a statistical life. Multiple one-way sensitivity analyses were performed to evaluate model robustness. Our model demonstrated that USO costs more than surveillance ($6,403.43 vs. $5,381.39 per case of incidental endometrioma). However, USO improved outcomes with fewer deaths (0.28% vs.1.50%) and fewer cases of ovarian cancer (0.42% vs. 2.96%) than surveillance. The ICER revealed that USO costs $83,773.77 per death prevented and $40,280.46 per case of ovarian cancer prevented compared to surveillance. As both values were well below the WTP threshold, USO is cost-effective and the preferred strategy. If USO were chosen over surveillance for premenopausal patients with incidental endometriomas, one diagnosis of ovarian cancer would be prevented in every 40 patients and one death averted in every 82 patients. We performed one-way sensitivity analyses for all input variables and determined that there were no reasonable inputs that would alter our conclusions. USO is cost-effective and the preferred strategy compared to surveillance for the management of incidental endometrioma in a premenopausal patient not desiring fertility. USO incurs fewer deaths and fewer cases of ovarian cancer with costs below national willingness to pay thresholds.