Impact of Obesity on the Outcomes and Cost of Robotic Surgery for Stage IA Endometrial Cancer: A Regional Perspective from Japan

Background The incidence of endometrial cancer in Japan has more than doubled over the past 2 decades because of increasing obesity rates and the unique physiological traits of Asian populations. The aim of this retrospective study was to examine the impact of obesity on surgical outcomes, prognosis, and costs. Methods A total of 197 patients with stage IA endometrial cancer who underwent robot-assisted hysterectomy, bilateral salpingo-oophorectomy, and lymphadenectomy/biopsy from 2018 onward were included. Patients were divided into the BMI < 30 kg/m² group (n = 117) and the BMI ≥ 30 kg/m² group (n = 80). The clinical and pathological factors, surgical outcomes, perioperative complications, and treatment costs were compared. The median follow-up period was 34.9 months (range: 6.1–84.2). Results In the BMI ≥ 30 kg/m² group, significant differences in comorbidities, including diabetes mellitus (19.7% vs. 51.3%), hypertension (43.6% vs. 58.8%), and hyperlipidemia (29.9% vs. 50%), were detected. However, no significant differences were found in operative time, blood loss volume, perioperative complication rates, or 5-year cancer-specific survival rates (97.6% vs. 100%). Surgical and hospitalization costs were higher in the BMI ≥ 30 kg/m² group, indicating a financial burdensome for both patients and healthcare facilities. Additionally, a higher prevalence of newly developed lifestyle-related diseases, such as cardiovascular diseases and diabetes, was observed during the follow-up (2.5% vs. 10%). Conclusions While obesity (BMI ≥ 30) did not significantly impact surgical outcomes or cancer prognoses, it did increase treatment costs and the risk of lifestyle-related diseases. Thus, preventive strategies, including lifestyle counseling, are needed to reduce obesity-related health burdens.