Impact of Obesity and Metabolic Burden on Survival Outcomes in Ovarian and Uterine Cancer: A Clinical Cohort Study With Complementary Population-Level Contextual Analysis

Abstract

Background: Obesity is a modifiable risk factor for gynecological cancers, but its relationships with survival, metabolic comorbidity, and population-level burden remain insufficiently defined.Methods: We retrospectively analyzed 273 patients with histologically confirmed ovarian (n = 138) or uterine cancer (n = 135) from two centers between 2012 and 2022. Patients were classified by BMI as normal weight (<24 kg/m²), overweight (24–28 kg/m²), or obese (≥28 kg/m²). Cancer type was adjusted in regression models and stratified survival analyses due to differences in etiology, treatment, and prognosis, while pooled estimates were exploratory. Clinicopathological features, metabolic comorbidities, treatment patterns, and survival were compared using Kaplan–Meier analysis and Cox regression. GBD 2021 data provided BMI-attributable deaths and DALYs for ovarian and uterine cancer across 204 countries (1990–2021).Results: Obese patients were more likely to have uterine cancer than normal-weight and overweight patients (72.4% vs. 42.3% and 39.0%; P < 0.001). Hypertension, type 2 diabetes, and dyslipidemia were significantly more frequent in the obese group, whereas chemotherapy use was lower (48.7% vs. 73.2%; P < 0.001). In exploratory multivariable Cox regression, FIGO stage III–IV was the strongest predictor of mortality (HR = 2.99; 95% CI, 1.33–6.69; P = 0.008), while overweight status was associated with lower mortality compared with normal weight (HR = 0.50; 95% CI, 0.28–0.90; P = 0.020). This overweight association was not supported by a significant overall Kaplan–Meier difference or by significant subgroup interactions and should be interpreted cautiously. No significant BMI–mortality association was observed in obese-versus-normal subgroup analyses. Globally, high BMI was attributed by the GBD framework to an estimated 18,978 ovarian cancer deaths and 35,907 uterine cancer deaths in 2021. The absolute burden increased markedly from 1990 to 2021, especially in low- and middle-SDI countries.Conclusion: Obesity was associated with uterine cancer predominance, greater metabolic comorbidity, and altered treatment patterns in this exploratory clinical cohort. The overweight association with lower mortality is hypothesis-generating and may reflect residual confounding, cancer-type imbalance, nutritional status, prediagnostic weight loss, body composition, or treatment differences. The growing BMI-attributable gynecological cancer burden in developing regions highlights the need for prevention strategies integrating weight control, metabolic health, and socioeconomic context.