The obesity paradox in endometrial cancer: Epidemiology of obesity among endometrial cancer patients and impact on inpatient hospitalization outcomes.

e17648 Background: Obesity is a well-established risk factor for endometrial cancer. However, its impact on clinical outcomes remains unclear (PMID: 36672434). We aim to examine the impact of obesity among outcomes and healthcare utilization in hospitalized endometrial cancer patients from a national sample. Methods: All adult hospitalizations with a diagnosis of endometrial cancer and obesity, including class III obesity, were identified among Nationwide Inpatient Sample (NIS) database between 2016 and 2020. Epidemiologic characteristics, inpatient mortality, mean length of stay (LOS), mean Total Hospital charges (THC) were compared between obese and non-obese groups. Statistics were performed using univariate and multinomial logistic regression. Results: A total 198,710 admissions with endometrial cancer were identified, 33.9% (n = 67,320) with obesity and 18.0% (n = 35,730) with class III obesity. Class III obesity was most prevalent in middle-aged group 45-65 years old (49.5%) compared to the youngest (10.1%) and the oldest (40.4%) groups. Black (aOR 0.92, p=0.009) and Hispanic (aOR 0.77, p<0.001) individuals had lower odds of obesity compared to White individuals, while higher income groups had lower odds of obesity than the lowest income quartile. Income and obesity were not associated in the Hispanic individuals. Obesity was linked to higher odds of acute kidney injury (aOR 1.24, p<0.001) and heart failure (aOR 2.29, p<0.001), but not pulmonary embolism or sepsis. Inpatient mortality was 3.6% (n = 7,240), with 26.6% (n = 1,925) of deaths occurring in obese patients. Obesity was associated with lower mortality (aOR 0.69, 95% CI: 0.61-0.78, p<0.001). trend seen across most subgroups except for Black individuals (aOR 0.77 (0.53 - 1.11), p=0.158). Obese patients had longer LOS (5.42 vs 5.03 days, p<0.001) and higher THC ($64,112 vs $55,030, p<0.001). Class III obesity was similarly linked to lower mortality (aOR 0.70, 95% CI: 0.60 – 0.82, p<0.001), longer LOS (5.7 vs. 5.1 days, p<0.001), and higher THC ($66,197 versus $56,329, p<0.001). Among metastatic endometrial cancer (n = 70,860), 26.0% (n = 18,445) had obesity, including 11.4% with class III obesity. Mortality was 6.8% but was not significantly associated with obesity. Obesity correlated with longer LOS (7.1 vs. 6.2, p<0.001) and higher THC (70,490 vs. 59313, p<0.001). Conclusions: Obesity, including class III obesity, while increasing the risk of developing endometrial cancer was associated with low inpatient mortality among endometrial cancer, while The LOS and THC were higher for obese patients. The association varied by ethnicity and the presence of metastasis. Prospective studies are needed to elucidate the cause of this variation to make targeted interventions.