Abstract 642: Increasing BMI is associated with tumor volume and uterine weight in endometrial cancer

Abstract

Abstract Obesity and diabetes is associated with increased risk and worse outcomes in endometrial cancer (EC). Our previous work has found that obesity leads to more aggressive tumor behavior and a doubling of tumor size in EC mouse models. Thus, we explored the association between endometrial tumor volume (TV) and uterine weight (UW) as a function of BMI in EC patients. We performed a retrospective review of EC patients diagnosed and treated from 2005-2010 at a single tertiary care center. Tumor histology, dimensions, stage, grade, and UW were extracted from surgical pathology reports. Patient age, BMI, and diabetic status were also collected. TV was determined using the formula TV=l*d*w*pi/6. Independent variables include obesity classification, BMI, and diabetic status. Univariable and multivariable regression models were used to assess strength of association. A total of 564 EC patients were evaluated, with either endometrioid (n=522) or serous (n=42) histologies (Table 1). Within the endometrioid subgroup, associations were noted for both increased TV and UW with obesity (TV p=0.02; UW p<0.001) and BMI (TV p=0.007; UW p<0.001). Within the serous subgroup, increased TV was associated with obesity and BMI (p<0.001; p=0.007), but UW was only associated with obesity (p=0.005) and not BMI (p=0.07). Controlling for stage and grade, multivariable models demonstrated similar patterns with obesity status and BMI within both subgroups. Multivariable analyses also demonstrated that having diabetes (n=160) was associated with both higher TV and UW in the endometrioid subgroup (TV p=0.004; UW p=0.02), but not in the serous subgroup (TV p=0.71; UW p=0.12). Obesity and increasing BMI appear to be associated with both increased TV and UW in EC patients, consistent with our previously described findings in murine models. Diabetes was also associated with higher TV and UW, but was only significant in patients with endometrioid ECs. Our results may partially account for the worse outcomes seen in obese EC patients. Table 1EC HistologyMedianIQREndometrioid (n=522)Uterine Weight (g)Non-obese118.183.0-157.5Obese140.0103.8-200.0Tumor Volume (cm3)Non-obese3.6950.927-9.664Obese4.3591.419-14.216Serous (n=42)Uterine Weight (g)Non-obese116.667.4-166.6Obese189.8127.6-252.6Tumor Volume (cm3)Non-obese3.2490.601-9.382Obese23.8247.356-59.494 Citation Format: Yingao Zhang, Nerlyne Desravines, Dominic T. Moore, Paola A. Gehrig, Leslie H. Clark, Victoria L. Bae-Jump. Increasing BMI is associated with tumor volume and uterine weight in endometrial cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 642.