The impact of obesity on surgical staging, complications, and survival with uterine cancer: a Gynecologic Oncology Group LAP2 ancillary data study

Abstract

Objective: To determine the association of body mass index (BMI) on complications, recurrence, and survival in GOG LAP2, a randomized comparison of laparoscopic versus open staging in clinically early stage uterine cancer (EC).

Methods: An ancillary data analysis of GOG LAP2 was performed. Categorical variables were compared using Pearson chi-square test and continuous variables using the Wilcoxon-Mann-Whitney and Kruskal-Wallis tests by BMI group. Survival was estimated using the Kaplan-Meier method. Cox proportional hazards model was used to evaluate independent prognostic factors on survival. Statistical tests were two-tailed with α=0.05, except where noted. Statistical analyses utilized R programming language.

Results: 2596 women were included. BMI (kg/m(2)) groups were <25 (29.5%), 25-30 (28.2%), 30-35 (21%), 35-40 (10.9%), and ≥40 (10.4%). Stage (p=0.021), grade (p<0.001), and histology (p=0.005) differed by BMI. Obese women were less likely to have high risk (HR) disease (+lymph nodes/ovaries/cytology) or tumor features that met GOG99 high intermediate risk (HIR) criteria (p<0.001). Adjuvant therapy (p=0.151) and recurrence (p=0.46) did not vary by BMI. Hospitalization >2days, antibiotic use, wound infection, and venous thrombophlebitis were higher with BMI ≥40. BMI (p=0.016), age (p<0.0001), race (p=0.033), and risk group (p<0.0001) predicted all-cause mortality. BMI was not predictive of disease-specific survival (p=0.79), but age (p=0.032) and risk group (p<0.0001) were significant factors.

Conclusion: Obese women have greater surgical risk and lower risk of metastatic disease. BMI is associated with all-cause but not disease-specific mortality, emphasizing the detrimental effect of obesity (independent of EC), which deserves particular attention.

Keywords: Endometrial cancer; LAP2; Obesity.