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

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.

CONCLUSIONS

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.