Treatment effects, disease recurrence, and survival in obese women with early endometrial carcinoma : a Gynecologic Oncology Group study

Abstract

Background: The objective was to examine whether rates of disease recurrence, treatment-related adverse effects, and survival differed between obese or morbidly obese and nonobese patients.

Methods: Data from patients who participated in a randomized trial of surgery with or without adjuvant radiation therapy were retrospectively reviewed. RESULTS.: Body mass index (BMI) data were available for 380 patients, of whom 24% were overweight (BMI, 25-29.9), 41% were obese (BMI, 30-39.9), and 12% were morbidly obese (BMI, > or =40). BMI did not significantly differ based on age, performance status, histology, tumor grade, myometrial invasion, or lymphovascular-space involvement. BMI > 30 was more common in African Americans (73%) than non-African Americans (50%). Patients with a BMI > or = 40 compared with BMI < 30 (hazards ratio [HR], 0.42; 95% confidence interval [CI], 0.09-1.84; P = .246) did not have lower recurrence rates. Compared with BMI < 30, there was no significant difference in survival in patients with BMI 30-39.9 (HR, 1.48; 95% CI, 0.82-2.70; P = .196); however, there was evidence for decreased survival in patients with BMI > or = 40 (HR, 2.77; 95% CI, 1.21-6.36; P = .016). Unadjusted and adjusted BMI hazards ratios for African Americans versus non-African Americans in the current study differed, thus suggesting a confounding effect of BMI on race. Eight (67%) of 12 deaths among 45 morbidly obese patients were from noncancerous causes. For patients who received adjuvant radiation therapy, increased BMI was significantly associated with less gastrointestinal (R, -0.22; P = .003) and more cutaneous (R, 0.17; P = .019) toxicities.

Conclusions: In the current study, obesity was associated with higher mortality from causes other than endometrial cancer but not disease recurrence. Increased BMI was also associated with more cutaneous and less gastrointestinal toxicity in patients who received adjuvant radiation therapy. Future recommendations include lifestyle intervention trials to improve survival in obese endometrial cancer patients.