Impact of body mass index on treatment outcomes in endometrial cancer patients receiving doxorubicin and cisplatin: a Gynecologic Oncology Group study.

Objectives: To evaluate the association between body mass index (BMI) and outcomes in women with advanced or recurrent endometrial cancer treated with doxorubicin/cisplatin.
Methods: Data from patients treated on five Gynecologic Oncology Group trials were retrospectively reviewed. BMI was categorized as normal (< 25), overweight (> or = 25 to < 30), obese (> or = 30 to < 40), and morbidly obese (> or = 40). BMI was analyzed for associations with demographics, clinical characteristics, toxicity, progression-free survival (PFS), and overall survival (OS).
Results: Among 949 patients, 533 (56%) had recurrent disease, 227 (23.9%) had Stage IV disease, and 189 (19.9%) had Stage III disease. Mean BMI was 29.8; 29.6%, 27.0%, 33.2% and 10.2% of patients, respectively, were categorized as normal, overweight, obese, and morbidly obese. The mean BMI was significantly different when compared by age group (p<0.001), stage (p=0.047), histologic type (p=0.024), and tumor grade (p=0.014). Older patients and those with clear cell, poorly differentiated tumors, or stage IV disease had a lower BMI. No significant associations between PFS and BMI were detected. Increasing BMI was significantly associated with an increased risk of death in Stage III/IV (HR=1.86, 95% CI 1.16-2.99 for BMI > or = 40 vs. BMI < 25) but not recurrent patients. Higher BMI patients had less Grade 3/4 toxicities than normal patients (p<0.001) but this difference disappeared for obese patients receiving > or = 95% of the calculated dose.
Conclusions: BMI was not predictive of PFS in this endometrial cancer population although morbidly obese patients had decreased OS in primary Stage III/IV patients. Toxicities decreased with increasing BMI, perhaps secondary to capped dosing.