The Effect of Body Mass Index and Weight Change on Late Gastrointestinal Toxicity in Locally Advanced Cervical Cancer Treated With Intensity-modulated Radiotherapy

Objective: To evaluate the effects of body mass index (BMI) and weight change during radiotherapy on the development of toxicity in patients with locally advanced cervical cancer (LACC) treated with intensity-modulated radiotherapy (IMRT). Methods: A total of 245 patients were analyzed after undergoing definitive IMRT treatment between 2004 and 2015 for stage IB2 to stage IVA LACC. The patients were divided into 3 groups: underweight (BMI <18.5 kg/m(2)), normal weight (BMI 18.5-24.9 kg/m(2)), and overweight (BMI >= 25.0 kg/m(2)). The relationships between toxicity, clinical factors, and the bowel dose-volume histogram were analyzed. V45 indicated the bowel volume that received a radiation dose of 45 Gy. Results: The median follow-up period was 63 months. The V45 was similar among the 3 groups. The 5-year rates of grade 3 or higher late gastrointestinal toxicities were 18.6%, 4.0%, and 4.2% for the underweight, normal weight, and overweight groups, respectively (P = 0.002). In the multivariable analysis, underweight (hazard ratio, 13.99; 95% confidence interval, 3.22-60.82; P < 0.001) and weight loss (> - 5%) (hazard ratio, 5.91; 95% confidence interval, 1.75-19.98; P = 0.004) were significant predictors of grade 3 or higher-grade late gastrointestinal toxicities. Conclusion: A BMI of less than 18.5 kg/m(2) and weight loss (>-5%) were associated with a higher risk of grade >= 3 or higher late gastrointestinal toxicity in patients with LACC treated with definitive IMRT. Future research on the development of a standardized and structured approach to improve the therapeutic ratio for the supportive care of patients with LACC is needed.