Prognostic Impact of a Body Mass Index Decrease during First Chemotherapy in Patients with Advanced Follicular Lymphoma

Objective Follicular lymphoma (FL) is an indolent B-cell malignancy, usually treated by immunochemotherapy in advanced-stage and high-tumor-burden cases. Although some reports have shown no significant relationship between the pre-treatment body mass index (BMI) and the overall survival (OS) in FL, little is known regarding BMI changes during chemotherapy. We analyzed the impact of a BMI decrease during chemotherapy on the OS in FL patients. Methods We retrospectively analyzed 56 patients with untreated advanced FL who underwent chemotherapy at our institute between July 2009 and December 2020. The BMI change was defined based on the BMI before and at three months after the first chemotherapy session. The cut-off for a BMI decrease was set at 1.42 kg/m2 according to the receiver operating characteristics curve for the OS. We compared the survival outcome between two BMI groups based on this cut-off. Results A BMI decrease was significantly associated with a worse OS (5-year OS: 86.7% vs. 60.5%, p=0.019), although the pre-treatment BMI showed no significant relationship with the survival. The adverse impact of a BMI decrease remained in a multivariate analysis for the OS (hazard ratio, 3.972; p=0.045). The decreased-BMI group tended to show a higher cumulative incidence of early-onset histological transformation (HT) than the non-decreased-BMI group (20% vs. 0.0%). A BMI decrease during chemotherapy in previously untreated FL patients might reflect the hyperactivation of tumor-induced metabolism related to HT. Conclusion A BMI decrease during chemotherapy might be an independent adverse prognostic factor in FL patients. BMI changes in addition to the condition of FL patients should be monitored during chemotherapy.