▪ IntroductionPrior studies have demonstrated weight gain among recipients of chemotherapy for various solid tumors, though there is little evidence describing weight changes during and after treatment in patients with non-Hodgkin lymphoma (NHL). Weight gain during and after treatment can contribute to an increased risk of chronic conditions including: diabetes, coronary disease, and hypertension. This is important for long-term health in patients with diseases that are potentially curable or associated with long-disease free intervals, such as diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL). We investigated the magnitude of weight change during and after treatment in a cohort of DLBCL and FL patients. MethodsDLBCL and FL patients diagnosed between 1998 and 2008 and treated with combination chemotherapy +/- rituximab, were identified in the Veterans Health Administration database. Data on weight at time of first treatment (baseline) and at all recorded weight measurements up to 5 years after treatment initiation was obtained. Additional data included: height, age, race, co-morbidities, date of diagnosis, disease stage, LDH at diagnosis, B-symptoms, and treatment details (drugs, dates, and dosages). Only patients treated with CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) +/- rituximab or CVP (cyclophosphamide, vincristine, and prednisone) +/- rituximab were included in the study cohort. Patients were categorized as gaining or losing 0-2.5%, 2.5-5%, 5-7.5%, 7.5-10%, or >10% of baseline weight. Weight change during treatment was calculated utilizing baseline and weight measurement at or near 3 months following treatment initiation. B-spline modeling was applied to further evaluate trends in weight change over time within the cohort. Results2,159 patients met inclusion criteria. Mean age at diagnosis was 63.1 years, 96.6% of patients were men, and 59.5% of patients had stage III/IV disease. Mean Charlson co-morbidity score was 2.2. B-symptoms were noted at diagnosis in 48.4% of patients and LDH was elevated in 47.2% of patients. Mean and median weight change at 3 months after treatment initiation were -1.9 kg and -1.1 kg respectively, or -2.1% and -1.3% of baseline weight. Figure 1 illustrates the distribution of weight change during treatment within the cohort. In B-spline analysis, weight loss was maximal at 4.14 months after first treatment, with subsequent weight gain until reaching a plateau at 22 months (Figure 2). Among patients with 24 months or more of follow-up data, 45.7% had gained weight at 3 months and 60.5% had gained weight at 24 months. Only 4.3% of patients had gained >10% of baseline weight at 3 months, while 23.0% had gained >10% at 24 months. Similarly, 15.4% of patients had gained >5% of baseline weight at 3 months, while 38.5% had gained >5% at 24 months. Of the patients that gained weight at 3 months, 9.3% had gained >10% of baseline weight, while of the patients that gained weight at 24 months, 38.0% had gained >10%. Patients who gained weight in the first 3 months after treatment initiation were more likely to gain >10% baseline weight at 24 months compared to those who lost weight in the first 3 months. [Display omitted] [Display omitted] DiscussionThese results suggest that in contrast to other malignancies, most patients with NHL who are treated with multi-agent chemotherapy actually experience weight loss rather than weight gain over the course of treatment. Despite this initial trend, a majority of these patients undergo significant weight gain after the conclusion of therapy and in subsequent months. This poses a long-term health risk, particularly to patients who achieve a complete remission and long-term disease control. The timing of greatest weight gain in the 6-18 months after treatment initiation suggests an opportune time for initiation of a diet or exercise intervention to reduce weight gain shortly after the end of treatment. Disclosures:No relevant conflicts of interest to declare.