IBCL-490 POD24 and Serous Effusion Involvement Impact on Overall Survival in Follicular Lymphoma Attended at the National Cancer Institute in Mexico: A Survey of 370 Patients

Abstract

Follicular lymphoma (FL) is the most common indolent lymphoma. However, outcomes with standard treatments are suboptimal. Therefore, the identification of factors influencing overall survival (OS) are required. Retrospective analysis, to identify factors influencing on overall survival (OS) in patients with FL. Patients ≥ 18 years of age, with histological diagnosis of FL, without previous treatment, attended at the Instituto Nacional de Cancerología (Mexico City, Mexico) from Jan-2010 to December 2020. Clinical, biochemical and histological variables were included. Descriptive analysis was done for demographic and clinical characteristics. Median and Standard deviation (SD) was used, as a measure of dispersion. OS was defined since diagnosis until the date of the last follow-up or death. Survival curves were calculated by the Kaplan-Meier method, and differences between subgroups were compared with the Log-Rank test. Cox-regression analysis was used to identify the variables associated with overall survival. We included 370 patients (female: 216, 58.4%), with a median age of 54.09±12.49 years. Most of them had advanced disease (n=301, 81%) and low grade (n=228, 61%). Bulky disease was documented in 42.2%, bone marrow involvement in 31%, extranodal disease in 29.7%, and serous involvement in 17.6%. Only 329 cases received treatment, and the most frequent schema was CHOP-rituximab (n=315, 95%). Response rates were as follows: CR 73.5%, PR 9.7%, SD 2.4%, PD 6.2% and undetermined in 8.2%. 56.8% of patients received rituximab maintenance and 88/241 patients had progression of disease within 2 years (POD24). Transformation to DLBCL was documented in 3.7%. In our proportional hazards model, serous involvement (p=0.0031, HR: 2.749, 95%CI: 1.406-5.417) and POD24 (p<0.0001, HR: 21.45, 95%CI: 10.05-49.76) were significantly associated with OS. Additionally, the HRs were calculated for patients with POD at 0-6 months (HR: 8.055, 95%CI: 4.118-14.44), 7-12m (HR: 2.754, 95%CI: 1.542-4.611), 13-18m (HR: 8.515, 95%CI: 3.5-17.67) & 19-24m (HR: 3.9, 95%CI: 2.157-6.612), suggesting a cut-off point at 18 could better represent high-risk population in our cohort. In a LATAM reference center, serous involvement at diagnosis and POD24 were significantly associated with worse OS in patients with FL.