Pattern of extranodal involvement and its impact on survival in diffuse large B-cell lymphoma from a tertiary cancer center in rural India

Abstract

Introduction: Extranodal (EN) involvement in diffuse large B-cell lymphoma (DLBCL) carries poor prognosis. Both the number and the specific sites of EN involvement are important in predicting prognosis. Given that the epidemiologic pattern of DLBCL in India is different from the rest of the world and such data correlations are scarce from developing countries, we aimed to find out if specific site and number of EN involvement could predict survival in DLBCL. Methods: Patients with DLBCL treated with combination chemotherapy plus rituximab were included. Site and number of EN involvement were noted. Univariate analysis for survival was performed for EN involvement or not, specific site of involvement, and number of EN involvement (0/1 vs. ≥2). Results: Among a total of 177 patients, 92 (52%) patients had EN disease. When patients with 2 or more EN sites were compared against patients with 0 or 1 site, there was significant reduction in both progression-free survival (PFS) and overall survival (OS) (3-year OS of 55% vs. 79%, P = 0.001, 3-year PFS of 42% vs. 65%, P = 0.001). When specific EN sites were studied for correlation with survival, involvement of skin/soft tissue, and serosa were associated with significant reduction in 3-year OS (33% vs. 74%, P = 0.011, and 63% vs. 75%, P = 0.03, respectively) and 3-year PFS (25% vs. 62%, P < 0.001, and 46% vs. 62%, P = 0.01, respectively). Conclusion: Two or more EN sites in DLBCL predicted inferior survival. Serosal and skin/soft tissue involvement also predicted poor survival.