Diffuse Large B-Cell Testicular Lymphomas (Dlbcl-Tl): Survival Outcomes Over 20 Years

Due to their rarity (1-2% NHL, < 5% testicular neoplasms), treatment recommendations for DLBCL-TL are based on phase II studies. It is an aggressive entity more frequent in the elderly and prone to distant dissemination. After surgical resection, systemic treatment (anthracycline plus rituximab based), contralateral radiotherapy (RT) and central nervous system (CNS) prophylaxis are recommended. We characterized survival outcomes and relapse patterns in a single center over 20 years. Retrospective analysis of consecutive DLBCL-TL patients (pts) diagnosed and treated in a tertiary cancer center between 2000-2020. Demographic and clinical variables were retrieved from pts charts. Overall (OS) and progression free survival (PFS) were determined by Kaplan Meier method and stratified according to IPI. Thirty pts (4% of all DLBCL), median age 68.5 y (42-87), ECOG PS ≤2 were analyzed. Bilateral involvement was diagnosed in 10.0% and advanced disease (IIIE-IV) in 40.0%. Elevated LDH was found in 40.0% and 26.6% had >1EN site. Eleven pts were IPI low risk (L), 6 low-intermediate (L-I) and 13 intermediate-high and high (I-H+H). 19/24 pts had non-GC tumors by Hans algorithm. RCHOP like regimens were applied to 93.3% pts. Testicular RT was offered to 19 pts and CNS prophylaxis to 27 pts (27/27 intrathecal and 16/27 additional systemic methotrexate). With a median follow up of 46 mo, 16 pts progressed and 13 died. Median PFS and OS was 22.6 and 31.9 mo. One third of relapses affected EN sites; 45% occurred >2 years. OS in the L, L-I and I-H+H risk groups were 100%, 83.3% and 61.5% at 2y and 81.8%, 83.3% and 38.5% at 5y respectively. Corresponding values for PFS were 100%, 83.3% and 46.2% at 2y and 81.8%, 83.3% and 23.1% at 5 y. For comparison, OS of non-testicular DLBCL pts at 5y varied between 87.2% in L and 49.8% in H risk groups. Estimated median OS was not reached (NR) in the L and L-I and was 39.7mo (95% CI: 1.2-78.1) in the I-H+H risk groups (p=0.02). We confirm the prognostic impact of IPI in DLBCL-TL as high risk pts have limited survival outcomes, emphasizing the importance of early diagnosis and the need for new, tolerable therapeutic strategies in the elderly. TL presents a continuous pattern of relapse requiring prolonged follow up.