Secondary Central Nervous System (CNS) Involvement in Patients Diagnosed with Diffuse Large B-Cell Lymphoma (DLBCL) during the First Line R-CHOP Treatment and after the End of Treatment

Background: Secondary central nervous system (CNS) involvement is an unfavorable risk factor with an impact on overall survival (OS) in malignant lymphoma.

Methods: We conducted a retrospective analysis of secondary CNS involvement in patients diagnosed with Diffuse Large B-Cell lymphoma (DLBCL) on the first line treatment and after the end of treatment. We collected data on 361 patients diagnosed with DLBCL.

Results: The median age (range) was 66 (17-91) years. All patients received first-line R-CHOP21 (rituximab, cyclophosphamide, vincristine, doxorubicin, prednisone) between 2006-2011. Patients with primary involvement of testis, nasopharynx, orbit and CNS received CNS prophylaxis with 15 mg methotrexate intrathecally (IT). Secondary CNS involvement was confirmed in 18 (4.9%) patients which stands for 24.6% (18/73) patients with relapsed lymphoma. Median time from first R-CHOP to lymphoma relapse was 10 months (range 3-33). CNS involvement in first 12 months of treatment was 3.9% (95% CI: 1.8%, 5.8%). Median (range) OS from diagnosis of CNS involvement was 3 (3-79) months. Clinical stage III/IV, IPI 4, breast, 2 or more extranodal sites and NCCN-IPI unfavorable site involvement increased the risk of CNS involvement. Three patients who had received methotrexate IT prophylaxis had CNS involvement at relapse. No patient with primary testis involvement had CNS relapse.

Conclusion: Less than 5% of patients had secondary CNS involvement on first line treatment and after end of treatment. Advanced stage, high-risk IPI, 2 or more extranodal sites of involvement increased the risk of CNS involvement after first-line treatment for DLBCL. CNS prophylaxis appears effective in patients with primary testicular lymphoma