Diffuse large B-cell lymphoma with testicular involvement: outcome and risk of CNS relapse in the rituximab era

The addition of rituximab has improved outcomes in diffuse large B-cell lymphoma (DLBCL), however, there remains limited information on the impact of rituximab in those with testicular involvement. All patients with diffuse large cell lymphoma and testicular involvement treated with curative intent were identified in the British Columbia Cancer Agency Lymphoid Cancer Database. In total, 134 patients diagnosed between 1982 and 2015 with diffuse large cell lymphoma involving the testis were identified: 61 received CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone)-like chemotherapy and 73 received CHOP plus rituximab (R-CHOP). A greater proportion of R-CHOP treated patients had higher International Prognostic Index (IPI, P = 0·005). In multivariate analysis, the protective effect of rituximab on progression-free survival (hazard ratio (HR) 0·42, P < 0·001), overall survival (HR 0·39, P < 0·001) and cumulative incidence of progression (HR 0·46, P = 0·014) were independent of the IPI. However, in a competing risk multivariate analysis including central nervous system (CNS) prophylaxis and the CNS-IPI, rituximab was not associated with a decreased risk of CNS relapse. The addition of rituximab has reduced the risk of lymphoma recurrence in testicular DLBCL, presumably through improved eradication of systemic disease. However, CNS relapse risk remains high and further studies evaluating effective prophylactic strategies are needed.