Influence of rituximab and central nervous system directed prophylactic therapy on central nervous system relapse in high-risk diffuse large B-cell lymphoma

Mahender Yellu, Gunjan Guha, Chandana Kamireddy, Zartash Gul, Tahir Latif


Background: Central nervous system (CNS) relapse in patients with diffuse large B-cell lymphoma (DLBCL) although rare, can be devastating. Conflicting reports have been published regarding the protective effect of systemic rituximab therapy and likely reduction in incidence of CNS relapse in post-rituximab era.
Methods: We retrospectively identified all the DLBCL patients at our institute between 2004 and 2014 who received systemic rituximab-based chemo-therapy at initial presentation. Patients were categorized into two groups, “standard risk” with no risk factors and “high risk” with one or more of the following risk factors, elevated lactate dehydrogenase (LDH) (above the institute normal), international prognostic index (IPI) ≥3, involvement of testis, breast, bone, kidneys, adrenal gland, retroperitoneal lymph nodes, para-meninges, and bone marrow. Descriptive statistics were used to analyze inci-dence of CNS relapse, patient and disease characteristics. Historically reported incidence rates were used for comparison.
Results: A total of 122 patients received rituximab-based therapy at the initial diagnosis; 73 patients (60%) qualified for standard risk; 49 patients (40%) met the criteria for “high risk” based on the above definition. Standard risk group received no CNS directed prophylaxis and none of these patients had CNS relapse. Thirty-one of 49 (63%) “high risk” patients received CNS prophylaxis, mainly intrathecal (IT) methotrexate. Five patients (4.0%) developed CNS relapse in the entire study population. Percentage of patients developed CNS relapse in high-risk patients was 10.2% (5/49). Median time to relapse was 8.76 months and median survival after CNS relapse was 9.16 months. Four out of five patients who developed CNS relapse received prophylaxis with IT.
Conclusions: CNS relapse continued to be a rare but devas-tating complication in post rituximab era, however our study confirms that majority of the DLBCL patients do not need CNS directed therapy. Current CNS directed therapies are probably inadequate to prevent CNS relapse in high risk DLBCL patients, therefore further research to develop better agents is needed in this area.