Central Nervous System Prophylaxis Utilization in Patients With Newly Diagnosed Diffuse Large B-Cell Lymphoma Within a Large Community Health System

Purpose: The impact of central nervous system (CNS) prophylaxis in diffuse large B-cell lymphoma (DLBCL) is contentious. The CNS International Prognostic Index (IPI) calculator offers prognostic guidance in identifying those patients who may be at highest risk of disease progression or relapse to the CNS. However, it is unclear whether this tool has guided clinician decision-making in a real-world setting. Studies have suggested that CNS prophylaxis may not offer clinically significant benefit in terms of preventing CNS disease progression. Given this, we investigated the utilization of CNS prophylaxis within our own population and documentation of the CNS-IPI score.

Methods: We retrospectively evaluated patients with newly diagnosed DLBCL between January 1, 2014, and December 31, 2017. Patients were assessed for receipt of CNS prophylaxis in the form of intrathecal (IT) chemotherapy and/or high-dose intravenous (IV) methotrexate. CNS-IPI scores were calculated for all patients who received CNS prophylaxis or those who experienced CNS disease. Long-term outcomes at five years from diagnosis included CNS progression/relapse and survival.

Results: Of 234 patients who met criteria, 20 (8.6%) received either IV methotrexate or IT chemotherapy; most received IT methotrexate. No patients in the IT prophylaxis group developed CNS disease, while two of eight IV methotrexate patients experienced CNS disease involvement. The incidence of CNS progression was 3.7% in the no prophylaxis group and 10% in those who received prophylaxis.

Conclusions: This study revealed low utilization of CNS prophylaxis and CNS-IPI documentation in a community hospital system. Given large differences between groups, claims of CNS prophylaxis efficacy are unable to be made. CNS relapse rates were consistent with existing literature and promote continued evaluation of the utility of current CNS prophylaxis approaches in DLBCL. New unambiguously effective therapeutic approaches are needed and may encourage a higher rate of standardized use.