Evaluation of cerebrospinal clonal gene rearrangement in newly diagnosed non-Hodgkin's lymphoma patients.

Overt central nervous system (CNS) involvement in aggressive non-Hodgkin's lymphoma (NHL) is rare at diagnosis. Much effort is put to identify risk factors for occult CNS involvement, and the risk assessment of CNS relapse. Prophylactic treatment carries risk of adverse events and its efficacy is not clear. Detection of cerebrospinal fluid molecular gene rearrangement (GRR) as a method to detect occult disease has been studied in acute leukemia and primary CNS lymphoma. To date, the capacity of a positive GRR in newly diagnosed NHL patients to predict CNS relapse has not been addressed. We retrospectively studied the prognostic value of GRR in cerebrospinal fluid samples of 148 newly diagnosed patients with high grade NHL. We demonstrate that positive GRR at diagnosis does not affect PFS or OS and did not predict CNS relapse. However, although numbers were small, repeated positive samples (≥ 2) correlated with a higher risk for CNS relapse (p = 0.048), possibly stressing the need for an aggressive preventive approach.