Predictive factors for central nervous system involvement in non-Hodgkin's lymphoma: significance of very high serum LDH concentrations.

Factors predictive for central nervous system (CNS) involvement at presentation were investigated in 152 patients with non-Hodgkin's lymphoma (NHL) except for lymphoblastic cell lymphoma and small noncleaved cell lymphoma. Twelve patients developed CNS involvement during their disease course. The incidence was 7.9% of all the patients studied and 17.0% of the patients with serum LDH concentration > or = two times the upper limit of normal (2N). By univariate analysis, stage IV disease (P = .023), a serum LDH concentration > or = 2 N (P = .009), and bone marrow involvement (P = .016) were risk factors for CNS involvement. Multivariate logistic regression analysis identified a serum LDH concentration > or = 2 N (P = .032) as an independent predictor for CNS involvement. All 12 patients who developed CNS involvement were among the 126 patients with diffuse lymphoma, whereas none of the 17 patients with follicular lymphoma developed CNS involvement, although the difference was not statistically significant. The median survival of the patients with CNS involvement was only 4.5 months. We conclude that a serum LDH concentration > or = 2N at presentation is a significant predictive factor for CNS involvement for NHL patients without lymphoblastic lymphoma and small noncleaved cell lymphoma. Therefore, we would suggest that CNS prophylaxis should be considered for patients with a serum LDH concentration > or = 2N at presentation and diffuse lymphoma once a complete remission is achieved.