Multivariate analysis of prognostic factors in patients with non HIV-related primary cerebral lymphoma. A proposal for a prognostic scoring.

Between 1982 and 1991, 41 patients were treated for non HIV related primary cerebral lymphoma (PCL) in our institute. The purpose of this study was to perform a multivariate analysis of prognostic factors for survival in these patients. The presence of a CSF protein level over 0.6 g l-1 at diagnosis was found to be the most significant unfavourable prognostic factor in univariate analysis and had not previously been reported. Among the five significant prognostic factors at diagnosis, (age over 60 years, performance status--ECOG scale--over 2, memory dysfunction, non hemispheric tumour site, CSF protein level over 0.6 g l-1 at the diagnosis), three independent factors were identified in multivariate analysis: (1) CSF protein level (P = 0.007; RR = 4.7); (2) PS > 2 (P = 0.04, RR = 2.65); (3) age over 60 (P = 0.08; RR = 2.43). Using the regression coefficient of these three parameters, we determined a prognostic index which allowed us to distinguish three risk groups whose theoretical median survival is 4, 20 and 54, months respectively in patients with non HIV related PCL. These results indicate that PCL is an heterogeneous disease in terms of the prognostic in which three subgroups with discriminant survival can be identified.