Splenic marginal zone lymphoma: a prognostic model for clinical use.

The Integruppo Italiano Linfomi (IIL) carried out a study to assess the outcome of splenic marginal zone lymphoma and to identify prognostic factors. We studied 309 patients: the 5-years cause-specific survival (CSS) was 76%. In univariate analysis the parameters predictive of shorter CSS were hemoglobin < 12 g/dl (p=0.00002), albumin < 3.5 g/dl (p=0.001), IPI 2-3 (p=0.00001), LDH >normal (p=0.00001), age >60 years (p=0.01), platelets < 100,000/ml (p=0.04), HbsAg-positivity (p=0.01), no splenectomy at diagnosis (p=0.006). Hemoglobin < 12 g/dl, LDH >normal, albumin < 3.5 g/dl maintained a negative influence on CSS in multivariate analysis. Using these 3 variables, we identified 3 prognostic categories: low-risk group (41%) with no adverse factors, intermediate-risk group (34%) with one factor, high-risk group (25%) with 2 or 3 factors. The 5-years CSS was 88% for the low-risk, 73% for the intermediate-risk, and 50% for the high-risk group. The cause-specific mortality rate (x1000 p-yrs) was 20 for the low-risk, 47 for the intermediate-risk, and 174 for the high-risk group. This latter group accounted for 54% of all lymphoma-related deaths. In conclusion, using readily available factors, this prognostic index may be a useful tool for evaluating the need for treatment as well as the intensity of therapy in an individual patient.