Should alpha interferon be used as primary treatment for hairy cell leukemia? Italian Cooperative Group for Hairy Cell Leukemia.

To answer the question of whether interferon (IFN) should replace splenectomy, we reviewed the Italian HCL Registry: the records of 450 patients with hairy cell leukemia (HCL), seen from 1975 to 1988 were analysed. Of these, 321 were considered for the study: 231 had been splenectomized, 46 of them receiving subsequently IFN and 90 patients had IFN as initial therapy. Patients treated with splenectomy showed different survival according to Jansen and Hermans' staging system, which identified two risk groups: stage 1 and stages 2 and 3, p = 0.0329. On the contrary, patients treated with IFN did not show significantly different survival according to stage. By the comparison of stage 1 patients, either treated with splenectomy or with IFN, no statistical difference in survival was registered. Different survivals emerged for patients stage 2 + 3, which improved when treated with IFN, p = 0.0324. The median failure free survival (FFS) after splenectomy resulted in 89 months versus 33 months after IFN. In conclusion, splenectomy still remains the primary therapy for HCL patients stage 1. For high risk patients, stages 2 and 3, IFN should be adopted as first line therapy, improving substantially the survival. The short duration of response to IFN suggests a sequential combination of the two treatments for this group of patients, IFN reducing tumor mass quite safely and splenectomy assuring long lasting stable disease.