Abstract

Twenty patients with previously untreated hairy cell leukemia were randomized to undergo either splenectomy or to receive interferon alfa-N1, a highly purified natural alpha interferon, as primary therapy. A response in the peripheral blood elements to a hemoglobin greater than 110 gm/l, a granulocyte count greater than 1 x 10(9)/l, and a platelet count greater than 100 x 10(9)/l (Catovsky criteria) was noted in all ten patients receiving alpha interferon but in only three of the patients undergoing splenectomy (P = less than .01). Median time to response was longer in the ten interferon patients (153 days) than in the three splenectomy responders (20 days). Median time to treatment failure was significantly greater in the alpha interferon patients (greater than 18 months) than in the splenectomy patients (less than 1 month). Survival was no different since patients relapsing following splenectomy subsequently responded to alpha interferon. A significant decrease in leukemic bone marrow infiltration was observed in seven of ten patients receiving alpha interferon and in none of the patients undergoing splenectomy. Side effects, primarily infections, were more frequent in patients receiving interferon. Alpha interferon is preferable to splenectomy as initial treatment for hairy cell leukemia.