Prophylactic heparin therapy in acute promyelocytic leukemia

Twenty‐four patients with acute promyelocytic leukemia were reviewed. Group I, treated between July 1970 and September 1973, received arabinosylcytosine and 6‐thioguanine, and there was one complete remission, with 4/7 dying during induction with intracerebral hemorrhages, and 2/7 dying within one month. Group II, treated between May 1974 and March 1975, received daunomycin and arabinosylcytosine without heparin and 2/8 went into remission, with 6/8 dying during induction, 5 with intracerebral hemorrhages. Group III, treated between March 1975 and November 1976, received the identical chemotherapy as group II but with the addition of prophylactic heparin and there were 7/9 complete remissions, with 2/9 dying with intracerebral hemorrhages. In Group III there was an increased incidence of remission induction when compared to Group II (p < 0.05) or when compared to Groups I and II combined (p < 0.05). There was also a decreased incidence of fatal hemorrhage in Group III. This suggests that prophylactic heparin is useful during remission induction in acute promyelocytic leukemia.