[Late (after 5-year remission) recurrences of acute leukemia in children (a cooperative study)]

Cooperative investigations were conducted in seven Pediatric Hematologic Clinics (in Moscow, Leningrad, Kiev, Minsk and Tbilisi) to study the nature of late (after five years of remission) relapses of acute leukemia that were diagnosed in 21.6% of cases (in 80 out of 371 children) with long-term remissions. Late relapses in most patients occurred on the 6-7th year of remission. In cases when the treatment was abolished, relapses took place 1-2 years after the abolition. Extramedullary foci of leukemic lesions (CNS, sexual glands, etc.) were detected more frequently (41 children). Bone marrow lesions were recorded in 21 combined relapses were observed in 8 patients. It has been stressed that initial risk factors should be taken into consideration, and current diagnostic tests should be applied to individualize therapy at all the stages of the treatment.