Late effects in survivors of infant leukemia

Little is known about the incidence of and risk factor for late effects of infant leukemia. We evaluated 19 children with acute lymphoblastic leukemia and 15 with acute myeloid leukemia who were diagnosed at age 12 months or younger and have survived for more than 5 years after the diagnosis (median length of follow-up, 13 years; range, 5.7-29 years). Ten patients received chemotherapy alone (group A), 17 received chemotherapy and CNS-directed ra diation therapy (CRT) (group B), and seven received chemotherapy, CRT and b one marrow transplantation (group C). The most frequently observed late seq uelae included problems in growth (66% of survivors), learning (50%), hypot hyroidism (15%), and pubertal development (12%). Cataract, cardiac and hear ing abnormalities occurred in 6% of patients. Only eight patients (24%) sur vive without late effects. In comparison to patients in group A, patients i n groups B and C had a higher incidence of having at least one late complic ation (P = 0.009), a greater decrease in height Z score at 5 years after di agnosis (P = 0.023), and a higher incidence of academic difficulties (P = 0 .004). The estimated odds of academic difficulties increased by 18% (P = 0. 032) for each month younger in age at the time of CRT. These results indica te that late sequelae are common in longterm survivors of infant leukemia a nd are often related to CRT and the patient's age at the time of CRT.