MYELOID NEOPLASIA Brief report Long-term risk for subsequent leukemia after treatment for childhood cancer: a report from the Childhood Cancer Survivor Study

Previous investigations of cancer survi-vors report that the cumulative incidence of subsequent leukemia plateaus be-tween 10 and 15 years after primary therapy. Risk beyond 15 years has not been comprehensively assessed, primar-ily because of lack of long-term follow-up. Among 5-year survivors from the Child-hood Cancer Survivor Study cohort, 13 pathologically confirmed cases of sub-sequent leukemia occurred> 15 years after primary malignancy, with a mean latency of 21.6 years (range, 15-32 years). Seven were acute myeloid leukemia (2 acute promyelocytic leukemia with t(15;17), 2 with confirmed preceding my-elodysplastic syndrome), 4 acute lympho-blastic leukemia (2 pre-B lineage, 1 T cell, 1 unknown), and 2 other. Two acute my-eloid leukemia cases had the 7q dele-tion. The standardized incidence ratio was 3.5 (95 % confidence interval, 1.9-6.0). Me-dian survival from diagnosis of subse-quent leukemia was 2 years. This is the first description of a statistically signifi-cant increased risk of subsequent leuke-mia> 15 years from primary diagnosis of childhood cancer. (Blood. 2011;117(23): 6315-6318