8530 Background: Subsequent malignant neoplasms (SMNs) are a leading cause of late mortality in survivors of childhood cancer. Using the Childhood Cancer Survivor Study (CCSS) cohort, we determined the risk of carcinomas occurring as SMNs excepting breast, thyroid and skin cancers. Methods: A retrospective cohort of 14,352 five-year survivors of childhood cancers treated at 25 US and Canadian institutions was assembled. SMNs were ascertained through self-administered questionnaires and confirmed with pathology reports. Cumulative incidence, age- and gender-matched standardized incidence ratios (SIRs) were calculated. Results: In 71 individuals, 71 carcinomas of interest were found at a median age of 27 years (range 10–44 years) and a median elapsed time of 15 years (range 6–28 years) from first malignancy. Twenty-five (35%) SMNs occurred in the genitourinary system, 23 (32%) in the head and neck area, 16 (23%) in the digestive tract, 4 (6%) in the thorax and the remainder (4%) in other sites. Fifty-nine s...