Study design and cohort characteristics of the childhood cancer survivor study: A multi‐institutional collaborative project

TLDR

Long‑term health outcomes of childhood cancer survivors have gained increasing attention, and the CCSS provides a resource to study risks of second malignancies, endocrine and reproductive outcomes, cardiopulmonary complications, and psychosocial issues. The CCSS was created as a multi‑institutional consortium to assemble a large, diverse, well‑characterized cohort of 5‑year survivors of childhood and adolescent cancer diagnosed before age 21 between 1970‑1986. Eligibility required diagnosis before age 21 between 1970‑1986 and survival of at least five years; data were collected via a 24‑page baseline questionnaire and comprehensive medical record abstraction across 25 institutions. Among participants, 78 % received radiotherapy and 73 % chemotherapy; the cohort’s first‑diagnosis distribution was leukemia 33 %, lymphoma 21 %, neuroblastoma 7 %, CNS tumor 13 %, bone tumor 8 %, kidney tumor 9 %, and soft‑tissue sarcoma 9 %, making the CCSS the largest and most extensively characterized cohort of childhood and adolescent cancer survivors in North America.

Abstract

Increased attention has been directed toward the long-term health outcomes of survivors of childhood cancer. To facilitate such research, a multi-institutional consortium established the Childhood Cancer Survivor Study (CCSS), a large, diverse, and well-characterized cohort of 5-year survivors of childhood and adolescent cancer.Eligibility for the CCSS cohort included a selected group of cancer diagnoses prior to age 21 years between 1970-1986 and survival for at least 5 years.A total of 20,276 eligible subjects were identified from the 25 contributing institutions, of whom 15% are considered lost to follow-up. Currently, 14,054 subjects (69.3% of the eligible cohort) have participated by completing a 24-page baseline questionnaire. The distribution of first diagnoses includes leukemia (33%), lymphoma (21%), neuroblastoma (7%), CNS tumor (13%), bone tumor (8%), kidney tumor (9%), and soft-tissue sarcoma (9%). Abstraction of medical records for chemotherapy, radiation therapy, and surgical procedures has been successfully completed for 98% of study participants. Overall, 78% received radiotherapy and 73% chemotherapy.The CCSS represents the largest and most extensively characterized cohort of childhood and adolescent cancer survivors in North America. It serves as a resource for addressing important issues such as risk of second malignancies, endocrine and reproductive outcome, cardiopulmonary complications, and psychosocial implications, among this unique and ever-growing population.