On entry into the cohort, participants, including both survivors and siblings, completed a baseline questionnaire that collected basic demographic and health-related information. For participants under age 18 at baseline, the questionnaire was completed by a parent or guardian. Follow-up questionnaires are mailed to participants approximately every two years to update baseline data and to gather additional information on questions of interest.

In addition to completing the baseline questionnaire, survivors agreed to release medical records of their cancer treatment; participating centers provided detailed abstracts of treatment records for all consenting survivors enrolled in the cohort from their site. Treatment information includes cumulative dose-specific exposure to chemotherapy, surgical procedures, and radiation therapy. The latter is evaluated by the radiation physics center at M.D. Anderson Cancer Center.

Sex
Survivors
Siblings
Males 7,709 Males 1,846
Female 6,643 Female 2,000
Current age (as of 5/1/2000)
Survivors
Siblings
9-15      53
16-20    597 16-20    320
21-25 2,769 21-25    675
26-30 3,017 26-30    688
31-35 3.239 31-35    707
36-40 2,528 36-40    656
41-45 1,481 41-45    446
46-50    615 46-50    229
51-55    106 51-55      71
Original cancer diagnosis of survivors
Leukemia 4,830
Brain/central nervous system 1,872
Hodgkin disease 1,926
Non-Hodgkin lymphoma 1,082
Kidney 1,255
Neuroblastoma    953
Soft-tissue sarcoma 1,245
Bone 1,189