Acute Lymphoblastic Leukemia and Klinefelter's Syndrome

Collins' law states that the period of risk for tumor recurrence is the age of the child at diagnosis plus 9 months. The purpose of this study is to validate this rule through a retrospective review of common pediatric tumors seen at 1 institution. Inclusion criteria for this study included an age at diagnosis of < 16 years old, minimum follow-up time of the Collins risk period (CRP) if child did not relapse and treatment with curative intent. The records of 424 children seen and treated for neuroblastoma (n = 98), Wilms tumor (n = 86), rhabdomyosarcoma (n = 82), medulloblastoma (n = 59), Ewing sarcoma (n = 43), ependymoma (n = 25), supratentorial PNET (n = 22), and synovial sarcoma (n = 9) from 1960 to 2001 were reviewed. CRP was calculated using the age of child at initial diagnosis plus 9 months. The median follow-up time was 164 months (range, 11–484 months), while the median follow-up/CRP ratio was 4.89 (range, 1.0–48.0). A total of 183 of 424 (43.2%) patients relapsed, with 180 (98.4%) relapses occurring during the CRP. Relapses beyond the CRP were seen in 3 young children (ages 7 months, 24 months, and 2 weeks at initial diagnosis) with a diagnosis of Wilms tumor (n = 2) and supratentorial PNET (n = 1) at 1, 3, and 26 months post-CRP. Collins' law is a useful and simple way of predicting risk period for relapse in the tumor types studied.