Congenital anomaly and childhood cancer: A population-based, record linkage study.

BACKGROUND: The cause of the majority of childhood malignancies is unknown. Association with the presence of congenital anomalies has been noted in some studies. In this study, we describe and quantify the association between congenital anomalies and childhood cancer. PROCEDURE: Cases from the Northern Congenital Abnormality Survey (NorCAS) and the Northern Region Young Persons Malignant Disease Registry (NRYPMDR) were matched using four key variables: surname at birth, date of birth, postcode at birth, and infant gender. All potential matches were checked manually. A second match was performed for children with matched birth dates, postcodes and gender but different surnames, to identify children whose surname at diagnosis was not the same as at birth.
RESULTS: Thirty-nine children with a congenital anomaly and a diagnosis of cancer were identified from a cohort of 599,290 children born during 1985-2001. There was an almost threefold overall increased risk of malignancy among these children (RR = 2.9; 95% CI 2.1, 3.9), particularly of acute lymphoblastic leukaemia (RR = 2.7; 95% CI 1.5, 5.0), acute myeloblastic leukaemia (RR = 22.0; 95% CI 12.1, 40.0), other leukaemia (RR = 7.5; 95% CI 1.3, 43.6) and lymphomas (RR = 5.3; 95% CI 2.4, 12.0). This increased rate remained when children with Down syndrome were excluded (RR = 1.8, 95% CI 1.2, 2.7).
CONCLUSION: Our findings suggest that children born with congenital anomalies are at increased risk of certain types of cancer. Further linkage studies between high quality registers, may provide insights into the origins of such malignancies. (c) 2008 Wiley-Liss, Inc.