| Abstract |
- Background: High birthweight is an established risk factor for childhood leukaemia.
Its association with other childhood cancers is less clear, with studies hampered by low
case numbers. Methods: We used two large independent datasets to explore risk associations between
birthweight and all subtypes of childhood cancer. Data for 16 554 cases and 53 716 controls
were obtained by linkage of birth to cancer registration records across five US
states, and 23 772 cases and 33 206 controls were obtained from the UK National
Registry of Childhood Tumours. US, but not UK, data were adjusted for gestational age,
birth order, plurality, and maternal age and race/ethnicity. Results: Risk associations were found between birthweight and several childhood cancers, with strikingly similar results between datasets. Total cancer risk increased linearly with each 0.5 kg increase in birthweight in both the US [odds ratio 1.06 (95% confidence
interval 1.04, 1.08)] and UK [1.06 (1.05, 1.08)] datasets. Risk was strongest for leukaemia
[USA: 1.10 (1.06, 1.13), UK: 1.07 (1.04, 1.10)], tumours of the central nervous system
[USA: 1.05 (1.01, 1.08), UK: 1.07 (1.04, 1.10)], renal tumours [USA: 1.17 (1.10, 1.24), UK:
1.12 (1.06, 1.19)] and soft tissue sarcomas [USA: 1.12 (1.05, 1.20), UK: 1.07 (1.00, 1.13)]. In
contrast, increasing birthweight decreased the risk of hepatic tumours [USA: 0.77 (0.69, 0.85), UK: 0.79 (0.71, 0.89) per 0.5 kg increase]. Associations were also observed between
high birthweight and risk of neuroblastoma, lymphomas, germ cell tumours and malignant
melanomas. For some cancer subtypes, risk associations with birthweight were
non-linear. We observed no association between birthweight and risk of retinoblastoma
or bone tumours. Conclusions: Approximately half of all childhood cancers exhibit associations with
birthweight. The apparent independence from other factors indicates the importance
of intrauterine growth regulation in the aetiology of these diseases.
- Keywords: Intrauterine growth, Case-control study, Childhood cancer, Birthweight
|
|---|