Association between birth weight and risk of nonneurological childhood cancers: a systematic review and meta-analysis.

Objectives: This systematic review aims to synthesize the available literature to determine the association between birthweight and the risk of nonneurological childhood cancers.

Methods: We conducted a systematic search of PubMed, Web of Science, and Scopus databases up to May 2023 to identify observational studies. Heterogeneity between studies was evaluated using the I2 statistics. Publication bias was assessed using Begg and Egger tests. We calculated the odds ratio (OR) or risk ratio (RR) with a 95% confidence interval (CI) using a random-effects model.

Results: Of 11 034 studies retrieved from the search, 56 studies (including 10 568 091 participants) were eligible. The ORs (95% CI) of low (<2500 g) versus normal birthweight (2500-4000 g) and childhood cancers were as follows: leukemia, 0.92 (0.77-1.11); acute lymphoblastic leukemia, 0.82 (0.72-0.94); acute myeloid leukemia, 0.98 (0.77-1.24); lymphoma, 0.99 (0.47-2.10); Hodgkin, 0.79 (0.61-1.03); non-Hodgkin, 0.85 (0.60-1.20); neuroblastoma, 1.34 (1.14-1.58); retinoblastoma, 0.95 (0.68-1.32); rhabdomyosarcoma, 0.86 (0.61-1.20); embryonal, 0.97 (0.66-1.43); alveolar, 1.92 (0.43-8.51); and Wilms tumor, 1.01 (0.83-1.24). The ORs (95% CI) of high (>4000 g) versus normal birthweight and childhood cancers were as follows: leukemia, 1.30 (1.18-1.42); acute lymphoblastic leukemia, 1.27 (1.16-1.39); acute myeloid leukemia, 1.13 (0.98-1.30); lymphoma, 1.69 (0.72-3.94); Hodgkin, 1.22 (1.02-1.46); non-Hodgkin, 1.22 (0.80-1.86); neuroblastoma, 1.20 (1.02-1.41); retinoblastoma, 1.17 (0.93-1.48); rhabdomyosarcoma, 1.07 (0.90-1.27); embryonal, 1.22 (1.00-1.49); alveolar, 1.02 (0.46-2.27); and Wilms tumor, 1.49 (1.34-1.67).

Conclusion: This meta-analysis identified high birth weight as a potential risk factor for some childhood cancers, while low birth weight might be protective against a few.