This study aimed to systematically review literature on the association between birth weight and pediatric cancer risk. Sixteen studies were qualitatively synthesized and seven were quantitatively synthesized. The results found an overall direct correlation between higher birth weight (≥2500g) and higher childhood cancer risk, while lower birth weight (<2500g) was associated with lower risk. However, for acute lymphocytic leukemia specifically, risk was higher for birth weights under 2500g. Significant heterogeneity between studies means these findings should be interpreted cautiously. Prospective cohort studies are needed to better understand the impact of prematurity on pediatric cancer development.

1. OBJECTIVES
McClarin, L 1,2, Wallace, A. 1, Holmes, L Jr.1,3
Nemours Office of Health Equity & Inclusion, 2200 Concord Pike Wilmington, DE, 198031, Epidemiology and Biostatistics Department, University of
Maryland-College Park, College Park, MD, 20742 2 University of Delaware, Biological Sciences Department, Newark, DE 197133
CONCLUSION
METHODS
• We performed a systematic literature review and
quantitative evidence synthesis (QES).
• We searched through MEDLINE via PubMed with relevant
search terms and only included studies that met the
following criteria:
• Studies published in English between the years 2004
and 2014
• Sample size larger than 20 human cases
• Measured the risk for pediatric cancer by assessing its
association to birth weight.
• All eligible studies were compared to assess the
association of birth weight on pediatric cancer risk for the
qualitative synthesis.
• For the QES, we extracted data from all eligible studies
based on four predetermined outcome categories.
• Heterogeneity test was performed indicating significant
variability between studies.
• Random effect method for the pooled summary estimate of
risk was used.
RESULTS
• Of the 980 studies identified through searching, 16 were
eligible for the qualitative synthesis and 7 studies were
eligible for the QES.
• A direct correlation between overall childhood cancer risk
and birth weight was observed, with children at lower birth
weight associated with lower risk for overall cancer
(<2500g, odds ratio, 0.91,99%CI,0.72-1.09) relative to
children at higher birth weight (≥2500g, Odds ratio, 1.31,
99%CI, 1.10-1.52).
RESULTS
• Cancer is the leading cause of disease-related mortality
among children.
• Birth weight has been shown to be associated with
pediatric cancer risk.
• There remains inconsistent findings as to the impact of low
versus high birth weight on pediatric cancer risk.
• The purpose of this study was to identify and synthesize
the findings of non-experimental studies which assessed
the association between birth weight and pediatric cancer
risk.
Birth Weight and Pediatric Cancer Carcinogenesis: A systematic review and quantitative
evidence synthesis
• Acute Lymphocytic Leukemia inversely corrected with birth
weight; <2500 g (18.% 95% CI -11.3-47.08); Birth weight ≥
2500 g (15.3% 95% CI 8.2-22.4)
• The observed data may be due to sparse data bias as few
children in the lowest birth weight strata may not survive
long enough to be diagnosed or may expire with cancer
without being diagnosed.
• In summary, neither direct nor inverse correlation between
prematurity and childhood cancer risk can be established
on the basis of this QES.
• With the observed significant heterogeneity among the
studies that constitute this QES, caution should be
exercised in the interpretation and application of these
data.
• These inconsistent findings are suggestive of the need for
prospective cohort designs in the assessment of the effect
of prematurity on childhood cancer development.