Birth-weight and Risk of Breast Cancer: A Systematic Review Study

Abstract

Introduction: Observational studies have linked the risk of breast cancer to birth weight, however, findings are not consistent. Therefore, the objective of this study was to investigate and quantify the level of risk of breast cancer associated with birth-weight among women.

Methodology: A systematic search of literature was conducted from 1990-2016 using the following databases: PUBMED, DH-Data, EMBASE, MEDLINE, PSYCINFO and GOOGLE SCHOLAR. 13 relevant articles were identified for the systematic review, out of which 5 were suitable for meta-analysis. The computer software Review Manager (RevMan) 5.2 was used for the meta-analysis.

Results: Most of the studies reviewed reported significant increased risk of breast cancer among participants with high birth weight. There were indications that this relationship is more pronounced among premenopausal women. In addition, the meta-analysis further revealed that women with suboptimum birth-weight (<3,500g) are at lesser risk of breast cancer when compared with optimum birth-weight 3,500g-4,500g (OR= 1.17 (95% CI 0.98, 1.39)); while optimum birth-weight (3,500g-4,500g) women are at lesser risk of breast cancer when compared with women with above-optimum birth-weight (>4,500g) (OR=0.87 (95% CI 0.66, 1.15).

Conclusion and Implications for Translation: This study revealed that the risk of breast cancer increases with increasing high birth weight especially among premenopausal women, thus suggesting early onset of breast cancer in this group. There is a clear relationship between high birth weight and risk of breast cancer; the developmental origin of health and diseases theory as postulated by Baker may be the strongest biological mechanism to explain this finding. Prevention programs through health education and early diagnosis strategies targeted at this group might be promising strategies to tackle global burden of breast cancer.

Key words: • Breast cancer • Birth-weight • Level of risk • Developmental origin of disease • Systematic review

© 2018 Ojeifo and Anjorin. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.