Being breastfed in infancy associated with an increased risk of CRC during adulthood

This study, “Being Breastfed in Infancy and Risk of Colorectal Cancer and Precursor Lesions,” is led by Chen Yuan et al.

Emerging evidence highlights perinatal and early-life exposure importance in CRC development. In this study, researchers investigated this association between a history of being breastfed and CRC risk and its precursor lesions among 66,634 women aged 46–93 years from the Nurses’ Health Study and 92,062 women aged 27–68 years from the Nurses’ Health Study II.

Study results of this research could be summarised as

• During 3.5 million person-years of follow-up, 1490 incident cases of CRC were identified in these two cohorts.
• There was an association between having been breastfed and a 23% increased CRC risk.
• CRC risk increases with the duration of being breastfed.
• Researchers validated these findings using breastfeeding information from the mothers of a subset of participants.
• Among younger participants (Nurses’ Health Study II), there was an association between being breastfed and an increased risk of high-risk adenomas under age 50, with an odds ratio of 1.46.
• There was an association between having been breastfed and an increased risk of CRC among participants aged ≤55 years, with hazard ratio of 1.38.

Concluding further, they said, “Based on the findings from our research, there is an association between being breastfed in infancy and increased risk of CRC in adulthood, including younger adults.”

Further investigations are warranted to understand the underlying biological mechanisms, as this association does not establish causation, they noted

National Institutes of Health supported Nurses’ Health Study.

Further reading:

https://www.cghjournal.org/article/S1542-3565%2823%2900673-0/fulltext