Birth size linked to breast cancer later

LONDON, Oct. 1 (UPI) -- Researchers in England suggest birth size may predict susceptibility to breast cancer later in life.

Researchers at the London School of Hygiene and Tropical Medicine study found for every pound increase in birth weight the risk of breast cancer increased 7 percent.

However, birth length, more than birth weight or head size, was seen as the strongest independent predictor of risk.

The study, published in the journal PLoS, based on a examination of data from 32 studies, included 22,058 cases of breast cancer among a total of more than 600,000 women.

"Our study indicates that birth size is a marker of susceptibility to breast cancer in adulthood, at least in developed countries," study leader Isabel dos Santos Silva said in a statement. "The breast cancer association appeared to be largely independent of known risk factors. Little is known on how the pre-natal environment may affect breast cancer risk later in life. Further research is needed to unravel the biological mechanisms underlying the birth size -- breast cancer association."

The researchers note the positive association with breast cancer risk was found in studies where birth size was based on birth records, but not in studies based on adult self-reports, which, the researchers point out, tend to be less accurate