Girls reaching puberty at an earlier age are likely to face a higher risk of developing breast cancer in later life, according to a new study.
The study published in “Adolescent Health” was led by Frank Biro, a leading expert on puberty.
The study said that girls who enter puberty early in life have a longer window of susceptibility. This window stays propped open for too long as their bodies have higher concentrations of growth hormone and experience a slower progression during puberty. This would result in longer exposure to environmental factors that might influence the developing breast tissue, the study said. .
Noting that numerous studied have shown a link between early puberty and breast cancer risk, Biro said that their study was backed by data gathered over years. The study was a comprehensive one that looked into the changes young women experience.
The new study said that hormonal factors found in adult women associated with elevated breast cancer risk also are associated with early puberty. The researchers said that these included higher concentrations of the growth factor IGF-1 and the ratio between the hormones estrone and androstenedione. IGF-1 is a potent growth stimulant associated with breast density and breast cancer in adult women. A greater ratio of estrone to androstenedione leads to greater overall exposure to estrogen, another risk factor for breast cancer, the study said.
The girls who experience early puberty can take steps throughout their lives to reduce their breast cancer risk, the researchers said.
The study began in 2004 as part of the “Growing Up Female” study conducted by the Breast Cancer and the Environment Research Program in collaboration with two other medical centers in New York City and Northern California. They worked with parents and schools to follow a group of more than 370 girls who entered the study at ages six and seven. The study is an account of the data from more than 180 girls, all from the Cincinnati region, who had stayed with the project all 14 years.