Study: Early Puberty Ups Risk for Those Susceptible to Breast Cancer

For women genetically susceptible to breast cancer, an early puberty puts them at particularly high risk of developing breast cancer later in life, according to University of Southern California researchers.

But for women who are not genetically susceptible to breast cancer, the timing of puberty appears to have little or no impact on their risk, the researchers reported in the New England Journal of Medicine.

Researchers have increasingly believed that a women's risk of breast cancer is linked to her lifelong exposure to the sex hormone estrogen, but the new study suggests that early puberty -- with its rush of hormones -- may be particularly ominous for some women.

The findings are based on a study of 1,811 pairs of female twins, one or both of whom had breast cancer.

Among the 209 pairs of identical twins who both had breast cancer, the first twin to reach puberty was five times more likely to get the disease first. The link was even stronger when menstruation began before the age of 12.

The findings suggest that a subset of women exists who may be at increased risk of developing breast cancer from exposure to hormones at the time of puberty, concluded Dr. Ann S. Hamilton of the University of Southern California.

Other Sources: New England Journal of Medicine