AMSTERDAM, Netherlands, Sept. 25 (UPI) -- A new study says left-handed women may have an increased risk for breast cancer before reaching menopause.
Researchers with the University Medical Center in the Netherlands studied more than 12,000 middle-age Dutch women between 1982 and 2000, and found that the left-handed women in the study were more than twice as likely as right-handed women to develop breast cancer before going through menopause, the Washington Post reported.
They speculate the left-handed women may be at risk for breast cancer because they were exposed to higher levels of certain hormones in the womb.
The association held up even after the researchers took into account other factors, such as social and economic status, smoking habits, family history of breast cancer and reproductive history.
"The origin of the association may lie in intrauterine exposure to steroid hormones," the researchers wrote in a paper published online by the British Medical Journal.
Women exposed in the womb to the hormonal drug diethylstilbestrol, or DES, for example, were more likely to be left-handed, the researchers noted.
