Researchers believe that a recent seven per cent fall in breast cancer cases in the US could be related to a decrease in the number of women taking hormone replacement therapy (HRT).
Breast cancer incidence had been increasing for 20 years in the US until 2003, when there was a seven per cent drop.
Among 50 to 69-year-old women suffering from forms of breast cancer that are sensitive to hormones, the fall was even more noticeable, with the number of cases decreasing by 12 per cent.
A team of researchers at the M.D.Andersen Cancer Centre at the University of Texas believe that the health scare in 2002 which led many women to give up HRT could explain the drop, as the growth of some breast cancers is fuelled by hormones.
"HRT had been proposed as a possible factor, although the magnitude of any effect was not known," revealed senior investigator Professor Donald Berry.
"Now the possibility is that the effect is much greater than originally was thought plausible, and that is a remarkable finding," he told the Times.