Scientists have found new evidence that would further explain that there is a link between use of hormone replacement therapy and breast cancer risk.
A new study has shown that the number of Australian women aged over 50 diagnosed with breast cancer has dropped by 7 per cent with 600 fewer cases between 2001 and 2003, during which there was also a 40 per cent decrease in use of hormone replacement therapy (HRT).
A drop in the number of breast cancer cases with the reduction in hormone therapy use women experiencing menopause may explain the association.
Dr Andrew Penman, CEO at the Cancer Council NSW, said the "findings are great news for women".
"The correlation between the drop in breast cancer cases and HRT use is clear and its importance can't be underestimated," Sydney Morning Herald quoted Dr Penman, as saying.
However, Dr Helen Zorbas, director of the National Breast and Ovarian Cancer Centre said that though the link was "likely" the study did not categorically show a reduction in HRT caused the decrease in cancer rates and did not change the advice to women regarding the use of HRT for the short-term relief of menopausal symptoms such as hot flushes.
"There may be other factors which could be contributing to this decrease in breast cancer incidence," she said.
Zorbas also said that for every 1000 women in their 50s taking HRT over five years, there would be an additional four women diagnosed with breast cancer but the risk returned to normal within a few years of stopping treatment.
"All the data ... shows that taking combined HRT does increase the risk for breast cancer with the longer duration of use increasing the risk," she added.
Many women had stopped using HRT after it was found to increase breast cancer rates in the controversial Women's Health Initiative report in 2002.