A discovery by Australian scientists could help clinicians decide which women with breast cancer will make good candidates for anti-estrogen therapies, such as tamoxifen, and which will not.

Over 12,000 Australian women are diagnosed with breast cancer each year, roughly 70% of which will have cancers treatable with tamoxifen. Unfortunately, 30% or more of these women may not respond well to such anti-hormone therapy long-term.

Work done by a research team headed by Associate Professor Liz Musgrove and Professor Rob Sutherland of Sydney's Garvan Institute of Medical Research has correlated expression of certain functionally-related estrogen-regulated genes with predictable clinical outcomes. This expanded knowledge about estrogen action and endocrine resistance should allow clinicians to make better, more informed, choices in the future.

The novel findings were published in the Public Library of Science journal PLoS ONE.