Blood test could predict breast cancer 20 years early

Checking blood hormone levels could be a simple, cheap, and effective way to predict breast cancer risk in postmenopausal women--even as much as 20 years in the future. Researchers from Brigham and Women's Hospital looked at data from the Nurses' Health Study and presented the results at the 11th Annual AACR International Conference on Frontiers in Cancer Prevention Research.

The Nurses' Health Study is a long-term study of women designed to look at risk factors in cardiovascular disease and cancer; it started in 1976. The researchers measured hormone levels from blood samples from 1989-1990 and 2000-2002 in women with or without postmenopausal breast cancer who were not taking hormone therapies.

They found that those women who had the highest levels of three hormones, estradiol, testosterone and dehydroepiandrosterone sulfate (DHEAS), had a higher risk of breast cancer (50% to 107% greater) than women with the lowest levels, reaching as far as 16 to 20 years in the future. The risk associated with these increased hormone levels was more closely linked with hormone receptor-positive breast cancers and with more aggressive breast cancers.

"The relationship was comparable or possibly stronger for recurrent and fatal breast cancer than it was for overall breast cancer risk, although these results were based on relatively small numbers of participants," said Xuehong Zhang of Brigham and Women's Hospital.

The team linked increased levels of another biomarker, sex hormone-binding globulin, with reduced risk of breast cancer. Women with the highest levels had almost a third lower breast cancer risk than women with the lowest levels.

This study was small and needs to be expanded and lengthened. After this, the next step would be to see if adding information on hormone levels to current methods of predicting risk would help pick out those women who could benefit from more regular checks, or preventive medications. If the results do pan out, the tests may only need to be repeated every 10 to 20 years.

- read the press release