High estrogen levels noted in breast cancer patients

Blood taken from women whose breast cancer returned showed high levels of estrogen, even though many had been treated with estrogen blocking drugs.

Researchers say the discovery suggests women who have breast cancer should take extra steps such as regular exercise and weight management to reduce their estrogen levels.

Estrogen is strongly linked with the initial development of many breast cancers. But, few studies have looked at its role in the cancer recurrence.

Details on this newest research are in the journal Cancer Epidemiology, Biomarkers and Prevention.