Estrogen Plays Surprise Role in Breast Cancer...( Study finds it may slow disease if an...),Health

Study finds it may slow disease if anti-estrogen therapies stop working

TUESDAY, Aug. 18 (HealthDay News) -- Researchers report that the paradoxical strategy of treating breast cancers that have become resistant to anti-estrogen therapies with estrogen actually shrank some tumors.

Not only that, but the estrogen made some of the tumors sensitive to anti-estrogen drugs once again.

The findings, reported in the Aug. 19 issue of the Journal of the American Medical Association, are preliminary, one expert cautioned.

"It's an interesting observation, but it needs to be expanded into a large trial," said Dr. Jay Brooks, chairman of hematology/oncology at Ochsner Health System in Baton Rouge, La. "There's probably something biologically going on here that we don't quite understand. The question is, can we translate this into really clinically meaningful responses?"

"The history of treating patients with estrogen goes back to the 1940s when physicians started to treat patients with advanced breast cancer with diethylstilbestrol or DES [a synthetic estrogen]," explained Dr. Matthew Ellis, a professor of medicine at Washington University School of Medicine, an oncologist with the Siteman Cancer Center in St. Louis and a co-author of the study. "The ancient literature is full of grainy photographs with lung metastases or local, advanced breast cancer or bone metastases getting better with this paradoxical treatment."

That treatment protocol was displaced by the anti-estrogen therapy tamoxifen in the 1970s. And tamoxifen is now being replaced by stronger anti-estrogen drugs known as aromatase inhibitors.

"These drugs are a little more effective than tamoxifen ... so now you have a large population of patients with advanced breast cancer who have experienced treatment often with both estrogen-lowering agents," Ellis said. "We hypothesized that some of these patients could go back to estroge
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