Study may open new options for younger women with breast cancer

7:31am EDT

By Julie Steenhuysen

CHICAGO (Reuters) - The estrogen-blocking drug Aromasin worked better than the long-standing therapy tamoxifen at keeping cancers from returning in younger women with early stage breast cancer, a finding that may change the way the patients are treated, U.S. researchers said on Sunday.

Aromasin, a drug developed by Pfizer Inc that is sold generically as exemestane, is in a class of treatments called aromatase inhibitors that are typically used in post-menopausal women with low levels of estrogen.

Aromatase is an enzyme that converts the hormone androgen into small amounts of estrogen.

The drugs have largely been off-limits for younger women with working ovaries that produce estrogen.

In premenopausal women with hormone-sensitive cancers, the standard for preventing recurrence is five years of treatment with a drug called tamoxifen. For high-risk women, doctors in some countries recommend exemestane plus some form of therapy to shut down the ovaries, cutting off the supply of estrogen. That practice is not typically followed in the United States because there has not been enough evidence to show a benefit.

International researchers tested whether aromatase inhibitors combined with ovary-blocking treatments would do a better job than tamoxifen in two clinical trials involving 4,690 premenopausal women.....

http://www.reuters.com/assets/print?aid=USKBN0EC1DW20140601