The Hormone Therapy - Breast Cancer Connection

Hormones and the Breast Cancer Drop

Back in December the dramatic news broke that breast-cancer cases in the United States dropped 7 percent in 2003 -- the biggest drop in any single year and the biggest drop in two decades. But in the midst of this very good news on the cancer front, was there more bad news for the estimated 4.3 million American women taking hormone therapy (HT) for menopause?

Doctors and scientists said the startling drop in breast cancer seemed most likely to be the result of millions of women having abruptly stopped taking HT in 2002 when a major government study had raised such serious questions about the safety of taking estrogen and progestin that researchers quickly halted that part of the trial. The women who used that drug combination in the study -- the Women's Health Initiative (WHI) -- faced increased risk for breast cancer, heart attacks, and strokes. Once the news got out, sales of the drugs tumbled.

This latest breast-cancer caution -- courtesy of researchers from the University of Texas M.D. Anderson Cancer Center, the National Cancer Institute and UCLA -- sent women reeling again over the safety of taking hormones. We've consulted the nation's leading breast cancer and menopause experts to give you the following information to assess your options with your doctor.

That stunning 7 percent drop means that 14,000 American women didn't get breast cancer in 2003. Although we've known for years that taking hormones at menopause slightly increases a woman's risk of getting breast cancer, this new finding seemed to amplify this fact in the public's mind. Important unanswered questions remain, however. Doctors don't know whether the abrupt halt in hormone use in 2002 will result in a permanent decrease in breast cancer. One worry is that the tumors that weren't detected in 2003 will show up eventually; in other words, stopping hormones might slow their growth but not eliminate them. It's also possible that some small tumors that did not appear in 2003 will never appear because they could not grow without the extra hormones.

Most researchers caution that while the cancer drop and hormone halt may be linked, years' more study is needed to properly make a definitive connection. For example, three other factors might have contributed to the drop, though none was big enough to account for all of it: During that same period, Americans increased their use of calcium supplements, anti-inflammatory drugs, and the bone drug raloxifene. All are linked with lower breast cancer risk.

Another important question is whether fewer women actually had cancer in 2003 or whether doctors simply found fewer cancers. Mammography screenings dropped by 3.2 percent among menopausal women in 2003, compared with the year 2000. "Finding fewer breast cancers doesn't mean there are fewer," says James A. Simon, MD, clinical professor of obstetrics and gynecology at George Washington University. "My guess is that women who stopped their hormones didn't feel the need to get tested. If you don't check a temperature you don't find a fever."