Ditching HRT may Have Reduced Breast Cancer

Ivanhoe Newswire
Friday, December 15, 2006; 12:00 AM

(Ivanhoe Newswire) -- After studies published in 2002 linked hormone replacement therapy (HRT) with an increased incidence of breast cancer, many women just said no to HRT.

That might have been a very good idea. According to the results of a new population-based study, the incidence of breast cancer dropped sharply in 2003, with the biggest declines seen in estrogen-positive (ER-positive) breast cancers. Those cancers are known to need the hormone estrogen, which is included in HRT, to thrive.

Overall, breast cancer cases dropped by 7 percent, with ER-positive cases dropping by 8 percent and ER-negative cases by just 4 percent. In women ages 50 to 69, ER-positive cancers were down by 12 percent.

According to study authors, these are major and significant declines. While they cannot conclude for certain the declines were caused by the significant drop in the number of women using HRT after the 2002 reports appeared, they can find no other logical explanation. Officials estimate about 15 percent of women on HRT quit using it after the 2002 reports.

"Something went right in 2003, and it seems that it was the decrease in the use of hormone therapy," reports Peter Ravdin, M.D., Ph.D., a research professor at the University of Texas M. D. Anderson Cancer Center who participated in the study.

He and fellow investigators speculate cutting off estrogen from ER-positive cancers simply stopped or slowed their growth, making them fail to show up on mammograms. "Research has shown that ER-positive tumors will stop growing if they are deprived of the hormones, so it is possible that a significant decrease in breast cancer can be seen if so many women stopped using HRT," reports Dr. Ravdin.

The investigators believe their statistics translated to about 14,000 fewer women being diagnosed with breast cancer in 2003.

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SOURCE: Presented at the 29th annual San Antonio Breast Cancer Symposium in San Antonio, Dec. 14-17, 2006