As reported by the New Haven Register, December 15, 2006.

Breast Cancer Rates Drop in '03

By Abram Katz

U.S. breast cancer rates dropped dramatically in 2003, delighting oncologists and researchers, but leaving a mysterious question: Why?

The incidence of breast cancer in women dropped a remarkable 7.2 percent that year, meaning that about 14,000 women who were expected to develop the disease were spared.

The eye-opening analysis by Dr. Peter Ravdin, of the University of Texas, was presented Thursday at the San Antonio Breast Cancer Symposium.

The figures, gleaned from the National Cancer Institute, left doctors searching for an explanation.

Many attending the conference could not help but notice that the decrease came a year after worried post-menopausal women stopped hormone replacement therapy.

Hormone therapy with estrogen and progestin eases the extremely unpleasant menopausal symptoms some women endure. Many patients stopped after a Women’s Health Initiative study in 2002 found that the hormone regimen increased the risk of breast cancer and heart disease.

Cancer specialists at the symposium suggested that the drop in breast cancer is linked to the halt of hormone therapy.

However, the presentation left many unanswered questions, and the correlation between less estrogen consumption and fewer breast cancers is problematic.

"When I saw it, I couldn’t believe it," statistician Donald Berry of the University of Texas M.D. Anderson Cancer Center in Houston said of the drop.

Connecticut experts also had reservations.

"I’m delighted that breast cancer rates are dropping. Everyone can conjecture what the cause is," said Dr. Carolyn D. Runowicz, director of the Neag Comprehensive Cancer Center at the University of Connecticut Health Center.

Runowicz said that hormone-sensitive tumors usually take several or more years to develop. A significant decline in breast cancer one year after hormone use was apparently curtailed, while plausible, "is a little surprising," she said.

"The real take-home message is, for whatever reason, the breast cancer rate has dropped," she said.

Dr. Maysa Abu-Khalaf, of the Yale Comprehensive Cancer Center, said breast cancer statistics from 2004, which will not be available until 2007, will have to be analyzed to see if the decline is sustained.

Meanwhile, women are going to be even more cautious about hormone replacement, Abu-Khalaf said.

She said of the cancer statistic revealed Thursday, "You always have to take these with caution. The figures are retrospective," she said, which tends to reveal less information than prospective double-blind studies.

"In light of this data, use of hormone replacement therapy in women should be considered on an individual case basis, taking the benefits and risks into consideration," she said.

"What’s interesting is that the size of the drop in one year is significant. Follow up on future years will give us a better picture," Abu-Khalaf said.

Much information about Ravdin’s study must be clarified before the significance of the data becomes apparent, said Dr. Andrea Silber, medical oncologist and breast cancer specialist at the McGivney Center for Cancer Care at the Hospital of St. Raphael.

"If the decline in breast cancer is really linked to the decline in hormone replacement, you’d like to see a lengthier period, like several years," she said.

"Several things could explain the decline," Silber said. Intensive screening for breast cancer may be responsible, for example, she said. "Maybe women stopped taking hormone replacement before the Women’s Health Initiative announcement."

The statistical significance of data and the methodology of the analysis must be published before experts start looking for a cause and effect, she said.

"What will the data look like when it’s published? I don’t know. I don’t know the methodology," Silber said.

"While these figures are tantalizing and plausible, time will tell whether there’s a true association between the decline in hormone therapy and the incidence of breast cancer," Silber said.