UMC aided study reveals possible breakthroughs in breast cancer prevention

Tanith L. Balaban Arizona Summer Wildcat David S. Alberts, a UMC doctor and principal investigator for the Arizona Cancer Center's role in the six-year North American study of Tamoxifen, stops by the pharmacy at the Cancer Center to pick up an order of the drug. Tamoxifen may reduce the chances of breast cancer in high risk women, but in different studies has had mixed results.

Kathie Blackett's sister is dying of breast cancer.

But while Blackett, 58, is losing her sister, she's not losing her own health.

As a high-risk candidate for breast cancer, she took the drug Tamoxifen for five years as part of a nationwide study to reduce the chances of breast cancer - and has not developed the disease.

"It's the first real ray of hope in breast cancer prevention," said David S. Alberts, a University Medical Center doctor and principal investigator for the Arizona Cancer Center's arm of the six-year North American study.

The study, conducted by the National Surgical Adjuvant Breast and Bowel project and the National Cancer Institute, involved 13,388 healthy women determined to be at high risk for developing breast cancer. This includes women over 60 with one relative with breast cancer, or younger women with two or three relatives with breast complications.

The high risk women were split into two groups, and half were given Tamoxifen while the other group took a placebo pill, which is a sugar pill with no medicinal value.

The study reported a 45 percent reduction in breast cancer incidence for women who received Tamoxifen, prompting Alberts and other officials to cut the study short 14 months early to give women the option of switching from the placebo to Tamoxifen.

"It was decided that it was not fair to women to keep this information secret," Alberts said.

But the same week the positive results of Tamoxifen were touted on the cover of the Arizona Cancer Center's newsletter, Time magazine listed two European studies involving Tamoxifen as "Bad News for Breast Cancer." The European studies - one in Italy and another in Britain - found no reduction in breast cancer rates for women who received Tamoxifen therapy.

Alberts said the studies conflicted with the North American study in size, duration and in the manner they were administered.

The Italian study lasted for four years and involved 5,408 women. The British study included 2,500 healthy women with a family history of breast cancer. Both studies used placebos, but both also allowed women to take hormones.

Alberts said one factor alone could account for a huge difference in the findings.

"They allowed estrogen-replacement therapy, and estrogens are well known to compete with Tamoxifen - they can actually displace it."

Aside from the conflicting information, Tamoxifen can have serious side effects.

Blackett said she noticed an increase in hot flashes, but other patients suffered more serious problems.

Alberts said the downside of Tamoxifen therapy involves an increased risk of uterine cancer and blood clotting for some women who take the drug.

"All of the cases of uterine cancer found in the study were in the early stages and easily treated," he said.

Alberts said the focus of future research will be to find drugs similar to Tamoxifen that do not induce the negative side effects. One of these drugs, Reloxifen, will be compared with Tamoxifen in a study of 22,000 women to begin this fall.

A National Surgical Adjuvant Breast and Bowel project spokeswoman said Reloxifen may not carry one crucial side effect.

"So far, Reloxifen doesn't seem to stimulate the uterus like Tamoxifen can," said Lori Psillidis, NSABB's director of public relations.

Alberts was optimistic about the future for breast cancer prevention as an on-going development.

"There's every reason to think that you're going to see better and better drugs over the next t10 years," he said. "There are all kinds of possibilities."

Alberts added that the incidence of breast cancer is increasing. The National Breast Cancer Coalition reports there are more than 46,000 cases of breast cancer every year.