Hutch News Stories

ExCellent potential for cancer prevention

PHS leads study of low-risk drug that blocks estrogen production and may prevent breast cancer
Gabrielle Gunderson
Gabrielle Gunderson coordinates the ExCel study — a landmark trial to test the effectiveness of the breast-cancer treatment drug exemestane for cancer prevention in high-risk, postmenopausal women. Photo by Todd McNaught

Every 30 seconds, somewhere in the world, another woman is diagnosed with breast cancer. Now, a new study led by Hutchinson Center researchers will test whether a proven cancer-treatment drug can reduce the risk of breast cancer in postmenopausal women who are at high risk of developing the disease.

"We are excited to be one of the sites selected to participate in this landmark study," said Dr. Anne McTiernan, lead investigator for the Seattle ExCel study site and a researcher in the Public Health Sciences Division. "It would be great if a relatively low-risk medication that works for treatment might also prevent breast cancer."

The study medication, exemestane, is already used to prevent breast-cancer recurrence because it blocks the body from producing estrogen. Without estrogen, breast-cancer cells cannot survive. Earlier findings showed that exemestane was able to halt the occurrence of new cancers in the unaffected breast of women who have already had breast cancer, suggesting that it may prevent the disease in healthy women.

In the Center's first-ever collaboration with the National Cancer Institute of Canada, McTiernan and colleagues are recruiting 200 women over the next two years from the Pacific Northwest to join the ExCel study. The Hutchinson Center is one of only three sites in the western United States and joins 20 study locations nationwide. The trial of more than 4,500 women will also involve participants in Canada and Spain. Dr. Julie Gralow, associate professor of medical oncology at the University of Washington, is a co-investigator for the Seattle ExCel study clinical site.

Local recruitment is going well, according to Gabrielle Gunderson, study coordinator. "We are recruiting women through mailings, TV ads and newspaper articles. We're having a great response to our most recent mailing and received many inquiries over the phone and via e-mail from the media spots," she said.

The study is aimed at postmenopausal women at high risk of breast cancer due to factors such as being age 60 or older, having a family history of the disease, being younger than 12 at first menstrual period or having a history of benign breast disease.

Local participants must be willing to travel to Seattle for a clinic visit twice in the first year of the study, and once a year for four subsequent years. Clinic visits include physical and breast exams, a blood draw and a bone-density scan at the beginning of the study. Participants obtain annual mammograms through their own providers.

Breast cancer, the second leading cause of cancer death in women, is also treated with tamoxifen, which has been shown to reduce the incidence of breast cancer by 50 percent for women at high risk for the disease. But many women choose not to take this drug because of its known serious side effects like increased risk of stroke, blood clots in the legs and lungs, uterine cancer and hot flashes.

It is believed that exemestane is associated with fewer side effects. It may increase the risk of osteoporosis, and some women experience joint and muscle pain or nausea while using it. The trial will further study these side effects.

The ExCel study will also examine the impact of exercise in preventing breast cancer, as well exemestane's effect on quality of life and breast-tissue density, a factor that impacts the clarity of mammograms. Study leaders hope to have initial study results within four years.

"We hope that women in our community will consider participating in the trial, as the results may impact the future of breast-cancer prevention," McTiernan said.

Learn more about the ExCel study on the Center's Web site

Help Us Eliminate Cancer

Every dollar counts. Please support lifesaving research today.