After monitoring thousands of postmenopausal women at high risk of developing breast cancer for the past five years, the initial results of the study on tamoxifen and raloxifene were released last week.

Lori Garvey, director of communication and public relations at National Surgical Adjuvant Breast Cancer and Bowel Project, said both drugs showed promising results for preventing breast cancer.

“Both drugs reduced the risk of developing breast cancer by 50 percent,” Garvey said. “Both drugs were compared and found equivalent, with raloxifene having fewer side effects than tamoxifen.”

Women from central Illinois who were postmenopausal and at an increased risk of developing breast cancer participated in the study, 150 in all, said Jennifer Hendricks, PR & media relations coordinator at Carle Clinic.

The National Surgical Adjuvant Breast Cancer and Bowel Project led the trial. It was a double blind randomized study to compare tamoxifen, which has shown promise in preventing breast cancer to raloxifene, which has been used to treat osteoporosis in the past, Garver said.

She said the drugs have the capability to slow the growth and reproduction of breast cancer cells by blocking estrogen in the breast.

Participants were randomly assigned to receive either 60 mg of raloxifene or 20 mg of tamoxifen daily for five years and receive annual mammograms, according to the National Cancer Institute’s Web site. Garver said the women enrolled in the trial would be followed throughout their lifetime to check for long-term effects of the drugs.

Women who took raloxifene daily for at least four years had 36 percent fewer uterine cancers and 29 percent fewer blood clots compared to women taking tamoxifen, according to the National Cancer Institute.

The National Surgical Adjuvant Breast Cancer and Bowel Project hopes to launch another study where researchers will compare the success of raloxifene to another drug, Garver said.

Carle Clinic Association in Urbana was one of more 500 centers across the U.S., Canada and Puerto Rico to conduct the trial. As one of the largest cancer research programs in central Illinois, the Carle Cancer Center currently has more than 190 ongoing trials in conjunction with Mayo Clinic, the National Cancer Institute and other cancer centers and pharmaceutical companies, according to a press release.

Dr. Kendrith Rowland, principal investigator of the trial and head of cancer research at Carle Clinic Association said tamoxifen will still be the standard of care for pre-menopausal women at high risk for breast cancer at Carle Clinic.

“Raloxifene, which is only FDA approved for postmenopausal women will likely replace tamoxifen for postmenopausal women – although cost is often an issue and tamoxifen, now generic, is cheaper,” Rowland said. “Both are good for bone health.”

Postmenopausal women at high risk of developing breast cancer can purchase raloxifene on the market under the name Evista while tamoxifen is sold under the brand name Nolvadex, according to Carle Clinic.