Long on the defensive in the battle against breast cancer, a national research team made a cautious move toward the offensive earlier this week, announcing the dramatic results of a preventative study to reduce breast cancer.
Touting a 45 percent decrease in the development of breast cancer among high-risk patients who received the estrogen-like drug Tamoxifen, researchers from the National Surgical Adjuvant Breast and Bowel Project announced the trial’s outcome Monday.
An estimated 43,900 women will die from breast cancer in 1998, according to the National Cancer Institute.
The successful results prompted the project to conclude their study 14 months ahead of schedule, drawing criticism and curiosity from international scientists, many of whom find the results promising but inconclusive.
Although the results do not mean an immediate change for University physicians and scientists, they have raised a number of questions from patients and colleagues.
The study marks the first time the drug, used for 20 years to combat the recurrence of breast cancer, has been clinically tested as a preventative measure.
Tamoxifen is known to increase the chance of developing cancer in the uterus and blood clots in the lungs and major veins.
Supported by the National Cancer Institute, the scientists concluded the study prematurely in order to allow those participants who received placebos — a harmless unmedicated treatment given as medicine — to begin taking the drug. About 13,000 women participated in the study.
But the decision to terminate the study attracted criticism from a team of international scientists based in the United Kingdom also working on Tamoxifen research.
The short length of the study raises the question of whether Tamoxifen actually prevents breast cancer, or simply delays its appearance, said Dr. John Delaney, professor of surgery.
And further analysis of the project’s data will be needed to determine how the drug affects different demographic groups involved in the study, he said. Each group will need to weigh the possible side effects with the odds of developing breast cancer.
Although Delaney said the drug will not have any effect on the treatment he can provide for his patients, he also said he hopes the drug may someday stem the flow of cancer patients to his office.
“If they put me out of business, I’d be happy,” said Dr. Tanya Repka, an assistant professor in the Department of Medicine and a specialist in solid tumor transplant.
Repka participated in the project’s study as an oncologist — a physician who specializes in treatment of cancer — while working at Hennepin County Medical Center between April 1992 and September 1997.
As thrilled as she is with the results, Repka echoed the caution issued by doctors across the nation as news of the results spread: Tamoxifen is not for general use.
The life-threatening risk factors, such as uterine cancer and blood clots, do temper the results and possible uses for the drug, she said. But high-risk patients — such as women with close female relatives who have breast cancer — should consult their doctors and discuss the benefits and hazards, she said.
Primary care physicians, as well as specialists, will need to better understand the breast cancer assessment process in order to evaluate their patients, she said. A number of her own patients began calling after the study was released to ask if family members should consider taking the drug.
As a scientist studying hormone replacement therapy, Dr. Yusuf Abul-Hajj, a College of Pharmacy professor and head of the medicinal chemistry department, said the results are encouraging. Abul-Hajj has worked with Tamoxifen and similar estrogen-like drugs.
Tamoxifen is one of a handful of new drugs developing on the market that could be tweaked as scientists learn more about how genes and hormones relate. Understanding how the two communicate and influence cell development could lead to solutions for osteoporosis, breast cancer and uterine cancer.
As it stands, researchers are focusing their energies on treating patients with developed breast cancer cells, Abul-Hajj said. Monday’s results could shift that focus toward prevention.
–The Associated Press contributed to this report.