About one in eight women in the U.S. will develop breast cancer in their lifetime. And despite significant advances in treatment and detection, nearly one in seven die from it.
For women like Yakima resident Grace Smith, that probability hits close to home. Her twin sister is a breast cancer survivor, after a mastectomy, and her older sister died from the disease.
So when local doctors announced more than a decade ago that they'd be taking part in a national study on preventive drugs for breast cancer, Smith signed up for the clinical trial, along with 53 other women from the Yakima area.
"It was potentially, for me, the difference between life and death," she said.
Now, after 13 years, researchers have just concluded their study of nearly 20,000 women nationwide, and determined that the drug raloxifene is just as effective at preventing breast cancer as the more commonly used tamoxifen, and causes fewer serious side effects.
Tamoxifen has been used in hormone therapy to treat breast cancer for more than 30 years, while raloxifene was already on the market as a drug to prevent and treat osteoporosis in postmenopausal women.
The study looked at postmenopausal women at high risk for developing breast cancer based on family history and other health factors.
In Yakima, participants joined the study through host site North Star Lodge, Yakima Valley Memorial Hospital's cancer care center and one of more than 500 sites in the United States and Canada to participate.
Dr. Tom Boyd headed up the clinical trial at North Star, where women were given either tamoxifen or raloxifene every day for five years, then monitored for several years afterward.
Both medications were found to reduce the risk of developing breast cancer by about 50 percent, though the study shows that raloxifene carries a lower risk of blood clots or uterine cancer, which tamoxifen can cause in rare instances.
The drugs represent a significant step forward in medicine's approach to breast cancer, Boyd said.
"We often mistake the idea of doing mammography as prevention," he said. "Unfortunately, it's not preventing; it's detecting the cancer early. ... There's not that many things we do in the cancer arena that really seem to reduce the risk of cancer happening."
In targeting high-risk women with drugs like tamoxifen and raloxifene, however, "You're actually hoping to reduce the number of cases that develop, not simply find them earlier," he said.
The drugs work by plugging the receptor site that, when stimulated by estrogen, prompts breast cancer development.
In Yakima, of the 53 high-risk women who made it through all five years of the trial (different groups started at different times during the 13-year study), three developed breast cancer.
"I believe if you took the risks of those patients coming into the trial, you'd expect six to 10" to develop the disease, Boyd said.
Nationwide, the study found that of the 9,745 women who took raloxifene, 167 developed invasive breast cancer, compared to 163 of the 9,726 women on tamoxifen.
The study, funded by the National Cancer Institute, was one of the largest breast cancer clinical trials ever conducted. Most trials look at a few hundred to a few thousand patients, but to account for the fact that researchers were looking at pure prevention, they had to adjust for the fact that not everyone in the trial would have developed breast cancer anyway.
For the women involved, knowing that they were helping manage their care was the strongest motivation for continuing.
"If I would've gotten cancer (outside of the study) it would've been life-altering one way or another," said Smith, 64. "I thought it was very important that I be proactive with my health."
Like the other patients, she got an annual mammogram and took the pills every day for five years. The study also involved blood tests and an extensive yearly questionnaire to gauge overall health.
Smith didn't notice any side effects, but fellow study participant Mary Ellen Deprey, 72, left the study after four years because the tamoxifen gave her severe hot flashes.
But she's still glad she did the trial.
"I felt that, if there was some way I could contribute for my kids and my grandkids later on, it was well worth the time in doing it," she said. "It was an easy study to do and it had benefits both for (the doctors) and for me."
The trial was also quite a "feather in Yakima's cap," said North Star's primary breast cancer physician Dr. Vicky Jones. Yakima was one of only a handful of community sites in the study; most sites were part of large research universities.
"We've gotten over the years a lot of recognition ... for how well it was conducted in Yakima," Jones said. They were honored as one of the top enrolling programs in the nation for being attentive to which patients are eligible for new drug trials.
Now that doctors know the effectiveness of the two drugs, Boyd said the next step is getting them into mainstream use.
"The big challenge going forward for a study like this is not only completing the task, but translating it to the family practitioner ... rather than a cancer care center," he said. Then, "It becomes incorporated as a more routine assessment," and something family or primary care doctors would prescribe.
Overall, his patients seem pleased with their part in the study. Deprey called the trial "a wonderful experience."
"I'm glad to know that here in Yakima, we did some thing that was important for the rest of the world," she said.
Source: YellowBrix
