April 17, 2006
Lilly bone drug cuts breast cancer risk: study
WASHINGTON (Reuters) - Eli Lilly and Co's Evista
osteoporosis drug works as well as the older tamoxifen in
reducing the risk of breast cancer in high-risk women, with
fewer dangerous side effects, researchers said on Monday.
The results of the 19,000-woman Study of Tamoxifen and
Raloxifene (STAR) trial show that Evista, known generically as
raloxifene, is less likely than tamoxifen to cause blood clots
and uterine cancer.
"In STAR, both drugs reduced the risk of developing
invasive breast cancer by about 50 percent," the National
Cancer Institute said in a statement.
Tamoxifen, sold as a generic and by AstraZeneca Plc under
the brand name Nolvadex, has long been prescribed to treat and
prevent breast cancer. Lilly said it would seek U.S. Food and
Drug Administration approval to market Evista both for
osteoporosis and to prevent breast cancer.
"Today, we can tell you that for postmenopausal women at
increased risk of breast cancer, raloxifene is just as
effective, without some of the serious side effects known to
occur with tamoxifen," said study chair Dr. Norman Wolmark.
Breast cancer is the second leading cause of cancer death
among U.S. women, after lung cancer. More than 200,000 people
are diagnosed and another roughly 40,000 die from it each year,
according to the American Cancer Society. Globally, 1.2 million
women and a few men are diagnosed with breast cancer annually.
The lifetime risk for a woman in the industrialized world
is roughly one in nine. But the risk is much higher risk for
those with several risk factors including having a mother or
sister with the disease, never having had a child, or having
had a number of suspicious-looking breast lumps.
RAISING OTHER RISKS
Some women are nervous about taking tamoxifen because it
can raise the risk of uterine cancer and blood clots.
Evista does not carry these risks, the five-year STAR trial
"Women who were prospectively and randomly assigned to take
raloxifene daily, and who were followed for an average of about
four years, had 36 percent fewer uterine cancers and 29 percent
fewer blood clots than the women who were assigned to take
tamoxifen," the National Cancer Institute, which helped
organize the trial, said.
Both drugs come as pills and both mimic the effects of the
hormone estrogen on cells, although in a way that appears to be
safer than estrogen itself. Estrogen is linked to most breast
Both drugs also reduce the risk of osteoporosis. The
bone-thinning disease becomes much more common after women
enter menopause, as do cancer, stroke and heart disease.
STAR was one of the largest breast cancer prevention
clinical trials ever conducted, with 19,747 postmenopausal
women randomly given a daily dose of Evista or Nolvadex for
"Women taking either drug had equivalent numbers of
strokes, heart attacks, and bone fractures," the NCI said.
Among the 9,745 women in the raloxifene group, 167
developed invasive breast cancer, compared to 163 of 9,726
women in the tamoxifen group.