This is what was in the WSJ Interactive Edition:
The Wall Street Journal Interactive Edition -- April 7, 1998
Drug Found to Prevent Breast Cancer
Holds Serious Side Effects, Study Says
Associated Press
WASHINGTON -- A drug found to prevent breast cancer in half of
high-risk women also causes serious side effects, researchers cautioned
Monday, leaving women with a complex decision about the best course to
protect their health.
Federal officials said the breast cancer benefits from the drug are so clear
that they cut short a long-term clinical trial and notified the 13,388 women
participants of the findings. The 6,707 women in the study who had been
taking a placebo, or dummy drug, will be told they could now start taking
tamoxifen, officials said.
As a side benefit, the study also showed that tamoxifen lowered the risk
in older women of fractures of the back, neck or wrist due to brittle bones,
or osteoporosis.
In the study, the group of women taking the drug experienced 45% fewer
cases of invasive breast cancer compared to those taking placebo. There
were 85 invasive breast cancers among the tamoxifen group, vs. 154 in
the placebo group.
Women on tamoxifen also had fewer noninvasive breast cancers: 31
cases vs. 59 cases. Invasive cancer is that which spreads to adjacent
tissue or organs, while noninvasive cancer is confined. There were 47
bone fractures among those on the drug, compared with 71 among those
on placebo.
But the side effects of the drug were significant and serious. Among the
group on the drug, there were 33 cases of cancer of the uterine lining, vs.
14 cases in the placebo group. The drug group had 17 cases of blood
clots in the lung, including two deaths. This compares with six cases and
no deaths among the placebo group.
"The results tell us that breast cancer can be prevented, but there is no
simple take-home message," Dr. Richard Klausner, head of the National
Cancer Institute, said at a news conference Monday. "There are important
and serious side effects from this drug."
Because the issue is so complex, Mr. Klausner said the cancer institute is
developing guidelines to help women and their doctors decide when to use
the drug, tamoxifen.
In the drug group, there were 30 cases of blood clots in major veins,
compared with 19 cases in the placebo group. In some women,
tamoxifen also causes hot flashes and vaginal discharge, officials said.
Tamoxifen should be used only by women at high risk, Mr. Klausner
said. It doubles the risk of getting endometrial cancer, although that risk is
about equal to that of women on estrogen replacement therapy.
Tamoxifen also causes a tripling of risk for a blood clot in the lungs, a
potentially fatal disorder.
Nevertheless, tests of the drug, first reported over the weekend, mark "the
first time in history that we have evidence that breast cancer can not only
be treated, but also prevented," said Dr. Bernard Fisher, an Allegheny
University professor and scientific director of the study that involved more
than 13,000 women.
Tamoxifen has been used for 25 years to treat breast cancer, but the
study is the first to show the drug can prevent the disease in some women.
The drug is known as an "anti-estrogen" because it blocks the effects of
the hormone in some tissues and retards growth of cancer cells that
depend upon estrogen.
Mr. Klausner said it also is unclear just how long women should take the
drug. The study lasted only six years, and some women took the drug for
less, he said. Final effects of tamoxifen may still be years away, he said.
"This is the first imperfect, but very encouraging step," he said, toward
drugs that could protect people from lung, rectal, bowel or prostate
cancer. About 85 other drugs are being tested for this preventive effect.
Tamoxifen, made by Wilmington, Del.-based Zeneca Pharmaceuticals, is
widely used to prevent the spread or return of breast cancer. U.S. shares
of Zeneca Group, the British parent of Zeneca Pharmaceuticals, rose
7.1% Monday to close at $147 a share on the New York Stock
Exchange, a gain of $9.75. |
