Pubdate: Mon, 15 May 2000
Source: Reuters
Copyright: 2000 Reuters Limited.
Author: Maggie Fox, Health and Science Correspondent

NEW CANCER REPORT REMOVES SACCHARIN, ADDS ALCOHOL

WASHINGTON (Reuters) - The latest U.S. government report on what
causes cancer, issued on Monday, removed saccharin from the list of
suspected carcinogens, but added 14 substances, including second-hand
tobacco smoke and alcohol, as known causes.

It also added sunshine and sunlamps, silica dust and the breast-cancer
drug tamoxifen -- although the report noted that while cancer drugs
may increase the incidence of other cancers, the benefits often
outweigh the risks.

The National Institute for Environmental Health Sciences (NIEHS),
which issued the bi-annual report, said it removed saccharin as a
potential cancer-causing agent because tests that showed it caused
tumors in rats did not apply to humans.

It had been listed since 1981.

``Two decades ago, when saccharin was shown to produce bladder tumors
in rats, it was a prudent, protective step to consider the sweetener
to be a likely human carcinogen,'' NIEHS director Dr. Kenneth Olden
said in a statement.

``Studies now indicate that the rat bladder tumors arise from
mechanisms that are not relevant to the human situation.''

He also said humans had used saccharin for decades without increasing
rates of cancer.

Saccharin, sold since 1900, is the oldest sugar substitute on the
market. But the Food and Drug Administration (FDA) tried to ban it in
1977 when it was found to cause cancer in rats.

The U.S. public, faced with the loss of diet sodas, rebelled and
Congress blocked the action. Products containing saccharin now carry a
warning label instead.

When aspartame became available in 1981, it quickly dominated the
artificial sweetener market, in part because of superior flavor and in
part because of the cancer worries.

The NIEHS also removed ethyl acrylate, a substance used in making
latex paints and textiles, from the list. Both were removed at the
request of industry groups.

The report listed 218 substances known or suspected to cause cancer in
people. The NIEHS said 14 had either been upgraded to the ``known''
category or added to the list.

Second-hand smoke topped the upgraded list.

The report, published on the Internet at 
http://ehis.niehs.nih.gov/roc/toc9.html,
cited reports that showed second-hand smoke can cause lung cancer, as
well as studies showing that nonsmoking wives and co-workers of
smokers have higher rates of lung cancer.

Tobacco smoke was also listed as a known cause. ``Separate chemicals
identified in tobacco smoke were already listed as carcinogens in the
report,'' it said. The new listing came after 1996 revisions in the
review process.

Smokeless tobacco, including chewing tobacco and snuff, were listed,
as well as consumption of alcohol, too much sun and the use of tanning
beds or sun lamps.

Alcohol has long been associated with cancers of the mouth, pharynx,
larynx, and esophagus, and there may be a link with liver and breast
cancer. Chewing tobacco and snuff can cause cancer wherever they
contact the mouth or nose.

Other substances listed included:

- -- Crystalline silica dust small enough to breathe, a byproduct of
mining

- -- Strong inorganic acid mists containing sulfuric acid, produced in
the manufacture of alcohol, lead batteries, phosphate fertilizers,
soap and detergents, synthetic ethanol, and in pickling and other acid
treatments of metals

- -- Dyes metabolized to benzidine

- -- 1,3-Butadiene, used to make synthetic rubber

- -- Cadmium, used in batteries, coating and plating, plastic and
synthetic products and alloy

- -- Ethylene oxide, used to make other chemicals and to sterilize
medical devices

- -- Tamoxifen

``There has been concern expressed that the listing of tamoxifen ...
could raise concerns among patients regarding its use for cancer
treatment or prevention,'' the report said. It pointed out that
benefits can outweigh the risks.

Tamoxifen, made under the name Nolvadex by AstraZeneca, can increase
the risk of endometrial, or uterine, cancer. But endometrial cancer is
so rare that doctors say the higher risk is small.

Tamoxifen is the first drug to be shown to prevent breast cancer in
some women at high risk.

Substances added to the ``reasonably anticipated to be human
carcinogens'' list include diesel exhaust particulates, isoprene --
one of the components of rubber which is also naturally emitted by
plants -- chloroprene, phenolphthalein -- used in some laxatives --
tetrafluoroethylene and trichloroethylene.
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MAP posted-by: Allan Wilkinson