[paracelsus] Most Cancer Is Made, Not Born (fwd)

[Guest guest]

I thought that since this basically covers the environment etc., it would

be of interest.

Most Cancer Is Made, Not Born Yet little is spent to control avoidable

exposure to cancer-causing chemicals

Devra Lee

Thursday, August 10,

2000

The San Francisco Chronicle.

LIKE A RIFLE SHOT in the middle of the night, a new study from

Scandinavia provides shocking evidence of what growing numbers of cancer

doctors have long suspected. Most cancer is made, not born. In the

largest study ever conducted among twins, published in the New England

Journal of Medicine last month, researchers found that for all cancers

combined, identical twins -- sharing 100 percent of their genes --

developed the same disease about 10 percent of the time. For breast,

colon and prostate cancer, both twins had the disease between 14-30

percent of the time.

For most people, cancer comes not from preprogrammed genes, but from

conditions and exposures that are encountered throughout their lives.

When it comes to hormonal cancers, a series of studies shows the

critical role of the early environment. One study, from the London

School of Hygiene and Tropical Medicine in 1998, found that fraternal

twins -- sharing only 50 percent of their genes -- developed even more

hormonal cancers than did identical twins. Other new studies find that

girls who are heavier at birth also have a greater risk of developing

breast cancer.

Fraternal twins and higher birth-weight babies are known to experience

higher in utero hormone levels, which can fuel later abnormal cell

growth.

The ability of a number of persistent organic chemicals to stoke this

same growth is a matter of grave concern, according to several recent

national assessments in the United States and Europe.

Researchers in the Scandinavian study assumed that any common cancer in

twins was solely due to shared genetic defects. Cancer certainly runs

in families, but not just because of shared genes. A study in 1988

found that adopted children whose adoptive parents died of cancer had

five times the chance of getting the same disease, reflecting some

common life settings independent of inherited genes.

Smoking is the single-most important avoidable cause of cancer and is

directly responsible for 30 percent of all cases. What do this

Scandinavian study and other new reports tell us about the causes of the

other 70 percent?

In the United States, deaths from all cancers are declining, driven by

sharp reductions in smoking.

However, new cases of cancer not known to be linked to cigarettes are

growing -- among Generation X in the United States, young men are

developing four times more cancer and young women are developing

50 percent more cancer than did their grandparents.

National Cancer Institute researchers have shown that rates of

non-Hodgkin's lymphoma, kidney, brain, thyroid, bone marrow, liver and

testes cancer have more than doubled in the general population since the

last half of the past century. Why? These changes surely have nothing

to do with sudden shifts in inherited genetic defects.

Studies of farmers provide some clues. Although they are generally

healthier than the rest of us, farmers develop some types of cancer more

often. These same tumors that are common among farmers are becoming

increasingly common all over the world, according to reports from

several different national cancer institutes. Besides being one of the

most dangerous professions, farming includes regular contact with diesel

and other engine exhausts, pesticides, solvents and paints, animal

viruses and sunlight. Could growing general population exposures to

these same materials lie behind the rising incidence of these diseases

globally?

As to diet, evidence is compelling that animal fat plays a role in colon

and prostate cancer, but mixed for breast cancer. Fat, especially

animal or dairy fat, has been called the body's own hazardous-waste

site, as it tends to attract many toxic products. As to breast cancer,

contaminants in fat could be playing an important role.

Several studies from Canada and Denmark have found that women with the

disease have much more elevated levels of some toxic residues in their

bodies in the years before diagnosis than those without the disease.

Those with the highest exposures also have the poorest prognoses.

Dr.Tony Zheng and colleagues at Yale University recently reported that

women who ate the greatest amounts of well-

cooked red meat during the three years before diagnosis had three to

four times more breast cancer than those who consumed much less meat.

In addition to heterocyclic amines, known to damage genes, could this

meat also contain toxic compounds such as fat- seeking organochlorines,

or plastic contaminants migrating from food-packaging that can cause

abnormal cell growth? One clue comes from a Columbia University study,

which last month reported much higher levels of cancer-causing compounds

(called polycylic aromatic hydrocarbons)

directly bound up in the DNA of those with breast cancer.

Many of the proven causes of cancer today are hard to control, including

viruses, sunlight, medical procedures and drugs, and the addictive bad

habits of cigarette smoking, overeating, drinking alcohol and inherited

genetic defects. What we eat, where we live, how we work and play, what

we breathe, our good and bad habits --

all these affect the chances we will develop any disease. The

International Agency for Research on Cancer of the World Health

Organization (WHO) has identified more than 100 compounds, which are

regularly used today by painters, welders, electrician, plumbers and

others, that increase the risk of cancer.

Even for one of the best-studied causes of cancer that we know of,

radiation, genetics and gender make big differences in the chance the

disease will occur. A new study published in the government's journal,

Environmental Health Perspectives, and reported in the Washington Post

on July 18, found that early childhood X-rays increased the risk of bone

cancer about 1.6 times in all children. But, the risk that early X-rays

would cause bone cancer was six times higher in girls with a certain

genetic mutations, and much less in boys.

Some $33 billion and three decades into the War on Cancer, the costs of

treatment and worker lost-time each year run at more than $100 billion.

The United States spends about five times more per patient on

chemotherapy than the United Kingdom, but survival for most common

cancers does not differ.

Investments in controlling and studying avoidable environmental

contributions to cancer remain scandalously low. The budget for the

Occupational Safety and Health Administration -- the agency charged with

protecting workers --

remains stalled, despite an expanded mandate and growing evidence of

worker hazards, many of which are shared in the general population.

Fueled by a sophisticated disinformation campaign of the tobacco

industry -- just confirmed by the WHO -- we wasted 50 years debating the

importance of cigarettes. We cannot afford to make the same mistake

again.

Devra Lee is a visiting professor at the Heinz School, Carnegie

Mellon University, an adviser to the United Nations and World Bank, and

a former presidential appointee of the Clinton administration.

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