- The rate of testicular cancer, often
called the "young man's disease" because most get it before their
40th birthday, has risen by 60% in the past 35 years in Ontario.
- The statistics are similar across the
country. And not only are its victims getting younger, evidence suggests
the rise in testicular cancer is linked to a worldwide phenomenon of shrinking
testes, genital deformities, and low sperm counts. Some scientists believe
the culprit could be exposure to such organic chemicals as DDT and PCBs,
which disrupt the body's endocrine system.
- "This rise has been reported throughout
the Western world, so it doesn't seem like that much of an inference to
conclude that something strange is going on," said Dr. Laurence Klotz,
a professor of surgery at the University of Toronto.
- Cancer was far from Eric Desjardins'
mind three years ago as the 19-year-old rode his mountain bike to class.
Suddenly, a sharp groin pain sent him lurching toward the curb.
- The Kitchener-born college freshman feared
a sexual disease. So when his doctor told him the tender lump in his testes
was caused by cancer, he was stunned.
- "Cancer?" he shouted.
- "But I'm not even 20! I don't even
have a driver's licence! I'm too young to have cancer!"
- Mr. Desjardins' doctor told him the disease
was serious, but his chances were good.
- A study published today in the Canadian
Medical Association Journal says although testicular cancer is rising at
about 2% a year in Ontario, there have been great advancements in treatment.
What is more mysterious is its causes.
- Dr. Klotz, a leading Canadian authority
on testicular cancer, said it usually begins in the foetus, when male sex
organs are being formed.
- "The testicle is extremely sensitive
to hormonal influences in utero. And if those hormonal influences are deranged
even mildly, you get what's called dysgenesis, meaning you get malformation
of the cells," he said.
- When a boy hits puberty and his testicular
cells undergo rapid growth, these malformed cells can cause cancer.
- One reason the average age of victims
is getting younger is because boys -- like girls -- now reach puberty earlier.
In 1965, there were 69 cases of testicular cancer reported in Ontario males
aged 15 to 29. In 1995, there were 215, although the study suggests an
unexplained dropoff in the risk to young boys in the past five or six years.
- Testicular cancer is still rare in spite
of the steady increase. It strikes about six in 100,000 males in Canada
each year and is not usually fatal. About 65% of those with metastatic
disease -- meaning the cancer has spread through the body -- survive; about
97% of those whose cancer is isolated to the testes are cured. Overall,
the survival rate is 85%.
- Treatment is not a trivial matter, however.
It means surgical removal of a testicle, radiation, and often chemotherapy.
Some patients become sterile, like Mr. Desjardins, who wonders if living
in Canada's industrial heartland exposed him to chemical dangers.
- "If I want to have kids, obviously
I'll have to adopt," said Mr. Desjardins, whose cancer had metastasized.
- Scientists have been concerned about
the effects of so-called endocrine disruptors since the early 1980s, when
Scandinavian researchers began noticing changes in male sex characteristics.
For example, a Finnish study found an 11% reduction in the weight of testicles
between 1981 and 1991, combined with a 27% to 57% drop in incidence of
sperm production. A French group reported similar results.
- In 1996, Danish researchers reported
that fathers of 2,000 children with testicular cancer had double the average
rate of testicular cancer, and that brothers of 702 of these victims had
rates 12 times higher than expected.
- However, while animal studies have shown
environmental toxins can cause mutations in sex organs, data on humans
is contradictory and scarce. "I think most people feel there is a
link there but it hasn't been nailed down," said Dr. Klotz.
- Some researchers, for example, have suggested
the sedentary Western lifestyle is causing the problem.
- The increase may also have to do with
trends in Western society. For example, women who get pregnant at an older
age tend to produce less estrogen, a hormone that influences foetal development.
- "It may be that we're talking about
a sociodemographic shift more than an environmental cause," said Loraine
Marrett, a Cancer Care Ontario researcher.
- For that reason, most scientists say
the public should not panic.
- "The environmentalists are going
to jump on this," predicted Dr. Klotz.
- "We should not, however, conclude
that we are poisoning ourselves and poisoning our foetus' gonads by these
chemicals. We really aren't there yet."