Expansionary Institute

Forum Admin
futurist3000@aol.com

  Amy Dockser Marcus


Beyond Diet and Exercise


 Growing numbers of drugs are being tested to see if they can help prevent
cancer but all of them have side effects.



 Colon cancer, Lung cancer
 Drug: Celebrex (celecoxib)
 Side Effects: Diarrhea, indigestion



 Breast cancer
 Drug: Evista (raloxifene)
 Side Effects: Hot flashes, increased risk of blood clots in the veins



 Prostate cancer
 Drug: Proscar (finasteride)
 Side Effects: Loss of sexual potency, increased risk of high-grade cancer
   AT THE AGE OF 61, Nancy Ullman has never had a major health problem.
But for the past three years, she has been taking the drug Celebrex in
hope that it will lower her risk of getting colon cancer.

"I feel healthy now, but I want to find a way to prevent getting cancer,"
says Ms. Ullman, a travel consultant in Manhattan. "Wouldn't it be great
if a simple drug could do it?"

A quiet but important shift is taking place in the way physicians, and
their patients, think about cancer. For the past 30 years, the focus has
been on cure, with the pharmaceutical industry and federal government pouring
billions of dollars into the quest to develop drugs to combat tumors. While
that effort continues of course, an increasing number of doctors and medical
researchers are now searching for drugs that will prevent or delay the
onset of cancer in the first place.

"You don't wake up one day out of the blue with cancer -- there is an underlying
disease process," says Andrew Dannenberg, co-director of cancer prevention
at New York-Presbyterian Hospital in Manhattan. "We need to focus more
on stopping that process before it becomes cancer."

Two key developments are making it easier to determine who should try preventive
cancer drugs: growing scientific evidence of a genetic link to cancer and
a deepening awareness that many cancers start out years earlier as premalignant
lesions.

In all, more than 50 clinical trials are under way testing compounds and
drugs to prevent cancer. Most are still recruiting patients. Some doctors
aren't waiting for definitive research results and are already prescribing
these drugs for high-risk patients. Just yesterday, the Food and Drug Administration
approved a drug called Photofrin for use in killing abnormal and possibly
precancerous cells in patients with Barrett's esophagus, an ailment related
to acid reflux.

Ms. Ullman is part of a trial studying Pfizer Inc.'s Celebrex, a nonsteroidal,
anti-inflammatory drug used to treat arthritis. It has already been shown
to reduce precancerous polyps in patients with a rare genetic syndrome
that causes colorectal cancer. Now studies are evaluating whether it will
also help protect against the formation of these polyps in average individuals.
Oncologists are also studying Celebrex to see if it can help repair lung
damage from cigarette smoking.

Other drugs that have sparked interest among researchers include raloxifene,
an osteoporosis drug marketed by Eli Lilly & Co. under the brand name Evista,
for breast-cancer prevention, and finasteride -- sold as Proscar -- for
prostate-cancer prevention. Merck & Co., which makes Proscar, said it plans
to ask the FDA to approve the drug for use in cancer prevention.

The concept behind chemoprevention -- using drugs and compounds to delay,
reverse or prevent disease -- is best known in the field of preventing
heart disease. "We accept the idea of taking medicine to control our cholesterol
and lower our blood pressure to help prevent getting a heart attack," says
Waun Ki Hong, head of the division of cancer medicine at the University
of Texas M.D. Anderson Cancer Center in Houston. "We can control the process
of cancer development with drugs too."

Previous efforts, involving vitamins and aspirin, provide some reason for
optimism about the potential for drugs to stave off cancer. Earlier this
year, a study demonstrated that low doses of aspirin can prevent precancerous
polyps in people with a familial history of colorectal cancer. A huge study
is under way trying to determine whether selenium and vitamin E prevent
prostate cancer.

But prescribing drugs to prevent cancer is controversial. That is partly
because it is harder to pinpoint who would most clearly benefit from them
-- and consequently more difficult to weigh the potential risks of taking
the medicine for years on end. "There is currently no marker for cancer
risk equivalent to high cholesterol," says New York- Presbyterian's Dr.
Dannenberg.

Chemoprevention requires generally healthy people to take drugs or compounds
to prevent something that might, or might not, happen in the distant future.
Consequently, oncologists say it's usually worth discussing only for people
with a family history of cancer or with other high-risk factors.

"The risk-benefit analysis is different for preventing cancer than for
treating cancer," says Peter Scardino, chairman of the department of urology
at Memorial Sloan-Kettering Cancer Center in New York.

Like all drugs, the medicines being studied for cancer prevention have
potential side effects, some of them serious. Raloxifene has caused hot
flashes and leg cramps and, in some rare cases, blood clots in the veins.
Celebrex can cause diarrhea. Even aspirin has caused bleeding and an increased
risk of stroke in some people.

Dr. Scardino points to the recent finasteride trial for preventing prostate
cancer to illustrate some of the issues that remain at stake for the field
of cancer prevention in general. While the drug did clearly reduce the
risk of getting prostate cancer, those taking it reported decreases in
sexual potency and libido. More worrisome: There appeared to be an increased
risk of high-grade prostate cancer in those men who took the drug and did
get cancer. Doctors who worked on the trial say more research is needed
to explain why this may have happened.

Dr. Scardino questions whether it makes sense to put patients on drugs
that might prevent "cancers unlikely to pose a threat to their lives if
by taking the drug they are going to increase their risk of getting an
aggressive cancer that really will pose a risk to their lives?" Answering
that question still depends highly on an individual's particular risks
and priorities, something to be determined in consultation with a doctor.

The risk of side effects is one reason that cancer-prevention efforts have
traditionally focused on dietary and lifestyle changes rather than drugs.
People are urged to quit smoking. They are encouraged to exercise, eat
a diet rich in fruits and vegetables, and, after a certain age, to get
regular screening exams such as mammograms or colonoscopies. But for some
people -- particularly those who are genetically predisposed to get cancer
-- this may not be enough to stop tumors.

Still, some previous efforts at chemoprevention serve as cautionary tales.
Several years back beta-carotene seemed to show promise in reducing the
risk of lung cancer. But trials of men who were heavy smokers showed it
not only didn't prevent lung cancer, the people taking beta-carotene actually
got cancer at a higher rate than those on the placebo.

In a landmark study published last year, a task force of the American Association
for Cancer Research concluded that many cancers start out as premalignant
lesions that over time develop into cancer. Many oncologists have argued
that by treating these lesions with drugs, the process by which they eventually
become cancer can be stopped or delayed.

Finding these lesions is not as easy as measuring high cholesterol or high
blood pressure, though. Some, such as skin lesions, can be fairly easily
detected. Dentists spot such lesions in a patient's mouth during routine
checkups. Others will turn up during regular screenings, like a colonoscopy.
But an invasive biopsy is often required to detect a precancerous lesion.
Sending every man for a prostate biopsy or every smoker for a lung biopsy
is not as practical as measuring someone's blood pressure or doing a blood
test during a routine annual physical.

But the recognition that there is now a way to flag who might be at higher
risk to someday get cancer marks an important step in finding ways to prevent
the disease and in setting up trials to test various compounds. Many oncologists
say that precancer will increasingly be a focus of treatment efforts, particularly
as the population ages and starts doing regular screening exams that can
turn up precancerous lesions and as imaging technology gets more sensitive
and can detect such lesions more easily.

Several years ago, Phillip Comens, now 80, learned he had precancerous
lesions on his vocal chords. His doctor at M.D. Anderson put him on high
doses of a vitamin A derivative that caused his body to swell and his skin
to peel off in layers. "I peeled everywhere from head to toe," says Dr.
Comens, who still practices medicine in St. Louis. "It was very unpleasant."
But Dr. Comens says the lesions went away and haven't returned, and that
he was willing to suffer the side effects for a chance to reverse a process
that ultimately could have cost him his voice or his life.