TIME EUROPE
MARCH 20, 2000 VOL. 155 NO. 11
Everything You Need to Know about Colon Cancer and How to Prevent It
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The problem with having just one chemotherapy drug is that it limits your options. The cells that line the intestine are so used to acting as a garbage dump, explains Dr. Dennis Slamon of UCLA, that the ones "that eventually become malignant are less susceptible to chemotherapy."
But there's good news on the chemotherapy front. In 1998 the U.S. Food and Drug Administration approved Camptosar (also called CPT-11) for the treatment of advanced stages of colon cancer, and using Camptosar and 5-fu in combination seems to be most effective. It's a potent cocktail that not all patients can tolerate, but it has, in some small studies, doubled short-term survival rates. In Europe, a drug called Oxaliplatine has also proved effective, both alone and in combination with 5-fu. Oxaliplatine is not yet available in the U.S., but a Food and Drug Administration advisory board is set to discuss approval this week.
Looking to the future, researchers would like to take advantage of some of Mother Nature's own ideas to design new chemotherapy drugs. Scientists at Vion Pharmaceuticals of New Haven, Conn., are interested in co-opting a group of Salmonella bacteria that normally attack the intestines and cause dysentery. Salmonella bacteria, it happens, also happily infect all kinds of tumors, including colon cancer. By loading genetically crippled salmonella with one of the body's own cancer-fighting chemicals (a molecule called tumor necrosis factor), researchers at Vion hope to destroy or at least shrink a wide variety of cancers. Safety studies in humans are planned for later this year.
The best way to beat colon cancer today is to catch it early--and that means regular screening. It would help if there were just one screening test and some simple rules to follow about when to get it done, but that's not the case. So pay attention to the following guidelines. But first, a warning. If you experience any symptoms--especially bleeding from the rectum, unusual constipation, abdominal cramping or a narrowing of the feces--talk to your doctor immediately about taking a peek inside your colon.
All other things being equal, you should start screening by age 50. (Some doctors lean toward 40, but more on that later.)
If you have a family history of the disease, particularly among your siblings or parents, you may need to start in your 30s or 40s. A good rule of thumb is to begin getting tested 10 years before the youngest age at which colon cancer was diagnosed in any member of your family. "Don't wait for an invitation," says Dr. Bernard Levin of M.D. Anderson Cancer Center in Houston, Texas. "Tell your doctor, I want to get screened."
It's a good idea to keep track of other diseases that have affected your family. There's growing evidence that uterine and ovarian cancer may be genetically related to colon cancer. So if your Aunt Mary died of uterine cancer, don't assume you're in the clear if you've had a hysterectomy or if you're a man. You could be at greater risk of colon cancer as well. The same holds true if you suffer from inflammatory conditions of the intestines, like Crohn's disease or ulcerative colitis.
That's the "when" part of the equation. Now for what you should do. There are three different ways to get screened for colon cancer. Which method you choose depends a lot on the level of risk you're willing to live with. If you go for the most basic method, make sure you get both parts: a stool test, which looks for the presence of hidden blood, and a flexible sigmoidoscopy, in which a lighted tube is inserted into the lower third of the colon. The stool test should be repeated annually, since only one out of three tumors bleeds enough to be picked up by the test and then usually only after it has grown in size. The "flexi-sig"--which is performed without sedation and checks the left side of the colon, where two-thirds of the cancers are usually found--should be performed every five years, provided there's no change in symptoms or family history.
If you're not satisfied with checking out only part of your colon, you have two other options. Both require going on a liquid diet for 24 hours before the procedure and involve flushing the colon ahead of time. But they give more of the big picture.
In a double-contrast barium enema, a technician coats the inside of the intestine with the metallic dye and pumps the colon full of air. Then an X ray of the large intestine is taken, allowing doctors to visualize the outline of most abnormal growths. Provided the colon is clear, a barium enema should be repeated every five to 10 years.
The other option is a colonoscopy, the procedure Couric underwent for the Today show. It's both expensive and invasive, but under normal circumstances you have to do it only once a decade. "The preparation is a pain," Couric admits. The colonoscopy itself is conducted under a mild sedative. "I was chatting the whole time," Couric recalls, "bossing my camera crew around." There is a risk, albeit a small one, that the device can slip and punch a hole in the intestinal wall. Yet a colonoscopy offers a distinct advantage in that the doctor can remove any small precancerous polyps as soon as they are found, making it the only screening test that can prevent cancer, not just detect it.
That is why some doctors and quite a few activists are lobbying to make colonoscopy the test of choice. They point to small studies of people with a genetic predisposition to colon cancer that show that snipping out polyps on a regular basis decreases chances of developing the disease. Dr. Sidney Winawer of Memorial Sloan-Kettering Cancer Center in New York City is directing a larger study to see if that holds true for the general population.
"If we had systematic colonoscopy testing, no one would die of these cancers," says Sylviane Olschwang, a geneticist at the Inserm medical research institute in Paris. "But it's an aggressive test and would have to be offered three times in a lifetime. And it's not at all certain we'd get this test accepted in southern European countries. As soon as you're dealing with intestines, people don't want to know." Nevertheless, France has one of the best records in Europe on this front, with 52% of colorectal cancers cured thanks to early testing and over 1 million colonoscopies carried out each year. And the procedure is entirely covered by the country's national health system, so anyone with grounds for concern can see a specialist and have a test.
Executives at pharmaceutical giant Eli Lilly already offer free colonoscopies to all their employees starting at age 40. "The guidelines typically suggest screening at age 50, because that's when the incidence of colon cancer becomes statistically significant," says Dr. Gregory Larkin, director of corporate health services for Lilly. But since it takes precancerous polyps five to eight years to develop, he notes, why wait a decade to start removing them?
Still not ready to sign up for a colon exam? Researchers are trying to perfect the so-called virtual colonoscopy, which doesn't require threading any medical instruments into the colon. Instead, doctors rely on cat-scan imaging to create a computer-generated 3-d picture of the inside of the intestine. It's still not clear, however, how accurate the new technology is. So don't put off getting the tests that are available today in hopes of taking a less invasive one later.
While you're at it, try making a few changes in your lifestyle. Start by eating at least five servings of fruits and vegetables a day (a serving consists of a medium-size banana, apple or orange, half a cup of solid vegetables or a full cup of lettuce). There's evidence that natural compounds found in fruits and vegetables can help protect against colon cancer. Besides, fruits and vegetables lower your blood pressure and help protect your heart.
If that's too difficult, consider adding a multivitamin with 400 mcg of folic acid (one of the B vitamins) to your breakfast routine. Taking folic acid decreases the risk of developing colon cancer 75% over 15 years, according to a study of 90,000 nurses published two years ago. And don't forget to exercise. Joggers in particular seem to have a lower rate of colon cancer, but any physical activity is beneficial.
Whatever you do, don't let embarrassment stand in the way of your health. "There is no tradition of cancer prevention in Europe as there is in the United States," says Dr. Fabio Levi, head of the cancer epidemiology unit at the chuv University Hospital in Lausanne. "Colon cancer screening lags behind the U.S. The reason may be psychological. We are not as open when it comes to talking about intestinal functions. It takes time to change people's thinking."
Brenda Billingsley of Wilmington, Del., has changed her thinking. When she developed abdominal pains two years ago at age 48, she told her doctors about most of her symptoms. But she never talked about the way her stools had changed shape (and she wasn't asked). The pains must be menopause, the doctors decided. Then a year ago, during a flexible sigmoidoscopy, a physician discovered a tumor the size of a golf ball that had begun to spread. Aggressive treatment seems to have left Billingsley cancer-free. Now she's on a mission to persuade family and friends to be screened. "I just goad them until they do it," she says. Katie Couric would be proud.
Reported by Helena Bachmann/Geneva, Mairi Ben Brahim/London, David S. Jackson/Los Angeles, Nicholas Le Quesne/Paris, Alice Park/New York and Dick Thompson/Washington
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March 20, 2000
COVER STORY
Colon Cancer
Everything you need to know about colon cancer and how to prevent it
The Lives It Has Touched
From the White House to the film screen, colon cancer often strikes without warning
Just the Facts
How colon cancer forms, how to spot it, and what you can do to prevent it
Web Resources
Links to web resources on colon cancer
EUROPE
The Shadow of a Spy
NATO denies reports that a mole passed military secrets to the Serbs early in the Kosovo campaign
Red Ken Joins the Race
Former London leader Ken Livingstone defies Tony Blair and launches an independent bid for mayor
It's All the Rave
Ecstasy, once a drug confined to the club scene, is flooding many high schools and universities. Here's why
Don't Shoot the Pianist
The European Central Bank should not be blamed for the euro's weakness
AFRICA
Starting over after the Deluge
In the wake of widespread devastation and loss of life, the people of Mozambique begin, once again, the long task of recovery from national disaster
The Bare Necessities
Robert Mugabe's 20-year reign has left the Zimbabwean economy in ruins
BUSINESS
A German Behemoth
The merger of Deutsche Bank and Dresdner Bank opens a new chapter in Europe's financial history
Is That Really You, Alan?
Unusual comments from the Fed chief have people asking, Will the real Greenspan please stand up?
SCIENCE
Fire from the Sea
The bottom of the Mediterranean is dotted with volcanoes--and one may re-emerge as an island
THE ARTS
The Power and the Glory
A National Gallery exhibition charts the evolution of Christ's image from the Roman catacombs to Dalí's famous 1951 response to Hiroshima. So how will it play to non-believers?
Flights of Fantasy
Obsessed by dreams of flying, Belgian artist Panamarenko creates surreal machines to transport the imagination
DEPARTMENTS
World Watch
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