Colon cancer - ways to avoid colon cancer

By Michele Meyer, July, 1999

YOU DON'T WANT TO READ THIS STORY. BUT IF YOU DO, IT COULD SAVE YOUR LIFE.

Nobody wants to talk about rectal exams. Dr. Clifford Simmang knows that. He is the director of colon and rectal surgery at the University of Texas-Southwestern Medical Center in Dallas.

"The colon and rectum are considered a dirty part of the body," he says. "It's embarrassing for patients, and physicians can be reluctant to put patients through something they don't want done."

Colorectal cancer is America's number two cancer killer. It's the third most commonly diagnosed cancer among men and women in the U.S.

Yet more than nine of 10 deaths associated with cancer of the colon--the muscular tube that connects the small intestine to the rectum--could be avoided. The key is early detection and removal of premalignant polyp growths called adenomas that usually take a decade to become cancer, according to a Memorial Sloan-Kettering Cancer Center study in the New England Journal of Medicine. The secret is simple diagnostic tests.

"The sad thing is that colon cancer is a disease that's almost totally curable if caught early," says Dr. Gabriel Feldman, director of Colon Cancer Control at the American Cancer Society in Atlanta. "Yet only 40 percent of colon cancers are caught early."

If cancer is spotted before spreading, 92 percent of patients survive for five years or more. Once the disease has spread to the liver, the survival rate plummets to less than 3 percent.

Uneasiness led Billie Bond, 65, of Houston, to delay having an exam, even though she saw blood in the toilet, a warning sign of cancer. "I never thought I'd have cancer. No one in my family and no one I knew ever had colon cancer," she says. She ended up having surgery, radiation, and chemotherapy--and urging everyone she meets to be screened for colon cancer and avoid the same misery.

Who's at risk? Anybody can get colon cancer. Dr. Feldman says he knows of patients as young as 7 and as old as 97. But those most likely to get the disease are those age 50 and older. Dr. Carol A. Burke, a colon cancer specialist at the Cleveland Clinic Foundation, explains it this way: "As we age, our cells don't repair themselves as well as they used to, and genetic changes within the colon tissue predispose cells to grow out of normal control."

Anyone with a parent, sibling, or child with colon cancer or polyps has double-to-quadruple the risk, according to studies by Columbia University and Memorial Sloan-Kettering. A family history of breast, ovarian, uterine, stomach, or liver cancer also may increase your likelihood, but exactly how much is not yet known. And a personal history of polyps can triple your risk.

Your risk of getting this cancer also increases by 30 percent if you've had chronic inflammatory conditions, such as ulcerative colitis or Crohn's disease, for eight years or longer. These diseases lead to abnormal cells on the colon's lining, which, in turn, can lead to cancer.

How to protect yourself. Luckily, you can fight colon cancer through diet, exercise, and supplements. As many as three-fourths of cases are preventable by diet, estimates the American Institute of Cancer Research.

The research center and the American Cancer Society urge a diet of less than 20 percent fat, with five to eight servings of fruit and vegetables and 25 grams or more of fiber a day. In other words, half the fat and double the fruits, vegetables, and fiber of a typical American diet.

A low-fat, high-fiber diet speeds up transit time in the colon, giving carcinogens less time, in theory, to settle. Nonetheless, the long-held belief that fiber is strongly linked to colon cancer was recently challenged by a study at Harvard University and Brigham and Women's Hospital in Boston. Researchers tracked the eating habits of nearly 89,000 nurses over 16 years and found no drop in colon cancer among those who ate more fiber.

So what should you do? Until the more conclusive double-blind, placebo-controlled National Polyps Trial is completed in a few years, the best advice is to eat plenty of fiber. It's been proven to lower cholesterol and risk of heart disease and diabetes.

Cruciferous vegetables, such as broccoli, cauliflower, and brussels sprouts, also may counter colorectal cancer through their antioxidant ingredients known as sulforaphanes, says Bernard Levin, author of Colorectal Cancer: A Thorough and Compassionate Resource for Patients and Their Families, and vice president for cancer prevention at the University of Texas M.D. Anderson Cancer Center. These sulfur-containing antioxidants help stimulate the body's production of enzymes that rid the body of cancer-causing chemicals.

Reducing red meat consumption by one serving a day is believed to cut colorectal cancer risk by half. The theory is that fat may pass into the colon undigested, causing the bacteria that breaks it down to produce extra cancercausing compounds. These, in turn, may damage the colon lining.

Unlike fiber, exercise was proven a lifesaver by the Harvard nurses study. Just 30 minutes a day of walking cut colon cancer risk by 10 percent. The walking sped up the stool's journey through the colon. "You don't have to become a marathon runner to see the benefits," says Dr. Graham Colditz, professor of medicine at Harvard Medical School in Boston.

Popping a few supplements also may yield fast and firm results. In the same nurses' health study, women who took more than 400 micrograms of folic acid a day for 15 years saw their colon cancer risk drop by up to 75 percent.

Also, nurses who took four to six baby aspirin a week for 10 years witnessed a 30 percent drop in their risk of colon cancer. In another observational study of 1 million people, heavy aspirin users who took more than 16 tablets a week saw a 60 percent drop in colon cancer. But don't start an aspirin regime without first checking with your doctor. "Aspirin has its own risk of stomach ulcers," says Dr. Burke.

Calcium, a known osteoporosis fighter, cut the risk of recurrence of precancerous colon growths by 19 percent and the number of growths by 24 percent in a study of 832 men and women. They took 1,200 milligrams of calcium carbonate a day for three years. The study, conducted at Dartmouth University, was published last January in the New England Journal of Medicine.

Not as striking, but still noteworthy, was an Arizona Cancer Center 10-year study that showed taking 200 micrograms of selenium a day led to half as many colon cancer diagnoses in 1,312 patients.

Danger signs. Unfortunately, by the time colon cancer makes its presence clear, the chances of a cure drop to less than 60 percent, says Dr. Robert C. Kurtz, chief of gastroenterology and nutrition at Memorial SloanKettering. These late-appearing symptoms include rectal bleeding, anemia, abdominal cramps, and changes in your bowel habits, including constipation, diarrhea, and pencil-thin or black stools.

"Don't automatically attribute blood in your toilet bowl to hemorrhoids," Dr. Feldman says. "Assume it's cancer and then make sure it's not. And any constipation, diarrhea, or bloating that lasts more than a couple of weeks is worth a trip to the doctor."

Screening. The best--and fastest--way to spot colorectal cancer is through screening. "Otherwise, it's almost luck to pick it up early," says Jack Mandel, Ph.D., public health chairperson and professor at the University of Minnesota in Minneapolis.

Those with a family history of polyps or colorectal cancer should start screening 10 years prior to the age at which the youngest member of the family was diagnosed. People with inflammatory bowel diseases should start eight years after they were diagnosed with the disease.

Shelly Mendelson, 39, a kindergarten teacher and mother of two in Dallas, learned the hard way that screening counts. Two years ago when she saw a lot of blood in the toilet, she knew it wasn't normal, but she put off an exam. "I've always been the type of person afraid to go to the doctor."

By the time she finally was checked, doctors found a cancerous tumor the size of a golf ball in her colon. Chemotherapy, radiation, and surgery followed. "My attitude changed because, if they hadn't caught this, I could have been in deeper trouble. If you think something's wrong, don't put off going to the doctor. Take every test recommended for your age."

The screening for colorectal cancer, which should start at age 50, includes:

* Fecal-occult-blood, or hemoccult, test. This test, which you can buy at your local pharmacy, requires the patient to apply samples of three separate stools from three days onto cards. These are sent to a lab to be checked for any chemical trace of blood, a cancer warning sign.

If people over age 50 took this $10 test every year, as urged by the American Cancer Society, the death rate for colorectal cancer would be cut by a third, reports a University of Minnesota study of 50,000 people.

Though the fecal-occult-blood test is quite accurate in revealing blood in the stool, it's not perfect. Half of patients with colorectal cancer won't have blood in their stool. "And just because you have blood in your stool doesn't mean you have cancer," says Dr. Simmang. "You probably don't. The most common cause of bleeding is internal hemorrhoids."

For greater accuracy, refrain from the following for three days before the test: vitamin C tablets, citrus fruits and juices high in vitamin C, red meat, raw broccoli, cauliflower, horseradish, parsnips, radishes, turnips, melons, cherry tomatoes, beets, and sardines. All contain peroxidase, an enzyme that can make the test appear positive falsely. Aspirin and nonsteroidal anti-inflammatories should also be avoided for a week prior to the test since they may irritate the intestines and lead to a small amount of bleeding, says Dr. David E. Beck, chairman of colon and rectal surgery at the Ochsner Clinic in New Orleans.

* Digital rectal exam. In this test, a doctor manually checks the lowest four to five inches of the rectum, which is 95 percent likely to reveal cancer if it is there. The test should be conducted annually.

* Flexible sigmoidoscopy. A doctor inserts a lighted scope up the lower third to half of your colon (less than three feet) to look for growths, cancer, or inflammation. After an enema to clear the bowel, the test takes five to 10 minutes in the doctor's office and should be performed every five years. This exam, which costs less than $250, is covered by most health insurance and is about 90 percent accurate. The risk of complications, such as perforation of the colon, occur in only one of every 5,000 or more procedures.

"The failure of the exam is that up to half of colon polyps are above the reach of the sigmoidoscopy," Dr. Burke says. "If what we see is normal, it's not a reassurance that the rest of the colon is normal. It's like a mammogram of only one breast."

She recommends colonoscopy, in which a lighted scope explores the entire 6-foot colon. This test requires more thorough bowel cleansing and sedation. It will require you to take time off work. The exam takes 20 minutes, with a 30-minute wait afterward for drugs to wear off. Colonoscopy costs up to $2,000 since it often is performed on a hospital outpatient basis and rarely is covered by insurance, unless it has been ordered by a doctor as a follow up of polyps or abnormalities that were found on other screening exams. The advantage of colonoscopy is that polyps can be removed during the exam for analysis--which may be all that is needed to stop the cancer. The test is very accurate and needs to be repeated only once every 10 years.

"It's no big deal," recalls Rayna Eyster, 49, a high school teacher and mother of two from Bellville, Ohio, who first had the test a few years ago. "In fact, it's somewhat entertaining. You can watch the procedure on a video screen."

Double-contrast barium enema, often done along with a flexible sigmoidoscopy, fills the colon with air and barium, a chalky solution, so the colon's lining can be viewed on an X ray. Performed after the colon is cleaned, this test has an 85 percent accuracy rate, costs $350 or less, and should be performed every five to 10 years. "Its drawback," says Dr. Burke, "is that the bottom foot of the colon and rectum may not show up dearly on this test."

The bottom line, says Dr. Burke, is that all patients who have ANY symptoms, or who have risk factors for colon cancer and polyps, need to have a colonoscopy.

COPYRIGHT 1999 Meredith Corporation