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Conquering Colon Cancer...with Aspirin?

The death in 1998 of Jay Monahan, NBC "Today" show co-anchor Katie Couric's husband, brought colon cancer to the forefront,


Colon cancer has long been a disease that is ignored by the public, which is more than likely due to its lack of visibility and anatomic location. But the death in 1998 of Jay Monahan, NBC "Today" show co-anchor Katie Couric's husband, brought the disease to the forefront, whether we liked it or not.

We all remember Couric's televised colon-oscopy. Her constant televised reminders on gastrointestinal health have made an impact. People have begun to learn more about the disease, and the number of those screened for colon polyps, extra tissue growing in the large intestine, has risen 20 percent since she started her campaign in 1998.

Despite an increased awareness, close to 41 million people who should be screened for colon cancer neglect to do so each year. In addition, it is estimated that more than 145,000 Americans will be diagnosed with colorectal cancer and close to 57,000 will die from it. These statistics are frustrating when almost 90 percent of colon cancer cases could be cured if they are detected early enough.

Recent research shows that the latest medicinal ally in the battle against colon cancer is already in most people's medicine cabinets. Aspirin, the longtime cure-all, has yet another benefit: reducing the risk of colon cancer.

"Aspirin can decrease the risk of polyp formation, which reduces the risk of colon cancer," explains Dr. Mitchell Posner, professor of surgery and chief of the sections of general surgery and surgical oncology at the University of Chicago, one of many research facilities reporting the benefits of aspirin in colorectal health. "It's along the same vein as the Cox 2 inhibitors; it inhibits a pathway that is important for transforming normal tissue into malignant tissue."

Cox 2 inhibitors like Bextra, Celebrex and Vioxx have been getting a bad rap in the press lately because of negative side effects, including an elevated risk of heart attack and stroke. This makes aspirin a more attractive preventative treatment for those with a history of colon polyps.

"Aspirin works like Cox 2 inhibitors-- it works as an anti-inflammatory," says Dr. Robert E. Carroll, associate professor of medicine at the University of Illinois Medical Center at Chicago's section of digestive diseases and nutrition. "An approved study showed that if you take a Cox 2 inhibitor, it reduces your risk of adenomas recurring but also increases your risk of heart disease as shown in controlled trials. Aspirin has cardiovascular benefits, so it would be the better treatment for now."

The key to the aspirin studies is that they show a reduction in the risk of recurrence of adenomas or polyps; there's no evidence that aspirin can prevent the formation of polyps in people who don't have a history of adenomas.

"There are a whole bunch of studies that epidemiologically made a connection between a reduced risk of colon cancer and aspirin," says Dr. Carroll. "A statistical reduction in adenoma recurrence has been shown, but the thing to note is the study group. Because of the epidemiologic proof, there were three blinded control trials conducted. The studies showed a benefit for aspirin, but the perspective trials were looking at people who had polyps or colon cancer. There have been no studies done on people without a history of polyps, and it would be hard to do and even harder to get a real answer from because it would be difficult to know if people were really taking the aspirin as prescribed over a five-year time period."

Although the aspirin was shown to work in the reduction of polyp recurrence for those who've has a history of adenomas, too much of a good thing might not be good after all.

"The risk of reduction was only shown with baby aspirin (81mg)," reports Dr. Carroll. "There were no real benefits seen in those who took a full dose of aspirin (325mg)."

Another thing to consider is aspirin's history of increasing the risk of gastrointestinal bleeding. We all remember how aspirin lost some of its popularity with the public when internal bleeding became a known side-effect of the nonsteroidal anti-inflammatory drug or NSAID. And in the case of colorectal cancer prevention, this history should not be quickly forgotten.

"I think aspirin is no different than any medication--it has positives and negatives," theorizes Dr. Posner. "What you're trying to do is improve the therapeutic ratio by looking at benefits versus risk. So if you're healthy and taking aspirin, the side effects are not that great and the potential benefits might be real. At a certain age, if you have ulcer disease or other diseases that may cause bleeding, aspirin may not be that good for you. But in general I think it may be beneficial, but you should talk to your doctor about your own risks."

This uncertainty may be frustrating for patients, especially during the current storm of medicine recalls and warnings, but Dr. Carroll agrees that being diligent about knowing your medical history and risks is of utmost importance when it comes to determining what medicine works best for you.

"If you have heart disease you should use aspirin because of its beneficial effects," says Dr. Carroll. "The question is if you're healthy with a low risk of heart disease, should you start using aspirin as a preventative measure? You might not have any obvious risks that would stop you from taking aspirin, but if you do take it, you may have a mild risk of a bleeding episode. But as you age, aspirin may be a benefit because it reduces your risk of heart disease and colon cancer. But in the case of these findings, we need to use aspirin in the high risk group for now."

So what else can help in reducing your risk of colon cancer? "Like everything else in life, you have to find a comfort level and a balance in what you do," advises Dr. Posner. "You should exercise regularly, eat well and be cognizant of the fact that any of these diseases are certainly realities and following guidelines laid out by specialists is reasonable. But don't be overzealous--screening and taking aspirin shouldn't even be done until about 50."

New guidelines by the American College of Gastroenterology recommend that African Americans start screening by way of a colonoscopy or other approved screening method at the age of 45. This new guideline is a result of the group's higher colorectal cancer death rate. The guidelines also suggest the use of a colonoscopy as a "first-line" screening procedure for African Americans. One of the main factors motivating such a specific screening method is, in part, attributed to the fact that African Americans are more likely to have right-sided colorectal cancers and polyps, which cannot be detected by other screening methods like a flexible sigmoidoscopy.

Doctors also recommend screening earlier if you have a family history of gastrointestinal diseases. Although it may be uncomfortable to talk about, colon health is important. Colorectal disease is the second largest cancer killer in the country behind lung cancer. It's not an old man disease; it kills women, men and sometimes even young people. The key is knowing your risks and taking the appropriate precautions. o

What's the Deal with Aspirin Anyway?

Acetylsalicylic acid received a simpler name in 1899 when the Friedrich Bayer & Co. of Germany trademarked the name "Aspirin." The medicine's derivatives, however, had been curing aches and pains for centuries. In the 5th century B.C., Hippocrates wrote about a bitter white powder extracted from willow bark that reduced fevers and eased pain. History shows that American Indians and ancient Sumerians, Egyptians and Assyrians also used the extract as a remedy.

The active extract of the willow bark is known as salicin, and in the 1800s, researchers experimented with different ways of extracting the chemical, which was also found to be in meadowsweet flowers. The drug was extremely potent in its initial stages, causing digestive problems and diarrhea. Researchers struggled to come up with a synthesis of the medicine, something that wouldn't cause the severe side effects. Aspirin, the first synthetic drug, was discovered by a researcher at Bayer, and with it, the pharmaceutical industry was born.

Bayer lost its trademark in many countries after World War I, when the Allies seized and sold its foreign assets. Sterling Drug purchased the right to use "Aspirin" from the U.S. government in 1918, but in 1921, a U.S. federal court ruled the name a generic mark. In other countries, however, such as Canada, the name is still considered a protected trademark.

The dish on whether aspirin is good for you seems to be on an ever-moving pendulum. One minute the drug is being blamed for ulcers and internal bleeding and the next minute it's being touted as a preventative medicine extraordinaire. A perfect example of this is the recent news concerning the medicine's benefit for those with a history of colon polyps. Reports like these leave many people scratching their heads and asking what they should believe.

Aspirin is an NSAID, or a nonsteroidal anti-inflammatory drug. That means that aspirin relieves pain that is caused by swelling, which is why it is prescribed for those with arthritis, headaches, heart disease or those experiencing redness, fever or blood clotting. Aspirin is also used to reduce the risk of a second heart attack or stroke.

Aspirin acts as an inhibitor because it reduces the production of hormone-like prostaglandins, which can cause blood platelets to stick together. If the platelets continue to stick together, it can eventually lead to blocked blood vessels and prevent oxygen-rich blood from getting to various tissues in the body.

This can be seen in the case of aspirin and colorectal cancer. "Aspirin specifically works in the case of recurring polyps because it probably inhibits certain enzymes associated with adenoma growth thereby preventing recurrence," explains Dr. Robert E. Carroll, associate of professor of medicine at the University of Illinois Medical Center at Chicago's section of digestive diseases and nutrition.

The way aspirin works makes sense, but why doesn't it work for everyone? If you take a look at the back of any aspirin bottle, there is some sort of warning about stomach irritation. Therein lies the problem. Aspirin irritates the stomach lining and can sometimes cause nausea, heartburn, vomiting and if used over a long-term period, bleeding. In addition to internal bleeding, there's a risk of ulcers and holes in the stomach and intestines. With risks like these, even a young healthy person would not be prescribed a daily dose of aspirin.

A recent study presented to the American Stroke Association found that patients who stopped taking aspirin tripled their risk of another stroke. Studies like these continue to flood the medical community with regard to the benefits of aspirin. But like everything else, aspirin has its flaws and should not be seen as "the miracle drug". If you're anxious to jump on the aspirin bandwagon, make sure you treat it like any other drug; the pros and cons should be weighed and a doctor should give you the stamp of approval before starting a daily aspirin regime.

Published: August 01, 2005
Issue: Fall 2005