http://www.cancer.org/cancer/news/low-dose-aspirin-lowers-colon-cancer-risk
http://blog.doctoroz.com/is-this-right-for-you/aspirin-is-this-right-for-you
http://consumer.healthday.com/general-health-information-16/aspirin-news-46/aspirin-s-ability-to-prevent-colon-cancer-may-depend-on-your-genes-687112.html
 

Low-Dose Aspirin May Lower Colon Cancer Risk

Article date: October 22, 2010

By Eleni Berger

Daily use of low-dose aspirin can lower the risk of developing colon cancer and the risk of dying from it, according to a new long-term study.

That's potentially good news for people who already take aspirin to reduce their risk of heart attack or stroke. But it doesn't mean otherwise healthy people should start popping baby aspirin just to try to prevent colon cancer, according to American Cancer Society experts.

Significant reduction in incidence and mortality

The new study looked at the combined results of 4 clinical trials that randomly assigned more than 14,000 people to take daily aspirin or a placebo for periods of about 3 to 7 years, depending on the trial. The original studies were meant to find out if aspirin could prevent cardiovascular events like stroke or blood clots, but included enough data to allow the researchers to investigate colon cancer cases and deaths, too.

After 20 years of follow-up, colon cancer cases were reduced by 24% and colon cancer deaths by 35% in the group assigned to take aspirin compared to the placebo group.

Daily low doses (75mg - 300 mg) of aspirin were just as effective as higher doses. Taking aspirin for 5 years or longer reduced risk more than taking aspirin for less time.

The research team was led by Peter M. Rothwell, FMedSci, of the University of Oxford in England. The results were published this week in The Lancet.

Aspirin as cancer prevention not currently recommended

Previous research has shown that daily high doses of aspirin can reduce the risk of colon cancer, notes Eric Jacobs, PhD, strategic director of epidemiology at the American Cancer Society.

"The new study now fills an information gap by demonstrating that the lower doses of aspirin typically taken for heart disease prevention are adequate to reduce risk not only of colorectal polyps, but also of colorectal cancer," he adds.

Nevertheless, the American Cancer Society does not recommend taking aspirin as a colon cancer prevention measure, Jacobs emphasizes.

"Aspirin, even at low doses, substantially increases the risk of serious, occasionally fatal, gastrointestinal bleeding," he says. "Current evidence suggests that very low doses of aspirin, such as 81 mg, may increase risk of gastrointestinal bleeding as much, or nearly as much, as higher doses, such as 500 mg. Decisions about whether an individual should start taking aspirin should continue to be made by balancing the benefits of aspirin use in preventing cardiovascular disease against the risks of gastrointestinal bleeding, taking into account each individual’s medical history and risk factors."

The new study did not look at the side effects from taking aspirin.

Screening still crucial

One proven method for preventing colon cancer is to get screened for the disease. "It is still very important to get screened for colorectal cancer so that colorectal polyps can be detected and removed before they ever turn into cancer," Jacobs says.

The American Cancer Society recommends regular colon cancer screening for men and women starting at age 50. People who are at a higher-than-average risk of the disease (such as those with a family history of colon cancer) may need to begin getting tested earlier, or have more frequent tests.

That goes even for people who take aspirin regularly for other reasons, Jacobs notes. "Aspirin use will not prevent most cases of colorectal cancer."
 

Aspirin: Is This Right for You?

 

Aspirin has a wide range of health benefits and treatment abilities. Many would consider it a “miracle drug” because it can not only ease everyday aches and pains, but it may save your life. That’s why it’s on Doctor Oz’s ultimate supplement checklist.

People use aspirin to relieve muscle aches, headaches and toothaches and to reduce swelling, prevent blood clots and, most importantly, improve survival after a heart attack. New studies even suggest that taking aspirin can reduce your risk of cancer. However, is this drug for you? And is it completely safe?

How Does Aspirin Work?
Aspirin calms down inflammation in your body. In reaction to infection or injury, the body increases the production of natural compounds that lead to inflammation. While inflammation on some levels is beneficial, too much inflammation is bad. It causes pain, swelling and redness. Long-term inflammation can increase your risk for chronic pain, heart disease and cancer.

When you take aspirin, it blocks a category of those inflammation-causing compounds, called cyclooxygenases, which helps relieve pain and swelling. It also attacks and blocks another natural compound called thromboxane, that promotes blood clotting.

Heart attacks often occur when blood clots form over cholesterol plaques within blood vessels around the heart. The cholesterol plaque itself forms a partial blockage; if the plaque ruptures, it attracts platelets, which form a clot. As the clot grows, it can block the artery and halt blood flow to heart muscle tissue – causing a heart attack. By thinning the blood, aspirin makes it harder for that clot to form and keeps blood flow open.

Can It Prevent Cancer?
Additionally, news reports back in March revealed more studies that suggest taking a daily aspirin may reduce your risk of getting cancer. Three European studies published in Lancet analyzed over 50 studies on aspirin and cancer and confirmed that taking a daily aspirin for at least three years reduces one’s risk of developing cancers. Those who did develop cancer tended to have less severe cases of cancer. The evidence is especially strong for preventing colon cancer; however, there is also compelling evidence for lung, pancreatic and esophageal cancers as well.

It’s quite possible that the cancer benefits comes from the aspirin-induced reduction in overall inflammation.

Is It Safe?
Aspirin is mostly safe, but no drug comes without side effects. Aspirin should be avoided in those who are allergic to it or to NSAIDs. Talk to your physician before taking aspirin if you have a history of ulcers, gastritis, kidney disease, gout, asthma, or NSAID-induced bronchospasm. Aspirin should also be avoided in those who are taking blood thinners or have bleeding disorders, like hemophilia.

Aspirin is also known to increase one’s risk for GI bleeding. Hence, it should be avoided in those who have gastrointestinal bleeding problems.

Never give aspirin to minors, as it can cause very serious medical consequences. Ask your child’s pediatrician about appropriate pain or fever-relief medications.

How Much Should I Take?
Always consult your physician or pharmacist before adding any medications, prescribed or otherwise, to your regimen. However, general guidelines are as follows:

• For a headache or muscle ache, take 325 mg of aspirin every 4-6 hours.
• To prevent a heart attack, take two low-dose (81 mg) aspirin every day if you’re at risk or over 40.
• If you think you’re having a heart attack, take 325 mg of aspirin, and make sure to chew the aspirin before swallowing, because it gets into the bloodstream quicker.
•  

Aspirin's Ability to Prevent Colon Cancer May Depend on Your Genes

Benefit was seen only with enzyme present, but study isn't definitive

By Randy Dotinga
HealthDay Reporter

WEDNESDAY, April 23, 2014 (HealthDay News) -- Aspirin seems to halve the risk of colon cancer in people with high levels of a genetic enzyme found in the colon, a new study says.

Many questions remain, however, regarding who should take aspirin to potentially ward off colon cancer. The research isn't definitive, there's no easy test for patients to take to assess potential benefits, and aspirin can cause serious side effects.

"There is very strong evidence that aspirin reduces the risk of colon cancer, but we're not yet at the point where we're recommending that treatment," said study co-author Dr. Andrew Chan, an associate professor at Harvard Medical School and gastroenterologist at Massachusetts General Hospital.

Still, the new study "provides proof that we may be able to go beyond traditional risk factors to try to determine if someone can benefit from aspirin therapy," he said.

According to the American Cancer Society, the lifetime risk of colon cancer is 1 in 20. While regular colonoscopies that search for signs of cancer are now recommended for people over 50, about 50,000 people will die in the United States of colon cancer this year, the cancer society estimates.

Scientists have tried for years to determine whether aspirin's benefits as a colon-cancer prevention tool outweigh the potential for side effects such as bleeding in the stomach. On the bright side, aspirin is one of the most inexpensive drugs available, costing as little as a penny a pill.

While research suggests that aspirin has benefits, Chan said, it's still not clear exactly how it may keep colon cancer at bay. Chan's team launched the new study to see if people with colon cancer had higher or lower levels of a genetic enzyme known as 15-PGDH that's found in the mucous membranes of the colon.

The enzyme plays a role in removing proteins known as prostaglandins that have been linked to colon cancer, Chan said. "If people are lacking this enzyme, aspirin may not cooperate as well with that person's body to get rid of prostaglandins," he said.

Most people appear to have the enzyme, Chan said, but it's not clear how many have levels that would allow aspirin to boost their chances of avoiding colon cancer.

In the study, researchers looked at tissue samples from 270 colon cancer patients. These patients were among nearly 127,900 people whose medical histories were tracked over many years.

The participants were followed in the 1980s and 1990s when daily aspirin therapy was less common than it is today. The study defined aspirin users as those who took at least two 325-milligram (mg.) aspirins a week. While two 325-mg. aspirins a week amounts to more than a daily dose of 81 mg. of "baby" aspirin, which people often take as part of heart therapy, Chan said the difference is negligible.

Those who had higher levels of the enzyme and took aspirin regularly had a 51 percent lower risk of colon cancer than those who didn't take aspirin. But those who had lower levels of the enzyme only had a 10 percent lower risk of colon cancer if they took aspirin regularly, the study found.

The findings were published in the April 23 issue of Science Translational Medicine.

A test could be developed to detect the enzyme levels to see if certain people should take aspirin to prevent colon cancer, Chan said. Such a screening would require colon tissue that could be obtained during a colonoscopy. It would be safe, Chan said, but the cost is unknown.

Chris Paraskeva, a colon cancer specialist and head of the School of Cellular and Molecular Medicine at the University of Bristol in England, said the study appears to be valid and is "potentially very useful."

However, he added, "I would not recommend the general healthy public take aspirin without consulting their doctor first."

More information

For more about colon cancer, see the American Cancer Society.

SOURCES: Andrew Chan, M.D., MPH, associate professor, department of medicine, Harvard Medical School, and associate professor of medicine, gastroenterology, Massachusetts General Hospital, Boston; Chris Paraskeva, BSc., DPhil, head of school, School of Cellular & Molecular Medicine, University of Bristol, U.K.; April 23, 2014, Science Translational Medicine