Metformin & Cancer Prevention

Diabetes drug metformin may prevent cancer   By Aaron Derfel, Postmedia News January 19, 2012 MONTREAL - The most widely prescribed drug to treat Type 2 diabetes might also help prevent colon cancer in those who are considered at high risk, suggests new research carried out by a team of Montreal scientists.

Metformin has already been shown in previous studies to cut cancer rates by 40 per cent in those taking the medication, compared with diabetics who are not.

Researchers at McGill University and the Universite de Montreal sought to understand exactly how Metformin might prevent cancer. The prevailing theory before their lab study was that since cancer cells have a voracious appetite for glucose, using a drug to lower glucose levels in the blood for the treatment of Type 2 diabetes might also inadvertently block cancer.

The researchers did confirm that the glucose-lowering action of Metformin does play a subtle role in preventing cancer. But they also made a much more important and unexpected discovery:Metformin protects cells from DNA damage that can lead to cancer.

``Surprisingly, we found that Metformin protected DNA from mutations,'' said the study's director, Dr. Michael Pollak, a professor in McGill's departments of medicine and oncology.

``It is remarkable that Metformin - an inexpensive, off-patent, safe and widely used drug - has several biological actions that may result in reduced cancer risk.''

Cells burn nutrients to produce energy. That burning-off process produces what Pollak likens to a kind of cellular exhaust, known as reactive oxygen species. It's this exhaust that can cause DNA damage inside cells, which in turn can spark cancer.

Metformin acts as a cellular exhaust ``filter,'' Pollak explained, reducing reactive oxygen species.

``The drug seems to selectively prevent (the cellular exhaust) production ... such as those found in cells with oncogenic mutations,'' said study co-author Gerardo Ferbeyre, of U de M's department of biochemistry.

The researchers made the discovery by treating pre-cancerous breast and colon cells with Metformin. The results of their study were published Wednesday in the journal Cancer Prevention Research.

Study Finds Many Patients Dissatisfied With Hospitals

WASHINGTON — Many hospital patients are dissatisfied with some aspects of their care and might not recommend their hospitals to friends and relatives, the federal government said Friday as it issued ratings for most of the nation’s hospitals, based on the first uniform national survey of patients. For complete story, click here.

Response Genetics Signs Agreement With Roche Diagnostics to Support Cancer Test Development

Tuesday, 03 February 2009 00:00 Response Genetics, Inc. RGDX, a company focused on the development and sale of molecular diagnostic tests for cancer, announced today it has signed a nonexclusive license with Roche Diagnostics for the use of Response Genetics’ patented PCR analysis to assess human epidermal growth factor type 2 (HER2) gene expression. The accurate measurement of HER2 gene expression can assist physicians with treatment decisions for patients with cancers in tissues such as breast. For complete story, click here.

Improved behavior and screening responsible for cancer death decline

An article published in the Fall, 2008 issue of the Journal of Economic Perspectives concludes that improved behavior and increased screening among Americans are major contributors to the 13 percent decline in cancer mortality from 1990 to 2004 recently announced by the National Cancer Institute. In a study that is the first to evaluate the reasons for the decline, David Cutler of Harvard University examined data for breast, colorectal, lung and prostate cancer, and uncovered three factors leading to improved cancer survival. The most important of these is cancer screening, such as mammography and colonoscopy, which can detect cancer at an early, treatable stage. Second in importance is improved personal behavior, including a reduction in smoking. Dr Cutler ranks improved treatments, including surgery, chemotherapy and radiation as third in importance, and notes that their contribution comes at a high cost. "Drugs that are quite expensive have been shown to extend life by only a few months among patients with metastatic cancer, which raises questions about the relative value of such costly treatments," Dr Cutler stated. "In contrast, while screening can be expensive, increased screening has led to significantly longer life expectancy for those diagnosed early with colorectal or breast cancer."

"We typically think of the war on cancer as developing a new cure," Dr Cutler remarked. "An equally important question is figuring out how we can take what we know and make it work for more people. We should think about the war as not just developing the next weapon, but using what we have in a smarter way. A health care system working for cancer would prevent people from getting it, catch it early, and then treat people accordingly. If our healthcare system was focused in this way, there could be a huge benefit."

Garvan To Play A Role In International Cancer Genome Consortium

Minister for Health and Ageing, The Hon. Nicola Roxon MP, has announced that Australia would make a substantial contribution to the International Cancer Genome Consortium by tackling pancreatic cancer, one of the deadliest cancers and fourth most common cause of cancer death. The consortium brings together the world's leading scientists, through 11 funding organizations in 8 countries, and aims to catalogue the genetic changes of the 50 most common cancer types. The Australian team will be led by Professor Sean Grimmond from the University of Queensland's Institute for Molecular Bioscience in Brisbane and Professor Andrew Biankin from the Garvan Institute of Medical Research in Sydney. It will also involve collaborative contributions from the Walter and Eliza Hall Institute of Medical Research in Melbourne, Johns Hopkins University in Maryland, the Ontario Institute for Cancer Research and the University of California, San Francisco.

Professor Biankin, also a surgeon at Sydney's Bankstown Hospital, has treated hundreds of patients with pancreatic cancer. "It's a very aggressive cancer, killing around 90% of people within a year of diagnosis," he said. "Unlike the other common cancers, survival rates have not improved in over 30 years."

"Now that the technology and knowledge exists to process vast amounts of data quickly, it will allow us to uncover many of the triggers and genetic mechanisms underlying the disease, and therefore improve treatment."

The project is being funded through the National Health and Medical Research Council of Australia (NH&MRC), and at $27.5 million it is the largest single grant the NH&MRC has ever awarded. Further support will be provided by The Cancer Council NSW, the Queensland Government, the Garvan Institute and the University of Queensland. Applied Biosystems Inc. and Silicon Graphics, large international companies specialising in gene sequencing and array analysis and high performance computing systems respectively, are also making significant contributions.

Professor Rob Sutherland, Director of Garvan's Cancer Research Program, as well as Inaugural Director of the planned Garvan St. Vincent's Campus Cancer Centre, acknowledges the great potential for discovery. "We are thrilled to be part of an international team that is throwing its spotlight and resources on this particular cancer," he said.

"A decade ago, it took years to sequence one person's DNA, so we could only dream about identifying the detailed gene mutations that lead to the initiation and progression of different cancers. Today it's possible to sequence 500 hundred individual cases of 50 types of cancer in 5 years."

"While no-one is under the illusion that we'll cure all cancers within the next 5 years, this international collaboration will greatly accelerate progress."

"Some cancers may be cured, some will be targeted more effectively, others will be progressively demystified. Medical research is a long-term process of discovery."

Notes:

ABOUT GARVAN

The Garvan Institute of Medical Research was founded in 1963. Initially a research department of St Vincent's Hospital in Sydney, it is now one of Australia's largest medical research institutions with nearly 500 scientists, students and support staff. Garvan's main research programs are: Cancer, Diabetes & Obesity, Immunology and Inflammation, Osteoporosis and Bone Biology, and Neuroscience. The Garvan's mission is to make significant contributions to medical science that will change the directions of science and medicine and have major impacts on human health. The outcome of Garvan's discoveries is the development of better methods of diagnosis, treatment, and ultimately, prevention of disease.

Source: Alison Heather Research Australia

NCI - New Research & Treatment

Research into the causes, prevention, and treatment of breast cancer is under way in many medical centers throughout the world. Causes of breast cancer

Studies continue to uncover lifestyle factors and habits that alter breast cancer risk. Ongoing studies are looking at the effect of exercise, weight gain or loss, and diet on breast cancer risk.

Studies on the best use of genetic testing for BRCA1 and BRCA2 mutations continue at a rapid pace. Other genes that contribute to breast cancer risk are also being identified. This will occur more rapidly now that the human genome has been sequenced.

Potential causes of breast cancer in the environment have also received more attention in recent years. While much of the science on this topic is still in its earliest stages, this is an area of active research.

A large, long-term study funded by the National Institute of Environmental Health Sciences (NIEHS) is now being done to help find the causes of breast cancer. Known as the Sister Study, it has enrolled 50,000 women who have sisters with breast cancer. This study will follow these women for at least 10 years and collect information about genes, lifestyle, and environmental factors that may cause breast cancer. An offshoot of the Sister Study, the Two Sister Study, is designed to look at possible causes of early onset breast cancer. To find out more about these studies, call 1-877-4-SISTER (1-877-474-7837) or visit the Sister Study Web site (www.sisterstudy.org).

Chemoprevention

Results of several studies suggest that selective estrogen-receptor modulators (SERMs) such as tamoxifen and raloxifene may lower breast cancer risk in women with certain breast cancer risk factors. But so far, many women are reluctant to take these medicines because they are concerned about possible side effects.

Newer studies are looking at whether aromatase inhibitors -- drugs such as anastrozole, letrozole, and exemestane -- can reduce the risk of developing breast cancer in post-menopausal women. These drugs are already being used as adjuvant hormone therapy to help prevent breast cancer recurrences, but none of them is approved for reducing breast cancer risk at this time.

Evirolimus (Afinitor^®) is a new type of targeted therapy drug that was recently approved to treat kidney cancer. In one study, letrozole plus evirolimus worked better than letrozole alone in shrinking breast tumors before surgery. More studies using this drug are planned.

Fenretinide, a retinoid, is also being studied as a way to reduce the risk of breast cancer (retinoids are drugs related to vitamin A). In a small study, this drug reduced breast cancer risk as much as tamoxifen. Other drugs are also being studied to reduce the risk of breast cancer.

For more information, see the American Cancer Society document, Medicines to Reduce Breast Cancer Risk.

Female Hormone Replacement Therapy

For women on HRT, tenderness may be warning sign By Julie Steenhuysen Tue Oct 13, 10:28 am ET

CHICAGO (Reuters) – Women whose breasts became tender after taking hormone replacement therapy had nearly twice the risk of developing breast cancer than women whose breasts did not become tender on the drugs, U.S. researchers said on Monday.

They said breast tenderness may be a way to identify women who have a higher risk of developing breast cancer while taking hormone replacement therapy to treat menopause.

"We report that an increase in breast tenderness, easily detected by physicians or patients, identifies a population at particular risk for breast cancer," Dr. Carolyn Crandall of the University of California Los Angeles and colleagues reported in the Archives of Internal Medicine.

The team analyzed data on the more than 16,000 women who took estrogen-plus-progestin as part of the widely publicized Women's Health Initiative or WHI study, which was halted in 2002 when researchers found healthy menopausal women who took the drugs were more likely to develop breast cancer.

Most of the women in the WHI studies took Premarin or Prempro made by Wyeth.

Doctors now recommend hormone replacement therapy for women suffering severe menopause symptoms, but caution that they should use the lowest dose possible for the shortest period of time.

Crandall and colleagues culled through the data to see if breast tenderness played a role in breast cancer risk. In the study, 8,506 took estrogen plus progestin and 8,102 got placebo pills.

The women had mammograms and breast exams at the start of the trial and every year after that. They reported whether they had breast tenderness at the beginning of the trial and a year later.

Based on their analysis, the researchers found women who took hormone treatments had triple the risk of developing breast tenderness.

And those who had breast tenderness after taking the pills were at 48 percent higher risk of invasive breast cancer than other women who took hormone replacement therapy.

The team said the relationship between breast tenderness and breast cancer risk was not clear.

It may be that hormone therapy is causing breast-tissue cells to multiply more rapidly, but the team could not tell that by the study, Crandall said.

"We need to figure out what makes certain women more susceptible to developing breast tenderness during hormone therapy," Crandall said in a statement.

The team said breast tenderness while taking combination hormone therapy "may be a marker of increased breast cancer risk," and women who develop breast tenderness after taking the drugs should consult their doctors about whether they should continue on the therapy.

Wyeth said in a statement that while the findings are interesting and may warrant further study, breast tenderness is not an established risk factor for breast cancer.

They said breast tenderness can occur in up to 25 percent of women after starting combined hormone therapy and is usually transient.

"Wyeth continues to support the appropriate use of hormone therapy and recommends that it be used at the lowest dose for the appropriate duration consistent with treatment goals and risks for the individual woman," the company said.

More than 400,000 women die from breast cancer globally each year. About 75 percent of breast cancers are estrogen-receptor positive, meaning they are fed by estrogen.

Agent Orange Diseases & VIetnam era Service Members

New bill to aid vets hurt by Agent Orange - by land & sea

BY Jake Pearson DAILY NEWS WRITER

Wednesday, October 28th 2009, 4:00 AM

The U.S. military dumped nearly 20 million gallons of the deadly herbicide to remove foliage during the Vietnam War.

Bobby Condon was a young kid from Flatbush when he enlisted in the U.S. Navy to fight in the Vietnam War.Nicknamed "Brooklyn" by fellow soldiers, Condon, now 63, has developed an Agent Orange-linked cancer - but was denied coverage by the Veterans Administration because he never set foot in Vietnam.

"I would have flown to Saigon and put my feet on the ground for 30 minutes [had I known]," said Condon, a flight operator on the USS Intrepid who last year was diagnosed with chronic lymphocytic leukemia (CLL), an incurable form of cancer. "But I was denied and I didn't get nothing."

This week, Sen. Kirsten Gillibrand will introduce legislation that will require coverage for the estimated 800,000 nationwide "blue-water vets," like Condon, who have illnesses linked to Agent Orange exposure but never set foot in Vietnam.

"Because of technicality in the law, hundreds of thousands of American veterans are being denied the health care benefits they need and deserve," said Gillibrand, adding there are about 13,500 such veterans in New York State.

The U.S. military dumped nearly 20 million gallons of the deadly herbicide to remove foliage during the Vietnam War. In 1991, Congress passed legislation requiring the VA to cover all sicknesses linked to Agent Orange exposure. But in 2002, the VA changed its policy to cover only those veterans who had "boots on the ground," excluding sailors and pilots such as Condon.

"I didn't even hear about Agent Orange until I came back," said Condon, who believes he got sick from working on planes that were flown through Agent Orange drop zones.

A spokesman for the VA wouldn't comment on pending legislation.

The Benefits of Flaxseed

Is flaxseed the new wonder food? Preliminary studies show that flaxseed may help fight everything from heart disease and diabetes to breast cancer.

By Elaine Magee, MPH, RD WebMD Feature

Reviewed by Louise Chang, MD

Some call it one of the most powerful plant foods on the planet. There’s some evidence it can help reduce your risk of heart disease, cancer, stroke, and diabetes. That’s quite a tall order for a tiny seed that’s been around for centuries: flaxseed.

Flaxseed was cultivated in Babylon as early as 3000 BC, according to the Flax Council of Canada. By the 8^th century, King Charlemagne believed so strongly in the health benefits of flaxseed that he passed laws requiring his subjects to consume it. Fast-forward 13 centuries, and some experts would say we have preliminary research to back up what Charlemagne suspected all those years ago.

These days, flaxseed is found in all kinds of foods, from crackers to frozen waffles to oatmeal. In the first 11 months of 2006, 75 new products were launched that listed flax or flaxseed as an ingredient. Not only has consumer demand for flaxseed gone up, agricultural use has also increased -- to feed all those chickens laying eggs that are higher in omega-3 fatty acids.

Although flaxseed contains all sorts of healthy components, it owes its healthy reputation primarily to three ingredients:

• Omega-3 essential fatty acids, "good" fats that have been shown to have heart-healthy effects. Each tablespoon of ground flaxseed contains about 1.8 grams of plant omega-3s.
• Lignans, which have both plant estrogen and antioxidant qualities. Flaxseed contains 75- 800 times more lignans than other plant foods
• Fiber. Flaxseed contains both the soluble and insoluble types.

The Health Benefits of Flax

Although Lilian Thompson, PhD, an internationally known flaxseed researcher from the University of Toronto, says she wouldn’t call any of the health benefits of flax "well established," research indicates that flax’s possible health benefits include reducing the risks of certain cancers as well as cardiovascular disease and lung disease. Here are more details:

Cancer

Recent studies have suggested that flaxseed may have a protective effect against cancer, particularly breast cancer, prostate cancer, and colon cancer. At least two of the components in flaxseed seem to contribute, says Kelley C. Fitzpatrick, M.Sc., director of health and nutrition with the Flax Council of Canada.

In animal studies, the plant omega-3 fatty acid found in flaxseed, called ALA, inhibited tumor incidence and growth.

Further, the lignans in flaxseed may provide some protection against cancers that are sensitive to hormones. Some studies have suggested that exposure to lignans during adolescence helps reduce the risk of breast cancer, Thompson says.

Lignans may help protect against cancer by:

• Blocking enzymes that are involved in hormone metabolism.
• Interfering with the growth and spread of tumor cells.

Some of the other components in flaxseed also have antioxidant properties, which may contribute to protection against cancer and heart disease.

Cardiovascular Disease

Research suggests that plant omega-3s help the cardiovascular system via several different mechanisms, including anti-inflammatory action and normalizing the heartbeat, Fitzpatrick says.

Several studies have suggested that diets rich in flaxseed omega-3s help prevent hardening of the arteries and keep plaque from being deposited in the arteries, partly by keeping white blood cells from sticking to the blood vessels’ inner linings.

"Lignans in flaxseed have been shown to reduce atherosclerotic plaque buildup by up to 75%," Fitzpatrick says.

Because plant omega-3s may also play a role in maintaining the heart’s natural rhythm, they may be useful in treating arrhythmia (irregular heartbeat) and heart failure, although more research is needed on this.

Eating flaxseed daily may help your cholesterol levels, too. Small particles of LDL or "bad" cholesterol in the bloodstream have been linked to an increased risk of heart disease, obesity, diabetes, and metabolic syndrome. A French-Canadian study in menopausal women reported a decrease in these small LDL particles after the women ate 4 tablespoons of ground flaxseed daily for a year. Fitzpatrick says the cholesterol-lowering effects of flaxseed are the result of the synergistic benefits of omega 3 ALA; fiber and lignans.

Diabetes

Preliminary research also suggests that daily intake of the lignans in flax may modestly improve blood sugar (as measured by hemoglobin A1c blood tests in adults with type 2 diabetes).

Inflammation

Two components in flaxseed, ALA and lignans, may reduce the inflammation that accompanies certain illnesses (such as Parkinson's disease and asthma) by helping to block the release of certain pro-inflammatory agents, Fitzpatrick says.

The plant omega-3 ALA has been shown to decrease inflammatory reactions in humans. And studies in animals have found that lignans can decrease levels of several pro-inflammatory agents.

Reducing inflammatory reactions associated with plaque buildup in the arteries may be another way flaxseed helps prevent heart attack and strokes.

Hot Flashes

One preliminary study on menopausal women, published in 2007, reported that 2 tablespoons of ground flaxseed (taken twice each day) cut the women's hot flashes in half. And, the intensity of their hot flashes dropped by 57%. The women noticed a difference after taking the daily flaxseed for just one week, and achieved the maximum benefit within two weeks.

Who Shouldn’t Use Flaxseed?

Until more is known, Thompson says pregnant women and possibly breastfeeding mothers should not supplement their diets with ground flaxseed.

"Our own animal studies showed that flaxseed exposure during these stages may be protective against breast cancer in the offspring, but a study of another investigator showed the opposite effect," Thompson says.

Tips for Using Flaxseed

Many experts believe it's better to consume flaxseed than flax oil (which contains just part of the seed) so you get all the components. But stay tuned as researchers continue to investigate.

Tips for Using Flaxseed continued...

"Ground flaxseed, in general, is a great first choice but there may be specific situations where flax oil or the lignans (taken in amounts naturally found in flaxseed) might be as good," Thompson says.

And how much flaxseed do you need? The optimum dose to obtain health benefits is not yet known. But 1-2 tablespoons of ground flaxseed a day is currently the suggested dose, according to the Flax Council of Canada.

Here are more tips for using, buying, and storing flaxseed:

• Buy it ground or grind it yourself. Flaxseed, when eaten whole, is more likely to pass through the intestinal tract undigested, which means your body doesn't get all the healthful components. If you want to grind flaxseed yourself, those little electric coffee grinders seem to work best.
• Milled = ground = flax meal. Don’t be confused by the different product names for ground flaxseed. Milled or ground flaxseed is the same thing as flax meal.
• Buy either brown or golden flaxseed. Golden flaxseed is easier on the eyes, but brown flaxseed is easier to find in most supermarkets. There is very little difference nutritionally between the two, so the choice is up to you.
• Find it in stores or on the Internet. Many supermarket chains now carry ground flaxseed (or flaxmeal). It’s usually in the flour or "grain" aisle or the whole-grain cereal section, often sold in 1-pound bags. You can also find it in health food stores, or order it through various web sites.
• Check the product label. When buying products containing flaxseed, check the label to make sure ground flaxseed, not whole flaxseed, was added. Flaxseed is a featured ingredient in cereals, pasta, whole grain breads and crackers, energy bars, meatless meal products, and snack foods.
• Add flaxseed to a food you habitually eat. Every time you have a certain food, like oatmeal, smoothies, soup, or yogurt, stir in a couple tablespoons of ground flaxseed. Soon it will be a habit and you won’t have to think about it, you’ll just do it.
• Hide flaxseed in dark, moist dishes. The dishes that hide flaxseed the best usually have a darkly colored sauces or meat mixtures. No one tends to notice flaxseed when it's stirred into enchilada casserole, chicken parmesan, chili, beef stew, meatloaf or meatballs. For a 4-serving casserole, you can usually get away with adding 2-4 tablespoons of ground flaxseed. For a dish serving 6-8, use 4-8 tablespoons.
• Use it in baking. Substitute ground flaxseed for part of the flour in recipes for quick breads, muffins, rolls, bread, bagels, pancakes, and waffles. Try replacing 1/4 to 1/2 cup of the flour with ground flaxseed if the recipe calls for 2 or more cups of flour.
• Keep it in the freezer. The best place to store ground flaxseed is the freezer. Freeze pre-ground flaxseed in the bag you bought it in, or in a plastic sealable bag if you ground it yourself. The freezer will keep the ground flax from oxidizing and losing its nutritional potency.
• Whole flaxseed keeps longer. The outside shell in whole flaxseed appears to keep the fatty acids inside well protected. It’s a good idea to keep your whole flaxseed in a dark, cool place until you grind it. But as long as it is dry and of good quality, whole flaxseed can be stored at room temperature for up to a year.

Flaxseed Recipe

Ready to try flaxseed? Here’s a recipe to get you started from The Flax Cookbook: Recipes and Strategies for Getting The Most from The Most Powerful Plant on the Planet.

Fruity Flaxseed Muffins

These moist and high-flavor flax muffins really do taste better than they sound.

Ingredients:

1/2 cup crushed pineapple with juice, canned

1/2 cup finely chopped apples (with peel)

2 tablespoons canola oil

1 large egg, higher omega-3 if available, beaten lightly

2 egg whites (or 1/4 cup egg substitute)

1 cup fat free sour cream

1/4 cup dark molasses

1/2 cup raisins, currants (or any other dried fruit, chopped)

1 1/4 cup unbleached white flour

1/2 cup whole-wheat flour

1 teaspoon baking powder

1 teaspoon baking soda

1/4 teaspoon salt

3/4 cup ground flaxseed

Directions:

1. Preheat oven to 400 degrees. Line muffin pan with paper or foil liners. Coat inside of liners with a quick squirt of canola cooking spray.
2. In large mixing bowl, beat together the pineapple with juice, apples, canola oil, egg, egg whites or egg substitute, sour cream, and molasses until mixture is light and fluffy. Stir in raisins or dried fruit.
3. In medium bowl, whisk together flours, baking powder, baking soda, salt and flaxseed. Beating on low speed, add flaxseed mixture to sour cream mixture just until combined (batter will be a little lumpy). Spoon batter by 1/4 cupful into prepared muffin pan.
4. Bake in center of preheated oven for about 20 minutes or until muffins are golden brown and springy to the touch.

Yield: 12 muffins

Nutritional Analysis: Per muffin: 194 calories, 5 g protein, 31 g carbohydrate, 5.5 g fat, .8 g saturated fat, 2.1 g monounsaturated fat, 2.6 g polyunsaturated fat, 20 mg cholesterol, 4.5 g fiber, 224 mg sodium, 1.7 g omega-3 fatty acids. Calories from fat: 28%.

Recipe reprinted with permission.

Daily Aspirin Linked to Steep Drop in Cancer Risk

MONDAY, Dec. 6 (HealthDay News) -- Long-term use of a daily low-dose aspirin dramatically cuts the risk of dying from a wide array of cancers, a new investigation reveals. Specifically, a British research team unearthed evidence that a low-dose aspirin (75 milligrams) taken daily for at least five years brings about a 10 percent to 60 percent drop in fatalities depending on the type of cancer.

The finding stems from a fresh analysis of eight studies involving more than 25,500 patients, which had originally been conducted to examine the protective potential of a low-dose aspirin regimen on cardiovascular disease.

The current observations follow prior research conducted by the same study team, which reported in October that a long-term regimen of low-dose aspirin appears to shave the risk of dying from colorectal cancer by a third.

"These findings provide the first proof in man that aspirin reduces deaths due to several common cancers," the study team noted in a news release.

But the study's lead author, Prof. Peter Rothwell from John Radcliffe Hospital and the University of Oxford, stressed that "these results do not mean that all adults should immediately start taking aspirin."

"They do demonstrate major new benefits that have not previously been factored into guideline recommendations," he added, noting that "previous guidelines have rightly cautioned that in healthy middle-aged people, the small risk of bleeding on aspirin partly offsets the benefit from prevention of strokes and heart attacks."

"But the reductions in deaths due to several common cancers will now alter this balance for many people," Rothwell suggested.

Rothwell and his colleagues published their findings Dec. 7 in the online edition of The Lancet.

The research involved in the current review had been conducted for an average period of four to eight years. The patients (some of whom had been given a low-dose aspirin regimen, while others were not) were tracked for up to 20 years after.

The authors determined that while the studies were still underway, overall cancer death risk plummeted by 21 percent among those taking low-dose aspirin. But the long-term benefits on some specific cancers began to show five years after the studies ended.

At five years out, death due to gastrointestinal cancers had sunk by 54 percent among those patients taking low-dose aspirin.

The protective impact of low-dose aspirin on stomach and colorectal cancer death was not seen until 10 years out, and for prostate cancer, the benefits first appeared 15 years down the road.

Twenty years after first beginning a low-dose aspirin program, death risk dropped by 10 percent among prostate cancer patients; 30 percent among lung cancer patients (although only those with adenocarcinomas, the type typically seen in nonsmokers); 40 percent among colorectal cancer patients; and 60 percent among esophageal cancer patients.

The potential impact of aspirin on pancreatic, stomach and brain cancer death rates was more problematic to gauge, the authors noted, due to the relative paucity of deaths from those specific diseases.

They also found that higher doses of aspirin did not appear to boost the protective benefit. And while neither gender nor smoking history appeared to affect the impact of low-dose aspirin, age definitely did: the 20-year risk of death went down more dramatically among older patients.

And while cautioning that more research is necessary to build on this "proof of principle," the authors suggested that people who embark on a long-term, low-dose aspirin regimen in their late 40s and 50s are probably the ones who stand to benefit the most.

Dr. Alan Arslan, an assistant professor in the departments of obstetrics and gynecology and environmental medicine at NYU Langone Medical Center in New York City, described the findings as "very significant."

"[This] is the largest study to show that people who take aspirin for a long period of time have a reduced risk of death from many cancers, especially gastrointestinal cancers," he noted.

"The take-home message for patients is that if someone is taking low-dose or regular aspirin, it may put them at a reduced risk of death from cancer," Arslan added. "However, if someone is not already taking aspirin they should talk with their physician before starting. Aspirin has risks of side effects, including bleeding and stroke."