The FDA has approved Cologuard, a new, stool-based, at-home colon cancer test that detects DNA mutations and red blood cells that may indicate colorectal cancer. Cologuard, which is ordered through a doctor’s office and requires no bowel prep or dietary restrictions, may help detect colorectal cancer at its earliest, asymptomatic stages. Further screening, including colonoscopy, would be advised for patients who test positive with Cologuard. Cologuard detects about 92.3% of abnormalities compared to 74% with a fecal immunochemical test (FIT). Stool DNA testing is not currently recommended to screen for colorectal cancer by the U.S. Preventive Services Task Force which recommends FIT, sigmoidoscopy or colonoscopy.
Fear Is a Deterrent
During colonoscopy, precancerous lesions are detected and removed, yet many people are fearful or wary of the procedure. In Germany, where colonoscopy is part of the national cancer screening program for insured people aged 55+, only 1/5 of eligible people get the test. To learn the risks of colonoscopy Professor Hermann Brenner evaluated data of 30,000+ individuals who had undergone the test between 2001-2008 and found that intestinal bleeding requiring hospitalization occurred in about 5 in 10,000 colonoscopies. Injuries to the intestinal wall occurred in less than 1 in 1,000 exams and deaths were not more frequent in the colonoscopy group than in a control group of the same size. Half of new colon cancer cases and deaths could be avoided with colonoscopy, says Brenner.
But Two New Causes Loom Large
Deaths from cancer continue to decline but those linked to obesity and the human papillomavirus (HPV) are rising, says a report compiled by several health agencies including the American Cancer Society (ACS) and the CDC which praise the dramatic decrease in smoking for the lower statistics. However, “Over the next 10 years, a combination of high caloric intake and low physical activity is going to surpass tobacco as a cause of cancer deaths,” said Dr. Otis Brawley, ACS, in an NBC interview. It’s estimated that bad diet, lack of exercise and obesity are risks for 1/3 of cancers including pancreatic, breast and colon cancers. In addition, head and neck cancers, associated with HPV are on the rise and accounted for 3.3% and 2% of all cancer cases in 2009 among women and men, respectively.
A Christmas Miracle
Mistletoe may have potential as an alternative therapy for sufferers of colon cancer. Researchers with the University of Adelaide in Australia have found that one type of mistletoe extract, from a species known as Fraxini, was highly effective against colon cancer cells in a laboratory culture and gentler on healthy intestinal cells as compared with chemotherapy. Chemotherapy alternatives are often sought due to harsh side effects such as mouth ulcers and hair loss. Fraxini mistletoe grows on ash trees and its extract has been considered a viable alternative therapy in overseas countries, states Zahra Lotfollahi, the project research lead. Colon cancer is the second greatest cause of cancer death in the Western World.
Shows Who Benefits the Most
People with colon cancer that contains a mutated PIK3CA gene that is tied to its growth and spread may benefit the most from aspirin, according to results of research out of Harvard Medical School. Over 900 people diagnosed at different stages of the disease were given a survey every two years and tested for a mutation. Over 13 years, the risk of death by taking aspirin was cut by 82 percent and only two of the 62 people with the mutation in their tumors died within 5 years compared to 23 of the 90 people with the mutation who did not take aspirin. There was no difference between baby and regular aspirin and a test for the gene is cost effective and could be done in most cancer centers. Future studies will only involve those with the mutation to determine if aspirin affects the outcome.
Fiber, Antioxidant Combination
Black carrots – which are actually deep purple in color – may have a leg up on orange carrots in its cancer-fighting abilities. Carrots, available year-round but are at their peak in the fall, are known for being detoxifying to the liver. The less commonly known black carrot contains antioxidant compounds which can play an important role in cancer protection. Polyphenols, which also give blueberries and red wine their vivid color, work together with the high fiber content of the carrot to be protective during digestion in the stomach and small intestine. This, says Dr. Anneline Padayachee from the University of Queensland, can have a shielding effect on the colon as it transports waste through the body. [See Dr. Padayachee's comment below for a clarification.]
But Does Not Raise Risk Either
Taking B-vitamins such as folic acid, B6 and B12 will have no bearing on your colon cancer risk, finds a new study from Harvard Medical School. Researchers compared taking a B-vitamin combination pill to an inactive placebo in more than 5400 older women and found no evidence that the supplements will either increase or reduce the risk of colon polyps, a precursor to cancer. As many as 35 percent of Americans take dietary supplements, but the American Cancer Society does not recommend them for preventing any type of cancer. Their advice is to consume a healthful diet increasing fruit and vegetable intake and limiting red meat, being physical active, losing weight as needed, and getting the recommended colorectal cancer screenings, particularly after the age of 50.
Causes Insulin Overexpression
New research has revealed that diets high in fat are linked to an increased risk of colon cancer because they modify genes associated with breaking down carbohydrates, fats and amino acids. This modification of genes that changes their expression is done via methylation, or the addition of a methyl group which is made up of one carbon atom and three hydrogen atoms. Looking at healthy colon tissue from cancer patients showed that fats alter insulin genes which cause them to overexpress the glucose-lowering hormone. Studies show that people with colon cancer have altered glucose metabolism and insulin signaling. Insulin feeds cancer cells. Researchers hope they can observe these changes in healthy tissues so colon cancer screenings and diagnosis can be done with blood or saliva.
Women Benefit More
Women who eat at least three servings of fish per week appear to have a reduced risk of developing certain types of colon polyps. Researchers with Vanderbilt-Ingram Cancer Center believe the omega-3 fatty acids in fish help to reduce inflammation in the body which is protective against the development of polyps, small growths in the lining of the colon which may potentially develop into colon cancer, the fourth most common cancer in the US. In a study of more than 5,000 participants, women who ate fish regularly had about a 33 percent reduction in risk. Interestingly, fish intake did not appear to protect men as well, which may be linked to background diet versus differences in biology said Harvey Murff MD MPH, an associate professor of medicine.
Might Help a Poor Diet
Researchers publishing in the Canadian Journal of Physiology and Pharmacology (CJPP) have reported that taking multivitamin-mineral supplements may help reduce the risk of colon cancer. Rats that were fed high-fat, low-fiber diets, a known risk factor for cancer, were divided into six groups and exposed to different combinations of dietary supplements and carcinogens. The carcinogenesis induced in the study rats mimicked that of human colon cancer. Those animals that received a multivitamin showed a significant (84 percent) reduction in the formation of pre-cancerous lesions and did not develop tumors. The authors suggest that the nutrients provided in the supplements contribute a chemoprotective effect.
May Create a Microenvironment
Researchers who sequenced colon tissue DNA at the Dana-Farber Cancer Institute found that a significant amount of Fusobacterium DNA was present in all nine samples of colorectal cancer. DNA from nine healthy samples was also analyzed side by side as a comparison. This particular bacterium has been linked to ulcerative colitis, an inflammatory bowel disease that has been linked to an increased risk of colorectal cancer. Scientists want to see if Fusobacterium creates a "microenvironment" in which cells interact with each other in certain ways that encourages the cancer to grow. Some scientists also hypothesize that the cancer cells may provide a fertile environment for the bacterium. Future studies will involve determining if Fusobacterium induces colon cancer in animals.
Shows Risk Factor and Prevention
New research shows that vitamin D mitigates the growth and aggressiveness of colon cancer. Experiments in mice and human colon cancer cells found that vitamin D receptors (VDR) disrupt the beta-catenin activity, a protein that accumulates in cells early on in carcinogenesis. Mice without the VDR developed bigger and more aggressive tumors compared to mice with the VDR. Its absence in human colon cancer cells was associated with increasing concentrations of beta-catenin. The idea that the loss of the VDR fuels tumor growth was supported by the profile of 67 percent of advanced colon cancer tumors. The results suggest that chronic vitamin D deficiency may increase the risk of aggressive colon cancer but vitamin D3 may help in the early stages by activating the VDR.
Fiber and Exercise Decrease Risk
The World Cancer Research Fund and the American Institute for Cancer Research have gathered several years’ worth of published studies and note that there is convincing evidence that red meat, processed meat, and excess body fat – particularly around the abdomen – increase the risk of colorectal cancer. The researchers say that easting 3.5 ounces of red meat every day – which includes beef, lamb and (yes) pork – the risk of colorectal cancer is 17 percent higher than someone who eats no red meat. Processed meat eaten once a day can increase risk by 26 percent. To reduce this risk, the evidence points toward eating more foods that contains dietary fiber, such as fruits, vegetables, whole grains and beans, and exercising more.
Pick an NSAID, Any NSAID
A large study of the 19 different non-steroidal anti-inflammatory drugs (NSAIDs) involving over 300,000 people found they all decreased the risk of colorectal cancer. Taking NSAIDs everyday decreased the risk of colon cancer by 28 percent but monthly use cut the reduced risk in half. People with family members who had it lowered their risk by 28 percent when they took an NSAID every day, but only by 11 percent when taken weekly. Aspirin reduced the risk of rectal cancer by 62 percent but did not affect the risk of developing colon cancer while non-aspirin NDSAIDs lowered the risk of colon cancer by 56 percent but did not lower rectal cancer risk. There were several limitations to the study and researchers want to understand which types of colon cancer will benefit the most from aspirin.
One Factor Ups Risk and Benefit
New research has found that people with higher level s of soluble tumor necrosis factor receptor-2 (sTNFR-2) benefit the most by taking aspirin or another non-steroid anti-inflammatory drug (NSAID). This inflammatory factor present in the blood could be used as a biomarker to determine if taking aspirin or another NSAID would help a person lower his or her risk of cancer. A study looking at three inflammatory factors and the risk of colorectal cancer found that people who had higher baseline sTNFR-2 levels had a 60 percent increased risk of it cancer and taking NSAIDs was more likely to reduce that risk compared to others with lower baseline levels. This study also suggests that each inflammatory pathway plays a different role in the risk of developing cancer.
Milk Does a Body Good
Encourage your child to choose milk at school instead of other beverages and you could reduce his or her risk of developing bowel cancer as an adult. A national study published in the American Journal of Epidemiology found that the risk of bowel cancer was 30 percent lower in people who drank school milk daily. The study, conducted at the University of Otago in New Zealand, followed people who drank school-provided milk between the years of 1937 and 1967. The researchers suggest that calcium is likely the protective mineral, as other studies have concluded that total calcium intake is associated with a decreased risk of digestive system cancers. Cancers of the colon and rectum in the United States affect over 140,000 each year, according to the National Cancer Institute.
ConsIstency Is Key
Consistent physical activity lowers the risk of dying from colon cancer finds a study from Washington U School of Medicine and Barnes-Jewish Hospital. Working with colleagues from the American Cancer Society, researchers examined years of data from 150,000 people to determine whether changes in activity levels affected either the incidence of colon cancer or the risk of death from the disease. They found that those who participated in a program of regular exercise for at least 10 years had the lowest mortality risk from the disease. Researchers say that the benefits of regular exercise accrue over time, but it’s never too late to start exercising. "You go for a 30-minute walk every day, and you're going to reduce your risk of a number of diseases,” says author Kathleen Y. Wolin.
Many Key Nutrients for Health
In a study of over 132,000 men and women followed for about 26 years, adherence to the DASH diet (Dietary Approaches to Stop Hypertension) was associated with a 20 percent lower risk of developing colorectal cancer. The DASH diet involves higher intakes of whole grains, fruits and vegetables; moderate intake of low-fat dairy products; and lower intake of red or processed meats, desserts and sweetened beverages. It was originally designed as a dietary approach to lower blood pressure because it is low in sodium and higher in the minerals potassium, calcium and magnesium. These minerals, plus vitamin D, folate and fiber, appear to be protective against the development of colon and rectal cancers. The lowered fat content of the diet is also beneficial in reducing risk.
High Fiber Foods Still Better
High glycemic foods are those carbohydrates which cause blood sugar to rise rapidly. These foods, including white bread, white rice, and potatoes, have been thought to contribute to colon cancer risk because high blood sugar levels trigger the release of insulin and related hormones that may stimulate the growth and spread of cancer cells. However, a new observational study on 73,000 Chinese women seems to indicate that there is no evidence to suggest such a link. In Asian populations, rice and other starchy foods are part of the traditional diet, yet out of the study cohort, less than one percent ultimately received a diagnosis of colon cancer over the ten-year study period. The study was published in the October issue of the American Journal of Clinical Nutrition.
One Marker, Eleven Cancers
Research in the United States and France has shown that at least 11 different cancers have the same genetic marker. They looked at cancers of the prostate, breast, colon, pancreas, bladder, kidneys, lungs, liver, stomach, testicles and ovaries. After looking at tumors in 1,336 cancer patients, they were able to find the follicle-stimulation hormone (FSH) receptor. It is normally only found in the reproductive organs, but researchers found it in the blood vessels of tumors at all stages of growth. Upon examination of the receptors, they confirmed that they were present in the blood vessels of tumors but not in those of normal tissue. Researchers are excited about the prospect of a universal marker for testing and one target against multiple types.
Two a Day Keeps the Polyps Away?
The National Health Services Bowl Cancer Screening Programme in England is going to recruit about a 1,000 people to determine if taking eicosapentaenoic acid (EPA) and aspirin daily reduce the risk of polyps that are often a precursor to bowel cancer. Individually, both have been shown to lower the incidence of bowel polyps and researchers believe that there may be a synergistic effect if both are taken. Both drugs have few side effect and people who have had heart attacks or strokes are already on them. If this study shows that taking both drugs reduce the risk of developing polyps, it could be given to people who have a history of polyps and are likely to develop them in the future and those are at risk would need fewer checkups. The study will begin in April or May of 2011.
Rectal cancer rates in people under the age of 40 are on the rise - and have been climbing steadily for the last twenty years, say researchers who remain baffled as to the causes for this increase. Both rectal and colon cancers are believed to share the same risk factors but while the incidence of colon cancer remains steady, the incidence of rectal cancer has grown by almost four percent. "We've scoured the literature for a cause and spoken to others in the field and we haven't identified anything that is able to explain this," said lead author Dr. Joshua Meyer, Fox Chase Cancer Center, Philadelphia. Researchers caution doctors to follow up with young patients who exhibit rectal bleeding and not to assume bleeding is caused by something else, like hemorrhoids.
21 Million Cancer Cases a Year?
The World Health Organization (WHO) has announced that they expect 21 million new cases of cancer to be diagnosed annually by 2030, while nearly 13 million deaths will be attributed to the disease by that time. According to their study 12.7 million new cancer cases occurred in 2008, while 7.6 million cancer patients died during that same period. That same study showed that lung cancer is the most diagnosed of cancers, afflicting 1.8 million patients in 2008, while breast cancer was second at 1.4 million cases and colorectal cancers rounded out the top three at 1.2 million cases. The study also found that lung cancer is the most deadly with 1.4 million people killed, followed by stomach cancer with 740,000 deaths and liver cancers with 690,000 people dying from the disease.
One Pill Equals Half the Prep
A colonoscopy can make a difference in finding colon cancer in time for effective treatment, but the procedure isn’t a patient favorite because preparing for the test means drinking a gallon of fluid containing a mixture of polyethylene glycol and electrolytes to clean out the bowels. Researchers have discovered that a pill already approved as a treatment for chronic constipation can be used in place of half the liquid requirement. Dr. Chetan Pai, the study's lead author, says most people don’t want to have a colonoscopy because of the preparation, but might be encouraged to have the test done if there was a better way to prepare for it. This new prep could be especially beneficial for patients over 50, who have an especially hard time drinking a whole gallon of fluid.
Fish or Flax Provide Benefits
People whose diets are rich in omega-3 fatty acids are not only protecting their heart and brain, but may also be cutting their risk for colon cancer. Research from the National Institute of Environmental Health Sciences in North Carolina examined the relationship between polyunsaturated fatty acid intake and bowel cancer risk in over 1800 Americans who were both Caucasian and African American. Two primary omega-3 fatty acids, EPA and DHA, were found to decrease the risk of colon cancer, with the most prominent benefit shown in white Americans. In addition to fatty fish, omega-3 fatty acids can be found in flaxseed and other seed oils such as walnut. The research was published in the April issue of the American Journal of Epidemiology.
Colon Cancer May Have New Enemy
Researchers report that a form of the drug naproxen blocks a process that leads to colon cancer. Naproxen is more commonly known by the brand names Aleve, Anaprox & Naprosyn. The drug has only been tested in the lab at this time, but Dr. Margie Clapper, of the Cancer Prevention & Control Program, reported, “it appears that the investigational form of naproxen we studied may be more effective than standard naproxen in inhibiting colorectal tumor development.” Researchers found that this new type of naproxen, NO-naproxen, appeared to block a signaling pathway that plays a role in colon cancer formation. Dr. Clapper stated that NO-naproxen is much better than naproxen in “nipping this whole process in the bud.” More testing is being done but there are no results to report at this time.