Patient Education Resources/Links

How can I be screened for colon cancer?

Good question! Women are used to having mammogram's to screen for breast cancer, and men are more aware of the PSA test to check for prostate cancer. Unfortunately, many people are not as aware that colon cancer is the second leading cause of cancer deaths, but it is very preventable. Polyps are abnormal growths that can become cancerous as they grow. These polyps are easily removed via colonoscopy when detected early.

Screening should begin at age 50 for people of average risk and typically involves performing a colonoscopy. Colonoscopies are generally performed as an outpatient procedure (while sedated) and the results are available immediately.

Are Gastroenterology procedures painful?

Although most people understand the importance of screening, they put-off scheduling a gastroenterology procedure because they are afraid it will be painful and/or uncomfortable. This “myth” is not always true. During the procedure the patient is medicated allowing them to sleep comfortably throughout the entire procedure.

What are the symptoms of Colon Cancer?

While colorectal cancer often develops with no symptoms, which is why screening for the disease is so crucial, some symptoms can occur, particularly in the advanced stages of the disease, including:

• Rectal bleeding
• Blood in or on the stool (bright red)
• Change in bowel habits
• Stools that are narrower than usual
• General stomach discomfort (bloating, fullness, and/or cramps)
• Diarrhea, constipation, or feeling that the bowel does not empty completely
• Frequent gas pains
• Weight loss for no apparent reason
• Constant tiredness
• Vomiting

What causes a polyp to form?

The exact causes of polyps are uncertain, but they appear to be caused by both inherited and lifestyle factors. Genetic factors may determine a person's susceptibility to the disease, whereas dietary and other lifestyle factors may determine which individuals at risk actually go on to form polyps (and later cancers). Diets high in fat and low in fruits and vegetables may increase the risk of polyps. Lifestyle factors such as cigarette smoking, a sedentary lifestyle, and obesity may also increase the risk.

How can you prevent polyps from forming?

Few studies have been able to show that modifying lifestyle reduces the risk of colon polyps or cancer. However, lifestyle modifications such as reducing dietary fat, increasing fiber, ensuring adequate vitamin and micro-nutrient intake, and exercise, may improve general health. Studies have shown that getting adequate calcium in the form of diet or supplement can reduce the risk of polyps.

Exactly what is a “pre-cancerous” polyp? If the polyp is removed, does that mean I am cured?

The term "pre-cancerous" polyp can have two possible interpretations. One interpretation describes the evolution of the lining of the colon from normal colon cells to colon cancer. In this evolution, the patient first develops a polyp, the cells on the polyp then become atypical or dysplastic. Next, the polyp degenerates into an early cancer, still continued to the polyp itself, and finally there is an invasive colon cancer. Some people refer to all of the polyps up to the point of cancer as "pre-cancerous" polyps.

The other interpretation relates to classification of polyps and their malignant potential. There are two broad categories of polyps that are commonly found during cancer screening: adenomatous polyps and hyperplastic polyps. Adenomatous polyps are the type of polyps associated with an increased risk of colon cancer and are sometimes referred to as "pre-cancerous." Types of polyps in this category include villous adenomas, tubulo-villous adenomas, tubular adenomas, serrated adenomas and adenomatous polyps. Hyperplastic polyps, on the other hand, are the other large category of polyps and are not associated with an increased risk of colon cancer.

If an adenomatous polyp is discovered on sigmoidoscopy, many physicians would recommend a full colonoscopy to examine the remainder of the bowel. Removal of a benign polyp does prevent a cancer from developing at that one location, but the patient is likely to develop polyps at other locations. Close follow up is indicated for these patients.

Can polyps "fall off" or take care of themselves without having them removed?

Polyps have a slow growth rate and studies show polyps that are 10 mm or less have a fairly stable size over a three-year interval. A true polyp will never "fall off" or take care of itself on its own

What foods or what diet should I follow to prevent colorectal cancer from occurring? Are there any foods that actually cause colorectal cancer?

There are no foods that cause colorectal cancer. However, studies of different populations have identified associations that may affect your risk of developing colorectal cancer, or the precancerous lesions called polyps. There appears to be a slightly increased risk of developing colorectal cancer in countries with higher red meat or non-dairy (meat-associated) fat intake. For example, the U.S. and Canada have much higher rates of colorectal cancer than countries like Japan or Nigeria, and this correlates to meat and fat consumption. Similarly, there has been an association with decreased rates of colorectal cancer and increased fiber intake. Recent studies have questioned this association, but in general we recommend a diet high in vegetable fiber and low in fat and moderate to low in red meat. Finally, calcium and folic acid appear to have protective effects in the colon. There remain many unanswered questions in this area. No matter what your dietary intake is, don't forget to ask your doctor about the appropriate screening test to identify polyps and early cancers!

Can flax seed or green tea prevent colorectal cancer?

Cruciferous vegetables seem to covey some protection against colorectal cancer. There is an explosion of literature looking at the effect of green tea and colon cancer. Tea catechins and related polyphenols may have an inhibitor effect on colon cancer. Grape juice may have a similar inhibitory effect to green tea on human colon cancer cell lines. Clinical trials are needed to determine true efficacy. If your pocket book will permit purchase of green teas, there is probably little harm in consuming green teas.

Does fiber play a protective role in colorectal cancer?

The question of whether fiber plays a protective role against colorectal cancer has become quite controversial. Early studies suggested that fiber is indeed protective, whereas more recent and highly publicized studies find no protective effect. Pending additional studies that may resolve this controversy, a high fiber diet is recommended because of its overall nutritional value and because it promotes good bowel function. Furthermore, fiber is also beneficial for individuals with diabetes, heart disease, hypertension and a variety of other medical conditions.

Does food intolerance or lactose intolerance increase your risk for colon or rectal cancer?

I am not aware of hard data that consumption of lactose products or that lactose intolerance is a risk factor for colorectal cancer. However, there is a huge amount of new literature, suggesting probiotic therapy is healthy, and that microflora of the colon may be altered by dietary dairy products such that the risk for colon cancer is retarded.

What are early symptoms of this type of cancer?

Colorectal cancer can be associated with unexplained weight loss, change in bowel habits from what is considered normal for a given individual — either constipation or diarrhea — unexplained anemia (low blood count), visible blood in the stool, hidden blood in the stool (which is checked by smearing stool on a special piece of card called fecal occult blood test), and unexplained or sustained abdominal pain. It is also important to remember that colon cancer may be silent and not associated with any symptoms. That is why early detection through screening is so important.

Is it possible to have colon or rectal cancer without having polyps?

Colorectal cancer can occur without polyps, but it is an uncommon event. Individuals with long-standing inflammatory bowel diseases, such as chronic ulcerative colitis and Crohn's colitis, are at increased risk for developing colorectal cancer that occurs in the absence of polyps. The greater the extent of colonic involvement by inflammatory bowel disease and the greater the duration of the disease, the greater the risk of colorectal cancer. Colorectal cancers in individuals with chronic inflammatory bowel disease may appear as flat, plaque like lesions or may even be indistinguishable from the surrounding colon tissue. Large mass-like lesions with distinct margins seen with most colorectal cancers are uncommon in inflammatory bowel disease.

Colorectal cancer associated with inflammatory bowel disease accounts for less than 1 percent of all colorectal cancers diagnosed in the United States each year. There are also reports that suggest some tiny colon cancers may arise in flat colon tissue which is either entirely normal or contains a small flat area of adenomatous (precancerous) tissue. This type of colorectal cancer is the exception to the rule and is considered a rare event. The vast majority of colorectal cancers arise from pre-existing adenomatous (precancerous) polyps.

Is it possible to have blood in your stool, but not have colon cancer?

Yes, it is possible to have blood in your stool but not have colon cancer. Hemorrhoids, anal fissures or tears, infections of the colon (infectious diarrhea), inflammatory bowel disease (ulcerative colitis or Crohn's colitis), colonic diverticula and abnormal blood vessels (arteriovenous malformations or angiodysplasia) may all be associated with bleeding from the rectum or colon. Blood in the stool may also occur from lesions in the stomach and small intestine such as peptic ulcer disease, angiodysplasia and Crohn's disease of the small intestine. Rectal bleeding of any amount or blood in or on the stool is never normal and should not be ignored, as some causes of rectal bleeding and blood in the stool (colon cancer) are more serious than others. Speak with your gastroenterologist about any rectal bleeding and schedule a colonoscopy to get the bleeding properly checked out.

What is the best colon cancer screening test?

Colonoscopy is the only method that has a high sensitivity for all polyps, both small and large, and which presents the capability of removing them at the time of the procedure. Virtual colonoscopy is a possibility for screening, but that is not yet approved. Should virtual colonoscopy become an approved screening maneuver, there is a probability of missing small or flat lesions. In addition, any abnormality which is seen will require a colonoscopic examination to verify the finding or for polyp removal. Other, newer screening procedures include testing for abnormal DNA in the stool and the possible combination of a flexible sigmoidoscopy and a barium enema, which is currently suggested if colonoscopy is not generally available. However, for the removal of polyps, there is only one procedure that is currently useful, and that is colonoscopy.

Are colorectal screening tests done by your general practitioner or should they be done by gastroenterologists or other experts?

There are several types of colorectal cancer screening tests. Fecal occult blood tests are usually provided by your general practitioner for you to take home with instructions for the test and how to return them to the laboratory for development. Flexible sigmoidoscopy, which evaluates the lower 1/3 of the colon with an endoscope, is performed by some but not all general practitioners. General practitioners who do not perform flexible sigmoidoscopies in their office typically refer patients to a gastroenterologist of other specialist for the procedure. Colonoscopy is a more extensive endoscopic evaluation of the entire length of the colon and is not done by general practitioners; it is done by gastroenterologists or other gastrointestinal specialists. The colonoscopy is considered the gold standard procedure for colon cancer screening by the American Cancer Society and many more professional organizations, and it is highly recommended that your general practitioner refer you to a Board Certified gastroenterologist or endoscopist to have the test done.

Irritable Bowel Syndrome a risk factor for developing colorectal cancer?

Irritable bowel syndrome (IBS) is a chronic functional problem of the gut usually characterized by patterns of diarrhea and loose stools alternating with constipation. It may also be associated with abdominal cramping and pain. IBS is not associated with an increased risk of developing colorectal cancer. Patients with IBS have normal life expectancies. Although patients with IBS are not at increased risk for colorectal cancer, they are not at decreased risk either, and should follow the recommended screening guidelines like everyone else in the population. If your IBS symptoms change from their usual behavior or regular pattern, or if you see blood in your stool, please notify your physician and gastroenterologist.

Can young people get colorectal cancer? If there is no family history and if the person is under 30, should they be concerned about getting colorectal cancer?

In general, it is very uncommon for young people to get colorectal cancer. However, there are two well recognized hereditary syndromes in which cancer can develop in young people. The first is Familial adenomatous polyposis (FAP). This is a disease in which there is a mutation of a tumor suppressor gene and affected people develop hundreds to thousands of precancerous polyps in the colon. Unless the colon is removed, 100 percent of these patients will get colorectal cancer, usually by the late 30's. The disease is inherited directly from an affected parent (autosomal dominant inheritance), which means that each child has a 50 percent or 1 in 2 chance of inheriting the abnormal gene. If the gene is inherited, the child will eventually develop polyps. The average age for polyp development in this syndrome is the mid-teens, although children as young as eight or 10 have sometimes been found with polyps.

If a family is known to have FAP, the affected parent and at risk children may be screened for a gene mutation with a genetic test. Children from families who refuse or cannot have genetic tests start having sigmoidoscopies or colonoscopies at about 10 or 12 years old and every 6 to 12 months to look for the presence of polyps. Once numerous polyps start developing surgery is planned. The good news about this disease is that the surgical options are very good and now the colon can often be removed by a mini-or laparoscopic approach. The bowel is put directly back together and no bag is necessary. People move their bowels normally.

The other well recognized inherited disorder is hereditary non-polyposis colorectal cancer (HNPCC). In this syndrome cancers also occur early and develop from polyps. But here, there are not the hundreds of polyps seen in FAP. The disease presents at a later age, too. The standard recommendation is colonoscopy in at risk children of affected families beginning at age 25 and repeated every two years. Genetic testing may also be helpful here. So, there are specific recommendations for children in families with high rates of colorectal cancer. But the specific syndrome must be known. It is very important for kids from families like these to be seen by experts who have experience with these syndromes and in institutions where genetic counseling and testing services are available.

It is possible, although quite rare, for sporadic colon cancer to occur in young people outside of those affected by FAP or HNPCC.