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Colon Cancer FAQ

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• Aren’t there other tests that could detect colon cancer? The thought of a colonoscopy makes me nervous.

  Sure there are, but not all screening techniques are equal. At a minimum, each man and woman should have an annual fecal occult blood test (FOBT), which uses a smear of stool on a specially treated card, with their primary care physician plus a flexible sigmoidoscopy (which looks at a short segment of the bowel) every three to five years or a colonoscopy every ten years. A patient might have a negative FOBT but have precancerous or cancerous growths in the colon. A sigmoidoscopy detects cancers with 45 percent less accuracy than a colonoscopy. A barium enema, done in the Radiology department, detects only 30 to 50 percent of cancers compared to a colonoscopy.

• Why does a colonoscopy detect more cancers than other methods?

  A colonoscopy examines the entire length of the lower bowel, and provides the opportunity to remove and biopsy polyps.

• What is a polyp?

  A polyp is a mass of overgrown tissue on the surface of the bowel. By age 50, one in four people have polyps. Removing a cancerous polyp before it penetrates the bowel wall is essential. Virtually all colon cancer develops from adenomatous polyps in the colon, generally referred to simply as colon polyps. A personal or family history of polyps puts one at higher risk for colon cancer. Polyps don't always become cancerous, but risk of developing cancer increases with the number and size of colon polyps seen.

• How frequently are polyps cancerous?

  Approximately one percent of polyps with a diameter less than a centimeter are cancerous. If there is one polyp that size, the American Cancer Society (ACS) recommends that the doctor remove it and that a repeat colonoscopy is done three to five years later. Without any polyps, the recommended repeat date is ten years later. If there is more than one polyp or the polyp is bigger than a centimeter, there is an even higher risk for colon cancer. Up to 50 percent of polyps greater than two centimeters (about the diameter of a nickel) are cancerous.

• What about a family history of colon polyps…does that change anything?

  When it comes to polyps and colon cancer risk, family history is important. If one or two first degree relatives (defined as parents, siblings or children) have ever had any colon polyps, the American Cancer Society (ACS) recommends a first colonoscopy at age 40 or ten years before the age when the relative's polyp was found, whichever is earlier. So if a brother had a polyp removed when he was age 45, the ACS recommends a colonoscopy at age 35 for the patient.

• Here is what the American Cancer Society writes about the familial link to colon cancer:

  Familial disease
  About 30 percent of people who develop colorectal cancer have disease that is familial. People who have a strong family history of colorectal cancer (as defined above), especially if the relatives are affected before the age of 60, are considered at increased risk of developing this disease. People with a family history of colorectal cancer need to talk with their doctor about beginning colorectal cancer testing before the age of 50.
  
  Inherited disease
  About another 10 percent of people who develop colorectal cancer have an inherited genetic susceptibility to the disease. Approximately three to five percent of colorectal cancers are associated with the inherited colorectal cancer syndrome, called hereditary non-polyposis colorectal cancer (HNPCC), or Lynch syndrome. Another one percent of colorectal cancer cases are associated with the inherited syndrome, called familial adenomatous polyposis (FAP).
  
  Familial adenomatous polyposis (FAP) is a disease where people typically develop hundreds of polyps in their colon and rectum. Usually this occurs between the ages of five and 40. Cancer usually develops in one or more of these polyps beginning at age 20. By age 40, almost all people with this disorder will have developed cancer if preventive surgery is not done. FAP is sometimes associated with Gardner syndrome, a condition that involves benign (noncancerous) tumors of the skin, soft connective tissue and bones. About one percent of all colorectal cancers are due to FAP.
  
  Hereditary nonpolyposis colon cancer (HNPCC) is another clearly defined genetic syndrome. It accounts for three to five percent of all colorectal cancers. This syndrome also develops when people are relatively young. These people have polyps, but they only have a few, not hundreds as in FAP. Women with this condition also have a very high risk of developing cancer of the endometrium (lining of the upper part of the uterus). Other cancers associated with HNPCC include cancer of the ovary, stomach, small bowel, pancreas, kidney, ureters (tubes that carry urine from the kidneys to the bladder) and bile duct.
  
  Doctors have found that most families with HNPCC have certain characteristics:

  • At least three relatives have colorectal cancer.
  • Two successive generations are involved.
  • At least one relative had their cancer when they were younger than age 50.
  • At least two of the people are first-degree relatives.

  These are called the Amsterdam criteria. If any of these hold true for your family, then you might want to seek genetic counseling. But even if your family history satisfies the Amsterdam criteria, it doesn’t mean you have HNPCC. Only about 60 percent of families who have the Amsterdam criteria have HNPCC. The other 40 percent do not; and although their colorectal cancer rate is higher than normal (about two times), it is not as high as that of people with HNPCC (about six times).
  
  A second set of criteria for HNPCC, which has been recently revised, is called the Bethesda criteria. These are used to determine whether a person with colorectal cancer should have their cancer tested for genetic changes called microsatellite instability (MSI). These criteria include at least one of the following:

  • The person is younger than 50 years.
  • The person has or had another cancer (endometrial, stomach, pancreas, ovary, kidney or ureters, bile duct) that is associated with HNPCC.
  • The person is younger than 60 years and the cancer has certain characteristics seen with MSI when viewed under the microscope.
  • A first-degree relative has been diagnosed with a noncolorectal cancer often seen in HNPCC carriers (endometrial, stomach, pancreas, ovary, kidney, ureters or bile duct) and is younger than 50 years.
  • The person has two or more second-degree relatives who had an HNPCC-related tumor at any age.

  MSI testing is the first step in laboratory testing to identify people with HNPCC. If a patient meets Bethesda criteria and has a tumor with MSI, more genetic testing will be needed to confirm that there is a mutation of one of the HNPCC genes. Still, the majority of people who meet the Bethesda criteria do not have HNPCC. On the other hand, about two percent of people with colorectal cancer who do not meet any of these criteria still have HNPCC when they are tested.
  
  Doctors should also be suspicious of HNPCC if, instead of colorectal cancer, the family members have other cancers associated with this gene mutation. These are endometrial cancers, ovarian cancers, small bowel cancers, or cancer of the lining of the kidney or the ureters. Still, one family member younger than age 50 must have been diagnosed with colorectal cancer before a diagnosis of HNPCC is considered.
  
  Accurate identification of families with these inherited syndromes is important. Then doctors can recommend specific measures, such as screening and other preventive measures, at an early age. Because several types of cancer can be associated with inherited colorectal cancer syndromes, all people should check their family medical history for polyps or any type of cancer. Those who develop polyps or cancer should inform other family members. People with a family history of colorectal polyps or cancer should consider genetic counseling, to review their family medical tree and determine whether genetic testing may be right for them. This will help them to make decisions about getting screened and treated at an early age.

• Besides colon polyps, is there anything else that might increase my risk of colon cancer?

  You should begin screening earlier if you have a personal or family history of colorectal cancer (which can involve the colon, the rectum, or both), polyps, rectal bleeding or long-standing inflammatory bowel disease such as ulcerative colitis.

• Tell me more about inflammatory bowel disease and increased risk. What is the connection?

  Chronic inflammatory bowel disease (IBD), including ulcerative colitis and Crohn's disease, is a condition in which the colon is inflamed over a long period of time. If you have chronic inflammatory bowel disease, your risk of developing colorectal cancer is increased. You should start being screened by colonoscopy eight to 12 years after you were first diagnosed with IBD and testing should be repeated frequently (every one to two years). Often the first sign that cancer may be developing is called dysplasia. Dysplasia is a term that refers to cells that are no longer normal but they are not cancer yet. Inflammatory bowel disease is different than irritable bowel syndrome (IBS), which does not carry an increased risk for colorectal cancer.

• Are men at higher risk than women for developing colon cancer?

  Colorectal cancer affects an equal number of men and women. Colorectal cancer is the second leading cause of cancer deaths in the United States. The number of new cases and the number of deaths to colorectal cancer has been decreasing as preventive screening and colon health awareness has increased.

• Why is age so important in screening for colorectal cancer?

  The risk of colorectal cancer tends to increase after the age of 40. Beginning at age 50, all men and women should be screened for colorectal cancer, even if they are not experiencing problems or symptoms. Annually, approximately 130,000 new cases of colorectal cancer are diagnosed in the United States and 56,000 people die from the disease. It has been estimated that increased awareness and screening could save 30,000 lives each year.

• What are the risks for women?

  After lung cancer and breast cancer, colorectal cancer is the third leading cause of cancer deaths in women in the United States.

• Does race affect colorectal cancer screening recommendations?

  The American College of Gastroenterology recommends that African Americans should have colon screening for cancer at age 45, instead of 50. The recommendation is because African Americans are diagnosed with colorectal cancer at a younger age than Caucasians. African Americans who develop colorectal cancer have decreased survival, compared with Caucasians. They further recommend colonoscopy to be the preferred screening procedure for African Americans (rather than flexible sigmoidoscopy) because African Americans have more right-sided cancer and polyps and flexible sigmoidoscopy cannot reach the right side of the colon.

• How is a colonoscopy done?

  Colonoscopy is almost always done on an outpatient basis. A mild sedative is usually given before the procedure and then a flexible, slender tube is inserted into the rectum to look inside the colon. The test is safe and the procedure itself typically takes less than 30 minutes. It is a camera-assisted study of the internal structures and tissues of the entire large intestine, which is also known as the colon, the rectum and the anus. Samples of tissue (known as biopsies) can be taken at the time of the procedure.

• How do I prepare for a colonoscopy?

  Preparation for the test includes a bowel cleansing routine (prescribed by the doctor performing your colonoscopy) to clear any stool from your colon and nothing to eat or drink after midnight on the day of the test. It is usually performed as an outpatient procedure with mild sedation and pain medicine. You will need someone who can drive you home afterwards, since you will be a little drowsy and will not be allowed to drive or operate machinery that day.

• Why is early detection so important?

  There were 106,680 new cases of colon cancer in 2006 and 55,170 deaths from colon and rectal cancers combined. When colon cancer is localized to the bowel and surgical resection of the affected bowel is the primary form of treatment, the cure rate is 50 percent. The longer cancerous cells stay inside the bowel, the more damage they can cause.
  
  Why is that?
  The prognosis of patients with colon cancer is related to the following:

  • Degree of penetration of cancer cells through the bowel wall.
  • Presence or absence of lymph node involvement.
  • The presence of metastasis (spread of cancer cells to other parts of the body.)

  Early detection and treatment is therefore essential to a patient’s outcome.

• What are the colon cancer risk factors?

  1. Age
  Age is the number one risk factor for colon cancer. By age 50, one in four people have polyps.
  
  2. Alcohol
  While wine has shown a protective effect, other alcohol (primarily liquor) appears to increase the risk of colon cancer. Increased risk seems to be mainly associated with distilled spirits like gin, vodka and bourbon. Colorectal cancer has been linked to the heavy use of alcohol. While some of this may be due to the effects of alcohol on folic acid in the body, it still would be wise to avoid heavy alcohol use.
  
  3. Diabetes
  A study published in the Journal of Gastroenterology found that insulin dependency contributes to colon cancer development. In general, diabetics are up to 40 percent more likely to develop colon cancer than people who don't have diabetes. They also tend to have a higher death rate after diagnosis.
  
  4. Diet
  Diets high in fat and cholesterol (especially from animal sources) have been found to cause colon cancer. The American Cancer Society recommends choosing most of your foods from plant sources and limiting your intake of high-fat foods such as those from animal sources. The American Cancer Society also recommends eating at least five servings of fruits and vegetables every day and several servings of other foods from plant sources, such as breads, cereals, grain products, rice, pasta or beans. Many fruits and vegetables contain substances that interfere with the process of cancer formation.
  
  5. Environment
  The risk of developing colon cancer varies throughout the world. Studies indicate that colon cancer rates are lowest in Kuwait, India and Romania and highest in the United States, Switzerland and Canada. Why these rates differ isn't clear.
  
  6. Ethnicity, Race and Social Status
  Research has found genetic mutations that cause colon cancer in Jewish people of Ashkenazi descent. In fact, Ashkenazi Jews are two-to-three times more likely to develop colon cancer than members of the general population. In general, minority populations are at greater risk of dying from colon cancer because they receive preventive care less often. This includes racial minorities such as African Americans, Hispanics, Native Americans and Vietnamese, as well as social minorities such as gays and lesbians.
  
  7. Exercise
  If you are not physically active, you have a greater chance of developing colorectal cancer.
  
  8. Gender
  A review of colorectal cancer cases worldwide found that men and women are at equal risk.
  
  9. Genetics
  Researchers estimate that about 25 percent of colon cancer cases have some sort of genetic link. Examples of the most common genetic causes of colon cancer include mutations leading to FAP (familial adenomatous polyposis) and HNPCC (hereditary non-polyposis colorectal cancer). The word ‘polyposis’ refers to polyp development.
  
  10. Obesity
  If you are very overweight, your risk of dying from colorectal cancer is increased.
  
  11. Smoking
  Recent studies indicate that smokers are 30 to 40 percent more likely than nonsmokers to die from colorectal cancer. Smoking may be responsible for causing about 12 percent of fatal colorectal cancers. Almost everyone knows that smoking causes cancers in sites in the body that come in direct contact with the smoke, such as the mouth, larynx and lungs. However, some of the cancer-causing substances are swallowed and can cause digestive system cancers, such as esophageal and colorectal cancer. Some of these substances are also absorbed into the bloodstream and can increase the risk of developing cancers of the kidneys, bladder, cervix and other organs.
  
  12. Night-shift work
  Results of one single study suggest working a night shift at least three nights a month for at least 15 years may increase the risk of colorectal cancer in women. The study authors suggested this might be due to changes in melatonin (a hormone that responds to changes in light) levels in the body. More research is needed to confirm or refute this finding, however.

• Can you explain more about each type of screening test for colorectal cancer?

  Exams and Tests Explained:

  • For a digital rectal exam, the doctor gently inserts a gloved, lubricated finger into the rectum and feels for abnormal areas. Fifteen percent of colorectal cancers can be detected by digital rectal examination.
  • The stool test for blood (FOBT) checks for hidden or occult blood in the stool. Sometimes colorectal cancers can cause bleeding that cannot be seen. For this test, a small amount of stool is placed on a plastic slide or on special paper. The stool may be tested in the doctor's office or sent to a lab.
  • A sigmoidoscopy exam allows the doctor to visualize up to 25 inches of the lower bowel. For this exam, the doctor gently inserts a small, flexible, lighted tube into the rectum and lower colon. Approximately 72 percent of all colorectal cancers occur in this area.
  • A colonoscopy is an examination of the rectum and entire colon using a lighted instrument called a colonoscope. Colonoscopy can find precancerous or cancerous growths throughout the colon, including the upper part of the colon, where they would be missed by sigmoidoscopy. However, it is not known whether this benefit outweighs the risks of colonoscopy, which include possible bleeding, and puncturing of the lining of the colon. More research is needed to address these issues.

• Is there anything I should be looking for to report to my doctor that might indicate a need for earlier screening or screening out of the expected interval of every ten years?

  Symptoms to Report to Your Doctor:

  • A change in usual bowel habits (constipation, diarrhea or both)
  • Stools that are narrower than usual
  • Blood in or on the stool
  • General stomach discomfort, such as bloating, fullness and/or cramps
  • Frequent gas pains
  • A feeling that the bowel does not empty completely
  • Weight loss with no known reason
  • Constant tiredness

• How can I contact the Digestive Disease Center to schedule an appointment?

  After discussing a screening colonoscopy with your primary care physician and having obtained a referral for the procedure, call (773) 564-5199 to schedule your test.

• I live alone and don’t have anyone to drive me to the test. What can I do?

  Weiss offers a Courtesy Van to help with your transporation needs.