FREQUENTLY ASKED QUESTIONS IN COLON CANCER AND COLONOSCOPY
By: Donnazon Reyes, M.D.
Edited by: Felix Domingo, Jr. M.D.
- WHAT IS COLON CANCER?
- WHAT ARE THE CAUSES OF COLON CANCER?
- HOW FATAL IS COLON CANCER?
- WHO ARE AT RISK OF COLON CANCER?
- WHAT ARE THE SIGNS AND SYMPTOMS OF COLON CANCER?
- IS COLON CANCER PREVENTABLE?
- WHAT ARE THE TESTS AVAILABLE FOR SCREENING?
- WHAT IS A COLONOSCOPY?
- IS COLONOSCOPY PAINFUL?
- WHAT ARE THE COMPLICATIONS OF COLONOSCOPY?
- WHEN SHOULD COLONOSCOPY BE DONE?
- WHAT ELSE CAN I DO TO PREVENT COLON CANCER?
WHAT IS COLON CANCER?
Colorectal (large intestine) cancer is a disease in which malignant (cancer) cells form in the inner lining of the colon or rectum. Colon and rectum is the last part of your digestive sy stem, whose mainrole is for absoprtion of water and nutrients. The large intestine is about 120 cm in length and the last 6 inches of which is the rectum
WHAT ARE THE CAUSES OF COLON CANCER
Most colon cancers begin as polyps which, if not removed, can be cancerous. The development of more than 75-90% colorectal cancer can be avoided through early detection, and remove of precancerous lesions.
Not all polyps have the potential to transform into cancer. Those that do have the potential are called adenomas. It takes more than 10 years in most cases for an adenoma to develop into cancer. This is why some colon cancer prevention tests are effective even if done at 10-year intervals.
HOW FATAL IS COLON CANCER?
Colorectal cancer is the 2nd most frequent cause of cancer death in the U.S. In the Philippines, it is the fourth leading cause of morbidity and mortality after lung, breast, and cervical cancer. Unfortunately, few people realize that simple tests can be used to prevent this fatal disease.
WHO ARE AT RISK OF COLON CANCER?
- Everyone age 50 and older
- Men and women
- Anyone with a family history of colorectal cancer
- Anyone with a personal history of colorectal cancer or adenomas at any age, or cancer of endometrium (uterus) or ovary diagnosed before age 50
WHAT ARE THE SIGNS AND SYMPTOMS OF COLON CANCER?
Symptoms of colorectal cancer vary depending on the location of the cancer within the colon or rectum, though there may be no symptoms at all.
The most common presenting symptom of colorectal cancer is rectal bleeding. Cancers arising from the left side of the colon generally cause bleeding, or in their late stages may cause constipation, abdominal pain, and obstructive symptoms. On the other hand, right-sided colon lesions may produce vague abdominal aching, but are unlikely to present with obstruction or altered bowel habit. Other symptoms such as weakness, weight loss, or anemia resulting from chronic blood loss may accompany cancer of the right side of the colon.
IS COLON CANCER PREVENTABLE?
Yes, colon cancer is preventable with proper screening technique.
WHAT ARE THE TESTS AVAILABLE FOR SCREENING?
- Fecal occult blood test.
- Double contrast barium enema (DCBE).
- Sigmoidoscopy.
- Colonoscopy
- Computerized topographic (CT) colonography and magnetic resonance (MR) colonography
- Fecal DNA testing.
WHAT IS A COLONOSCOPY?
Colonoscopy is a procedure which enables a physician (usually a gastroenterologist) to directly image and examine the entire colon. It is effective in the diagnosis as well as in providing therapy (for example, removal of polyps or control of bleeding). It is also used for screening for colon cancer.
A colonoscope is a flexible and steerable instrument to evaluate the entire colon (large intestine). The large intestine is approximately 3 – 4 feet long. A colonoscope is engineered such that biopsies of suspicious areas can be obtained, and polyps (which may turn into cancer) can be remove
IS COLONOSCOPY PAINFUL
No, colonoscopy is usually not painful! Almost all colonoscopies can be performed using “intravenous sedation” or “twilight sedation” in which you are very drowsy, but comfortable and still breathing on your own.
WHAT ARE THE COMPLICATIONS OF COLONOSCOPY?
Colonoscopy has been found to be extremely safe when performed by a well trained physician such as a gastroenterologist. Although quite rare, most complications are related to sedation administration (cardiac and respiratory problems); the colon may also become partially torn (perforated) and this may require surgery. Rarely, bleeding from polyp removal or from the procedure itself may require additional treatment such as hospitalization and/or blood transfusions.
WHEN SHOULD COLONOSCOPY BE DONE?
If you have no colorectal symptoms, family history of colon cancer, polyps or inflammatory bowel disease you should have your first exam at age 50 whether you are a man or a woman since colon cancer affects both EQUALLY!
If one or more first degree relative (parent, sibling or child) has had a precancerous polyp or colon cancer, the general guideline is to begin colon cancer screening 10 years younger than the youngest age of the family member with colon cancer, or age 40, whichever is younger.
WHAT ELSE CAN I DO TO PREVENT COLON CANCER
Recent observations suggest regular use of non-steroidal anti-inflammatory drugs or aspirin, reduce the chances of colorectal cancer death by 30-50%. These drugs also have risks, particularly intestinal bleeding, and patients should consult their physician as to whether regular use of these agents is appropriate. Folate, calcium, and post-menopausal estrogens each have a modest protective benefit against colon cancer. A high fiber (vegetables) and low fat diet, regular exercise, maintenance of normal body weight and cessation of smoking are also beneficial. None of the measures is as effective as or should replace colorectal cancer screenining.
