Cancer, the uncontrolled growth and spread of abnormal cells, is one of the leading causes of death worldwide. There are many types of cancer and it is usually classified by the part of the body where it starts. In the United States, colorectal cancer is the third most common cancer in men and women (third to prostate and lung in men, and to breast and lung in women). More worrisome is that after lung cancer, colorectal cancer is the second most common cause of death by cancer.
The colon (or large intestine) is the last section of the digestive system and its main function is to reabsorb water and to store non-absorbed food and fiber that will be eliminated by defecation from the rectum (last portion of the colon). Most colorectal cancers begin as polyps, which are growths on the inside walls of the colon or rectum. Polyps vary in size, from a few millimeters to a few centimeters and grow over time. As polyps may become cancerous, they must be removed to prevent development of colorectal cancer.
The colorectal cancer awareness month was created to make the community aware of this disease and to educate how to prevent it. In 2010, it was estimated that 142,570 new cases of colon cancer were diagnosed and 51,370 deaths were caused by colon cancer (second leading cause of cancer death in US).
Men and women are at similar risk to develop colorectal cancer. The risk increases with age as the majority occurs in people age 50 and older. It is important to know also that the majority of people diagnosed with colon cancer have no prior history of colon cancer or polyps. People with a first degree relative (parent or sibling) with colon cancer or polyps have an increase risk at an earlier age, usually at 40 years old but sometimes even earlier. Other risk factors include smoking, alcohol use, obesity, sedentary lifestyle, and diet (occidental – high in red meat intake, low in vegetables).
The way to reduce your risk is to get regular screenings to find polyps before they turn into a cancer or to detect cancer at an early stage. A screening test is a procedure done to detect polyps in an individual with no symptoms. The screening test includes Fecal Occult Blood Test (FOBT), flexible sigmoidoscopy, colonoscopy, double contrast barium enema, and CT colonography (virtual colonoscopy).
The most effective screening test (and recommended by the American College of Gastroenterology) is the colonoscopy: it uses a flexible lighted tube to examine the inside of the entire colon. The flexible tube allows for the removal of polyps and tissue for biopsy. The advantages are that the patient is comfortable (he receives a sedative during the procedure) and the ability to remove any polyps detected. Screening colonoscopies have shown a reduction of death by colon cancer.
Screening save lives by detecting polyps in the colon allowing us to remove them before they become cancerous or finding cancer at an early stage when treatment works best. Once colon cancer has developed, it may cause different symptoms including rectal bleeding, abdominal pain, constipation or diarrhea, and weight loss.
Most people don’t get screened because they are not aware they are at risk for colorectal cancer, the misconception of having pain during a colonoscopy, embarrassment, and cost (it is important to know that screening tests are covered by most insurance plans, including Medicare).
A colonoscopy is done every 10 years unless there is history of colon cancer or polyps in the immediate family (in such cases it is every 5 years). If polyps are found, it is recommended every 3 to 5 years. High risk patients, such as patients with inflammatory bowel disease (Ulcerative colitis or Crohn’s colitis) or patients with uncommon familial cancer syndromes, may require more frequent colonoscopies.