What You Should Know About Colorectal Cancer

Importance of Colorectal Cancer

Did you know that colorectal cancer is one of the most common forms of cancer involving the gastrointestinal tract? It develops from the cells which line the inner part of your large intestine and rectum (the portion right before the anus). This disease accounts for approximately 15% of all cancers in the United States and may be on the rise in young people as well. While we do not know what causes all of these cancers, most colon cancers are thought to arise in colon polyps which can become cancerous. They usually don’t cause any symptoms on their own, and with early detection, such polyps can easily be removed, before they develop into invasive cancers.

Risk Factors

Some of the cancer promoting factors have been identified and are listed below:

1. Age of onset: Most colon cancers arise after age 50 and increase in frequency as you get older. This is the reason why most screening recommendations suggest that screening for this cancer should start when you reach age 50. See your healthcare provider once you turn 50 to ask for screening, or earlier if you have a family history. Also see our blog piece on “Screening for Colorectal Cancer.”
2. Known causes: There are several things that may put you at risk for getting colorectal cancer, including:
   1. Diet:
      1. Eating foods or substances which contain cancer-promoting chemicals: Charred barbecued foods which are blackened. The blackening process unfortunately produces many cancer-promoting chemicals.
      2. A diet low in non-absorbable fiber. This is thought by some to promote constipation which allows cancer causing chemicals to linger in your intestine, thus increasing the risk of cancer formation
   2. Smoking: The smoke from cigarettes or cigars contains cancer-promoting chemicals and much of this is swallowed. Cigarette/cigar smoking is also a risk factor for oral and esophageal cancer, as well as lung cancers.
   3. Chronic inflammatory bowel diseases such as ulcerative colitis or Crohn’s disease. These diseases presumably cause excess cell division of the cells lining your large intestine which allows more cancer-promoting agents to disrupt the cells DNA, causing a cancer to form.
   4. Genetic or familial causes:  Some colorectal cancers run in certain families and have a genetic basis. If a family member has had colorectal cancer, this puts you at higher risk for developing this cancer as well. Consider asking your family members in private if they would be willing to share this information with you to better get an understanding of your family history and risk.  Genetic testing may also be useful for those who are unable to obtain this information from living or deceased relatives. Your healthcare provider can arrange genetic testing for you if appropriate.
3. Symptoms produced by colorectal cancer: NOTE: most early colorectal cancers (those limited to the intestines) produce no symptoms since they are too small to cause blockage of the intestine (see attached figures). However, these small cancers are the ones most easily cured (usually by surgery).  If you wait for symptoms, you may be too late to be cured. This is why we screen for colorectal cancer (see our blog “Screening for Colorectal Cancer”). Common symptoms when they do occur include:
   1. Blood in the stool
   2. Fatigue (may be due to chronic blood loss)
   3. Constipation
   4. Various pains and problems as the cancer spreads from the intestine to other organs (most commonly to the liver, lungs, bone, lymph nodes or “glands”).

More information? For answers to more questions about this type of cancer, contact us at Take CHARGE of Your Health (see contact information below) or visit our Medical Health Consultation page.