Colon Cancer

At a Glance

Colorectal cancer is the cancer which grows in the tissues of the colon and rectum.
  • One of the more commonly diagnosed cancers in the U.S.
  • With early detection, colorectal cancer is essentially curable.
  • Risk Factors include age more than 50, polyps, family history, inflammatory bowel disease, high fat/low fiber diet, and smoking.
  • Several tests may detect colorectal cancer at early stages, allowing the polyps or tumors to be removed.
  • Symptoms include blood in your stool, unexplainable weight loss, frequent diarrhea or constipation, or a feeling of incomplete emptying after a bowel movement.
It is estimated that in 2015 there will be 1,658,370 colon cancer diagnosis in men and women and 589,430 deaths in the U.S. However, the statistics misrepresent this fact: That colorectal cancer is one of the more survivable and curable forms of cancer. If discovered early through tests, colorectal cancer can be removed and with further vigilance, essentially cured. The colon and rectum make up the large intestine, which plays an important role in the body’s ability to process waste. The colon makes up the first five to six feet of the large intestine, and the rectum makes up the last six inches, ending at the anus.

Understanding Colorectal Cancer

Cancer occurs when cells become abnormal and divide without control or order. Like all other organs of the body, the colon and rectum are made up of many types of cells. Normally, cells divide to produce more cells only when the body needs them. This orderly process helps keep us healthy. If cells keep dividing when new cells are not needed, a mass of tissue forms. This mass of extra tissue, called a growth or tumor, can be benign or malignant. Benign tumors are not cancer. They can usually be removed and, in most cases, they do not come back. Most important, cells from benign tumors do not spread to other parts of the body. Benign tumors are rarely a threat to life. Malignant tumors are cancer. Cancer cells can invade and damage tissues and organs near the tumor. Also, cancer cells can break away from a malignant tumor and enter the bloodstream or lymphatic system. This is how cancer spreads from the original (primary) tumor to form new tumors in other parts of the body. The spread of cancer is called metastasis. When cancer spreads to another part of the body, the new tumor has the same kind of abnormal cells and the same name as the primary tumor. For example, if colon cancer spreads to the liver, the cancer cells in the liver are colon cancer cells. The disease is metastatic colon cancer (it is not liver cancer). Colorectal cancer can begin in either the colon or the rectum. Cancer that begins in the colon is called colon cancer, and cancer that begins in the rectum is called rectal cancer.

Risk Factors

The exact cause of colorectal cancer is not known. However, there are certain risk factors that are responsible for the development of this disease—
  • Age over 50 –It is more common in people over 50, and the risk increases with age.
  • Colorectal polyp– growths inside the colon and rectum that may become cancerous
  • Family history and personal history– Close relatives like parents, brothers, sisters or children of a person with a history of colorectal cancer are somewhat more likely to develop this disease themselves, especially if the relative had the cancer at a young age. If many close relatives have a history of colorectal cancer, the risk is even greater.
A person who already had colorectal cancer may develop colorectal cancer a second time. Also, women with a history of cancer of the ovary, uterus or breast are at a somewhat higher risk of developing colorectal cancer.
  • Genetic alterations– Changes in certain genes increase the risk of colorectal cancer. Most common types of inherited colon cancer are hereditary nonpolyposis colon cancer and familial adenomatous polyposis, caused by changes in HNPCC gene and FAP gene respectively.
  • Inflammatory bowel diseases—persons with Ulcerative colitis or Crohn’s disease for many years are at increased risk of developing colorectal cancer.
  • Diet—diets that are high in animal fat and low in calcium, folate and fibres may increase the risk of colorectal cancer. Studies also suggest that a diet very low in fruits and vegetables also increases the risk of developing colorectal cancer.
  • Tobacco smoking—persons who smoke cigarettes may be at increased risk of developing polyps and colorectal cancer.