Colorectal cancer, or colon cancer, occurs in the colon or rectum. The rectum is the passageway that connects the colon to the anus.
Colon cancer, when discovered early, is highly treatable. Even if it spreads into nearby lymph nodes, surgical treatment followed by chemotherapy is highly successful. In the most difficult cases — when the cancer has metastasized to the liver, lungs, or other sites — treatment can prolong and add to one’s quality of life. Most colon cancers develop first as colorectal polyps, which are abnormal growths inside the colon or rectum that may later become cancerous.
Colon cancer affects men and women of all racial and ethnic groups and is most often found in people 50 years or older. It is the third most common cancer in the United States, behind only lung and prostate cancers in men and lung and breast cancers in women. Colon cancer is the second leading cause of cancer death in the United States.
Studies have found the following risk factors for colon cancer:
Age over 50, colon polyps, family history of colon cancer, genetic alterations, Ulcerative colitis or Crohn’s disease, and tobacco use.
Colon cancer first develops with few, if any, symptoms. It is important not to wait for symptoms before talking to your doctor about getting screened. However, if symptoms are present, they may include:
- A change in your bowel habits, including diarrhea or constipation or a change in the consistency of your stool
- Feeling that your bowel does not empty completely, rectal bleeding, or finding blood (either bright red or very dark) in your stool
- Finding your stools are narrower than usual
- Persistent abdominal discomfort, such as cramps, gas, pain, or feeling full or bloated
- Losing weight with no known reason
- Weakness or fatigue
- Having nausea or vomiting
These symptoms can also be associated with many other health conditions. Only your doctor can determine why you’re having these symptoms. Usually, early cancer does not cause pain. It is important not to wait to feel pain before seeing a doctor.
There are a few different ways your doctor can screen you for colon cancer. The best way is thought to be a colonoscopy. If your physical exam and test results do not suggest cancer, your doctor may decide that no further tests are needed and no treatment is necessary. However, your doctor may recommend a schedule for checkups.
If tests show an abnormal area (such as a polyp), then a biopsy to check for cancer cells may be necessary. Often, the abnormal tissue can be removed during a colonoscopy or sigmoidoscopy. A pathologist checks the tissue for cancer cells using a microscope.
The process used to find out if cancer has spread within the colon/rectum or to other parts of the body is called staging. The information gathered from the staging process determines the stage of the disease. It is important to know the stage in order to plan treatment.
Treatment depends mainly on the location of the tumor in the colon or rectum and the stage of the disease. Treatment for colorectal cancer may involve surgery, chemotherapy, biological therapy, or radiation therapy. Some people have a combination of treatments. Treatment for colon cancer is sometimes different than treatment for rectal cancer. Cancer treatment can be local therapy or systemic therapy.
For more information on Colon Cancer visit Colon Cancer Alliance
*Information from the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), the Colon Cancer Alliance and 
