What is Colon Cancer?

Colon cancer is the cancer of the large intestine (colon). Colon and rectal cancer are often referred together as as “colorectal cancer.” According to the Centers for Disease Control and Prevention (CDC), colorectal cancer is the second leading cause of cancer deaths in the United States. It is estimated that 1 in 20 (5%) will develop colorectal cancer during their lifetime in the US.

Colon Cancer

Symptoms of Colon Cancer

Most patients with colon cancer do not show symptoms. However, as the disease progresses the following symptoms may appear:

  • A change in bowel habits or a change in the consistency of the stool.
  • Persistent abdominal discomfort, such as cramps, gas or pain.
  • Unexplained weight loss.
  • Black or dark-colored stools.
  • Tiredness, weakness or fatigue.
  • Nausea or vomiting.
  • Low iron level (iron deficiency anemia).

Causes of Colon Cancer

Colon cancer occurs when the cells lining the colon multiply rapidly out of control. Although the exact cause of colorectal cancer is unknown, various risk factors have been identified.

Risk Factors of Colon Cancer

Risk factors of colon cancer include:

  • Age 50 or older.
  • Family history of colorectal cancer.
  • Patient history of other cancer.
  • Smoking.
  • Excessive alcohol consumption.
  • Decreased dietary fiber intake.
  • Eating red or processed meats.
  • Obesity.
  • Inflammatory bowel disease.
  • Colorectal polyps.

Prevention of Colon Cancer

The following efforts may lower the chance of developing colon cancer:

  • Losing weight.
  • Stopping smoking.
  • Eating a healthy diet with an increased consumption of fiber-rich fruits and vegetables.

It is recommended those above 50 years old should undergo a regularly scheduled colonoscopy to screen for cancer and locate suspicious colorectal polyps at the earliest stage possible.

Complications from Colon Cancer:

Untreated and undiagnosed colon cancer is lethal.

Cancerous cells in the colon will continue to grow, causing partial- or complete intestinal obstruction resulting in severe abdominal pain, constipation, and vomiting.

Colon cancer may also involve spread to other organs of the body such as the liver, stomach, lungs, and brain creating widespread problems — ultimately resulting in death.

Diagnosis of Colon Cancer

If your doctor or nurse is concerned that you could have colon cancer, they may advise for colonoscopy.

Colonoscopy is a procedure in which a scope is inserted into your anus allowing the colon to be visualized. Cancers growing within the large intestine and rectum can be seen during a colonoscopy. At the same time, a piece of abnormal-looking tissue can be taken for examination (biopsy), confirming the presence of cancer.

Treatment of Colon Cancer

When colon cancer is confirmed by biopsy, further testing (“staging”) is undertaken to learn the extent of the colon cancer and if it is limited to the colon or involves other organs of the body.

Further treatment depends upon the results of the staging and the general health of the patient.

Surgical Management of Colon Cancer

Surgery is often the initial treatment of colon cancer. During the surgery, the cancerous part of the colon is removed along with some surrounding tissue. See Surgery for Colon Cancer.

In most cases, after removing a cancerous section of the colon, the two ends of the colon are reconnected immediately. In other cases, the two ends cannot be reconnected immediately. In this case, the surgeon will sew the colon to an opening in the skin on the abdomen (called colostomy). Patients will wear a bag over the colostomy to collect bowel movements.

The colostomy is usually temporary. The two ends of the colon can often be reconnected after a few months, sometimes after chemotherapy is completed. Some patients will need the colostomy permanently.

Medical Management of Colon Cancer

Medical management is usually comprised of chemotherapy and correction of anemia.

Chemotherapy is an aggressive treatment given to slow or stop the growth of cancer cells. After the surgery, microscopic cancer cells may still be present. These cells should be removed for a complete cure. If these cells are left without treatment, they will multiply and form cancer again.

Most chemotherapy treatments involve a combination of several drugs. These drugs are given at different intervals. Health care providers will inform patients regarding the drugs, the duration, and expected side effects of the treatment.

Follow Up

Follow-up care after treatment for colon cancer is crucial. Undetected cancer cells can remain in the body after treatment. Healthcare providers will monitor recovery and check for cancer recurrence at specific intervals.