Cancer of the colon or rectum is also called colorectal cancer. In the United States, it is the fourth most common cancer in men and women. Caught early, it is often curable.

It is more common in people over 50, and the risk increases with age. You are also more likely to get it if you have

Polyps - growths inside the colon and rectum that may become cancerous
A diet that is high in fat
A family history or personal history of colorectal cancer
Ulcerative colitis or Crohn's disease

Symptoms can include blood in the stool, narrower stools, a change in bowel habits and general stomach discomfort. However, you may not have symptoms at first, so screening is important. Everyone who is 50 or older should be screened for colorectal cancer. Treatments include surgery, chemotherapy, radiation or a combination.

Colon cancer is the growth of malignant tumors on the inner walls of the colon, a portion of the large intestine which is connected to the rectum. It often occurs along with the cancer of the rectum, a condition referred to as colorectal cancer. The disease often arises from polyp growth, which can multiply and spread over time to invade adjacent organs and tissues. They can spread to distant organs like the lungs or the liver in a process called metastasis, which is more threatening and may require more aggressive measures. However, colon cancer is treatable when spotted early.

Causes of Colon Cancer

Colon cancer is the third leading cancer in men and the fourth in women. It is common in the Western world, with a lesser incidence in Asia and Africa. Western diets which consists of fatty and highly-processed foods have been speculated to have an effect on the rise of colon cancer in Western countries. It has been suggested that the by-products of fat metabolism may give rise to the formation of carcinogens in the colon. Experts stress the importance of diets high in vegetables and fiber to help the body get rid of these by-products on a regular basis to reduce the risk of getting the disease. Other causes thought to increase a person's risk for colon cancer include a family history of colorectal cancer, presence of polyps in the intestine, and chronic ulcerative colitis or an inflammation in the large intestine.

The majority of people diagnosed with colon cancer happens to be people in their 40s and up, with the average age of people developing colon cancer at 62 years. Although the disease has been found in virtually all ages, this may indicate that age may also be a possible risk factor for the development of the disease. Studies have also shown the people who smoked or drank heavily were at an increased risk for developing the disease.

Signs and Symptoms

Colon cancer may present itself in a host of nonspecific symptoms. However, the most common signs and symptoms associated with the disease may include:

Change in bowel movement
Narrow stools
Diarrhea or constipation
Red or dark blood portions in stool
Cramps, abdominal pain, bloating
Unexplained weight loss
Vomiting
Fatigue

Although there are many ways to diagnose any colorectal disease, the most common diagnostic procedures are a fecal occult blood test and a biopsy. A fecal occult blood test detects the presence of blood in the stool, which may indicate bleeding anywhere in the digestive track. In most cases a positive result in a fecal occult blood test may be the only indication of the presence of a disease in the colon.

A colonoscopy may be performed to visualize the inside of the colon and remove any suspected growths or polyps for microscopic examination in a procedure called a polypectomy. A biopsy, performed by a pathologist, is the only procedure which can determine if the affected tissue is malignant (cancerous) or not.

Treatment

Treatment depends on the stage of the cancer. However, almost all cases, regardless of stage, have to undergo surgery to remove all the affected portions of the colon to prevent the cancer from spreading to other sites. Other treatment options include chemotherapy(the use of drugs) and radiation to kill cancerous cells. Almost all patients with stage III cancer who have undergone the initial surgery receive chemotherapy for 6-8 months after the surgery. 5-Fluorouracil, a chemotherapy drug has been shown to be effective in raising the chances for a cure in some patients.

Outlook

Colon cancer can be treated once it is caught early, giving most patients a survival rate of five years following the diagnosis(called the five-year survival rate). Patients with stage I-III cancers and who live past the five-year survival rate after treatment are often considered cured. The chances for survival often depend on the type of medical intervention done and the presence or absence of metastasis to other organs in the body.

Understanding What Is Colon Cancer Recommended Resources:

Penn State Milton S. Hershey Medical Center

Learn. Genetics - Genetic Science Learning Center