Kevin Lutz, MD, FACP
Apr 1 2018

Colorectal cancer is a disease in which malignant cells form in the tissues of the colon. These cancerous cells form tumors, which usually take years to develop.


Colorectal cancer is a disease in which malignant cells form in the tissues of the colon. These cancerous cells form tumors, which usually take years to develop.

The colon and rectum make up the large intestine, which performs an important function in the body’s ability to process waste. The colon makes up the first 5 to 6 feet of the large intestine, and the rectum makes up the last 6 inches, ending at the anus. Colorectal cancer most often begins as a polyp, a noncancerous growth that may develop on the inner wall of the colon or rectum as people get older. If not treated or removed, a polyp can become a potentially life-threatening cancer. Recognizing and removing precancerous polyps can prevent colorectal cancer.

What are the causes and risk factors of colorectal cancer?

While there is no explicit cause of colorectal cancer, certain factors can increase risk of developing the disease. These factors include:

  • Age: More than 90% of people are diagnosed with colorectal cancer after age 50.
  • Family history of colorectal cancer (especially parents or siblings)
  • Personal history of Crohn’s disease or ulcerative colitis for eight years or longer
  • Colorectal polyps
  • Personal history of breast, uterine or ovarian cancer
  • African-American race
  • Low-fiber, high-fat diet
  • A sedentary lifestyle: getting regular physical activity may reduce the risk of colorectal cancer
  • Diabetes, obesity, smoking, alcohol

What are the symptoms of colorectal cancer?

Colorectal cancer may not present with any symptoms, especially in the early stages. If there are symptoms, they may include: constipation, diarrhea, changes in stool color, a narrow shaped stool, blood in the stool, unexplained weakness, unintended weight loss, or abdominal cramping and pain.

How can colorectal Cancer be prevented?

Regular screenings for Colorectal Cancer, by means of a colonoscopy, when prescribed by your doctor. People with an average risk of colorectal cancer can consider screening beginning at age 50. But people with an increased risk, such as those with a family history of colorectal cancer, should consider screening sooner. Colorectal cancer is the fourth most common type of cancer diagnosed in the United States. Deaths from colorectal cancer have decreased with the use of colonoscopies and fecal occult blood tests, which check for blood in the stool.

The following may lower a person’s risk of colorectal cancer:

Aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) - Some studies suggest that aspirin and other NSAIDs may reduce the development of polyps in people with a history of colorectal cancer or prior polyps. However, regular use of NSAIDs may cause major side effects, including bleeding of the stomach lining. Taking aspirin or other NSAIDs are not a substitute for having regular colorectal cancer screenings. Diet and supplements - A diet rich in fruits and vegetables and low in red meat may help reduce the risk of colorectal cancer. Some studies have also found that people who take calcium and vitamin D supplements have a lower risk of colorectal cancer.

What is the treatment for colorectal cancer?

Surgical Treatment - Surgery to remove the colorectal cancer is almost always required for a complete cure. The tumor and lymph nodes are removed, along with a small portion of normal colon on either side of the tumor.

Medical Treatment - Chemotherapy may help reduce the risk of cancer recurrence and death from cancer. Chemotherapy may be offered after surgery depending on the stage of the cancer or prior to surgery with the goal of shrinking the cancer before an operation. Chemotherapy before surgery is more common in rectal cancer than in colon cancer.

For more information, please visit: