Colon Cancer

What Is Colon Cancer?

Colon cancer is a type of cancer that develops in the tissues of the colon or rectum. The colon and rectum are parts of the digestive system. This type of cancer develops from polyps or growths in the inner lining of the colon.

Colorectal (colon and rectum) cancers are the third most common type of cancer in both males and females in the U.S. These cancers are typically diagnosed in people 50 and older. There is a growing number of people under 50 are diagnosed with colon cancer. Colorectal cancer is now the leading cause of cancer death in men. It is the second leading cause of death in women under 50. Lifetime risk of developing colon cancer is 1 in 23 for men and 1 in 25 for women.

Colorectal cancer occurs when there are changes in your genetic material. These mutations can happen during your lifetime, and the exact cause is unknown. Certain genetic changes that raise the risk of colon cancer are inherited. Your lifestyle and the environment also can affect your risk of developing colon cancer.

Prevention

Colon cancer is about 95% preventable. The best way to prevent colon cancer from developing is to reduce your risk. Make these changes to help lower your risk:

• Eat vegetables, whole grains and healthy fats.
• Exercise daily to lose and maintain weight.
• Limit alcohol and stop smoking.
• Stop carrying extra pounds.

Colon Cancer Screening

Health screenings look for disease before you have symptoms. A colorectal screening looks for precancerous colon polyps and signs of colon cancer. Colon cancer is highly treatable when detected early.

Colon cancer (colorectal) screening uses a colonoscopy to look inside the colon and rectum. Colon cancer screenings can identify and remove polyps before they become cancerous. A polyp is a small, abnormal growth in the lining of the colon. It can take 10 to 15 years for a polyp to become cancerous. Screening also can detect cancer early when it is easier to treat.

People with an average risk of colon cancer should start regular screenings at age 45. If you have a high risk of developing colon cancer due to family history, previous polyps, previous cancer or other factors, you may need to start screening at age 40 or earlier. Talk with your doctor about when to start screening.

Colon cancer screening helps save lives.

Signs and Symptoms

In early stages, colon cancer may not cause any symptoms. When symptoms appear, they can be similar to symptoms of less serious conditions. It’s important to talk with your doctor about symptoms that you experience.

Colon cancer symptoms include:

• Belly pain
• Bloated stomach
• Blood in stool
• Changes in bowel habits
• Fatigue
• Frequent gas or cramps
• Unexplained weight loss

Risk Factors

• Age
• Diet high in red and processed meat
• Family history of colon or rectal cancer
• Genetic conditions, such as familial adenomatous polyposis (FAP) or Lynch syndrome (hereditary non-polyposis colorectal cancer)
• History of inflammatory bowel disease (IBD), such as ulcerative colitis and Crohn’s disease
• Lifestyle factors, such as lack of exercise, obesity, smoking and alcohol consumption
• Low vitamin D levels
• Personal or family history of adenomas (polyps) in the colon or rectum

Diagnosis

A doctor who specializes in gastroenterology (GI) can diagnose colon cancer. Your doctor will ask about your medical history and any family history of colorectal cancer. They also will conduct a physical exam, including a rectal exam to check for lumps.

Your gastroenterologist may use a combination of imaging tests, lab tests and diagnostic procedures to diagnose or rule out colon cancer.

Diagnostic Procedures

Colonoscopy: This is the gold standard test to diagnose colorectal cancer. A long flexible scope (colonoscope) with a camera is used to look inside the whole colon and rectum for polyps. Removing polyps helps prevent the development of cancer. Studies have shown that removing polyps during a colonoscopy can reduce the risk of developing colorectal cancer by more than 95%.

Sigmoidoscopy: This procedure looks inside the rectum and lower colon (sigmoid) for polyps or cancer. The procedure is like a colonoscopy, but it examines only the lower colon (sigmoid) and the rectum.

Imaging Tests

CT scan: A computer uses a series of X-rays to make pictures of the colon. The detailed images may show polyps or anything unusual on the inside surface of the colon.

Double-contrast barium enema: A liquid with barium (a metallic compound) is put into the rectum to coat the lower gastrointestinal tract. Then, X-rays are taken.

Lab Tests

Blood tests: Complete blood counts (CBC), comprehensive metabolic panels (CMP) and carcinoembryonic antigen CEA) assays may show signs of colon cancer.

DNA tests: A stool test that looks at DNA that comes from cells lining the colon and rectum. It looks for abnormal DNA that may be from a cancer.

Fecal occult blood testing: A test to check stool for blood that can only be seen with a microscope.

Treatment

Treatment options for colon cancer depend on your age, overall health, how advanced the cancer is and what type of cancer you have. Treatment options can include medications, procedures and/or surgery combined with lifestyle management.

Medications

Chemotherapy: Cancer treatment using drugs that are injected into the bloodstream or pills taken by mouth. The medications travel through the blood and destroy cancer cells.

Immunotherapy: This type of cancer drug is based on biologics that find and destroy colorectal cancer cells. These medications work with your immune system to fight cancer.

Targeted therapy: Treatment uses drugs to identify and attack specific cancer cells. Targeted therapy does not harm normal cells.

Procedures

Cryosurgery: A procedure that uses an instrument called a cryoprobe to freeze and destroy abnormal tissue.

Radiation therapy: Cancer treatment that uses high-energy rays to damage cancer cells and prevent them from growing. Radiation may be used before surgery to shrink a tumor. It may be used after surgery to go after cells that can’t be removed.

Radiofrequency ablation: A procedure that uses a probe that with tiny electrodes to destroy cancer cells.

Surgery: Surgery is the most common treatment for early-stage colon and rectal cancers. Your surgeon removes the tumor and some of the surrounding tissue. The type of surgery depends on the stage and location of the cancer. Some cancers can be completely removed with surgery.

If your colon cancer goes away with treatment, your cancer team will continue to monitor you for several years. When the treatment ends, your doctor will recommend which testing you will need going forward and when the testing should be done.

Lifestyle Management

Getting regular exercise, maintaining a healthy weight, reducing or eliminating alcohol and smoking have been shown to decrease the likelihood of colon cancer recurring.

Clinical Trials

Clinical trials help determine new treatment options for diseases and conditions. Patients with colon cancer have access to clinical trials and should speak with their doctor to determine what trials might work best for them.