Colon Cancer Basics

Colon cancer is considered one of the most preventable cancers, yet it remains the second leading cause of cancer deaths in the United States.  In nearly all cases, colon cancer starts as a precancerous growth in the colon called an adenomatous polyp, which rarely causes symptoms.  During the colonoscopy, detected polyps can be removed before they turn into cancer.

Risk Factors

Every one of us is at risk for colon cancer.  The lifetime risk is 1 in 19 people or about 6% of Americans. Although the exact cause is not known, there are some factors that increase a person's risk of developing colorectal polyps and cancer.  These risk factors include:

• Age
• African American race
• Smoking
• Obesity
• Poor diet
• Inflammatory bowel disease
• Family history of colon polyps and cancer

Prevention

Screening for colon cancer should begin at the age of 50.  However, if personal risk factors or a family history of colorectal polyps or cancer is present, screening should begin earlier depending on the circumstances.  The best screening evaluation is a colonoscopy; other screening modalities include: a stool testing for occult blood, flexible sigmoidoscopy, barium enema, or CT colonography (virtual colonoscopy).  On average, 15 percent of women and 25 percent of men over age 50 will have precancerous polyps detected during colonoscopy screening.

Symptoms

Unfortunately, colon cancer can strike without any signs or symptoms.  Some possible symptoms include: constipation, diarrhea, narrowing of stools, incomplete evacuation, bowel incontinence, blood in the stool, unexplained anemia, unusual abdominal pain or bloating, unexplained weight loss, and vomiting.  If you experience any of these signs or symptoms, it is important to see your doctor for evaluation.

Treatment

Colon cancer can be prevented by removing polyps during the colonscopy screening.  If cancer occurs and is more advanced, it requires surgery in nearly all cases for a complete cure. Radiation and chemotherapy are sometimes used in addition to surgery.  Between 80-90% of patients are restored to normal health if the cancer is detected and treated in the earliest stages.

To access a free colon cancer risk assessment, view patient testimonials and other health information related to colon cancer awareness, click here.

Learn more about colon and rectal cancer treatment at Cleveland Clinic's Digestive Disease Institute.