Erica Pettke, MD, MPH, FACS, a colon and rectal surgeon at Penn Medicine, discusses colorectal cancer, its causes, screening and treatment options, including surgery.

Among adults, colorectal cancer is the third most common cancer in the United States. It is also the second most common cause of cancer-related deaths every year.

Fortunately, the overall prognosis is quite favorable if colorectal cancer is discovered early. Up to 90 percent of patients whose colorectal cancer is diagnosed and treated in the early stages can be cured.

Most colon and rectal cancers begin as adenomas, or small polyps, that can progress over time and invade the wall of the bowel. In their later stages, colon and rectal cancer cells can spread to other parts of the body.

Know your risk for colorectal cancer

Roughly 75 percent of colorectal cancers occur in individuals who have an "average risk" of developing the disease, meaning that they aren't suffering from any gastrointestinal conditions or have a family history of colorectal cancer, but you may have certain lifestyle risk factors (i.e., be over age 50, be a heavy drinker or smoker, etc.). Factors that have been identified to increase your risk, include:

• Age: Most people diagnosed with colorectal cancer are over 50. However, in recent years there has been an increase in the number of people under the age of 50 being diagnosed.
• A personal history of colorectal polyps or colorectal cancer.
• Inflammatory bowel disease (IBD): Chronic inflammatory diseases of the colon, such as ulcerative colitis or Crohn's disease, can increase the risk of colorectal cancer.
• Family history of colorectal cancer: First-degree relatives of individuals with colorectal cancer are at increased risk of developing cancer themselves. Know your family history of colorectal cancer.
• Inherited colorectal cancer syndromes: Genetic syndromes present in some families, such as, familial adenomatous polyposis (FAP) or hereditary nonpolyposis colon cancer (HNPCC), can increase the risk of colon cancer.
• Racial/Ethnic background: African Americans have a higher incidence of colorectal cancer as compared to other groups in the United States.
• Lifestyle factors: A diet high in fat and low in fiber as well as obesity can increase the risk for colorectal cancer.

Colorectal screening saves lives

Since the early 1980s, the mortality from colorectal cancer has decreased steadily in the United States. In large part, these declines can be attributed to increased awareness and more pervasive screening. However, recent data show that one in three adults between the ages of 45 and 75 are not up to date on recommended screening for colorectal cancer.

There are several different types of screenings available for individuals of average risk, be sure to ask your care provider which type might be right for you.

Colonoscopy: Colonoscopies are perhaps the most common procedure for colorectal cancer screenings. This test is typically performed by a gastroenterologist using a slender, flexible tube with a light and a video camera on the end that will allow the doctor to review the entire colon. This test is painless and typically takes about a half hour. It is recommended every 10 years and has traditionally been recommended for adults starting at the age of 45; however if you are known to be at risk for colon cancer, you may want to receive a colonoscopy at a younger age.

CT Colonography: Also known as a virtual colonoscopy, this study uses a series of x-rays to provide a detailed view of the inside of the colon. It requires the same bowel preparation as a colonoscopy and, if used, it is recommended every five years.

Stool-Based Tests:

• High-sensitivity guaiac fecal occult blood test (gFOBT): A test that checks for blood in three consecutive stool samples. If used, this test is recommended annually and is often performed at home.
• Fecal immunochemical test (FIT): A test that uses antibodies to detect blood in the stool. If used, this test is recommended annually and only requires one stool sample.
• Stool DNA test (sDNA-FIT): A test that detects altered DNA (blood) in the stool. If used, this test is recommended every one to three years.

Flexible sigmoidoscopy: Flexible sigmoidoscopy is an exam that's used to evaluate the lower part of the colon using a flexible tube with a tiny video camera at the tip. If necessary, the doctor may also perform a biopsy during this procedure. This exam is recommended every five years.

Fecal occult blood test: test that checks for blood in three consecutive stool samples. This test is recommended annually and is often performed at home.

No matter what screening method is right for you, early detection is key when it comes to colorectal cancer and could save your life.

Learn more about colon cancer