Colorectal cancer screening tests

Colon cancer is common. It's also preventable and treatable if caught early. If you're 45+, take advantage of these screenings.

Colorectal cancer almost always starts with a small growth in the colon or rectum called a polyp. Left undetected, polyps can be cancerous and grow into tumors that can spread. However, found early, doctors can remove polyps and stop colorectal cancer before it starts.

Detecting polyps is the job of screening tests. The Centers for Disease Control recommends:

• For those at average risk, regular screening between ages 45 and 75
• For those at increased risk, a personalized strategy agreed upon by you and your provider

Test types

Several screening tests can be used to find polyps or colorectal cancer. They fall into two categories—stool tests and visual exams.

Stool tests

Stool tests start at home using a kit prescribed by your health care provider. You collect a small amount of stool and return it to a lab where it’s checked either for blood or cancer cells.

• The Guaiac-based Fecal Occult Blood Test (gFOBT)/ Fecal Immunochemical Test (FIT)
  Test looks for blood in the stool.
  Frequency: Annually

• The FIT-DNA test
  Test looks for certain DNA changes from cancer or polyp cells.
  Frequency: Every three years

Visual exams

With these screenings, a provider visibly checks for polyps or cancer in the rectum and colon.

• Flexible Sigmoidoscopy
  Exam is done using a long, thin, flexible, lighted tube inserted through the rectum.
  Frequency: Every five years, or every 10 years along with a yearly FIT stool test

• Colonoscopy
  The sigmoidoscopy uses a lighted tube inserted through the rectum. However, the colonoscopy not only detects but can also remove most polyps and some cancers. Colonoscopy is also used to follow up on suspicious results from another test.
  Frequency: Every 10 years

• CT Colonography (Virtual Colonoscopy)
  Computed tomography (CT) colonography, also called a virtual colonoscopy, uses X-rays and computers to produce images of the colon, which are displayed on a computer screen for the doctor to analyze.
  Frequency: Every five years

How do I know which screening test is right for me?
The “best test” is the one you actually complete. Beyond that, there is no single answer. Each test has advantages and disadvantages. Talk to your doctor about your family and health history, the pros and cons of each test, and how often to be tested.