Cancer: Colorectal Cancer Screening
Colorectal caner is one of the most common cancers found worldwide: it is the 3rd leading cause of death in the United States in 2021. Most colorectal cancer arises from adenomatous or precancerous polyps, progression from adenomatous to cancerous polyp on average is 10 years. The United States Preventative Task Force or USPTF currently recommends screening for colorectal cancer in patients aged 45 to 75 years. The USPTF have concluded there are substantial net benefits in screening for colorectal cancer in adults aged 50-75. Benefits of early detection include decreased mortality or death related to colorectal cancer before symptoms develop. Preventative screening can prevent colorectal cancer by detecting and removing precancerous polyps before they progress to cancer. Hyperplastic polyps can be detected as well, they are not precancerous but all colon polyps found are removed for biopsy to determine pathology.
Screening Options
Stool Based Testing: High sensitive guiac fecal occult blood testing (gFOBT) uses chemical detection of blood in stool
Fecal immunochemical test (FIT): uses antibodies to detect blood in stool
Stool DNA: uses biomarkers to detect cancer cells shed from lining of colon & rectum in stool
All abnormal stool based studies require follow up colonoscopy
Flexible sigmoidoscopy: insertion of short, thin, flexible lighted tube into rectum to check for polyps or cancer in the lower third of the colon. Usually an in office procedure without anesthesia
Colonoscopy: similar to flexible sigmoidoscopy but a longer, thin, flexible lighted tube is inserted into the rectum to check for polyps or cancer in the entire colon. Usually done at day surgery center with anesthesia
Computer Tomography Colonography: uses x-rays and computers to produce images of the entire colon for doctors to analyze
Frequency of testing:
High sensitive guiac fecal occult blood testing: yearly
Fecal Immunochemical Test: yearly
Stool DNA: every 3 years
Flexible sigmoidoscopy: every 5 years
Colonoscopy: every 10 years if no polyps found
CT Colonography: every 5 years
Each screening option comes with certain advantages and disadvantages. Deciding on a colorectal cancer screening option is an individualized discussion to have with your medical provider based on risk factors such as family history, genetics and age. Regardless of which option is chosen, preventative screening and early detection saves lives.
