Interval colorectal cancer is defined as colorectal cancer diagnosed within 60 months of a negative colonoscopy.
The incidence of interval colorectal cancers varies, but depending on the study cited, can be up to 9% of all colorectal cancers. Interval colorectal cancers are more frequently found in the right colon (or ascending colon)
Risk factors include:
Being female
Being older
Having a family history of colorectal cancer
Having a history of diverticulosis
Having other comorbidities
Having a poor bowel prep (not being cleaned out great) or difficult colonoscopy in the past
Having a history of right-sided polyps
Unfortunately, interval cancers DO occur, and there can be up to an 8-10% or greater risk of missed lesions during colonoscopy depending upon multiple factors, including, but not limited to, the quality of your prep, therefore sooner intervals for colon cancer surveillance or screening should be considered particularly if you develop any symptoms or changes in your personal or family history.
Annual FIOBT (Fecal immunochemical Occult Blood Test) or interval fecal occult blood testing should NOT be considered a substitute for colonoscopy.
Please notify our office immediately if anything changes in your medical or family history, or if you develop any alarming symptoms such as rectal bleeding, a change in your bowel habits, a change in the caliber of your stools, abdominal pain, unintentional weight loss, back pain, fevers, chills or sweats, anemia or iron deficiency.