Preventable interval cancers often caused by neoplasms missed at colonoscopy

More thorough colonoscopies could potentially detect a significant number of neoplasms that eventually cause interval cancers, according to a study.

A population-based case-control study included 78 patients who developed interval cancers 1 to 10 years after a negative colonoscopy. These patients were compared with 433 patients with colorectal cancers detected via colonoscopy as well as with 515 controls with a negative colonoscopy.

More interval cancers (56.4%) occurred among women, compared to 33.7% of cancers detected by screening (P=.0001). Location in the cecum or ascending colon occurred in 47.4% of interval cancers but only 29.1% of screening-detected cancers.

Among patients with interval cancers, prior negative colonoscopy was more often conducted based on a positive fecal occult blood test and was more commonly incomplete.

“The observed patterns suggest that a substantial proportion of interval cancers are due to neoplasms missed at colonoscopy and are potentially preventable by enhanced performance of colonoscopy,” the study authors said.

Disclosure: The research was supported by grants from the German Research Council and the German Federal Ministry of Education and Research. The sponsors had no role in the study design or in the collection, analysis, or interpretation of data.