Longterm prognosis in 600,000 individuals with a normal gastrointestinal mucosa - nationwide cohort study

Purpose and aimWe will examine the long-term prognosis of individuals with a normal gastrointestinal (GI) mucosa.

We are particularly interested in their risk of  death, colorectal cancer and inflammatory bowel disease (IBD).MethodsOur team has collected longitudinal tissue-based GI histopathology report data from all of the 28 pathology departments in Sweden, and identified 1.79 million unique individuals with histopathology data from 1965-2017 (>600 000 had a normal GI mucosa)[1].

Individuals with a normal mucosa will then be compared with age- and sex-matched reference individuals from the general population.

Through Cox regression, we will estimate hazard ratios (HRs) for death, colorectal cancer and inflammatory bowel disease, which will be identified from the Swedish nationwide health registers (the Cause of Death, Cancer and Patient Registers).

To minimize intrafamilial and environmental confounding we will also compare individuals with normal mucosa to their siblings.

Our preliminary data suggest that individuals with a normal GI mucosa are at a lower risk of colorectal cancer but at a higher risk of overall death compared with the general population.Importance1 in 20 individuals in Sweden (n>600 000) has a record of normal mucosa on GI biopsy (esophagus to the colorectum).

Swedish healthcare has numerous guidelines for following up patients with abnormalities and diseases, but no recommendations of follow-up for those who have a normal mucosa.