Post‐colonoscopy upper gastrointestinal malignancies in positive immunochemical fecal occult blood test patients: An Australian data linkage study

Abstract

Background and AimIn immunochemical fecal occult blood test (iFOBT) positive subjects, colonoscopy screening can detect colorectal cancers and advanced adenomas, yet most iFOBT‐positive subjects find no relevant lower gastrointestinal lesions. Limited data are available on upper gastrointestinal (UGI) cancer risk in iFOBT‐positive patients. This study investigated the incidence of UGI malignancies diagnosed within 3 years post‐colonoscopy after a positive iFOBT.MethodsRetrospective analysis of iFOBT‐positive patients aged 50–75 years who underwent a colonoscopy at a single institution. All patients with a diagnosis of UGI cancer within 3 years post‐colonoscopy were identified by linking with the Queensland Cancer Register. This was used to compare to the geographical population aged 50–74 years based on the Australian Bureau of Statistics and Queensland Cancer Council data.ResultsFrom 1748 eligible participants, 0.23% (95% confidence interval [CI] 0.06–0.58) were diagnosed with UGI cancer within 3 years post‐colonoscopy. This indicates an esophageal cancers rate of 114.42 per 100 000 (95% CI 100.56–298.28) and gastric cancer rate of 57.21 per 100 000 (95% CI 55.76–261.12). Of the patients with a UGI cancer, 75% would have had an unexplained iFOBT. Annual incidence for the same geographic region, ages, and period for the combined esophageal and gastric cancer was 36.08 per 100 000 (95% CI 32.87–39.52).ConclusionsAmong individuals with a positive iFOBT in a bowel cancer screening program, the rates of gastric and esophageal cancers were 2.7 and 7.5 times higher than the general population. Adding gastroscopy to a colonoscopy for iFOBT‐positive patients in cancer surveillance programs may be justifiable.