Prevalence and risk factors of upper gastrointestinal cancers missed during endoscopy: a nationwide registry-based study

Background A significant proportion of upper gastrointestinal cancers (UGICs) remain undetected during esopha-gogastroduodenoscopy (EGD). We investigated the characteristics and risk factors of UGICs missed during endoscopy. Methods In this nationwide registry-based study, we analyzed two large Polish datasets (National Health Fund and National Cancer Registry) to identify individuals who underwent EGD and were subsequently diagnosed with UGIC. Cancers diagnosed <6 months after EGD were defined as "prevalent" and those within >= 6-<36 months as "missed." We compared the characteristics of missed and prevalent cancers, and analyzed the risk factors for missed UGICs in a multivariable regression model. Results We included 4105399 patients (mean age 56.0 years [SD 17.4]; 57.5% female) who underwent 5877674 EGDs in 2012-2018. Within this cohort, 33241 UGICs were diagnosed, of which 1993 (6.0%) were missed. Within esophageal neoplasms, adenocarcinomas were more frequently missed than squamous cell cancers (6.1 % vs. 4.2%), with a relative risk of 1.4 (95% confidence interval [CI] 1.1-1.8, P= 0.01). Most gastric cancers were adenocarcinomas, of which 5.7% were classified as missed. Overall, a higher proportion of missed UGICs than prevalent cancers presented at an advanced stage (42.2% vs. 36.2%, P< 0.001). Risk factors for missed UGICs included initial EGD performed within primary (vs. secondary) care (odds ratio [OR] 1.3, 95%CI 1.2-1.5), female sex (OR 1.3, 95%CI 1.21.4), and higher comorbidity (Charlson comorbidity index >= 5 vs. 0; OR 6.0, 95 %CI 4.7-7.5). Conclusions Among UGICs, esophageal adenocarcinomas were missed most frequently. Missed cancers occur more frequently within the primary care sector and are found more often in women and individuals with multiple comorbidities.