Evaluating Gastric Cancer Misclassification: a Potential Explanation for the Rise in Cardia Cancer Incidence

Abstract

Although overall completeness of gastric cancer registration by the Swedish Cancer Registry was excellent, accuracy in registering cardia tumors was surprisingly low. Our estimates suggest that true cardia cancer incidence could be up to 45% higher or 15% lower than that reported in the Cancer Registry. This margin of error could accommodate the observed increase in cardia cancer in Sweden. Therefore, secular trends in cardia cancer incidence should be interpreted cautiously.