A prediction rule for estimating pancreatic cancer risk in chronic pancreatitis patients with focal pancreatic mass lesions with prior negative EUS-FNA cytology

Abstract Objective. Considerable false-negative endoscopic ultrasound guided fine needle aspiration (EUS-FNA) findings exist in chronic pancreatitis patients with focal pancreatic mass lesions. Our aim was to develop a prediction rule to stratify risk for pancreatic cancer in chronic pancreatitis patients with focal pancreatic mass lesions with prior negative EUS-FNA cytology. Material and methods. A total of 138 eligible consecutive patients were identified from three hospitals between January 2000 and May 2008. A final diagnosis of pancreatic mass lesions was confirmed histologically or verified by a follow-up of at least 12 months. A prediction rule was developed from a logistic regression model by using a regression coefficient-based scoring method, and then internally validated by using bootstrapping. Results. The rate of pancreatic cancer in the cohort was 18.1%. The prediction rule, which was scored from 0 to 10 points, comprised five variables: sex, mass location, mass number, direct bilirubin, an...