Individualized nomogram improves diagnostic accuracy of stage I-II gallbladder cancer in chronic cholecystitis patients with gallbladder wall thickening.

Background: Early diagnosis of gallbladder cancer (GBC) can remarkably improve the prognosis of patients. This study aimed to develop a nomogram for individualized diagnosis of stage I-II GBC in chronic cholecystitis patients with gallbladder wall thickening.

Methods: The nomogram was developed using logistic regression analyses based on a retrospective cohort consisting of 89 consecutive patients with stage I-II GBC and 1240 patients with gallbladder wall thickening treated at one biliary surgery center in Shanghai between January 2009 and December 2011. The accuracy of the nomogram was validated by discrimination, calibration and a prospective cohort treated at another center between January 2012 and December 2014 (n=928).

Results: Factors included in the nomogram were advanced age, hazardous alcohol consumption, long-standing diagnosed gallstones, atrophic gallbladder, gallbladder wall calcification, intraluminal polypoid lesion, higher wall thickness ratio and mucosal line disruption. The nomogram had concordance indices of 0.889 and 0.856 for the two cohorts, respectively. Internal and external calibration curves fitted well. The area under the receiver-operating characteristic curves of the nomogram was higher than that of multidetector row computed tomography in diagnosis of stage I-II GBC (P<0.001).

Conclusion: The proposed nomogram improves individualized diagnosis of stage I-II GBC in chronic cholecystitis patients with gallbladder wall thickening, especially for those the imaging features alone do not allow to confirm the diagnosis.