Risk score for malignancy in patients with suspicious gallbladder lesions: Retrospective analysis of 175 cases.

Background: Among cancers, carcinoma gallbladder has one of the most dismal prognosis. Early lesions are difficult to biopsy because of proximity to luminal structures and risk of biliary peritonitis. However, early surgery offers the only chance of a complete cure. Utilizing a risk score would allow characterization of the risk of malignancy and early referral to an oncology centre thereby resulting in better outcomes for patients with carcinoma gallbladder.

Methods: The aim of this study was to develop a risk score for carcinoma in patients with suspicious gallbladder lesions based on clinical presentation and imaging. All patients with suspicious gallbladder lesions on radiological imaging who underwent surgery were analyzed. Patients were considered for scoring if the ultrasound showed the gallbladder wall thickening (more than 4 mm) and computed tomography scan showed operable disease. Statistical analysis was done to derive a score for malignancy.

Results: Total 175 patients underwent an operation for suspicious gallbladder lesions from January 2005 to December 2014. The factors analyzed were clinical biochemical and imaging findings. Of these, 71 were benign on the final histopathology and 104 were malignant. The score was constructed with the following variables: female sex, high total bilirubin (≥ 1 mg/dL), presence of a mass, focal location of the lesion, presence of gallbladder stones and nodal involvement in the hepatoduodenal region on imaging. A model score and modified score were obtained. In this modified score, score of more than 8 out of 20 predicted malignancy with a sensitivity of 78% and specificity of 70.4%. Receiver operating characteristic (ROC) curve constructed with these variables had an area under curve of 0.828. There was no statistically significant difference between the model score and the modified score.

Conclusions: A pre-operative risk score was obtained for carcinoma gallbladder, which needs to be validated prospectively in future.