Preoperative Risk Score to Predict Occult Metastatic or Locally Advanced Disease in Patients with Resectable Perihilar Cholangiocarcinoma on Imaging.

Abstract

Many patients with resectable perihilar cholangiocarcinoma (PHC) on imaging are diagnosed intraoperatively with occult metastatic or locally advanced disease, precluding a curative-intent resection. This study aimed to develop and validate a preoperative risk score. Patients with resectable PHC on imaging who underwent operations in 2 high-volume centers (US and Europe) between 2000 and 2015 were included. Multivariable logistic regression analysis was used to develop the risk score. Cross-validation was used to validate the score, alternating the 2 centers as "training" and "testing" datasets. Of 566 patients who underwent operations, 309 (55%) patients had a resection, and in 257 (45%) patients, a curative-intent resection was precluded due to distant metastasis (n = 151 [27%]) or locally advanced disease (n = 106 [19%]). Preoperative predictors included bilirubin >2 mg/dL, bile duct involvement on imaging, portal vein involvement on imaging (≥180 degrees), hepatic artery involvement on imaging (≥180 degrees), and suspicious lymph nodes on imaging. The new risk score (c-index 0.75 after cross-validation) provided significantly more accurate predictions than the Bismuth classification (c-index 0.62), Blumgart T-staging (c-index 0.67), and cTNM staging (c-index 0.68). The new risk score identified 4 risk groups for occult metastatic or locally advanced disease: low (14.7%), intermediate (29.5%), high (47.3%), and very high risk (81.3%). The preoperative score groups also predicted survival after operation, irrespective of intraoperative findings (p < 0.001). The validated risk score can predict occult distant metastatic or locally advanced PHC based on 5 preoperatively available factors. The score can be useful in preoperative shared decision making and selection of patients in neoadjuvant clinical trials.