Golgi protein 73 (GP73) serum levels predict outcome after resection of biliary tract cancer

Background Tumor resection represents the only potentially curative therapy for patients with biliary tract cancer. Nevertheless, disease recurrence is common and 5-years survival rates have remained below 50 %. The Golgi protein 73 (GP73), a type II Golgi transmembrane protein, exerts important functions of intracellular protein processing and transportation. Circulating GP73 has recently been suggested as a novel biomarker for hepatocellular carcinoma (HCC) but its role in the context of biliary tract cancer (BTC) has remained unknown. In this study, we evaluate a potential role of circulating GP73 as a prognostic biomarker in patients with resectable BTC.

Methods GP73 serum levels were measured by immunoassay in n = 97 BTC and n = 40 HCC patients as well as n = 31 healthy controls. Results were correlated with clinical data.

Results Serum GP73 levels were significantly elevated in BTC patients compared to healthy controls but lower compared to HCC patients. The combination of GP73/CA19-9 showed a sensitivity and specificity of 83.5 % and 90.3 % for the differentiation of BTC patients and healthy controls. Importantly, BTC patients with baseline GP73 levels above the ideal cut-off value (42.47 ng/ml) showed a significantly reduced median overall survival (193 days) compared to patients with preoperative GP73 levels below this cut-off (882 days). These results were confirmed in uni- and multivariate Cox-regression analysis including several clinicopathological parameters such as age, ECOG performance status, tumor stage as well as established tumor markers and parameters of liver and kidney function.

Conclusion GP73 represents a previously unrecognized biomarker in patients with resectable BTC, which can help to identify patients with an impaired postoperative outcome. Measurement of GP73 serum levels might therefore become a novel tool in the challenging preoperative stratification process of patients with resectable BTC.

Publication History

Article published online:
07 September 2021