Predictors for thromboembolism in patients with cholangiocarcinoma.

Patients with cancer are at increased risk of thromboembolic events contributing significantly to cancer-related morbidity and mortality. Because cholangiocarcinoma is a rare type of cancer, the incidence of thromboembolism in this patient population is not well defined. Patients with cholangiocarcinoma treated at the University Cancer Center Leipzig between January 2014 and December 2018 were analyzed retrospectively regarding the incidence of arterial and venous thromboembolism. A total of 133 newly and consecutively diagnosed patients were included, of whom 22% had stage IV disease. Thromboembolism was diagnosed in 39 (29.3%), with 48% of the events occurring between 60 days prior and 30 days after the initial diagnosis. Arterial thrombosis accounted for 19% and portal venous thrombosis for 33% of the events, while the rest of events occurred in the non-portal venous system. In multivariable analysis, an ONKOTEV score ≥ 2 was the only independent predictor for thromboembolism. Serum CA 19-9 was available in 87 patients (65.4%). In this subgroup, CA 19-9 above the median of 97.7 U/ml and vascular or lymphatic compression were independent predictors for thromboembolism in the first year and CA 19-9 alone remained a significant predictor over the whole observation period. An ONKOTEV score ≥ 2 and increasing age were predictors of survival. A very high thromboembolic risk was observed in cholangiocarcinoma, comparable to the risk situation in pancreatic and gastric cancer. The ONKOTEV score and serum CA 19-9 are independent predictors of thromboembolic events. Prospective validation of our observations in this patient population is warranted.