Elevated levels of circulating osteopontin are associated with a poor survival after resection of cholangiocarcinoma.

•Cholangiocarcinoma (CCA) is a rare hepatic malignancy with increasing incidence and dismal prognosis.•Surgical treatment has remained the only potentially curative treatment option in daily practice.•It is unclear which patients benefit most from extended liver surgery.•Serum osteopontin represents a promising diagnostic and prognostic biomarker in resectable CCA.•Osteopontin levels might be helpful to identify CCA patients that benefit most from liver surgery.