The combination of preoperative D-dimer and CA19-9 predicts lymph node metastasis and survival in intrahepatic cholangiocarcinoma patients after curative resection

BACKGROUND: To investigate the predictive role of D-dimer and its combination of preoperative CA19-9 for lymph node metastasis (LNM) and prognosis in intrahepatic cholangiocarcinoma (ICC) patients who underwent curative-intent resection. METHODS: One hundred and seventy-three patients admitted to our hospital between April 2012 and December 2018 were included. The combination of preoperative D-dimer and CA19-9 (CPDC) was scored as 0 (decreased D-dimer levels with decreased CA19-9 levels), 2 (elevated D-dimer levels with elevated CA19-9 levels), or 1 (all other combinations). Multivariate logistic regression analysis was performed to identify independent factors. Cox proportional hazard regression was adopted for the multivariate survival analysis. RESULTS: The CPDC score was an independent predictor of LNM and overall survival (OS) in the multivariate analyses. For the prediction of LNM, the area under the curve (AUC) for the CPDC score was 0.722 (95% CI: 0.613–0.831, P<0.001), and for the prediction of survival, the AUC for the CPDC score was 0.756 (95% CI: 0.658–0.854, P<0.001). The predictive capacity of the CPDC score was higher than that of D-dimer or CA19-9. Kaplan-Meier curve analysis revealed that a CPDC =2 was significantly associated with a worse OS (P<0.001, median OS: 8.00 versus 19.00 months versus not reached) and shorter progression-free survival (PFS) (P<0.001, median PFS: 4.00 versus 11.00 versus 15.00 months) than a CPDC =1 or CPDC =0 in ICC patients. There were significant differences in the OS comparisons between any two groups. Decreased preoperative CPDC was associated with worse OS and PFS in all subgroups except in the HBsAg (+) group. In the cirrhosis, HBsAg (−) and tumour size ≥5 cm subgroups, there were significant differences in the OS and PFS comparisons between any two groups. CONCLUSIONS: The preoperative CPDC score is a convenient and powerful prognostic biomarker to predict LNM and OS for ICC patients after curative resection. Especially for radiologically-negative metastatic lymph node in ICC patients, CPDC could be helpful to assess the extent of lymph node dissection and make follow-up plans.