Clustering of patients with intrahepatic cholangiocarcinoma based on serum periostin may be predictive of prognosis

An effective serum biomarker may improve cholangiocarcinoma (CCA) management. Periostin (PN) has been demonstrated to be associated with aggressive CCA. The current study evaluated PN in blood serum for its diagnostic and prognostic potential in patients with CCA. Sera of 68 patients with CCA were collected prior to treatment, and PN levels were measured using an ELISA. Sera from 50 normal controls, 6 patients with benign liver diseases, 2 with hepatocellular carcinoma and 21 with breast cancer were analyzed. Immunohistochemistry of PN in CCA tissues was also investigated. The data were analyzed using the Mann-Whitney U test, Kaplan-Meier log rank tests, Cox proportional hazard regression models and Fisher's exact tests. The median serum PN level in patients with CCA was significantly increased compared with that in healthy controls, patients with benign liver diseases and patients with breast cancer (all P<0.05). Using an optimal threshold value of 94 ng/ml PN, the diagnostic values for CCA compared with other conditions demonstrated a sensitivity level of 0.38 [95% confidence interval (CI), 0.27-0.51], specificity of 0.90 (95% CI, 0.81-0.96), accuracy of 0.66 (95% CI, 0.58-0.74), positive predictive value of 0.76 (95% CI, 0.59-0.89) and negative predictive value of 0.63 (95% CI, 0.53-0.72) (P<0.001). Furthermore, PN stain in stromal fibroblasts in CCA tissues was associated with serum PN levels (P=0.001), and patients with CCA were classified as low (≤94 ng/ml) or high PN (>94 ng/ml) accordingly. High serum and tissue PN levels were significantly associated with reduced survival rate (P<0.001 and P=0.033, respectively). Serum PN was an independent prognostic factor with a hazard ratio of 3.197 (P=0.001). In conclusion, serum PN may be used to divide patients with intrahepatic CCA into high and low PN groups. Elevated serum PN may be utilized as a marker of poor prognosis in patients with CCA.