Low p27 expression is an independent predictor of survival for patients with either hilar or peripheral intrahepatic cholangiocarcinoma

Purpose and Experimental Design: The prognosis for intrahepatic cholangiocarcinoma (ICC) depends mainly on the feasibility of complete surgical resection. In the absence of demonstrated biological predictors of survival, we evaluated the prognostic value of the cyclin-dependent kinase inhibitor p27 by immunohistochemistry in a series of routine specimens from 47 ICC patients, 22 with the hilar and 25 with the peripheral subtype. Proliferation rate was also evaluated in the same cases by the MIB1 index. Tumors were scored as high, low, and negative p27 expressers (≥50%, <50%, and no positive nuclei, respectively). Results: High, low, and negative p27 expression was recorded in 18 (38%), 17 (36%), and 12 (26%) cases, respectively. No significant correlation was found between p27 expression and gender, age, tumor grade, tumor location, vascular or perineural invasion, or proliferative index. Tumors with low or absent p27 expression were associated with poor survival compared with the high-expresser group. Kaplan-Meier curves comparing different p27 expression levels with survival showed highly significant separation (P < 0.0001, log-rank test). With univariate Cox proportional hazard regression, only p27 score among all of the parameters was found to influence survival (P = 0.0003). Conclusion: We conclude that in ICC, low or absent p27 expression can predict poor survival, regardless of tumor location, pathological features, and tumor proliferation. Immunohistochemical detection of p27 on routine sections may provide the first biological prognostic marker for ICC, thus influencing the therapeutic strategies for these patients.