Circulating Tumor Cells Expressing Krüppel-Like Factor 8 and Vimentin as Predictors of Poor Prognosis in Pancreatic Cancer Patients

BACKGROUND: Circulating tumor cells (CTCs) with an epithelial-mesenchymal transition phenotype in peripheral blood may be a useful marker of carcinomas with poor prognosis. The aim of this study was to determine the prognostic significance of CTCs expressing Krüppel-like factor 8 (KLF8) and vimentin in pancreatic cancer (PC). METHODS: CTCs were isolated by immunomagnetic separation from the peripheral blood of 40 PC patients before undergoing surgical resection. Immunocytochemistry was performed to identify KLF8(+) and vimentin(+) CTCs. The associations between CTCs and time to recurrence (TTR), clinicopathologic factors, and survival were assessed. Univariate and multivariate analyzes were performed to identify risk factors. RESULTS: Patients with CTCs (n = 30) had a higher relapse rate compared to those without (n = 10) (70.0% vs 20.0%; P < 0.01). The proportion of KLF8(+)/vimentin(+) CTCs to total CTCs was inversely related to TTR (r = −0.646; P < 0.01); TTR was reduced in patients with > 50% of CTCs identified as KLF8(+)/vimentin(+) (P < 0.01). Independent risk factors for recurrence were perineural invasion and > 50% KLF8(+)/vimentin(+) CTCs (both P < 0.05). CONCLUSION: Poor prognosis can be predicted in PC patients when > 50% of CTCs are positive for KLF8 and vimentin.