Chromosomal aberrations, visualized using UroVysion® fluorescence in-situ hybridization assay, can predict poor prognosis in formalin-fixed paraffin-embedded tissues of cholangiocarcinoma patients

Cholangiocarcinoma (CCA) is a highly aggressive malignant tumor that has highest incidence in northeastern Thailand. The survival rate of CCA patients after receiving surgical treatment is quite low. Recently, genetic alterations including chromosome abnormalities have been studied as predictive factors and to aid planning for further treatment. This study aims to investigate the association between chromosomal aberrations, clinical data, and overall survival time of CCA patients. Formalin-fixed paraffin-embedded (FFPE) tissues from 194 CCA patients were examined. The copy numbers of chromosomes 3, 7, 17 and 9p21 were investigated using the UroVysion® fluorescence in-situ hybridization (FISH) assay. The overall survival time (OS) of CCA patients with or without polysomy of chromosomes 3, 7, 17 and/or loss of 9p21 were statistically analyzed in association with their clinicopathological parameters. Kaplan–Meier analysis was performed. The OS of patients with polysomy of chromosomes 3 + 7 was significantly shorter than those without this polysomy (log-rank P = 0.006; median OS 14.79 vs. 19.62 months). Moreover, patients with polysomy of chromosomes 3 + 7+17 and heterozygous for 9p21 loss have significantly shorter survival time than those without such chromosomal aberrations (log-rank P = 0.001; median OS 15.74 vs. 37.57 months). Interestingly, multivariate analysis revealed that polysomy of chromosomes 3 + 7 and of chromosomes 3 + 7+17 with 9p21 heterozygous loss were independent predictive factors of a poor OS (P = 0.027; P = 0.008, respectively).The chromosomal aberrations patterns which we evaluated using FISH; 1) polysomy of chromosomes 3 + 7 and 2) polysomy of chromosomes 3 + 7+17 with 9p21 heterozygous loss, have strong potential as indicators of poor prognosis in CCA patients.