Quantitative evaluation of vimentin expression in tumour stroma of colorectal cancer

Abstract

Recent studies have identified vimentin, a type III intermediate filament, among genes differentially expressed in tumours with more invasive features, suggesting an association between vimentin and tumour progression. The aim of this study, was to investigate whether vimentin expression in colon cancer tissue is of clinical relevance. We performed immunostaining in 142 colorectal cancer (CRC) samples and quantified the amount of vimentin expression using computer-assisted image analysis. Vimentin expression in the tumour stroma of CRC was associated with shorter survival. Overall survival in the high vimentin expression group was 71.2% compared with 90.4% in the low-expression group (P=0.002), whereas disease-free survival for the high-expression group was 62.7% compared with 86.7% for the low-expression group (P=0.001). Furthermore, the prognostic power of vimentin for disease recurrence was maintained in both stage II and III CRC. Multivariate analysis suggested that vimentin was a better prognostic indicator for disease recurrence (risk ratio=3.5) than the widely used lymph node status (risk ratio=2.2). Vimentin expression in the tumour stroma may reflect a higher malignant potential of the tumour and may be a useful predictive marker for disease recurrence in CRC patients.

Figure 1

Representative sections of high vimentin expression (A) and low vimentin expression (C) in tumour stroma. Images were analysed based on the colour selection. Image analysis figures are shown (B and D). Area labelled (in fluorescent green) was calculated accordingly. Surface area was calculated as 22.0 and 3.3%.

Figure 2

Survival curves were plotted using the Kaplan–Meier method for high vimentin (Vim High) expression and low (Vim Low) expression groups. (A) Overall survival. (B) Disease-free survival. Both end points were further analysed according to tumour staging (stages II and III).