Increased telomerase activity can be found in almost 90% of colorectal tumours. We aim to describe the preliminary results for quantification in plasma of hTERT mRNA in colorectal cancer patients.Materials and methods
Fifty patients undergoing surgery for colorectal cancer and a control group of 50 healthy volunteers were prospectively studied. Pre-operative venous blood samples were taken from all cancer patients and volunteers. Plasma hTERT expression was determined from peripheral blood based on real-time quantitative RT-PCR (qRT-PCR) method normalized to the amount of RNA input using 18S rRNA gene expression. Plasma pre-operative CEA levels were also determined.Results
Median values for normalized hTERT (hTERTN) gene expression were higher in colorectal cancer patients (11.62, range 0.23–47.67) than healthy volunteers (0.29, range 0.00–4.63) (P < 0.001). Individual data showed that 82% of colorectal cancer patients had hTERTN expression values superior to the maximum value observed in the control group. Sensitivity and specificity of the assay for colorectal cancer detection were 98% and 64%, respectively. No significant differences in hTERTN expression between gender or with age (P > 0.05). No significant correlation was found between hTERTN expression and CEA values (Spearman's rank test = 0.136, P = 0.348).Conclusions
These results show that detection of mRNA based on the qRT-PCR of the telomerase hTERTN gene in plasma clearly differentiates between healthy and colorectal cancer patients and that hTERTN can be detected and quantified in plasma. This opens up a new field as a noninvasive blood test for colorectal cancer diagnosis.