Characterisation of blood-derived exosomal hTERT mRNA secretion in cancer patients: A potential pan-cancer marker

Background:Telomerase (human telomerase reverse transcriptase (hTERT)) is considered a hallmark of cancer. The aim of our study was to evaluate the feasibility of the detection of hTERT transcripts in serum as a â pan-cancer' diagnostic method.Methods:Human telomerase reverse transcriptase mRNA levels were determined in serum and serum-derived exosomes from 133 patients with different malignancies and 45 healthy controls. In four patients hTERT mRNA levels were measured in different clinical stages.Results:Human telomerase reverse transcriptase transcript was absent in all controls and was variably detected in 67.5% of patients with all cancer types. A correlation between hTERT transcript levels and the clinical course was found in several cases.Conclusions:Human telomerase reverse transcriptase mRNA levels may reflect the tumour burden and the clinical status of the patient. In patients with detectable levels, this assay may potentially serve as a diagnostic and follow-up pan-cancer' marker. Owing to the large variety of patients and small sample size in each diagnosis, the statistical power is limited and will be explored further in larger groups.