Despite the fact that the mortality rate of many types of cancer has decreased
in the last decades, cancer remains one of the most challenging diseases in the world.
The number of newly diagnosed cases with advanced stages in different types of cancer
is still high because available tests are not efficient enough to be used for screening. In
addition, the available diagnostic tests failed to diagnose certain types of cancer until
late presentation. Furthermore, therapeutic agents currently in clinical use to treat a
certain type of malignant tumours still show a high rate of resistance in some patients.
Many types of available cancer biomarkers failed to manage and resolve this problem
because of the lack of both sensitivity and specificity of these markers. Advanced
researches in epigenetics highlight the importance of certain non-coding genes in
diagnosing and follow-up of patients with different types of cancer. One of these
substances is microRNAs (miRNAs) which showed high sensitivity and specificity as
cancer biomarkers. miRNAs are highly stable and expressed in different types of
human body samples; some of them are tissue specific. These features make them
available as cancer biomarkers, and they are started to be in clinical use recently.
Keywords: Biomarkers, Cancer, Diagnosis, Prognosis, Epigenetic, Clinical, Facts, Specificity, Sensitivity, Non-coding RNAs, Fluid, Sample, Tissue, Commercialized miRNAs, miRview test, miRNAs, Therapeutic resistance, Epithelial-mesenchymal transition
