The value of SHOX2 methylation test in peripheral blood samples used for the differential diagnosis of lung cancer and other lung disorders.

Methylation of the cytosine residues within the CpG dinucleotides plays an important role in the fundamental cellular processes, human diseases and even cancer. The DNA methylation represents a very stable sign and therefore may be used as a valuable marker for cancer screening. Epigenetic cancer biomarkers are independent of classical morphology and thus show extensive potential to overcome the limitations of cytology. Several epigenetic cancer markers have been reported to be detectable in body fluids such as bronchial aspirate, sputum, plasma and serum.Short stature homeobox gene 2 (SHOX2) encodes a homeo-domain transcription factor, which has been identified as a close homologue of the SHOX gene and both genes are involved in skeletogenesis and heart development. Methylation of SHOX2 gene has been shown to be present at high prevalence in carcinomas of lung, however may also be used to identify other tumour entities.In the presented study, we have compared suitability of two types of material associated with lung cancer for the detection of SHOX2 methylation. We have confirmed that methylation of SHOX2 gene represents reliable marker of lung malignancies. The parallel tests in the blood plasma revealed that it may represent a good alternative material for testing of the SHOX2 methylation, making the test available to patients who are unable to undergo bronchoscopy.