INTRODUCTION: DNA methylation is part of the epigenetic regulatory mechanism 
present in all normal cells. It is tissue-specific and stably maintained 
throughout development, but often abnormally changed in cancer. Non-small-cell 
lung carcinoma (NSCLC) is the most deadly type of cancer, involving different 
tumor subtypes. This heterogeneity is a challenge for correct diagnosis and 
patient treatment. The stability and specificity make of DNA methylation a very 
suitable marker for epigenetic phenotyping of tumors.
METHODS: To identify candidate markers for use in NSCLC diagnosis, we used 
genomewide DNA methylation maps that we had previously generated by MethylCap 
and next-generation sequencing and listed the most significant differentially 
methylated regions (DMRs). The 25 DMRs with highest significance in their 
methylation scores were selected. The methylation status of these DMRs was 
investigated in 61 tumors and matching control lung tissues by 
methylation-specific polymerase chain reaction.
RESULTS: We found 12 novel DMRs that showed significant differences between 
tumor and control lung tissues. We also identified three novel DMRs for each of 
the two most common NSCLC subtypes, adenocarcinomas and squamous cell 
carcinomas. We propose a panel of five DMRs, composed of novel and known markers 
that exhibit high specificity and sensitivity to distinguish tumors from control 
lung tissues.
CONCLUSION: Novel markers will aid the development of a highly specific 
epigenetic panel for accurate identification and subtyping of NSCLC tumors.