Epigenetics in Bladder Cancer: A Review of the Literature

Abstract

Bladder cancer (BC) is the 10th most frequent type of cancer worldwide, with around 549.000 new cases and 200.000 deaths/year and it has the highest incidence rates with a strong male and elderly predominance. Besides, BC is a significant burden on health-care systems in terms of long-term therapy due to its high risk of recurrence. The investigation for a biomarker that high sensitivity and specificity to be used in the diagnosis and follow-up of BC is still ongoing because cystoscopic imaging, which is currently using it as the gold-standard technique, is an invasive procedure. Opportunely, the recent epigenetic-based studies arc provided successful results for this subject. Therefore, in this study, we review that the DNA methylation and microRNAs relationship with BC were investigated in the light of current studies in the literature, particularly using the meta-analyses. The evaluation of the association of BC with DNA methylation showed that the hypermethylation was parallel with the muscle invasion, increased tumor stage and grade, poor prognosis, and cancer-associated mortality. Other than, many researchers suggest that various genes or gene panels as the methylation-based biomarkers for use in the follow-up of BC. Similarly, the miRNA panels may successfully differentiate BC samples from healthy controls, and provide successful estimations for survival and recurrence. To all appearances, the increase of the number of epigenetic-based research in BC not only will provide useful data for clarifying the BC progression, but will also increase the number of biomarkers with high sensitivity and specificity.