Low Frequency of Epigenetic Events in Urothelial Tumors in Young Patients

Abstract

Urothelial tumors in patients younger than 19 years have a low rate of epigenetic alteration. Tumors in patients older than 20 years have epigenetic profiles similar to those of tumors in patients within the typical bladder urothelial cell carcinoma age range.

Urothelial Neoplasms of the Urinary Bladder Occurring in Young Adult and Pediatric Patients

“…The study showed low incidence of global hypermethylation in patients <20 years of age with an average methyl index of 34.4% versus 60.0% and 52.3% for the 2 older groups. 79 There was significantly less methylation in patients <20 years of age at the adenomatous polyposis coli, Bcl2, O 6 -methylguanine-DNA methyltransferase, and E-cadherin loci compared with the 2 older groups. 79 Relative methyl quantification showed that there were significantly higher concentrations of methylated alleles for O 6 -methylguanine-DNA methyltransferase and adenomatous polyposis coli in the oldest versus the 2 younger groups.…”

“…79 There was significantly less methylation in patients <20 years of age at the adenomatous polyposis coli, Bcl2, O 6 -methylguanine-DNA methyltransferase, and E-cadherin loci compared with the 2 older groups. 79 Relative methyl quantification showed that there were significantly higher concentrations of methylated alleles for O 6 -methylguanine-DNA methyltransferase and adenomatous polyposis coli in the oldest versus the 2 younger groups. Tumor necrosis factor receptor superfamily member 25, endothelin receptor type B, and cyclin D2 hypermethylation occurred in patients <20 years of age and were not significantly different when compared with the 2 older patient groups.…”

“…Perhaps 1 possible argument is whether some of these differences are truly related to the patient's young age or may be because of the low grade and low stage nature of tumors studied. The subsequent study by Owen et al, 79 further showed that tumors in patients <20 years of age have lower epigenetic alteration rates compared with older patients. The study also suggested that patients older than 20 years are similar epigenetically regardless of age.…”

“…80,82 The presence of TNFSRF25 and cyclin D2 hypermethylation in young patients suggests that silencing seems crucial for urothelial tumorigenesis. 79 Thus, the study by Wild et al 31 showed that genetic alterations frequently seen in older adults are extremely rare in young patients <20 years of age. Perhaps 1 possible argument is whether some of these differences are truly related to the patient's young age or may be because of the low grade and low stage nature of tumors studied.…”

Urothelial Tumors of the Urinary Bladder in Young Patients: A Clinicopathologic Study of 59 Cases

“…Occupational exposure is another known risk factor for urothelial tumors in old patients, but its role is uncertain in young patients. Although urothelial tumors in young patients may lack some genetic alterations that are frequently observed in old patients [21,22], genetic factors are likely to play an important role in the early onset of urothelial tumors in young patients.…”