title: Molecular Features and Methylation Status in Early Onset (≤40 Years) Colorectal Cancer: A Population Based, Case-Control Study.
abstract: Colorectal cancer is usually considered a disease of the elderly. However, a small fraction of patients develops colorectal cancer earlier. The aim of our study was to define the frequency of known hereditary colorectal syndromes and to characterise genetic and epigenetic features of early nonhereditary tumors. Thirty-three patients ≤40 years with diagnosis of colorectal cancer and 41 patients with disease at >60 years of age were investigated for MSI, Mismatch Repair proteins expression, KRAS and BRAF mutations, hypermethylation, and LINE-1 hypomethylation. Detection of germline mutations was performed in Mismatch Repair, APC and MUTYH genes. Early onset colorectal cancer showed a high incidence of hereditary forms (18%). KRAS mutations were detected in 36% of early nonhereditary tumors. Early onset colorectal cancer disclosed an average number of methylated genes significantly lower when compared to the controls (p = 0.02). Finally both of the two groups were highly methylated in ESR1, GATA5, and WT1 genes and were similar for LINE-1 hypomethylation. The genetic make-up of carcinomas differs from young to elderly patients. Early onset tumors showed more frequently a constitutional defective of Mismatch Repair System and a minor number of methylated genes. Hypermethylation of ESR1, GATA5, and WT1 genes suggests possible markers in the earlier diagnosis of colorectal tumorigenesis.
authors.affiliation: Dipartimento di Medicina Diagnostica, Clinica e Sanità Pubblica, Università di Modena e Reggio Emilia, 41124 Modena, Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Magnani
authors.affiliation: Dipartimento di Chirurgia e Scienze Morfologiche, Università dell'Insubria, 21100 Varese, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Furlan
authors.affiliation: Dipartimento di Chirurgia e Scienze Morfologiche, Università dell'Insubria, 21100 Varese, Italy.
authors.forename: Nora
authors.initials: N
authors.lastname: Sahnane
authors.affiliation: Divisione di Anatomia Patologica, Policlinico di Modena, 41124 Modena, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Reggiani Bonetti
authors.affiliation: Dipartimento di Medicina Diagnostica, Clinica e Sanità Pubblica, Università di Modena e Reggio Emilia, 41124 Modena, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Domati
authors.affiliation: Dipartimento di Medicina Diagnostica, Clinica e Sanità Pubblica, Università di Modena e Reggio Emilia, 41124 Modena, Italy.
authors.forename: Monica
authors.initials: M
authors.lastname: Pedroni