BACKGROUND: Selection of patients with Lynch Syndrome (LS) for a genetic study involves the application of clinical criteria. To increase the rate of identification of mutations, the use of molecular studies as Microsatellite Instability (MSI) and Immunohistochemistry (IHC) in the tumor has been proposed. AIM: To demonstrate the usefulness of MSI and IHC in the detection of mutations in patients with LS. MATERIAL AND METHODS: From our Familial Colorectal Cancer Registry, families suspected of LS were selected according to Amsterdam or Bethesda clinical criteria. Screening of germline mutations of MLH1, MSH2 and MSH6 genes was performed. In addition, analysis of MSI and IHC were performed in colorectal tumors. RESULTS: A total of 35 families were studied (19 met Amsterdam and 16 met Bethesda criteria). Twenty one families harbored a germline alteration in MLH1, MSH2 or MSH6 (18 Amsterdam and 3 Bethesda). In these families, eighteen different alterations were found, 15 of which were mutations and 3 corresponded to variants of uncertain pathogenicity. On the other hand, 80% of the tumors showed positive microsatellite instability (27 MSI-high and 1 MSI-low), and immunohistochemical testing showed that 77% of tumors had the loss of a protein. Correlation between results of tumor molecular studies and the finding of germline nucleotide change showed that IHC and MSI predicted mutations in 81 and 100% of patients, respectively. CONCLUSIONS: MSI and IHC can efficiently select patients with a high probability of carrying a mutation in DNA repair genes.
BACKGROUND: Selection of patients with Lynch Syndrome (LS) for a genetic study involves the application of clinical criteria. To increase the rate of identification of mutations, the use of molecular studies as Microsatellite Instability (MSI) and Immunohistochemistry (IHC) in the tumor has been proposed. AIM: To demonstrate the usefulness of MSI and IHC in the detection of mutations in patients with LS. MATERIAL AND METHODS: From our Familial Colorectal Cancer Registry, families suspected of LS were selected according to Amsterdam or Bethesda clinical criteria. Screening of germline mutations of MLH1, MSH2 and MSH6 genes was performed. In addition, analysis of MSI and IHC were performed in colorectal tumors. RESULTS: A total of 35 families were studied (19 met Amsterdam and 16 met Bethesda criteria). Twenty one families harbored a germline alteration in MLH1, MSH2 or MSH6 (18 Amsterdam and 3 Bethesda). In these families, eighteen different alterations were found, 15 of which were mutations and 3 corresponded to variants of uncertain pathogenicity. On the other hand, 80% of the tumors showed positive microsatellite instability (27 MSI-high and 1 MSI-low), and immunohistochemical testing showed that 77% of tumors had the loss of a protein. Correlation between results of tumor molecular studies and the finding of germline nucleotide change showed that IHC and MSI predicted mutations in 81 and 100% of patients, respectively. CONCLUSIONS: MSI and IHC can efficiently select patients with a high probability of carrying a mutation in DNA repair genes.
Authors: Carlos A Vaccaro; Carlos Sarroca; Benedito Rossi; Francisco Lopez-Kostner; Mev Dominguez; Natalia Causada Calo; Raul Cutait; Adriana Della Valle; Lina Nuñez; Florencia Neffa; Karin Alvarez; Maria Laura Gonzalez; Pablo Kalfayan; Henry T Lynch; James Church Journal: Fam Cancer Date: 2016-07 Impact factor: 2.375
Authors: Benedito Mauro Rossi; Edenir Inêz Palmero; Francisco López-Kostner; Carlos Sarroca; Carlos Alberto Vaccaro; Florencia Spirandelli; Patricia Ashton-Prolla; Yenni Rodriguez; Henrique de Campos Reis Galvão; Rui Manuel Reis; André Escremim de Paula; Luis Gustavo Capochin Romagnolo; Karin Alvarez; Adriana Della Valle; Florencia Neffa; Pablo German Kalfayan; Enrique Spirandelli; Sergio Chialina; Melva Gutiérrez Angulo; Maria Del Carmen Castro-Mujica; Julio Sanchez de Monte; Richard Quispe; Sabrina Daniela da Silva; Norma Teresa Rossi; Claudia Barletta-Carrillo; Susana Revollo; Ximena Taborga; L Lena Morillas; Hélène Tubeuf; Erika Maria Monteiro-Santos; Tamara Alejandra Piñero; Constantino Dominguez-Barrera; Patrik Wernhoff; Alexandra Martins; Eivind Hovig; Pål Møller; Mev Dominguez-Valentin Journal: BMC Cancer Date: 2017-09-05 Impact factor: 4.430
Authors: Marcia Cruz-Correa; Julyann Pérez-Mayoral; Julie Dutil; Miguel Echenique; Rafael Mosquera; Keila Rivera-Román; Sharee Umpierre; Segundo Rodriguez-Quilichini; Maria Gonzalez-Pons; Myrta I Olivera; Sherly Pardo Journal: Hered Cancer Clin Pract Date: 2017-01-21 Impact factor: 2.857