Lynch Syndrome in Argentina: 20-year Experience at the Referral Registry (ProCanHe).

PIÑERO, TAMARA ALEJANDRA; KALFAYAN, PABLO GERMÁN; GONZÁLEZ, MARÍA LAURA; FERRO, FABIANA ALEJANDRA; HERRANDO, IGNACIO; SANTINO, JUAN PABLO; CAJAL, ANDREA ROMINA; FALCONI, DALVA; GUERRERO, GISELLA; PAVICIC, WALTER; VERZURA, MARIA ALICIA; RIGGI, MARÍA; DOMINGUEZ-VALENTIN, MEV; CHURCH, JAMES; PÄIVI PELTOMÄKI; MARTINS, ALEXANDRA; VACCARO, CARLOS A.

Congreso; Collaborative Group of the Americas. Inherited Colorectal Cancer, 21th Annual Meeting CGA-ICC; 2017

Registries in South America were initiated in the early 90´s with the help of Henry T. Lynch. The Programa de Cancer Hereditario (Pro.Can.He) is a multidisciplinary program established in 1996 at the Hospital Italiano, Argentina. The aim of the study is to update our 20-year experience to determine the applicability of genetic tests highlighting the most informative molecular findings in relation to Lynch syndrome.A total of 75 families (45 fulfilled Amsterdam Criteria [AC] and 30 Bethesda Criteria [BC]) (Graphic 1) were analyzed including tests done by international collaborations. Pathogenic variants were found in 24 out of 75 (32%) families, been 22 pathogenic and 2 likely  pathogenic (Graphic 2). Splice site and large rearrangements represented 8.3% (2/24) and 12.5% (3/24) of the variants (Graphic 3). 25% (6/24) of them were originally described in this series and 1 was a founding mutation from Piedmont, Italy. Affected genes include MSH2, MLH1, and MSH6 (12, 11, and 1 cases). Mutation detection rates in AC and BT families were 46.6% (N=21) and 10% (N=3), p<0.01. Among AC families, those with identified mutation had a lower median age of cancer onset and higher incidence of extra-CCR cancer than those without identified mutations (Table 1). Finally, Table 2 shows the in silico analysis of unreported variants and its predicted biological effects.