Spectrum and Frequency of Tumors, Cancer Risk and Survival in Chilean Families with Lynch Syndrome: Experience of the Implementation of a Registry.

Lynch syndrome (LS) is associated with the highest risk of colorectal (CRC) and several extracolonic cancers. In our effort to characterize LS families from Latin America, this study aimed to describe the spectrum of neoplasms and cancer risk by gender, age and gene, and survival in 34 Chilean LS families. Of them, 59% harbored , 23% , 12% and 6% variants. A total of 866 individuals at risk were identified, of which 213 (24.6%) developed 308 neoplasms. In males, CRC was the most common cancer (72.6%), while females showed a greater frequency of extracolonic cancers (58.4%), including uterus and breast ( < 0.0001). The cumulative incidence of extracolonic cancers was higher in females than males ( = 0.001). variants are significantly more associated with the development of CRC than extracolonic tumors (59.5% vs. 40.5%) when compared to (47.5% vs. 52.5%) variants ( = 0.05018). The cumulative incidence of CRC was higher in / carriers compared to carriers ( = 0.03). In addition, carriers showed higher risk of extracolonic tumors ( = 0.002). In conclusion, this study provides a snapshot of the LS profile from Chile and the current LS-associated diagnostic practice and output in Chile. Categorizing cancer risks associated with each population is relevant in the genetic counselling of LS patients.