Prevalence of BRCA1 and BRCA 2 and other mutations in Chilean population

Selman, Carolina; Hurtado, Mabel; Chahuan, Badir; Mella, Fabiola; Marsiglia, Hugo


Background: Arturo López Pérez Foundation (FALP) is a Chilean Institution aimed to treatment of cancer patients. Since 2016 it has an Unit for Oncological Genetic Counseling (AGO) for patients with warning flags of potential cases of cancer of genetic origin AGO Unit is aimed to capture patients with warning flags and deliver information through pre-test counseling, offer possibility of a genetic test and post-test counseling. The purpose of this review is to provide relevant results of four years of this Unit. Methods: A descriptive study was carried out from patient care in the Oncological Genetic Counseling Unit of FALP between 2016 and 2019. It was considered those cases in which the process of pretest/post-test counseling was performed. Six "warningflags" were established: cancer in patients under 50 years of age, triple negative breast cancer, breast cancer in men, ovarian cancer, history of 2 or more primary cancers and a family history of cancer The number of test performed was analyzed. The results were expressed in positive pathogenic variants, uncertain variants and negative results. Results: 365 genetic counseling processes were carried out during the period. The average consultation age was 43.2 years (20.8 and 75.5) and 90.1% (329 attentions ) were female. Of the patients, 79.7% (294) perform the genetic test. 18.5% tested positive for a pathogenic variant, 6.5% for a pathogenic variant plus an uncertain variable, and 2.8% for two pathogenic variants. The mutations found were BRCA2 32.6% BRCA1 29.1%, ATM 10.1% RAD51C 6.7% CDKN2 A 5.6%, MUTYH 3.4% TP53 3.4%, MSH2 3.4% RAD51D 2.4%), NF1 1.1%, NTHL1 1.1%, RET 1.1% A 64.9% (237 patients) had cancer diagnosed at the time of the consultation, versus 33.1% of healthy care. 2% had no information. The type of cancer present was 79.7% breast cancer (189), 8.0% ovarian cancer, 2.1% thyroid cancer, 1.7% breast and ovarian cancer, 0.9% colon and/or endometrial cancer and 7.6% other cancers. The warning flags present were 41.2% age below 50 years, 26.2% family history, 15.4% relatives of people with positive results, 8.5% patients with triple-negative breast cancer, 5.3% patients with ovarian cancer, 2.8% patients with 2 or more primary cancers, and 0.6% male breast cancer patients. Conclusions: The highest percentage of patient care was for women with breast cancer, under 50 years of age. The overall test positivity rate is a cumulative 29%. Mutations in BRCA 1 and BRCA 2 were the most detected mutations, as reported in the literature. The slight predominance of BRCA 2 may be due to a familiar component. This is the largest report made in the Chilean population.

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Fecha de publicación: 2020
Año de Inicio/Término: 29-31 Mayo 2020
Idioma: Inglés


Notas: Publicado en: Journal of Clinical Oncology 2020 38:15_suppl, e13553-e13553