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ABSTRACT A total of 1.67 million breast cancer cases per year are reported worldwide. Of these, 5%–10% are caused by inherited mutations. Phenocopy is a rare phenomenon, with only a few cases reported in the literature. In phenocopies, phenotypes identical to those with genetic origin occur because of environmental factors rather than familial mutations. We describe a case of phenocopy in a 44-year-old female patient with triple-negative breast cancer. The mother and sister wee heterozygous for c.1813delA, p.Ile605TyrfsTer9 in BRCA2 . The patient underwent genetic testing for BRCA1 and BRCA2 and exome sequencing. Familial or other cancer variants were not detected. The most accepted phenocopy theory is that patients without genetic variants but who are carriers of these mutations undergo cellular changes due to environmental factors, increasing the risk of breast cancer. Therefore, the detection of phenocopy in patients with breast cancer is important in clinical practice.

Resumo O câncer de mama representa um problema de saúde pública por ser a neoplasia maligna de maior incidência em mulheres no mundo. A forma hereditária corresponde a cerca de 5% a 10% de todos os casos e está diretamente relacionada à herança de mutações genéticas, sendo as principais nos genes supressores de tumor BRCA1 e BRCA2. A identificação dessas mutações é de extrema importância pelo elevado risco de desenvolvimento de câncer de mama nessa população, permitindo estratégias de rastreamento diferenciado e adoção de medidas de redução de risco. Entretanto, é importante e necessário refletir sobre os aspectos éticos relacionados ao uso indiscriminado de testes genéticos. O objetivo deste trabalho foi avaliar o conhecimento e a opinião de médicos de um centro de referência oncológico sobre a indicação dos testes genéticos de suscetibilidade ao câncer de mama mediante dilemas éticos aos quais são submetidos na prática médica.

A total of 1.67 million breast cancer cases per year are reported worldwide. Of these, 5%-10% are caused by inherited mutations. Phenocopy is a rare phenomenon, with only a few cases reported in the literature. In phenocopies, phenotypes identical to those with genetic origin occur because of environmental factors rather than familial mutations. We describe a case of phenocopy in a 44-year-old female patient with triple-negative breast cancer. The mother and sister wee heterozygous for c.1813delA, p.Ile605TyrfsTer9 in BRCA2. The patient underwent genetic testing for BRCA1 and BRCA2 and exome sequencing. Familial or other cancer variants were not detected. The most accepted phenocopy theory is that patients without genetic variants but who are carriers of these mutations undergo cellular changes due to environmental factors, increasing the risk of breast cancer. Therefore, the detection of phenocopy in patients with breast cancer is important in clinical practice. [ABSTRACT FROM AUTHOR]

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Introducción: Los síndromes de predisposición hereditaria al cáncer representan un 5-10% de los casos de cáncer, el más estudiado es HBOC producido por mutaciones en los genes BRCA1/2. Objetivos: Describir características clínicas, histopatológicas y VP en pacientes con HBOC en Córdoba, Argentina y compararla con aquellas sin mutaciones en BRCA1/2. Métodos: Análisis transversal, correlacional y observacional de pacientes de Córdoba. Se utilizó la prueba ANOVA, t de Student, tablas de contingencia y prueba exacta de Fisher, el nivel de significancia fue α=0,05. Resultados: Se estudiaron 155 mujeres con CM, CO y CM/CO. Se identificaron 40 mutaciones en BRCA1/2. No se encontraron diferencias en edad de diagnóstico entre pacientes con y sin mutaciones en BRCA1/2. Se encontró asociación significativa entre VP en BRCA1/2 y el tipo de cáncer (p=0,003); todos los casos con CM/CO presentaron mutaciones en BRCA1/2. No se encontró asociación significativa entre mutados/no mutados y AP, AF, RE-RP-HER2. El 23.1% y 38.1% de los casos de CM fueron TN en individuos con VP en BRCA 1 y 2 respectivamente. La prevalencia de mutaciones fue 25,8% y la prevalencia de VP noveles del 10,0%. Conclusiones: Las pacientes con CM-VP BRCA1/2 están asociadas con histología ductal, y menor edad de presentación con VP BRCA1. No encontramos diferencias significativas en edad de diagnóstico del CM entre pacientes con mutaciones BRCA1 y BRCA2, se observa una mayor proporción CM TN que en la población en general. En nuestra muestra, la prevalencia de mutaciones en BRCA1/2 entre los pacientes que reúnen criterios para HBOC es del 25,8%, con 10% de VP noveles.

A reparação dos danos que ocorrem na molécula de ADN é fundamental para manter a integridade do genoma e a viabilidade celular. Défices nos mecanismos de reparação desta molécula cursam com um aumento do risco para instabilidade genética e contribuem para a transformação neoplásica. As poly (ADP-ribose) polymerases (PARP) são um grupo de enzimas que apresentam um papel chave na sinalização e reparação dos erros no ADN. A inibição da sua atividade é uma estratégia terapêutica que tira partido do mecanismo de letalidade sintética e que pode ser usada no tratamento de tumores com defeitos específicos nas vias de reparação de ADN, nomeadamente em tumores com mutações nos genes supressores tumorais BRCA1 e BRCA2. Existem vários inibidores das PARP (iPARP) já aprovados pela Food and Drug Administration dos Estados Unidos da América e pela Agência Europeia do Medicamento e utilizados no tratamento do cancro da mama, ovário, pâncreas e próstata. No entanto, tal como acontece com outras terapias alvo, a resistência aos iPARP é comum apesar de bem tolerados e amplamente utilizados na prática clínica, e pode desenvolver-se através de vários mecanismos moleculares. Neste artigo, pretendemos realizar uma revisão atualizada sobre os iPARP e o seu principal modo de ação em células tumorais, dando a conhecer os vários mecanismos de resistência que têm sido recentemente revelados, assim como as atuais aplicações clínicas e a toxicidade associada a esta terapia alvo.

Introduction: Hereditary predisposition syndromes to cancer represent 5-10% of cancer cases, the most studied being HBOC produced by mutations in the BRCA1/2 genes., Objectives: To describe clinical, histopathological and PV characteristics in patients with HBOC in Córdoba, Argentina and compare it with those without BRCA1/2 mutations., Methods: Cross-sectional, correlational and observational analysis of patients from Córdoba. The ANOVA, Student's t test contingency tables and Fisher exact test were used the significance level was α = 0.05., Results: 155 women with BC, OC and BC/OC were studied. 40 BRCA1 / 2 mutations were identified. No differences were found in the age of diagnosis between patients with and without BRCA1/2 mutations. A significant association was found between VP in BRCA1/2 and the type of cancer (p = 0.003); all cases with BC/OC presented mutations in BRCA1/2. No significant association was found between mutated/non-mutated and personal history, family background, and ER-PR-HER2. 23.1% and 38.1% of BC cases were TN in individuals with VP in BRCA 1 and 2, respectively. The prevalence of mutations was 25.8% and the prevalence of novel PV was 10.0%., Conclusions: Patients with BC-VP BRCA1/2 are associated with ductal histology, and younger age of presentation with VP BRCA1. We did not find significant differences in the age at diagnosis of BC between patients with BRCA1 and BRCA2 mutations, a higher proportion of BC TN is observed than in the general population. In our sample, the prevalence of BRCA1/2 mutations among patients who meet criteria for HBOC is 25.8%, with 10% new pathogenic variant., (Universidad Nacional de Córdoba)

Repairing damage and errors that occur in the DNA molecule is essential to maintain the integrity of the genome and cell viability. Deficits in DNA repair mechanisms lead to an increased risk of genetic instability and contribute to neoplastic transformation. Poly (ADP-ribose) polymerases (PARP) are a group of enzymes that play a key role in signalling and repairing DNA errors. The inhibition of its activity is a therapeutic strategy that takes advantage of the mechanism of synthetic lethality and that can be used in the treatment of tumours with specific defects in DNA repair pathways, namely in tumours with mutations in the tumour suppressor genes BRCA1 and BRCA2. There are several PARP inhibitors (iPARP), already approved by the USA Food and Drug Administration and the European Medicines Agency used in the treatment of breast, ovarian, pancreatic and prostate cancer. However, as with other target therapies, despite being well tolerated and widely used in the clinical practice, iPARP resistance is common and can be developed through various molecular mechanisms. In this article, we intend to make an updated review on iPARP and its main role in tumour cells, highlighting the several resistance mechanisms that have been recently revealed, as well as the current clinical applications and toxicity associated with this target therapy.