Portadoras de mutaciones en BRCA1 y 2 en familias de alto riesgo del área de Ciudad Real (España): prevalencia mutacional y características clínico-patológicas del cáncer de mama y ovario / Carriers of BRCA1 and 2 mutations in high-risk families from Ciudad Real (Spain): mutational prevalence and clinical-pathological characteristics of breast and ovarian cancer

Objetivo: Determinar la prevalencia mutacional en BRCA1 y 2 de mujeres afectas por cáncer de mama/ovario en el área de Ciudad Real y describir las características clinicopatológicas de dichas neoplasias. Pacientes y métodos: Estudio descriptivo. Se evaluaron 111 pacientes de familias de alto riesgo y se analizaron los antecedentes oncológicos, familiares y las mutaciones halladas en BRCA1 y 2. Resultados: La prevalencia de mutaciones patogénicas en BRCA fue del 21,6% (16 en BRCA2 y 8 en BRCA1). En las portadoras de mutaciones en BRCA1 predominó el cáncer de mama: 10 casos (90,9%), tipo ductal infiltrante: 8 (72,7%), estadioII: 6 (54,5%), luminalA: 4 (36,4%), triple negativo: 4 (36,4%) y grado histológico2: 3 (27,3%) y3: 3 (27,3%). Las portadoras de mutaciones en BRCA2 desarrollaron cáncer de mama en 16 casos (80%), tipo ductal infiltrante: 11 (55%), estadioII: 11 (55%), luminalA: 10 (50%) y grado histológico2: 5 (25%). Conclusiones: En nuestro análisis, la prevalencia de mutaciones en BRCA2 fue superior a la registrada en BRCA1, en correspondencia con algunos estudios previos nacionales. Las características clinicopatológicas de los cánceres de mama/ovario en las portadoras de estas mutaciones fueron similares al perfil descrito en la literatura

Objective: To determine the mutational prevalence in BRCA1 and 2 among women with breast/ovarian cancer in Ciudad Real and to describe the clinical-pathological characteristics of these neoplasms. Patients and methods: Descriptive study. A total of 111 patients from high-risk families were evaluated and the oncological history, family history, and BRCA1 and 2 mutations found were analysed. Results: The prevalence of pathogenic mutations in BRCA was 21.6% (16 in BRCA2 and 8 in BRCA1). In BRCA1 mutations, breast cancer was predominant: 10 cases (90.9%), infiltrating ductal type: 8 (72.7%), stageII: 6 (54.5%), luminalA: 4 (36.4%), triple negative: 4 (36.4%) and histological grade2: 3 (27.3%) and3: 3 (27.3%). Among BRCA2 mutation carriers, 16 (80%) developed breast cancer: infiltrating ductal type: 11 (55%), stageII: 11 (55%), luminalA: 50% (10) and histological grade2: 5 (25%). Conclusions: In our analysis, the prevalence of mutations was higher in BRCA2 than in BRCA1, in agreement with some previous national studies. The clinical-pathological characteristics of breast/ovarian cancer in the carriers of these mutations were similar to the profile described in the literature

The highly prevalent BRCA2 mutation c.2808_2811del (3036delACAA) is located in a mutational hotspot and has multiple origins.

BRCA2-c.2808_2811del (3036delACAA) is one of the most reported germ line mutations in non-Ashkenazi breast cancer patients. We investigated its genetic origin in 51 Spanish carrier families that were genotyped with 11 13q polymorphic markers. Three independent associated haplotypes were clearly distinguished accounting for 23 [west Castilla y León (WCL)], 20 [east Castilla y León (ECL)] and 6 (South of Spain) families. Mutation age was estimated with the Disequilibrium Mapping using Likelihood Estimation software in a range of 45-68 and 45-71 generations for WCL and ECL haplotypes, respectively. The most prevalent variants, c.2808_2811del and c.2803G > A, were located in a double-hairpin loop structure (c.2794-c.2825) predicted by Quikfold that was proposed as a mutational hotspot. To check this hypothesis, random mutagenesis was performed over a 923 bp fragment of BRCA2, and 86 DNA variants were characterized. Interestingly, three mutations reported in the mutation databases (c.2680G > A, c.2944del and c.2957dup) were replicated and 20 affected the same position with different nucleotide changes. Moreover, five variants were placed in the same hairpin loop of c.2808_2811del, and one affected the same position (c.2808A > G). In conclusion, our results support that at least three different mutational events occurred to generate c.2808_2811del. Other highly prevalent DNA variants, such as BRCA1-c.68_69delAG, BRCA2-c.5946delT and c.8537delAG, are concentrated in hairpin loops, suggesting that these structures may represent mutational hotspots.

[Patients with clinical criteria for Lynch syndrome with and without mutations in DNA repair genes (MLH1 and MSH2). A challenge for the clinician]. / Pacientes con criterios clínicos de síndrome de Lynch con y sin mutación en genes reparadores del ADN (MLH1 y MSH2). Un reto para el clínico.

BACKGROUND AND OBJECTIVES: The objective was to study the clinicopathologic characteristics of patients diagnosed of colorectal cancer (CRC) with clinical criteria for Lynch syndrome, in our region, in order to assess and improve the care of them and their families in the Genetic Counseling Unit of our hospital. PATIENTS AND METHODS: This was an observational, transversal retrospective study. The studied sample was made up of all the patients with clinical criteria for Lynch syndrome, who underwent a molecular analysis test in the Genetic Counseling Unit of Salamanca, during the period 2004-2009. We included patient and tumor related variables and the presence or absence of mutations in MLH1 and MSH2. RESULTS: A total of 76 patients were included in the analysis. Fifteen of them carried a mutation either in MLH1 or in MSH2. The mean age at diagnosis of colorectal cancer was 51.2 and 54.3 years in the group with and without mutation respectively, with a similar gender distribution in both groups. A wide phenotypic heterogeneity was found in the sample. CONCLUSIONS: Lynch syndrome is an entity difficult to categorize from a clinical point of view. Therefore, it is important to be alert for a better management of these patients and their families.