Hereditary diffuse gastric cancer: updated clinical guidelines with an emphasis on germline CDH1 mutation carriers.

Germline CDH1 mutations confer a high lifetime risk of developing diffuse gastric (DGC) and lobular breast cancer (LBC). A multidisciplinary workshop was organised to discuss genetic testing, surgery, surveillance strategies, pathology reporting and the patient's perspective on multiple aspects, including diet post gastrectomy. The updated guidelines include revised CDH1 testing criteria (taking into account first-degree and second-degree relatives): (1) families with two or more patients with gastric cancer at any age, one confirmed DGC; (2) individuals with DGC before the age of 40 and (3) families with diagnoses of both DGC and LBC (one diagnosis before the age of 50). Additionally, CDH1 testing could be considered in patients with bilateral or familial LBC before the age of 50, patients with DGC and cleft lip/palate, and those with precursor lesions for signet ring cell carcinoma. Given the high mortality associated with invasive disease, prophylactic total gastrectomy at a centre of expertise is advised for individuals with pathogenic CDH1 mutations. Breast cancer surveillance with annual breast MRI starting at age 30 for women with a CDH1 mutation is recommended. Standardised endoscopic surveillance in experienced centres is recommended for those opting not to have gastrectomy at the current time, those with CDH1 variants of uncertain significance and those that fulfil hereditary DGC criteria without germline CDH1 mutations. Expert histopathological confirmation of (early) signet ring cell carcinoma is recommended. The impact of gastrectomy and mastectomy should not be underestimated; these can have severe consequences on a psychological, physiological and metabolic level. Nutritional problems should be carefully monitored

Hereditary diffuse gastric cancer : cancer risk and the personal cost of preventive surgery

Germline CDH1 mutation carriers are at risk for early-onset diffuse gastric cancer and female carriers have an additional risk of lobular breast cancer. Reliable estimates of cancer risk are essential for genetic counselling and clinical management of mutation carriers. Prophylactic total gastrectomy (PTG) to eliminate the gastric cancer risk is an option for mutation carriers. Current information on post-surgical outcomes and quality of life is limited. The objectives of this research were 1) To improve the evidentiary basis of genetic counselling by deriving reliable estimates of cancer risk in CDH1 mutation carriers; 2) To catalogue a comprehensive list of all novel and previously reported germline mutations to date; and 3) To provide data on post-surgical clinical outcomes and to describe the impact of the surgery on participants’ quality of life. Methods: Penetrance was derived from 67 mutation-positive families comprising 4031 individuals (350 affected with gastric cancer and 99 with breast cancer). Participants were recruited through multiple sources for clinical outcomes and quality of life study. Hospital records provided information on clinical outcomes. All participants were asked to complete validated questionnaires measuring generic and condition specific QOL (PROMIS, EORTC and SF 36v.II) at a single point. Results: By age 75 years, the cumulative incidence of gastric cancer was 70% (95% confidence interval [CI], 40%-94%) for males and 56% (95% CI, 27%-90%) for females. The risk of breast cancer for females was 42% (95% CI, 23%-68%) by 75 years. The mutational landscape of CDH1 did not reveal mutational hotspots but several shared mutations are seen in unrelated families. The 53 participants who had undergone PTG reported frequent symptoms of fatigue (59%), abdominal pain (55%), and diarrhea (45%). Cognitive, role and social function plus the symptoms anxiety, pain, taste, dyspnea and diarrhea were significant predictor variables for quality of life (p<0.05). Conclusions: Our more precise and robust penetrance figures will improve genetic counselling of unaffected carriers. Although this study reveals good overall QOL for individuals after PTG, attention should be given to managing symptoms as part of long term care to further enhance quality of life.Medicine, Faculty ofGraduat

Cáncer gástrico difuso hereditario (CGDH): presentación de una familia con una nueva mutación del gen CDH1

Introducción: el CGDH se hereda en forma autosómica dominante. Su sospecha se basa en los antecedentes familiares y su confirmación requiere estudios moleculares. En el 40% de las familias se logra identificar una mutación en el gen CDH1 de la caderina- E que permite discriminar a los portadores y no portadores. La prevención para los portadores de la mutación incluye la gastrectomía profiláctica o la vigilancia endoscópica cada 6 a 12 meses. Objetivo: presentar el caso de una familia con CGDH portadora de una mutación en gen CDH1 no previamente reportada. Caso: mujer de 28 años, gastrectomizada por cáncer gástrico de tipo difuso con antecedentes familiares de cáncer gástrico que mostraba un patrón de herencia autosómico dominante (afectación de 9 miembros en 5 generaciones). Con sospecha de CGDH se comenzó un plan de vigilancia endoscópica y se analizó el ADN purificado de la sangre periférica de la paciente afectada mediante la secuenciación directa del gen CDH1, en la cual se identificó una mutación sin sentido (non-sense) en la posición 1913 G>A (W638X) del exón 12. Conclusión: la recolección detallada de los antecedentes familiares permitió sospechar una entidad hereditaria muy poco frecuente. Los estudios moleculares confirmaron el diagnóstico, lo que posibilitará la estimación del riesgo individual en los familiares consanguíneos

Histologic and Genotypic Characterization of Lung Cancer in the Inuit Population of the Eastern Canadian Arctic

Inuit are the Indigenous Arctic peoples and residents of the Canadian territory of Nunavut who have the highest global rate of lung cancer. Given lung cancer’s mortality, histological and genomic characterization was undertaken to better understand the disease biology. We retrospectively studied all Inuit cases from Nunavut’s Qikiqtani (Baffin) region, referred to the Ottawa Hospital Cancer Center between 2001 and 2011. Demographics were compiled from medical records and tumor samples underwent pathologic/histologic confirmation. Tumors were analyzed by next generation sequencing (NGS) with a cancer hotspot mutation panel. Of 98 patients, the median age was 66 years and 61% were male. Tobacco use was reported in 87%, and 69% had a history of lung disease (tuberculosis or other). Histological types were: non-small cell lung carcinoma (NSCLC), 81%; small cell lung carcinoma, 16%. Squamous cell carcinoma (SCC) represented 65% of NSCLC. NGS on 55 samples demonstrated mutation rates similar to public lung cancer datasets. In SCC, the STK11 F354L mutation was observed at higher frequency than previously reported. This is the first study to characterize the histologic/genomic profiles of lung cancer in this population. A high incidence of SCC, and an elevated rate of STK11 mutations distinguishes this group from the North American population

Genetic Screening for Familial Gastric Cancer

<p>Abstract</p> <p>Approximately 10% of gastric cancer cases show familial clustering but only 1-3% of gastric carcinomas arise as a result of inherited gastric cancer predisposition syndromes. Direct proof that Hereditary Gastric Cancer a genetic disease with a germline gene defect has come from the demonstration of co-segregation of germline <it>E-cadherin </it>(<it>CDH1</it>) mutations with early onset diffuse gastric cancer in families with an autosomal dominant pattern of inheritance (HDGC). <it>E-cadherin </it>is a transmembrane calcium-dependent cell-adhesion molecule involved in cell-junction formation and the maintenance of epithelial integrity. In this review, we describe frequency and type of <it>CDH1 </it>mutations in sporadic and familial gastric cancer. Further we demonstrate the functional significance of some <it>CDH1 </it>germline missense mutations found in HDGC. We also discuss the <it>CDH1 </it>polymorphisms that have been associated to gastric cancer. We report other types of malignancies associated to HDGC, besides diffuse gastric cancer. Moreover, we review the data available on putative alternative candidate genes screened in familial gastric cancer. Finally, we briefly discuss the role of low-penetrance genes and <it>Helicobacter pylori </it>in gastric cancer. This knowledge is a fundamental step towards accurate genetic counselling, in which a highly specialised pre-symptomatic therapeutic intervention should be offered.</p

Hereditary diffuse gastric cancer: updated clinical guidelines with an emphasis on germline CDH1 mutation carriers.

Germline CDH1 mutations confer a high lifetime risk of developing diffuse gastric (DGC) and lobular breast cancer (LBC). A multidisciplinary workshop was organised to discuss genetic testing, surgery, surveillance strategies, pathology reporting and the patient's perspective on multiple aspects, including diet post gastrectomy. The updated guidelines include revised CDH1 testing criteria (taking into account first-degree and second-degree relatives): (1) families with two or more patients with gastric cancer at any age, one confirmed DGC; (2) individuals with DGC before the age of 40 and (3) families with diagnoses of both DGC and LBC (one diagnosis before the age of 50). Additionally, CDH1 testing could be considered in patients with bilateral or familial LBC before the age of 50, patients with DGC and cleft lip/palate, and those with precursor lesions for signet ring cell carcinoma. Given the high mortality associated with invasive disease, prophylactic total gastrectomy at a centre of expertise is advised for individuals with pathogenic CDH1 mutations. Breast cancer surveillance with annual breast MRI starting at age 30 for women with a CDH1 mutation is recommended. Standardised endoscopic surveillance in experienced centres is recommended for those opting not to have gastrectomy at the current time, those with CDH1 variants of uncertain significance and those that fulfil hereditary DGC criteria without germline CDH1 mutations. Expert histopathological confirmation of (early) signet ring cell carcinoma is recommended. The impact of gastrectomy and mastectomy should not be underestimated; these can have severe consequences on a psychological, physiological and metabolic level. Nutritional problems should be carefully monitored