Gastric neuroendocrine tumors in a BRCA2 germline mutation carrier:A case report

BACKGROUND The molecular changes present in gastric neuroendocrine tumors(NETs)include a loss of heterozygosity or mutation of MEN1,CDKN1B gene mutation,P27 heterozygous mutation,and ATP4A gene missense mutation.We identified and are the first to report a case of type 1 histamine-producing enterochromaffin-like cell NETs(ECL-cell NETs)with a BRCA2 gene germline mutation.CASE SUMMARY The patient had a history of iron-deficient anemia for 5 years,and gastroscopic examination indicated multiple gastric tumors.Then,the patient underwent distal gastrectomy.Microscopically,multifocal tumor cells were found in the mucosa and submucosa;tumor cells were organoid and arranged in nests and cords,and the stroma was rich in sinusoids.The surrounding gastric mucosa showed atrophy with mild intestinal metaplasia or pseudopyloric gland metaplasia.Neuroendocrine cells could be seen with diffuse linear,nodular,and adenomatous hyperplasia.Immunohistochemically,the tumor cells diffusely expressed cytokeratin,chromogranin,synaptophysin,and CD56.Whole-genome highthroughput molecular sequencing revealed a pathogenic germline mutation in the BRCA2 gene,a heterozygous germline frameshift mutation in exon 11,c.6443_6444del(p.S2148Yfs*2).The final diagnosis was gastric type 1 ECL-cell NETs with a BRCA2 gene germline mutation,accompanied by autoimmune gastritis.CONCLUSION This is the first report of a case of type 1 gastric ECL-cell NETs with a pathogenic germline mutation of the BRCA2 gene.The findings of this report will expand the germline mutation spectrum of gastric NETs and increase the understanding of the molecular changes present in these tumors for their improved diagnosis in the future.

Prevalence and clinical significance of pathogenic germline BRCA1/2 mutations in Chinese non-small cell lung cancer patients

Objective: Germline alterations in the breast cancer susceptibility genes type 1 and 2, BRCA1 and BRCA2, predispose individuals to hereditary cancers, including breast, ovarian, prostate, pancreatic, and stomach cancers.Accumulating evidence suggests inherited genetic susceptibility to lung cancer.The present study aimed to survey the prevalence of pathogenic germline BRCA mutations(gBRCAm) and explore the potential association between gBRCAm and disease onset in Chinese advanced non-small cell lung cancer(NSCLC) patients.Methods: A total of 6,220 NSCLC patients were screened using capture-based ultra-deep targeted sequencing to identify patients harboring germline BRCA1/2 mutations.Results: Out of the 6,220 patients screened, 1.03%(64/6,220) of the patients harbored the pathogenic gB RCAm, with BRCA2 mutations being the most predominant mutations(49/64, 76.5%).Patients who developed NSCLC before 50 years of age were more likely to carry gBRCAm(P = 0.036).Among the patients harboring classic lung cancer driver mutations, those with concurrent gBRCAm were significantly younger than those harboring the wild-type gBRCA(P = 0.029).By contrast, the age of patients with or without concurrent gBRCAm was comparable to those of patients without the driver mutations(P = 0.972).In addition, we identified EGFR-mutant patients with concurrent gBRCAm who showed comparable progression-free survival but significantly longer overall survival(P = 0.002) compared to EGFR-mutant patients with wild-type germline BRCA.Conclusions: Overall, our study is the largest survey of the prevalence of pathogenic gBRCAm in advanced Chinese NSCLC patients.Results suggested a lack of association between germline BRCA status and treatment outcome of EGFR-TKI.In addition,results showed a positive correlation between pathogenic gB RCAm and an early onset of NSCLC.

Germline MLH1 and MSH2 mutational spectrum including frequent large genomic aberrations in Hungarian hereditary non-polyposis colorectal cancer families:Implications for genetic testing

AIM: To analyze the prevalence of germline MLH1 and MSH2 gene mutations and evaluate the clinical characteristics of Hungarian hereditary non-polyposis colorectal cancer (HNPCC) families. METHODS: Thirty-six kindreds were tested for mutations using conformation sensitive gel electrophoreses, direct sequencing and also screening for genomic rearrangements applying multiplex ligation-dependent probe amplifi cation (MLPA). RESULTS: Eighteen germline mutations (50%) were identifi ed, 9 in MLH1 and 9 in MSH2. Sixteen of these sequence alterations were considered pathogenic, the remaining two were non-conservative missense alterations occurring at highly conserved functional motifs. The majority of the defi nite pathogenic mutations (81%, 13/16) were found in families fulfilling the stringent Amsterdam Ⅰ/Ⅱ criteria, including three rearrangements revealed by MLPA (two in MSH2 and one in MLH1). However, in three out of sixteen HNPCC-suspected families (19%), a disease-causing alteration could be revealed. Furthermore, nine mutations described here are novel, and none of the sequence changes were found in more than one family.CONCLUSION: Our study describes for the f irst time the prevalence and spectrum of germline mismatch repair gene mutations in Hungarian HNPCC and suspected-HNPCC families. The results presented here suggest that clinical selection criteria should be relaxed and detection of genomic rearrangements should be included in genetic screening in this population.

Detection of germline mutations of hMLH1 and hMSH2 based on cDNA sequencing in China

AIM： TO detect the germline mutations Of hMLH1 and hMSH2 based on mRNA sequencing to identify hereditary non polyposis oolorectal cancer （HNPCC） families. METHODS： Total RNA was extracted from peripberal blood of 14 members from 12 different families fulfilling Amsterdam criteria II. mRNA of hMLH1 and hMSH2 was reversed with special primers and heat-resistant reverse tmnscriptase, cDNA was amplified with expand long template PCR and cDNA sequendng analysis was followed. RESULT： Seven germline mutations were found in 6 families （6/12, 50%）, in 4 hMLH1 and 3 hMSH2 mutations （4/12, 33.3%）; （3/12, 25%）. The mutation types involved 4 missense, 1 silent and 1 frame shift mutations as well as 1 mutation in the non-coding area. Four out of the seven mutations have not been reported previously. The 4 hMLH1 mutations were distributed in exons 8, 12, 16, and 19. The 3 hMSH2 mutations were distributed in exons 1 and 2. Six out of the 7 mutations were pathological, which were dislTibuted in 5 HNPCC families. CONCLUSION： Germline mutations of hMLH1 and hMSH2 can be found based on cDNA sequencing so as to identify HNPCC family, which is highly sensitive and has the advantages of cost and time saving.

Clinicopathological features of typical and nontypical hereditary non-polyposis colorectal cancer and their germline mutation of hMLH_1 and hMSH_2

Objective To study the clinicopathological features of the Chinese hereditary non-polyposis colorectal cancer and its germline mutation of hMLH1 and hMSH2. Methods Thirteen typical Chinese hereditary non-polyposis colorectal carcinoma (HNPC) C kindreds and 19 nontypical HNPCC families were registered and followed up. The germline mutation of the hMLH1 and hMSH2 of 12 index cases of 6 typical and 6 nontypical NHPCC were screened by PCR-SSCP. Samples with abnormal mobility were sequenced direcdy. Results The average age of typical HNPCC was 47, no difference existed between sexs. Location of the tumors of typical HNPCC represented 44.7% on the right half colon and non-typical HNPCC 65. 8% on the rectum. The rate of the metachronos cancer was 11.5%. The 3 - , 5 - and 10 -year survival rate was 64. 0%, 45. 3% and 31. 2% respectively. Among 12 cases, 8 showed abnormal mobility. Except for an intron polymorphinism, six exons abnormalities were found in 5 of 12 proband. Sequencing showed 4 missense,7

胚系BRCA 1/2基因变异与乳腺癌患者临床特征的关系

目的分析乳腺癌胚系BRCA 1/2基因变异(germline BRCA 1/2 mutation,gBRCAm)类型和分布情况,研究其与临床特征的关系。方法采用二代测序对2019年6月至2021年4月于复旦大学附属中山医院就诊的146例乳腺癌患者进行gBRCAm检测。收集到其中94例乳腺癌患者的发病年龄、组织学分级、淋巴结状态以及雌激素受体(estrogen receptor,ER)、孕酮受体(progesterone receptor,PR)和人表皮生长因子受体-2(human epidermal growth factor receptor-2,HER-2)表达等信息。采用χ^(2)检验和Fisher精确检验分析gBRCAm与乳腺癌临床特征的关系。结果乳腺癌患者发生gBRCAm频率为12.3%。乳腺癌患者变异检出率显著高于公共数据库的报道(P=0.023)。94.4%的变异发生于外显子,5.6%发生于内含子的剪接区。移码变异、无义变异、大片段重排、剪接突变和同义突变分别占61.1%、16.7%、11.1%、5.5%和5.5%,其中1例为未报道的新变异位点。gBRCAm与乳腺癌发病年龄(P<0.001)、肿瘤家族史(P=0.008)、双侧乳腺癌(P=0.001)和三阴型乳腺癌(P=0.025)有关。在ER和PR阳性的乳腺癌患者中,携带胚系BRCA 2基因变异显著多于BRCA 1基因(P=0.041和P=0.026)。结论乳腺癌患者携带的gBRCAm多为移码突变,位于重要的基因功能区和结构域上,且早发、肿瘤家族史和三阴型乳腺癌患者多携带gBRCAm。

Mechanisms of acquired resistance of BRCA1/2-driven tumors to platinum compounds and PARP inhibitors

Molecular pathogenesis of tumors arising in BRCA1/2 germ-line mutation carriers usually includes somatic inactivation of the remaining allele of the involved gene.Consequently,BRCA1/2-driven cancers are sensitive to platinum-based therapy and poly(ADP-ribose)polymerase inhibitors(PARPi).Long-term exposure to these drugs may result in the emergence of secondary BRCA1/2 mutations,which restore the open-reading frame of the affected allele.This platinum/PARPi crossresistance mechanism applies both for BRCA1 and BRCA2 genes and has been repeatedly validated in various laboratory models and multiple clinical studies.There are some other routes associated with the partial rescue of BRCA1/2 function or the development of BRCA1/2-independent pathways for genomic maintenance;however,their actual clinical relevance remains to be established.In addition,studies on the short-term neoadjuvant therapy for ovarian cancer revealed that even chemonaive BRCA1-driven tumors contain a small proportion of BRCA1-proficient cells.These pre-existing cells with retained BRCA1 heterozygosity rapidly repopulate the tumor mass during platinum exposure,but become outcompeted by BRCA1-deficient cells during therapy holidays.Understanding of the platinum/PARPi resistance pathways has led to the development of novel therapeutic approaches,which aim to improve the management of BRCA1/2-related cancers and are currently undergoing preclinical and clinical evaluation.

Uncertainty following an inconclusive result from the BRCA1/2 genetic test:A review about psychological outcomes

BACKGROUND An inconclusive result from BRCA1/2 genetic testing indicates that a genetic variant of uncertain significance is detected.This case constitutes the majority of genetic test results,but studies specifically addressing the psychological adjustment of people with inconclusive results are scarce.AIM To examine psychological outcomes of receiving an uninformative BRCA1/2 test result.METHODS PubMed,PsychInfo,and Cochrane Central Register of Controlled Trials were screened for studies focusing on distress,anxiety,and depression levels in individuals with inconclusive genetic test results.This review is based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses method.RESULTS Studies on psychological outcomes of inconclusive BRCA1/2 focused on general and specific distress,anxiety,and depression.Overall,they produced mixed results.These inconsistent findings are probably due to the uncertainty caused by this type of result,that may also influence the decisions of individuals about surveillance and prophylactic options,reducing their compliance.In addition,this review highlights specific risk and protective factors that affect psychological adjustment in individuals with an inconclusive genetic testing result.CONCLUSION Individuals with inconclusive genetic test results need specific educational programs and support to better understand the meaning of their results in order to be able to make decisions about surveillance and prophylactic options.

Current progress and questions in germline genetics of prostate cancer

Dramatic progress has been made in the area of germline genetics of prostate cancer(PCa)in the past decade.Both common and rare genetic variants with effects on risk ranging from barely detectable to outright practice-changing have been identified.For men with high risk PCa,the application of genetic testing for inherited pathogenic mutations is becoming standard of care.A major question exists about which additional populations of men to test,as men at all risk levels can potentially benefit by knowing their unique genetic profile of germline susceptibility variants.This article will provide a brief overview of some current issues in understanding inherited susceptibility for PCa.

BRCA1/2 mutations and survival of high-grade endometrioid endometrial cancer

Background BRCA1/2 mutations have been shown to be associated with the development of many solid tumors including endometrial cancer(EC).The objectives of this study are to analyze the association between BRCA1/2 mutational status and clinicopathological characteristics as well as outcomes in EC patients.Methods 510 eligible EC patients from the Cancer Genome Atlas database were included in the study.The association between clinicopathological characteristics and different BRCA1/2 mutational status was compared and analyzed.Analyses of the impact of BRCA mutations on survival in EC patients was conducted using Kaplan-Meier survival analyses and Cox regressions.In order to control confounding bias between groups,propensity score matching method was used.Results Among the eligible patients,11(2.2%)harbored BRCA1 mutation,43(8.4%)harbored BRCA2 mutation,and 36(7.1%)harbored both.Body mass index,rates of hypertension history,proportion of non-endometrioid histology and rates of positive peritoneal cytology were lower in patients with BRCA1/2 mutations compared with the group of wild-type counterpart(p=0.020,0.048,0.001 and 0.012,respectively).Patients with BRCA1/2 mutations showed longer overall(OS)and recurrence-free survival(RFS)(in Kaplan-Meier analyses,p<0.001 and p=0.004,respectively;in Cox regressions,p=0.001 and 0.007,respectively).Further analyses showed that the impact of BRCA mutations on survival was significant only in patients with high-grade endometrioid EC.Based on the cohorts generated after propensity score matching,in high-grade endometrioid EC patients,the influence of BRCA1/2 mutations remained significant on OS,but not on RFS(p=0.003 and 0.057 in Kaplan-Meier analyses,p=0.020 and 0.071 in Cox regressions).Conclusion BRCA1/2 mutations are associated with better survival in patients with high grade endometrioid EC,indicating the value of BRCA testing in EC clinical management.

Genetic features of platinum-resistant ovarian cancer patients

The authors try to decide a problem of ovarian cancer resistance to platinum drugs by the way of correlation finding between platinum-resistance of tumor and presence of gene mutations in the patient.It was shown a variety of options for BRCA gene mutations in patients with ovarian cancer:BRCA 1(185delAG)-64.2%,BRCA 1(5382 insC)-55.7%,and BRCA 2(6174delT)-53.8%.Authors discovered a significant positive correlation between carriage of mutations in the BRCA genes 1/2 and the sensitivity of malignant ovarian tumors to chemotherapy with platinum.Mutations in these genes occurred significantly more often in patients with platinum-sensitive ovarian cancer.

Constitutional Mismatch Repair-Deficiency Syndrome Is a Rare Cause of Cancer Even in a Highly Consanguineous Population

Biallelic germline mutations in the mismatch repair genes, including MLH1, MSH2, MSH6 or PMS2, lead to a recessive constitutional mismatch repair-deficiency (CMMR-D) syndrome characterized by early onset malignancies in children and young adults. Because consanguinity unmasks autosomal recessive disorders, we hypothesized that the frequency of CMMR-D is inflated in the highly consanguineous population of Saudi Arabia. In this study, 371 pediatric and young adult?patient samples from Saudi Arabia that cover the tumor spectrum of CMMR-D syndrome were analyzed for biallelic germline mutations in the MLH1, MSH2, MSH6 and PMS2 with the use of direct genomic sequencing. However, none of the 371 patients involved in the study was found to have biallelic pathological mutations of MLH1, MSH2, MSH6 or PMS2. This result indicates that CMMR-D is exceptionally rare among pediatric cancer patients and adult early onset cancer patients, even in the highly consanguineous Saudi population. Our findings suggest that larger cohorts will be needed, particularly in outbred populations, to determine the frequency of CMMR-D and that routine screening for this syndrome among cancer patients is not warranted.