Evaluation of Bayesian Point-Based System on the Variant Classification of Hereditary Cancer Predisposition Genes.

PURPOSE: To assess the differences in variant classifications using the ACMG/AMP 2015 guidelines and the Bayesian point-based classification system (here referred to as the point system) in 115 hereditary cancer predisposition genes and explore variant sub-tiering by the point system. METHODS: Germline variant classifications for 721 pediatric patients from an in-house panel were retrospectively evaluated using the two scoring systems. RESULTS: 2376 unique variants were identified, with ∼23.5% exhibiting discordant classifications. Unique variants classified by the point system demonstrated a lower rate of variants of uncertain significance (VUS; ∼15%) compared to ACMG/AMP 2015 (∼36%). This change is attributed to unique variants with one benign supporting evidence (∼12%) or one benign strong evidence (∼4%) being classified as likely benign by the point system. Additionally, variants with conflicting/modified evidence (∼5% of 2376) are also resolved by the point system. Sub-tiering unique variants classified by the point system as VUS (n=354) indicates ∼77.4% were VUS-Low (0-1 points), while the remaining ∼22.6% were VUS-Mid (2-3 points) and VUS-High (4-5 points). CONCLUSION: The point system reduces the VUS rate and facilitates their sub-tiering. Future large-scale studies are warranted to explore the impact of the point system on improving VUS reporting and/or VUS clinical management.

A second hereditary cancer predisposition syndrome in a patient with lynch syndrome and three primary cancers.

Current National Comprehensive Cancer Network ® (NCCN ®) guidelines for Colorectal Genetic/Familial High-Risk Assessment provide limited guidance for genetic testing for individuals with already diagnosed hereditary cancer conditions. We are presenting the case of a 36-year-old woman who was diagnosed with Lynch Syndrome at age 23 after genetic testing for a familial variant (c.283del) in the MLH1 gene. The patient had a previous history of Hodgkin Lymphoma at the time of familial variant testing, and she would later develop stage IIIa cecal adenocarcinoma at age 33 and metastatic papillary thyroid carcinoma at age 35. The patient's family history included a first-degree relative who was diagnosed with colorectal cancer at age 39, multiple second-degree relatives with colorectal, endometrial, and stomach cancer, and third and fourth-degree relatives with breast cancer. In light of her personal and family history, a comprehensive cancer panel was recommended. This panel found a second hereditary cancer predisposition syndrome: a likely pathogenic variant (c. 349 A > G) in the CHEK2 gene. This specific CHEK2 variant was recently reported to confer a moderately increased risk for breast cancer. The discovery of this second cancer predisposition syndrome had important implications for the patient's screening and risk management. While uncommon, the possibility of an individual having multiple cancer predisposition syndromes is important to consider when evaluating patients and families for hereditary cancer, even when a familial variant has been identified.

Parallel DNA/RNA NGS Using an Identical Target Enrichment Panel in the Analysis of Hereditary Cancer Predisposition.

Germline DNA testing using the next-gene-ration sequencing (NGS) technology has become the analytical standard for the diagnostics of hereditary diseases, including cancer. Its increasing use places high demands on correct sample identification, independent confirmation of prioritized variants, and their functional and clinical interpretation. To streamline these processes, we introduced parallel DNA and RNA capture-based NGS using identical capture panel CZECANCA, which is routinely used for DNA analysis of hereditary cancer predisposition. Here, we present the analytical workflow for RNA sample processing and its analytical and diagnostic performance. Parallel DNA/RNA analysis allowed credible sample identification by calculating the kinship coefficient. The RNA capture-based approach enriched transcriptional targets for the majority of clinically relevant cancer predisposition genes to a degree that allowed analysis of the effect of identified DNA variants on mRNA processing. By comparing the panel and whole-exome RNA enrichment, we demonstrated that the tissue-specific gene expression pattern is independent of the capture panel. Moreover, technical replicates confirmed high reproducibility of the tested RNA analysis. We concluded that parallel DNA/RNA NGS using the identical gene panel is a robust and cost-effective diagnostic strategy. In our setting, it allows routine analysis of 48 DNA/RNA pairs using NextSeq 500/550 Mid Output Kit v2.5 (150 cycles) in a single run with sufficient coverage to analyse 226 cancer predisposition and candidate ge-nes. This approach can replace laborious Sanger confirmatory sequencing, increase testing turnaround, reduce analysis costs, and improve interpretation of the impact of variants by analysing their effect on mRNA processing.

Beyond germline genetic testing - heterozygous pathogenic variants in PMS2 in two children with Osteosarcoma and Ependymoma.

BACKGROUND: Lynch syndrome (LS) is not considered part of childhood cancer predisposition syndromes. CASE PRESENTATION: Analysis of a pediatric osteosarcoma (OS) displayed hypermutation (16.8), alternative lengthening of telomeres (ALT), loss of PMS2 expression in tumor tissue (retained in non-neoplastic cells), PMS2 loss of heterozygosity (LOH), and high-degree of microsatellite instability (MSI) tested by PCR. A heterozygous duplication c.1076dup p.(Leu359Phefs*6) in exon 10 of NM_000535.6:PMS2 was detected by SNV analysis in peripheral blood, confirming diagnosis of LS in the patient. The tumor molecular features suggest LS-associated development of OS. In a second case, whole-genome sequencing identified a heterozygous SNV c.1 A > T p.? in exon 1 of PMS2 in tumor and germline material of a girl with ependymoma. Tumor analysis displayed evidence for ALT and low mutational burden (0.6), PMS2 expression was retained, MSI was low. Multiplex ligation-dependent probe amplification identified no additional PMS2 variant and germline MSI testing did not reveal increased gMSI ratios in the patient´s lymphocytes. Thus, CMMRD was most closely excluded and our data do not suggest that ependymoma was related to LS in the child. CONCLUSIONS: Our data suggest that the LS cancer spectrum may include childhood cancer. The importance of LS in pediatric cancers necessitates prospective data collection. Comprehensive molecular workup of tumor samples is necessary to explore the causal role of germline genetic variants.

Radiation-Induced Lymphopoenia and Treatment Outcome in Hereditary Breast Cancer Patients.

Many breast cancer (BC) predisposition genes encode proteins involved in DNA damage repair (DDR). Identification of germline pathogenic va-riants (PV) in DDR genes raises the question whether their presence can influence the treatment outcomes and potential radiation-induced toxicity in their carriers treated by adjuvant radiotherapy, which has not yet been answered conclusively. We retrospectively examined records of 213 BC patients treated by adjuvant radiotherapy, including 39 (18.3 %) BRCA1/2 PV carriers, 25 carriers (11.7 %) of PV in other breast cancer-predisposing genes, and 149 (70 %) non-carriers. Our goal was to examine 5-year disease-free survival (5y DFS) rates among the study groups and determine the impact of radiotherapy-induced lymphopoenia (RIL) on this outcome. While we found no significant difference in 5y DFS between non-carriers and carriers of BRCA mutations (86.4 % vs 78.4 % P = 0.24) or between non-carriers and other studied mutations (86.4 % vs 93.3 %; P = 0.27), respectively, we observed that the entire group of PV carriers had a significantly lower proportion of patients without RIL (P = 0.04) than the non-carriers. In contrast, subsequent analyses indicated a non-significant trend toward an increased 5y DFS in PV carriers with RIL. Our single-centre study indicated that the presence of PV in BC patients has an insignificant impact on DFS but can reduce the risk of RIL associated with adjuvant radiotherapy. It remains unclear whether this may result from the paradoxical activation of anti-tumour immunity in PV carriers with higher lymphocyte consumption resulting from higher immune effectiveness.

The CFTR Gene Germline Heterozygous Pathogenic Variants in Russian Patients with Malignant Neoplasms and Healthy Carriers: 11,800 WGS Results.

More than 275 million people in the world are carriers of a heterozygous mutation of the CFTR gene, associated with cystic fibrosis, the most common autosomal recessive disease among Caucasians. Some recent studies assessed the association between carriers of CFTR variants and some pathologies, including cancer risk. The aim of this study is to analyze the landscape of germline pathogenic heterozygous CFTR variants in patients with diagnosed malignant neoplasms. For the first time in Russia, we evaluated the frequency of CFTR pathogenic variants by whole-genome sequencing in 1800 patients with cancer and compared this with frequencies of CFTR variants in the control group (1825 people) adjusted for age and 10,000 healthy individuals. In the issue, 47 out of 1800 patients (2.6%) were carriers of CFTR pathogenic genetic variants: 0.028 (42/1525) (2.8%) among breast cancer patients, 0.017 (3/181) (1.7%) among colorectal cancer patients and 0.021 (2/94) (2.1%) among ovarian cancer patients. Pathogenic CFTR variants were found in 52/1825 cases (2.85%) in the control group and 221 (2.21%) in 10,000 healthy individuals. Based on the results of the comparison, there was no significant difference in the frequency and distribution of pathogenic variants of the CFTR gene, which is probably due to the study limitations. Obviously, additional studies are needed to assess the clinical significance of the heterozygous carriage of CFTR pathogenic variants in the development of various pathologies in the future, particularly cancer.

Germline pathogenic variant spectrum in 25 cancer susceptibility genes in Turkish breast and colorectal cancer patients and elderly controls.

Inherited pathogenic variants account for 5% to 10% of all breast cancer (BC) and colorectal cancer (CRC) cases. Here, we sought to profile the pathogenic variants in 25 cancer susceptibility genes in Turkish population. Germline pathogenic variants were screened in 732 BC patients, 189 CRC patients and 490 cancer-free elderly controls, using next-generation sequencing-based multigene panel testing and multiplex ligation-dependent probe amplification testing. Pathogenic variants were detected in 17.2% of high-risk BC patients and 26.4% of high-risk CRC patients. More than 95% of these variants were clinically actionable. BRCA1/2 and mismatch repair genes (MLH1, MSH2 and MSH6) accounted for two-thirds of all pathogenic variants detected in high-risk BC and CRC patients, respectively. Pathogenic variants in PALB2, CHEK2, ATM and TP53 were also prevalent in high-risk BC patients (4.5%). BRCA1 exons 17-18 deletion and CHEK2 c.592+3A>T were the most common variants predisposing to BC, and they are likely to be founder variants. Three frequent MUTYH pathogenic variants (c.884C>T, c.1437_1439delGGA and c.1187G>A) were responsible for all MUTYH biallelic cases (4.4% of high-risk CRC patients). The total pathogenic variant frequency was very low in controls (2.4%) and in low-risk BC (3.9%) and CRC (6.1%) patients. Our study depicts the pathogenic variant spectrum and prevalence in Turkish BC and CRC patients, guiding clinicians and health authorities for genetic testing applications and variant classification in Turkish population.

Tumor surveillance for children and adolescents with cancer predisposition syndromes: The psychosocial impact reported by adolescents and caregivers.

PURPOSE: Individuals with cancer predisposition syndromes (CPS) are often followed in cancer screening programs, which aim to detect early stage tumors. While cancer surveillance has the potential to improve patient outcomes, its psychosocial impact is uncharacterized in the pediatric population. We examined the cancer surveillance experience from the perspectives of adolescents and parents of children at risk of developing cancer. PATIENTS AND METHODS: Using grounded theory and thematic analysis qualitative methodology, we conducted semi-structured interviews with parents and adolescents, separately. Interviews were transcribed verbatim and coded separately to derive overlapping and unique themes. RESULTS: We completed 20 semi-structured interviews (11 parents and nine adolescents). Positive experiences were related to feelings of reassurance and taking a proactive approach. Both adolescents and parents experienced worry, related to practical aspects of screening, and related to the reminder of cancer risk that manifests with surveillance appointments. This worry was cyclical, associated with appointments, and generally waned over time. Participants felt that the benefits of surveillance outweighed perceived challenges. Open communication with health care providers, and equipping parents/adolescents with vocabulary to discuss their diagnosis and care with others, were felt to be important for mitigating worries associated with cancer risk and surveillance. CONCLUSION: Parents and adolescents experience worry associated with surveillance for CPS, which may warrant regular psychosocial support, particularly during the first year following CPS diagnosis. Enhancing communication with the health care team and among and beyond immediate family members represents an additional important strategy to mitigate adverse experiences and perceptions.

Gynecological lesions in hereditary cancer predisposition syndromes.

Hereditary tumor syndromes with a possible manifestation in the female internal genital tract represent a heterogeneous group of diseases. The two most common entities are the hereditary breast and ovarian cancer syndrome, and the Lynch syndrome. The less common syndromes include the rhabdoid tumor predisposition syndrome, Cowden syndrome, tuberous sclerosis complex, DICER1 syndrome, nevoid basal cell carcinoma syndrome, Peutz-Jeghers syndrome, von Hippel-Lindau disease, and hereditary leiomyomatosis and renal cell cancer syndrome. The goal of this manuscript is to provide a comprehensive overview of those hereditary tumor syndromes which can manifest in the area of the female genital system, with an emphasis on their summary, the characteristics of the tumors which can develop in association with these syndromes, and the approach to the processing of prophylactically removed tissues and organs. The issue of Lynch syndrome screening is also discussed.

How I approach hereditary cancer predisposition in a child with cancer.

Approximately 10% of all children with cancer are affected by a monogenic cancer predisposition syndrome. This has important implications for both the child and her/his family. The assessment of hereditary cancer predisposition is a challenging task for clinicians and genetic counselors in daily routine. It includes consideration of tumor genetics, specific features of the patient, and the medical/family history. To keep up with the pace of this rapidly evolving and increasingly complex field of genetic susceptibility, we suggest a systematic approach for the evaluation of the child with cancer and her/his family by an interdisciplinary team specialized in hereditary cancer predisposition.

Effective Immunotherapy of Glioblastoma in an Adolescent with Constitutional Mismatch Repair-Deficiency Syndrome.

BACKGROUND: Individuals with constitutional mismatch repair-deficiency syndrome (CMMR-D) are characterised by early occurrence of colon cancer, haematological malignancies, and brain tumors (malignant gliomas, high-grade gliomas) in childhood, adolescence, and early adulthood. High mutational tumor burden is typical of glioblastoma in CMMR-D patients and could be a reason why this type of glioblastoma responds well to immunotherapies, including those that employ checkpoint inhibitors. OBSERVATION: We describe a case of an adolescent with CMMR-D that had been genetically proven by whole exome sequencing (c.2T>A/p.M1K and c.2521delT/p.W841fs PMS2 gene mutation). The patient presented successively with colon cancer and glioblastoma with a high mutational burden. The individualized glioblastoma therapy was based on the biological tumor profile and included immunotherapy with a combination of vaccination with autologous dendritic cells producing IL-12 and nivolumab, in addition to radiotherapy with metronomic temozolomide. The patient is still alive 21 months after the initial glioblastoma diagnosis and shows a complete therapeutic response documented by repeated magnetic resonance examinations. CONCLUSION: Individuals with CMMR-D should be regularly examined using established algorithms. Whole body magnetic resonance imaging can play a key role, because it enables the early diagnosis of malignancy during the asymptomatic period. Malignancies in CMMR-D patients usually exhibit a hypermutated genotype and respond to immunotherapy. Conventional glioblastoma therapy is only palliative. Patients can benefit from an individualized therapeutic plan based on the tumor biological profile. Extensive molecular analysis of the tumor tissue is necessary. Key words hereditary cancer predisposition syndromes - glioblastoma - whole exome sequencing - immunotherapy - vaccines - checkpoint inhibitors This study was supported by the research project of the Czech Ministry of Health AZV 16-33209A (Next generation sequencing and express profiling as diagnostic tools for personalized therapeutic plans in children with solid tumors). The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers. Submitted: 26. 9. 2018 Accepted: 18. 11. 2018.

Next generation immunohistochemistry: Emerging substitutes to genetic testing?

The identification of at-risk kindreds facilitates screening and risk reduction strategies for patients with hereditary cancer predisposition syndromes. Recently, immunohistochemistry (IHC) has emerged as a cost-effective strategy for detecting or inferring the presence of mutations in both tumors and the germline of patients presenting with tumors associated with hereditary cancer predisposition syndromes. In this review we discuss the use of novel IHC markers, including PRKAR1A, ß-catenin, SDHB, fumarate hydratase and 2SC, HRASQ61R, BAP1, parafibromin and glucagon, which have either established applications or show promise for surgical pathologists to complement morphological or clinical suspicion of hereditary cancer predisposition syndromes. Specifically, we focus on Carney complex, familial adenomatous polyposis (FAP)-associated cribriform-morular variant of papillary thyroid carcinoma, familial succinate dehydrogenase-related pheochromocytoma/paraganglioma syndromes, hereditary leiomyomatosis and renal cell cancer (HLRCC), medullary thyroid cancer and Multiple Endocrine Neoplasia 2 (MEN2), BAP1 hereditary cancer predisposition syndrome, Hyperparathyroidism-Jaw Tumor Syndrome (HPT-JT), and Pancreatic Neuroendocrine Tumor Syndrome (Mahvash disease).

[Prophylactic gastrectomy]. / Gastrectomies prophylactiques.

One to 3% of gastric cancers are secondary to genetic predisposition, notably hereditary diffuse gastric cancers (HDGC) caused by CDH1 gene mutations. According to French recommendations, in case of CDH1 gene mutation, a prophylactic total gastrectomy should be performed between 20 and 30 years old. This gastrectomy should remove all the gastric mucosa at both extremities (duodenal and esophageal sides). Histopathological examinations of prophylactic total gastrectomies in asymptomatic CDH1-mutated patients reveal microscopic foci of diffuse-type cancer in 90 to 100% of cases. Lymph node involvement and lympho-vascular invasion are extremely rare, justifying the use of a D1-only lymphadenectomy. In the context of prophylaxis, limited lymphadenectomy and the development of minimally invasive oesogastric surgery, the minimally invasive approach might be the preferred approach, in expert centers. Surgical outcomes seem to be similar to those after gastrectomy for cancer. Prophylactic total gastrectomy is the cornerstone of CGDH management, associated with multidisciplinary follow-up and mammary surveillance in women.

Adenomas from individuals with pathogenic biallelic variants in the MUTYH and NTHL1 genes demonstrate base excision repair tumour mutational signature profiles similar to colorectal cancers, expanding potential diagnostic and variant classification applications.

Background: Colorectal cancers (CRCs) from people with biallelic germline likely pathogenic/pathogenic variants in MUTYH or NTHL1 exhibit specific single base substitution (SBS) mutational signatures, namely combined SBS18 and SBS36 (SBS18+SBS36), and SBS30, respectively. The aim was to determine if adenomas from biallelic cases demonstrated these mutational signatures at diagnostic levels. Methods: Whole-exome sequencing of FFPE tissue and matched blood-derived DNA was performed on 9 adenomas and 15 CRCs from 13 biallelic MUTYH cases, on 7 adenomas and 2 CRCs from 5 biallelic NTHL1 cases and on 27 adenomas and 26 CRCs from 46 non-hereditary (sporadic) participants. All samples were assessed for COSMIC v3.2 SBS mutational signatures. Results: In biallelic MUTYH cases, SBS18+SBS36 signature proportions in adenomas (mean±standard deviation, 65.6%±29.6%) were not significantly different to those observed in CRCs (76.2%±20.5%, p-value=0.37), but were significantly higher compared with non-hereditary adenomas (7.6%±7.0%, p-value=3.4×10-4). Similarly, in biallelic NTHL1 cases, SBS30 signature proportions in adenomas (74.5%±9.4%) were similar to those in CRCs (78.8%±2.4%) but significantly higher compared with non-hereditary adenomas (2.8%±3.6%, p-value=5.1×10-7). Additionally, a compound heterozygote with the c.1187G>A p.(Gly396Asp) pathogenic variant and the c.533G>C p.(Gly178Ala) variant of unknown significance (VUS) in MUTYH demonstrated high levels of SBS18+SBS36 in four adenomas and one CRC, providing evidence for reclassification of the VUS to pathogenic. Conclusions: SBS18+SBS36 and SBS30 were enriched in adenomas at comparable proportions observed in CRCs from biallelic MUTYH and biallelic NTHL1 cases, respectively. Therefore, testing adenomas may improve the identification of biallelic cases and facilitate variant classification, ultimately enabling opportunities for CRC prevention.

Contributions of molecular analysis to the diagnosis and treatment of gastrointestinal neoplasms.

This review discusses the role of molecular analysis in the diagnosis and treatment of gastrointestinal (GI) neoplasms. It is divided into 3 sections. The first section describes clinical applications of 11 immunohistochemical stains (p53, HER2, KIT, SDHB, SMAD4, beta-catenin, L-FABP, MLH1, PMS2, MSH2, and MSH6), the results of which directly reflect underlying genetic or epigenetic events. These applications are mainly diagnostic but in a few instances are predictive. Germline mutation testing is a diagnostic cornerstone in the hereditary cancer predisposition syndromes (HCPSs). Section two will describe the genotype and phenotype of 8 HCPSs presenting in the GI tract. Where available, guidelines based on evidence and/or expert opinion as to whom to test are presented. With our ever-expanding knowledge of the molecular genetic basis of cancer and an increasingly "biologic-oriented" therapeutic armamentarium, pathologists play a vital role in directing molecular-based predictive testing. The final section will discuss the 4 most mature examples in the GI tract: (1) HER2 testing to select patients with advanced gastroesophageal adenocarcinoma for anti-HER2 therapy, (2) KIT and PDGFRA mutation analysis to direct tyrosine kinase inhibitor therapy in gastrointestinal stromal tumor, (3) DNA mismatch repair function testing to determine the applicability of adjuvant chemotherapy in patients with stage II colorectal cancer (CRC), and (4) KRAS mutation analysis and related testing to determine the appropriateness of anti-EGFR monoclonal antibody therapy in patients with metastatic CRC.

Germline Testing for the Evaluation of Hereditary Cancer Predisposition.

Germline testing for hereditary cancer predisposition has become increasingly important in the management of patients with cancer. Recent studies have demonstrated that hereditary cancer predisposition is more common than previously recognized and germline pathogenic variants may be actionable for patient treatment strategies. This article reviews the significance of hereditary cancer predisposition assessment and highlights the current practices in germline genetic testing approaches.

Identification of a Cancer-Predisposing Germline POT1 p.Ile49Metfs*7 Variant by Targeted Sequencing of a Splenic Marginal Zone Lymphoma.

Germline disruptive variants in Protection of Telomeres 1 (POT1) predispose to a wide variety of cancers, including melanoma, chronic lymphocytic leukemia (CLL), Hodgkin lymphoma, myeloproliferative neoplasms, and glioma. We report the first case of splenic marginal zone lymphoma (SMZL) arising in a patient with a germline POT1 variant: a 65-year-old male with an extensive history of cancer, including melanoma and papillary thyroid carcinoma, who presented with circulating atypical lymphocytosis. Bone marrow biopsy revealed 20% involvement by a CD5-CD10- B-cell lymphoma that was difficult to classify. During the clinical workup of his low-grade lymphoma, targeted next-generation sequencing (NGS) identified POT1 p.I49Mfs*7 (NM_015450:c. 147delT) at a variant allele frequency (VAF) of 51%. NGS of skin fibroblasts confirmed the POT1 variant was germline. This likely pathogenic POT1 loss-of-function variant has only been reported once before as a germline variant in a patient with glioma and likely represents one of the most deleterious germline POT1 variants ever linked to familial cancer. The spectrum of cancers associated with germline pathogenic POT1 variants (i.e., autosomal dominant POT1 tumor predisposition syndrome) should potentially be expanded to include SMZL, a disease often associated with the loss of chromosome 7q: the location of the POT1 genetic locus (7q31.33).

Inherited heterozygous Fanconi anemia gene mutations in a therapy-related CMML patient with a rare NUP98-HOXC11 fusion: A case report.

Fanconi anemia (FA) genes play critical roles in the repair of DNA lesions. Non-FA (or underlying FA) patients harboring heterozygous germline FA gene mutations may also face an increased risk of developing bone marrow failure, primary immunodeficiency disease, and hereditary cancer predisposition syndromes. We report a female patient who suffered from ovarian cancer at 50 years of age. During the initial treatment, six cycles of docetaxel and carboplatin (DC) combination chemotherapy were administered followed by two cycles of docetaxel maintenance therapy. Then, she received a routine follow-up every 3 months for the next 3 years, and all the results of the examination and laboratory tests were normal. Unfortunately, at 54 years of age, she developed a secondary cancer of therapy-related (t-) chronic myelomonocytic leukemia (t-CMML). After two courses of a highly intensive induction chemotherapy regimen with DAC (decitabine) and HAA (homoharringtonine, cytarabine), the patient suffered from severe and persistent bone marrow failure (BMF). Targeted next-generation sequencing (NGS) of a panel of 80 genes was performed on her initial bone marrow aspirate sample and identified PTPN11, NRAS, and DNMT3A somatic mutations. In addition, RNA sequencing (RNA-seq) revealed a rare NUP98-HOXC11 fusion. Whole-exome sequencing (WES) verified RAD51C, BRIP1, PALB2, and FANCG heterozygous germline mutations of the FA pathway, which were further confirmed in buccal swab samples by Sanger sequencing. For this patient, we hypothesized that an altered FA pathway resulted in genomic instability, hypersensitivity to DNA-crosslinking agents or cytotoxic chemotherapeutics, and unsuccessful DNA damage repair. Consequently, she developed ovarian cancer and secondary t-CMML and then suffered from BMF and delayed post-chemotherapy bone marrow recovery after several chemotherapy courses. This case highlights the importance of genetic counseling in patients with hematopoietic neoplasms with high clinical suspicion for carrying cancer susceptibility gene mutations, which require timely diagnosis and personalized management.

Germline Testing in a Cohort of Patients at High Risk of Hereditary Cancer Predisposition Syndromes: First Two-Year Results from South Italy.

Germline pathogenic variants (PVs) in oncogenes and tumour suppressor genes are responsible for 5 to 10% of all diagnosed cancers, which are commonly known as hereditary cancer predisposition syndromes (HCPS). A total of 104 individuals at high risk of HCPS were selected by genetic counselling for genetic testing in the past 2 years. Most of them were subjects having a personal and family history of breast cancer (BC) selected according to current established criteria. Genes analysis involved in HCPS was assessed by next-generation sequencing (NGS) using a custom cancer panel with high- and moderate-risk susceptibility genes. Germline PVs were identified in 17 of 104 individuals (16.3%) analysed, while variants of uncertain significance (VUS) were identified in 21/104 (20.2%) cases. Concerning the germline PVs distribution among the 13 BC individuals with positive findings, 8/13 (61.5%) were in the BRCA1/2 genes, whereas 5/13 (38.4%) were in other high- or moderate-risk genes including PALB2, TP53, ATM and CHEK2. NGS genetic testing showed that 6/13 (46.1%) of the PVs observed in BC patients were detected in triple-negative BC. Interestingly, the likelihood of carrying the PVs in the moderate-to-high-risk genes calculated by the cancer risk model BOADICEA was significantly higher in pathogenic variant carriers than in negative subjects. Collectively, this study shows that multigene panel testing can offer an effective diagnostic approach for patients at high risk of hereditary cancers.

Clinical practice of a genetics referral selection tool in pediatric cancer patients.

There are few guidelines for genetic counseling and management of pediatric cancer patients with probable cancer predisposition. In this study, we used a previously proposed patient selection tool by Jongmans and discussed the findings in regard to pediatric cancer patients we treated. Pediatric solid tumor patients who were treated in Kocaeli University Department of Pediatric Oncology were evaluated with the five main questions in Jongmans' referral tool. All of the patients and records of diagnostic imaging were examined and analyzed. One-hundred-twenty-three patients participated in the study. The most common indication for genetic counseling was 'consanguinity of the parents' with '≥2 malignancies at childhood age' following it. Fifty-two (42.28%) patients had indication for genetic counseling. We recommend developing and using genetics counseling selection tools such as Jongmans' which helps clinicians differentiate patients with probable cancer predisposition.