The Initial Journey of Patients with Metastatic Pancreatic Cancer (PaCTO Project): A Nationwide Survey among Portuguese Specialist Physicians.

Introduction: We aimed to characterize the initial healthcare journey of metastatic pancreatic ductal adenocarcinoma (mPDAC) patients in Portugal, including healthcare provision and factors affecting therapeutic decisions, namely BRCA mutations testing. Methods: This is a descriptive cross-sectional, web-based survey using a convenience sampling approach. Portuguese oncologists and pathologists that routinely work with mPDAC patients from the different geographical regions and settings were invited to participate in the study via email (December 2020). Descriptive statistical analyses were performed, with categorical variables reported as absolute and relative frequencies, and continuous variables with non-normal distribution as median and interquartile range (IQR) (Stata v.15.0). Results: Seventy physicians participated in the study (43 oncologists, 27 pathologists). According to the responses, a median of 28 patients per center (IQR 12-70) was diagnosed with PDAC in the previous year; 22 of them referring (IQR 8-70) to mPDAC. The pointed median time from patients' first hospital admission until disease diagnosis/staging is between 2 and 4 weeks. Endoscopic ultrasound with fine-needle biopsy is available in most hospitals (86%). Around 50% of physicians request BRCA testing; the assessment of additional biomarkers besides BRCA is requested by 40% of professionals. Half of them stated that BRCA testing should be requested earlier-upon histological diagnosis, especially because the median time for results is of 4.0 weeks (IQR 4-8). PARP inhibitors such as olaparib, when available, would be the therapy of choice for most oncologists (71%) if no disease' progression occurs after 4 months. Treatments' selection is usually grounded on clinical criteria (e.g., performance status, liver function). Around 45% of patients use FOLFIRINOX/mFOLFIRINOX as the first-line therapy. Gemcitabine + nab-paclitaxel is used by 35% of patients as the second-line therapy. Conclusions: Physicians in Portugal support the increasing role of patient-tailored treatments in mPDAC, whose selection should be grounded on tumoral subtyping and molecular profiling. Further efforts to develop multidisciplinary teams, standardized clinical practice, and optimize the implementation of new target therapies are needed.

Introdução: Este estudo teve como objetivo caracterizar o percurso inicial dos doentes com adenocarcinoma ductal pancreático metastático (ACDPm) em Portugal, incluindo a prestação de cuidados de saúde e determinação de fatores que afetam as decisões terapêuticas, nomeadamente o teste de mutações BRCA. Métodos: Trata-se de um estudo descritivo transversal (web-based) usando uma abordagem de amostragem por conveniência. Médicos oncologistas e anatomopatologistas portugueses dedicados ao ACDPm e de diferentes regiões geográficas e instituições foram convidados a participar do estudo por email (Dez-2020). Foram realizadas análises estatísticas descritivas, com variáveis categóricas relatadas como frequências absolutas e relativas, e variáveis contínuas com distribuição não-normal como mediana e intervalo interquartil (IIQ) (Stata v.15.0). Resultados: Setenta médicos participaram do estudo (43 oncologistas, 27 patologistas). De acordo com as respostas, uma mediana de 28 doentes por centro (IIQ 12­70) foi diagnosticada com ACDP no ano anterior; 22 deles (IIQ 8­70) referentes a ACDPm. O tempo médio desde a primeira admissão hospitalar dos doentes até o diagnóstico/estadiamento da doença foi entre 2­4 semanas. A ultrassonografia endoscópica com biópsia por agulha fina é realizada pela maioria dos hospitais (86%). Aproximadamente 50% dos médicos referem solicitar o teste BRCA; a avaliação de biomarcadores adicionais além do BRCA é solicitada por 40% dos profissionais. Metade dos médicos assume que o teste BRCA deveria ser solicitado mais precocemente ­ durante o diagnóstico histológico, principalmente porque o tempo médio para obtenção do resultado é de 4,0 semanas (IIQ 4­8). Os inibidores PARP, como o olaparibe, quando disponíveis, seriam a terapia de escolha para a maioria dos oncologistas (71%) caso não haja progressão da doença após quatro meses. A seleção dos tratamentos é usualmente baseada em critérios clínicos (por exemplo, performance status, função hepática). Em cerca de 45% dos doentes é utilizado FOLFIRINOX/mFOLFIRINOX como terapia de primeira linha. Um esquema com Gemcitabina + nab-paclitaxel é usado em 35% dos doentes como terapia de segunda linha. Conclusões: Os médicos em Portugal apoiam o papel crescente do tratamento individualizado no ACDPm, cuja seleção deve ser baseada na subtipagem tumoral e no perfil molecular. São necessários mais esforços para capacitar as equipas multidisciplinares, desenvolver práticas clínicas padronizadas e otimizar a implementação de novas terapias-alvo.

Cluster effect for SNP-SNP interaction pairs for predicting complex traits.

Single nucleotide polymorphism (SNP) interactions are the key to improving polygenic risk scores. Previous studies reported several significant SNP-SNP interaction pairs that shared a common SNP to form a cluster, but some identified pairs might be false positives. This study aims to identify factors associated with the cluster effect of false positivity and develop strategies to enhance the accuracy of SNP-SNP interactions. The results showed the cluster effect is a major cause of false-positive findings of SNP-SNP interactions. This cluster effect is due to high correlations between a causal pair and null pairs in a cluster. The clusters with a hub SNP with a significant main effect and a large minor allele frequency (MAF) tended to have a higher false-positive rate. In addition, peripheral null SNPs in a cluster with a small MAF tended to enhance false positivity. We also demonstrated that using the modified significance criterion based on the 3 p-value rules and the bootstrap approach (3pRule + bootstrap) can reduce false positivity and maintain high true positivity. In addition, our results also showed that a pair without a significant main effect tends to have weak or no interaction. This study identified the cluster effect and suggested using the 3pRule + bootstrap approach to enhance SNP-SNP interaction detection accuracy.

BUB1B monoallelic germline variants contribute to prostate cancer predisposition by triggering chromosomal instability.

BACKGROUND: Prostate cancer (PrCa) is the most frequently diagnosed cancer in men. Variants in known moderate- to high-penetrance genes explain less than 5% of the cases arising at early-onset (< 56 years) and/or with familial aggregation of the disease. Considering that BubR1 is an essential component of the mitotic spindle assembly checkpoint, we hypothesized that monoallelic BUB1B variants could be sufficient to fuel chromosomal instability (CIN), potentially triggering (prostate) carcinogenesis. METHODS: To unveil BUB1B as a new PrCa predisposing gene, we performed targeted next-generation sequencing in germline DNA from 462 early-onset/familial PrCa patients and 1,416 cancer patients fulfilling criteria for genetic testing for other hereditary cancer syndromes. To explore the pan-cancer role of BUB1B, we used in silico BubR1 molecular modeling, in vitro gene-editing, and ex vivo patients' tumors and peripheral blood lymphocytes. RESULTS: Rare BUB1B variants were found in ~ 1.9% of the early-onset/familial PrCa cases and in ~ 0.6% of other cancer patients fulfilling criteria for hereditary disease. We further show that BUB1B variants lead to decreased BubR1 expression and/or stability, which promotes increased premature chromatid separation and, consequently, triggers CIN, driving resistance to Taxol-based therapies. CONCLUSIONS: Our study shows that different BUB1B variants may uncover a trigger for CIN-driven carcinogenesis, supporting the role of BUB1B as a (pan)-cancer predisposing gene with potential impact on genetic counseling and treatment decision-making.

Corrigendum: Evaluation of PIK3CA mutations in advanced ER+/HER2-breast cancer in Portugal - U-PIK Project.

[This corrects the article DOI: 10.3389/fmolb.2023.1082915.].

Multiple TP53 p.R337H haplotypes and implications for tumor susceptibility.

The germline TP53 p.R337H mutation is reported as the most common germline TP53 variant. It exists at a remarkably high frequency in the population of southeast Brazil as founder mutation in two distinct haplotypes with the most frequent co-segregating with the p.E134∗ variant of the XAF1 tumor suppressor and an increased cancer risk. Founder mutations demonstrate linkage disequilibrium with neighboring genetic polymorphic markers that can be used to identify the founder variant in different geographic regions and diverse populations. We report here a shared haplotype among Brazilian, Portuguese, and Spanish families and the existence of three additional distinct TP53 p.R337H alleles. Mitochondrial DNA sequencing and Y-STR profiling of Brazilian carriers of the founder TP53 p.R337H allele reveal an excess of Native American haplogroups in maternal lineages and exclusively European haplogroups in paternal lineages, consistent with communities established through male European settlers with extensive intermarriage with Indigenous women. The identification of founder and independent TP53 p.R337H alleles underlines the importance for considering the haplotype as a functional unit and the additive effects of constitutive polymorphisms and associated variants in modifier genes that can influence the cancer phenotype.

Frequency of CDH1, CTNNA1 and CTNND1 Germline Variants in Families with Diffuse and Mixed Gastric Cancer.

The most well-characterized hereditary form of gastric cancer is hereditary diffuse gastric cancer (HDGC), an autosomal dominant syndrome characterized by an increased risk of diffuse gastric and lobular breast cancer. HDGC is predominantly caused by germline pathogenic variants in the CDH1 gene, and more rarely in the CTNNA1 gene. Furthermore, the International Gastric Cancer Linkage Consortium (IGCLC) guidelines do not clarify whether or not mixed gastric cancer (with a diffuse component) should be considered in the HDGC genetic testing criteria. We aimed to evaluate the contribution of CTNNA1 and CTNND1 germline variants to HDGC. Additionally, we also intended to compare the frequencies of CDH1 and CTNNA1 (and eventually CTNND1) germline variants between patients with diffuse and mixed gastric carcinomas to evaluate if genetic testing for these genes should or should not be considered in patients with the latter. We analyzed the CDH1 gene in 67 cases affected with early-onset/familial mixed gastric carcinomas and the CTNNA1 and CTNND1 genes in 208 cases with diffuse or mixed gastric cancer who had tested negative for CDH1 pathogenic germline variants. A deleterious CTNNA1 germline variant was found in 0.7% (1/141) of diffuse gastric cancer patients meeting the 2020 IGCLC criteria, as compared to the rate of 2.8% of CDH1 deleterious variants found by us in this setting. No deleterious variants were found in CTNND1, but six variants of uncertain significance were identified in this gene. We did not find any pathogenic CDH1, CTNNA1 or CTNND1 variant in index patients with early-onset/familial mixed gastric cancer, so there is no evidence that supports including this tumor type in the testing criteria for germline variants in these genes. The role of the CTNND1 gene in inherited gastric cancer predisposition is still unclear.

Gastric Cancer: A Practical Review on Management of Individuals with Hereditary or Familial Risk for Gastric Cancer.

Gastric adenocarcinoma is one of the most frequent and deadly cancers worldwide. However, its incidence is variable, being higher in eastern countries where screening the general population is recommended. On the other hand, in low to intermediate-risk countries, screening the general population may not be cost-effective, and therefore, it is necessary to be aware of high-risk populations that may benefit from adequate screening and surveillance. It is not always easy to identify these individuals, leading to a late diagnosis of gastric adenocarcinoma. In this review, the authors intend to summarize the data required to identify the population at risk of sporadic or familial gastric adenocarcinoma and the beginning of screening and its surveillance, with the final aim of increasing early detection of gastric adenocarcinoma and decreasing morbimortality. The authors highlight the importance to be aware of the several hereditary syndromes and MAPS recommendations and apply screen and surveillance protocols. The high-risk syndromes to gastric adenocarcinoma are gastric adenocarcinoma and proximal polyposis of the stomach, hereditary diffuse gastric cancer, and familial intestinal gastric cancer.

O adenocarcinoma gástrico é um dos cancros mais frequentes e mortais em todo o mundo. No entanto, a sua incidência é variável, sendo maior nos países orientais, onde o rastreio da população geral está recomendado. Por outro lado, nos países de risco baixo a intermediário, o rastreio da população geral pode não ser custo-efetivo e, portanto, é necessário conhecer quais são as populações de alto risco que podem beneficiar de rastreio e vigilância adequados. Porém, nem sempre é fácil identificar esses indivíduos levando a um diagnóstico tardio de adenocarcinoma gástrico. Nesta revisão, os autores pretendem resumir a informação necessária à identificação da população em risco de adenocarcinoma gástrico esporádico ou familiar e o início do rastreio e sua vigilância, com o objetivo final de otimizar a deteção precoce do adenocarcinoma gástrico e diminuir a morbimortalidade. Os autores salientam a importância de conhecer as diversas síndromes hereditárias e recomendações MAPS e aplicar protocolos de rastreio e vigilância. As síndromes de maior risco para adenocarcinoma gástrico são GAPPS, HDGC e FIGC.

Combined germline and tumor mutation signature testing identifies new families with NTHL1 tumor syndrome.

NTHL1 tumor syndrome is an autosomal recessive rare disease caused by biallelic inactivating variants in the NTHL1 gene and which presents a broad tumor spectrum. To contribute to the characterization of the phenotype of this syndrome, we studied 467 index patients by KASP assay or next-generation sequencing, including 228 patients with colorectal polyposis and 239 patients with familial/personal history of multiple tumors (excluding multiple breast/ovarian/polyposis). Three NTHL1 tumor syndrome families were identified in the group of patients with polyposis and none in patients with familial/personal history of multiple tumors. Altogether, we identified nine affected patients with polyposis (two of them diagnosed after initiating colorectal cancer surveillance) with biallelic pathogenic or likely pathogenic NTHL1 variants, as well as two index patients with one pathogenic or likely pathogenic NTHL1 variant in concomitance with a missense variant of uncertain significance. Here we identified a novel inframe deletion classified as likely pathogenic using the ACMG criteria, supported also by tumor mutational signature analysis. Our findings indicate that the NTHL1 tumor syndrome is a multi-tumor syndrome strongly associated with polyposis and not with multiple tumors without polyposis.

Implementation of upfront DPYD genotyping with a low-cost and high-throughput assay to guide fluoropyrimidine treatment in cancer patients.

OBJECTIVES: Genetic variants in the dihydropyrimidine dehydrogenase (DPYD ) gene are associated with reduced dihydropyrimidine dehydrogenase enzyme activity and can cause severe fluoropyrimidine-related toxicity. We assessed the frequency of the four most common and well-established DPYD variants associated with fluoropyrimidine toxicity and implemented a relatively low-cost and high-throughput genotyping assay for their detection. METHODS: This study includes 457 patients that were genotyped for the DPYD c.1129-5923C>G, c.1679T>G, c.1905 + 1G>A and c.2846A>T variants, either by Sanger sequencing or kompetitive allele specific PCR (KASP) technology. Of these, 172 patients presented toxicity during treatment with fluoropyrimidines (post-treatment group), and 285 were tested before treatment (pretreatment group). RESULTS: Heterozygous DPYD variants were identified in 7.4% of the entire series of 457 patients, being the c.2846A>T the most frequent variant. In the post-treatment group, 15.7% of the patients presented DPYD variants, whereas only 2.5% of the patients in the pretreatment group presented a variant. The KASP assays designed in this study presented 100% genotype concordance with the results obtained by Sanger sequencing. CONCLUSIONS: The combined assessment of the four DPYD variants in our population increases the identification of patients at high risk for developing fluoropyrimidine toxicity, supporting the upfront routine implementation of DPYD variant genotyping. Furthermore, the KASP genotyping assay described in this study presents a rapid turnaround time and relatively low cost, making upfront DPYD screening feasible in clinical practice.

Genetic landscape of homologous recombination repair genes in early-onset/familial prostate cancer patients.

Prostate cancer (PrCa) is one of the three most frequent and deadliest cancers worldwide. The discovery of PARP inhibitors for the treatment of tumors with deleterious variants in homologous recombination repair (HRR) genes has placed PrCa on the roadmap of precision medicine. However, the overall contribution of HRR genes to the 10%-20% of carcinomas arising in men with early-onset/familial PrCa has not been fully clarified. We used targeted next-generation sequencing (T-NGS) covering eight HRR genes (ATM, BRCA1, BRCA2, BRIP1, CHEK2, NBN, PALB2, and RAD51C) and an analysis pipeline querying both small and large genomic variations to clarify their global and relative contribution to hereditary PrCa predisposition in a series of 462 early-onset/familial PrCa cases. Deleterious variants were found in 3.9% of the patients, with CHEK2 and ATM being the most frequently mutated genes (38.9% and 22.2% of the carriers, respectively), followed by PALB2 and NBN (11.1% of the carriers, each), and finally by BRCA2, RAD51C, and BRIP1 (5.6% of the carriers, each). Using the same NGS data, exonic rearrangements were found in two patients, one pathogenic in BRCA2 and one of unknown significance in BRCA1. These results contribute to clarify the genetic heterogeneity that underlies PrCa predisposition in the early-onset and familial disease, respectively.

Practical lessons learned from real-world implementation of the molecular classification for endometrial carcinoma.

OBJECTIVES: This study aimed to explore the practical organisational aspects and difficulties in the implementation of the molecular classification of endometrial carcinoma (EC), and to demonstrate its potential impact in prognostic risk group classification. METHODS: We conducted a multicentre, retrospective cohort study of 230 patients with EC diagnosed between 2019 and 2022. Sample processing, clinicopathological, treatment and follow-up data were collected. Molecular classification was obtained by p53 and mismatch repair proteins immunohistochemistry, and POLE next-generation sequencing. RESULTS: Implementation was achieved through centralization of molecular analysis. In practice, it was possible to optimise turnaround times of complete integrative reports for hysterectomy specimens to a median time of 18 workdays. If genetic study was started in endometrial biopsies before surgery, 82.0% were available at the time of multidisciplinary tumour board, compared to 8.4% if performed in hysterectomy. ECs were classified as follows: 37.8% no specific molecular profile, 31.7% p53 abnormal, 24.3% mismatch repair deficient, and 6.1% POLE mutant. Integration of these results with traditional clinicopathologic factors led to a change in prognostic risk group in 15 (6.5%) patients, most being initially allocated to high-intermediate (n = 8) and low (n = 5) risk groups. Eight patients changed to a higher risk, and 7 to a lower risk group, whereas 2 remained in the same group. CONCLUSIONS: Centralization of EC molecular classification is a feasible option for countries with limited resources. Optimization of workflows may be achieved by earlier analysis in biopsies and prioritisation of patients whose results imply changes in risk group classification.

Ovarian cancer pathology characteristics as predictors of variant pathogenicity in BRCA1 and BRCA2.

BACKGROUND: The distribution of ovarian tumour characteristics differs between germline BRCA1 and BRCA2 pathogenic variant carriers and non-carriers. In this study, we assessed the utility of ovarian tumour characteristics as predictors of BRCA1 and BRCA2 variant pathogenicity, for application using the American College of Medical Genetics and the Association for Molecular Pathology (ACMG/AMP) variant classification system. METHODS: Data for 10,373 ovarian cancer cases, including carriers and non-carriers of BRCA1 or BRCA2 pathogenic variants, were collected from unpublished international cohorts and consortia and published studies. Likelihood ratios (LR) were calculated for the association of ovarian cancer histology and other characteristics, with BRCA1 and BRCA2 variant pathogenicity. Estimates were aligned to ACMG/AMP code strengths (supporting, moderate, strong). RESULTS: No histological subtype provided informative ACMG/AMP evidence in favour of BRCA1 and BRCA2 variant pathogenicity. Evidence against variant pathogenicity was estimated for the mucinous and clear cell histologies (supporting) and borderline cases (moderate). Refined associations are provided according to tumour grade, invasion and age at diagnosis. CONCLUSIONS: We provide detailed estimates for predicting BRCA1 and BRCA2 variant pathogenicity based on ovarian tumour characteristics. This evidence can be combined with other variant information under the ACMG/AMP classification system, to improve classification and carrier clinical management.

Evaluation of PIK3CA mutations in advanced ER+/HER2-breast cancer in Portugal - U-PIK Project.

Background: Around 40% of ER+/HER2-breast carcinomas (BC) present mutations in the PIK3CA gene. Assessment of PIK3CA mutational status is required to identify patients eligible for treatment with PI3Kα inhibitors, with alpelisib currently the only approved tyrosine kinase inhibitor in this setting. U-PIK project aimed to conduct a ring trial to validate and implement the PIK3CA mutation testing in several Portuguese centers, decentralizing it and optimizing its quality at national level. Methods: Eight Tester centers selected two samples of patients with advanced ER+/HER2- BC and generated eight replicates of each (n = 16). PIK3CA mutational status was assessed in two rounds. Six centers used the cobas® PIK3CA mutation test, and two used PCR and Sanger sequencing. In parallel, two reference centers (IPATIMUP and the Portuguese Institute of Oncology [IPO]-Porto) performed PIK3CA mutation testing by NGS in the two rounds. The quality of molecular reports describing the results was also assessed. Testing results and molecular reports were received and analyzed by U-PIK coordinators: IPATIMUP, IPO-Porto, and IPO-Lisboa. Results: Overall, five centers achieved a concordance rate with NGS results (allele frequency [AF] ≥5%) of 100%, one of 94%, one of 93%, and one of 87.5%, considering the overall performance in the two testing rounds. NGS reassessment of discrepancies in the results of the methods used by the Tester centers and the reference centers identified one probable false positive and two mutations with low AF (1-3%, at the analytical sensitivity threshold), interpreted as subclonal variants with heterogeneous representation in the tissue sections processed by the respective centers. The analysis of molecular reports revealed the need to implement the use of appropriate sequence variant nomenclature with the identification of reference sequences (HGVS-nomenclature) and to state the tumor cell content in each sample. Conclusion: The concordance rates between the method used by each tester center and NGS validate the use of the PIK3CA mutational status test performed at these centers in clinical practice in patients with advanced ER+/HER2- BC.

Genotype-first approach to identify associations between CDH1 germline variants and cancer phenotypes: a multicentre study by the European Reference Network on Genetic Tumour Risk Syndromes.

BACKGROUND: Truncating pathogenic or likely pathogenic variants of CDH1 cause hereditary diffuse gastric cancer (HDGC), a tumour risk syndrome that predisposes carrier individuals to diffuse gastric and lobular breast cancer. Rare CDH1 missense variants are often classified as variants of unknown significance. We conducted a genotype-phenotype analysis in families carrying rare CDH1 variants, comparing cancer spectrum in carriers of pathogenic or likely pathogenic variants (PV/LPV; analysed jointly) or missense variants of unknown significance, assessing the frequency of families with lobular breast cancer among PV/LPV carrier families, and testing the performance of lobular breast cancer-expanded criteria for CDH1 testing. METHODS: This genotype-first study used retrospective diagnostic and clinical data from 854 carriers of 398 rare CDH1 variants and 1021 relatives, irrespective of HDGC clinical criteria, from 29 institutions in ten member-countries of the European Reference Network on Tumour Risk Syndromes (ERN GENTURIS). Data were collected from Oct 1, 2018, to Sept 20, 2022. Variants were classified by molecular type and clinical actionability with the American College of Medical Genetics and Association for Molecular Pathology CDH1 guidelines (version 2). Families were categorised by whether they fulfilled the 2015 and 2020 HDGC clinical criteria. Genotype-phenotype associations were analysed by Student's t test, Kruskal-Wallis, χ2, and multivariable logistic regression models. Performance of HDGC clinical criteria sets were assessed with an equivalence test and Youden index, and the areas under the receiver operating characteristic curves were compared by Z test. FINDINGS: From 1971 phenotypes (contributed by 854 probands and 1021 relatives aged 1-93 years), 460 had gastric and breast cancer histology available. CDH1 truncating PV/LPVs occurred in 176 (21%) of 854 families and missense variants of unknown significance in 169 (20%) families. Multivariable logistic regression comparing phenotypes occurring in families carrying PV/LPVs or missense variants of unknown significance showed that lobular breast cancer had the greatest positive association with the presence of PV/LPVs (odds ratio 12·39 [95% CI 2·66-57·74], p=0·0014), followed by diffuse gastric cancer (8·00 [2·18-29·39], p=0·0017) and gastric cancer (7·81 [2·03-29·96], p=0·0027). 136 (77%) of 176 families carrying PV/LPVs fulfilled the 2015 HDGC criteria. Of the remaining 40 (23%) families, who did not fulfil the 2015 criteria, 11 fulfilled the 2020 HDGC criteria, and 18 had lobular breast cancer only or lobular breast cancer and gastric cancer, but did not meet the 2020 criteria. No specific CDH1 variant was found to predispose individuals specifically to lobular breast cancer, although 12 (7%) of 176 PV/LPV carrier families had lobular breast cancer only. Addition of three new lobular breast cancer-centred criteria improved testing sensitivity while retaining high specificity. The probability of finding CDH1 PV/LPVs in patients fulfilling the lobular breast cancer-expanded criteria, compared with the 2020 criteria, increased significantly (AUC 0·92 vs 0·88; Z score 3·54; p=0·0004). INTERPRETATION: CDH1 PV/LPVs were positively associated with HDGC-related phenotypes (lobular breast cancer, diffuse gastric cancer, and gastric cancer), and no evidence for a positive association with these phenotypes was found for CDH1 missense variants of unknown significance. CDH1 PV/LPVs occurred often in families with lobular breast cancer who did not fulfil the 2020 HDGC criteria, supporting the expansion of lobular breast cancer-centred criteria. FUNDING: European Reference Network on Genetic Tumour Risk Syndromes, European Regional Development Fund, Fundação para a Ciência e a Tecnologia (Portugal), Cancer Research UK, and European Union's Horizon 2020 research and innovation programme.

Cellular Aging Secretes: a Comparison of Bone-Marrow-Derived and Induced Mesenchymal Stem Cells and Their Secretome Over Long-Term Culture.

Mesenchymal stem cells (MSCs) hold promising therapeutic potential in several clinical applications, mainly due to their paracrine activity. The implementation of future secretome-based therapeutic strategies requires the use of easily accessible MSCs sources that provide high numbers of cells with homogenous characteristics. MSCs obtained from induced pluripotent stem cells (iMSCs) have been put forward as an advantageous alternative to the gold-standard tissue sources, such as bone marrow (BM-MSCs). In this study, we aimed at comparing the secretome of BM-MSCs and iMSCs over long-term culture. For that, we performed a broad characterization of both sources regarding their identity, proteomic secretome analysis, as well as replicative senescence and associated phenotypes, including its effects on MSCs secretome composition and immunomodulatory action. Our results evidence a rejuvenated phenotype of iMSCs, which is translated into a superior proliferative capacity before the induction of replicative senescence. Despite this significant difference between iMSCs and BM-MSCs proliferation, both untargeted and targeted proteomic analysis revealed a similar secretome composition for both sources in pre-senescent and senescent states. These results suggest that shifting from the use of BM-MSCs to a more advantageous source, like iMSCs, may yield similar therapeutic effects as identified over the past years for this gold-standard MSC source.

Exome sequencing of affected duos and trios uncovers PRUNE2 as a novel prostate cancer predisposition gene.

BACKGROUND: Prostate cancer (PrCa) is one of the most hereditable human cancers, however, only a small fraction of patients has been shown to carry deleterious variants in known cancer predisposition genes. METHODS: Whole-exome sequencing was performed in multiple affected members of 45 PrCa families to select the best candidate genes behind part of the PrCa missing hereditability. Recurrently mutated genes were prioritised, and further investigated by targeted next-generation sequencing in the whole early-onset and/or familial PrCa series of 462 patients. RESULTS: PRUNE2 stood out from our analysis when also considering the available data on its association with PrCa development. Ten germline pathogenic/likely pathogenic variants in the PRUNE2 gene were identified in 13 patients. The most frequent variant was found in three unrelated patients and identical-by-descent analysis revealed that the haplotype associated with the variant is shared by all the variant carriers, supporting the existence of a common ancestor. DISCUSSION: This is the first report of pathogenic/likely pathogenic germline variants in PRUNE2 in PrCa patients, namely in those with early-onset/familial disease. Importantly, PRUNE2 was the most frequently mutated gene in the whole series, with a deleterious germline variant identified in 2.8% of the patients, representing a novel prostate cancer predisposition gene.

KRAS and NRAS mutational analysis in plasma ctDNA from patients with metastatic colorectal cancer by real-time PCR and digital PCR.

PURPOSE: Mutations in the KRAS and NRAS (RAS) genes are negative predictors of response to anti-EGFR therapy in metastatic colorectal cancer (mCRC). The detection of mutations in circulating tumor DNA (ctDNA) has emerged as a less invasive strategy to assess the molecular profile of mCRC patients. We aimed to perform RAS mutational analysis in ctDNA from mCRC patients using BEAMing Digital PCR (OncoBEAM) and Idylla ctDNA qPCR and evaluate the concordance rate with RAS mutational status in tumor tissue and between these two methodologies with different limits of detection. METHODS: Blood samples were collected from 47 mCRC patients previously tested for RAS mutations in tumor tissue. DNA was extracted from plasma using the QIAamp Circulating Nucleic Acid Kit, and RAS mutation analysis was conducted using OncoBEAM RAS CRC and Idylla ctRAS assays. RESULTS: The overall agreement between tumor tissue and ctDNA analyses was 83% and 78.7% using the OncoBEAM and Idylla assays, respectively, with the concordance being 96.2% and 88.5% in naive treatment patients. The overall agreement between OncoBEAM and Idylla ctDNA analyses was 91.7%. CONCLUSIONS: Analysis of ctDNA is a viable strategy for clinical management of mCRC patients. Although the OncoBEAM assay sensitivity is somewhat higher, the fully automated Idylla platform also has good performance, while being cheaper and much less labor-intensive, for the detection of RAS mutations in plasma, either at diagnosis or after progression when considering anti-EGFR treatment rechallenge.

Expression Profiling in Ovarian Cancer Reveals Coordinated Regulation of BRCA1/2 and Homologous Recombination Genes.

Predictive biomarkers are crucial in clarifying the best strategy to use poly(ADP-ribose) polymerase inhibitors (PARPi) for the greatest benefit to ovarian cancer patients. PARPi are specifically lethal to cancer cells that cannot repair DNA damage by homologous recombination (HR), and HR deficiency is frequently associated with BRCA1/2 mutations. Genetic tests for BRCA1/2 mutations are currently used in the clinic, but results can be inconclusive due to the high prevalence of rare DNA sequence variants of unknown significance. Most tests also fail to detect epigenetic modifications and mutations located deep within introns that may alter the mRNA. The aim of this study was to investigate whether quantitation of BRCA1/2 mRNAs in ovarian cancer can provide information beyond the DNA tests. Using the nCounter assay from NanoString Technologies, we analyzed RNA isolated from 38 ovarian cancer specimens and 11 normal fallopian tube samples. We found that BRCA1/2 expression was highly variable among tumors. We further observed that tumors with lower levels of BRCA1/2 mRNA showed downregulated expression of 12 additional HR genes. Analysis of 299 ovarian cancer samples from The Cancer Genome Atlas (TCGA) confirmed the coordinated expression of BRCA1/2 and HR genes. To facilitate the routine analysis of BRCA1/2 mRNA in the clinical setting, we developed a targeted droplet digital PCR approach that can be used with FFPE samples. In conclusion, this study underscores the potential clinical benefit of measuring mRNA levels in tumors when BRCA1/2 DNA tests are negative or inconclusive.

Prostate cancer risk stratification improvement across multiple ancestries with new polygenic hazard score.

BACKGROUND: Prostate cancer risk stratification using single-nucleotide polymorphisms (SNPs) demonstrates considerable promise in men of European, Asian, and African genetic ancestries, but there is still need for increased accuracy. We evaluated whether including additional SNPs in a prostate cancer polygenic hazard score (PHS) would improve associations with clinically significant prostate cancer in multi-ancestry datasets. METHODS: In total, 299 SNPs previously associated with prostate cancer were evaluated for inclusion in a new PHS, using a LASSO-regularized Cox proportional hazards model in a training dataset of 72,181 men from the PRACTICAL Consortium. The PHS model was evaluated in four testing datasets: African ancestry, Asian ancestry, and two of European Ancestry-the Cohort of Swedish Men (COSM) and the ProtecT study. Hazard ratios (HRs) were estimated to compare men with high versus low PHS for association with clinically significant, with any, and with fatal prostate cancer. The impact of genetic risk stratification on the positive predictive value (PPV) of PSA testing for clinically significant prostate cancer was also measured. RESULTS: The final model (PHS290) had 290 SNPs with non-zero coefficients. Comparing, for example, the highest and lowest quintiles of PHS290, the hazard ratios (HRs) for clinically significant prostate cancer were 13.73 [95% CI: 12.43-15.16] in ProtecT, 7.07 [6.58-7.60] in African ancestry, 10.31 [9.58-11.11] in Asian ancestry, and 11.18 [10.34-12.09] in COSM. Similar results were seen for association with any and fatal prostate cancer. Without PHS stratification, the PPV of PSA testing for clinically significant prostate cancer in ProtecT was 0.12 (0.11-0.14). For the top 20% and top 5% of PHS290, the PPV of PSA testing was 0.19 (0.15-0.22) and 0.26 (0.19-0.33), respectively. CONCLUSIONS: We demonstrate better genetic risk stratification for clinically significant prostate cancer than prior versions of PHS in multi-ancestry datasets. This is promising for implementing precision-medicine approaches to prostate cancer screening decisions in diverse populations.

Male gender as a poor prognostic factor in Medullary Thyroid Carcinoma: behaviour or biological difference?

PURPOSE: Due to the low incidence and heterogeneous behaviour of medullary thyroid carcinoma (MTC), its prognostic factors are still not well stablished. While several large studies have investigated the impact of gender in differentiated thyroid cancer (DTC), its role in MTC outcomes remains controversial. We aim to identify MTC prognostic features, specially focusing on the role of gender. METHODS: Retrospective analysis of 76 patients diagnosed with MTC between 1984 and 2018 at a Portuguese Comprehensive Cancer Center. RESULTS: Patients presented a median age at diagnosis of 49 years and multiple endocrine neoplasia type 2 (MEN2) was identified in 27.6% of them, with those individuals being significantly younger (P<0.001). Most cases were diagnosed as stage IV disease (46.9%), except for the subgroup detected through pre-symptomatic genetic screening (55.6% at stage I). The 5- and 10-year survival rates were 87.6% and 75.6%, respectively. Univariate analysis identified male gender (P=0.010), age ≥45 years (P=0.007), presence of distant metastasis at diagnosis (P<0.01), capsule invasion (P=0.004), extrathyroidal invasion (P=0.003) and absence of biochemical cure after surgery (P=0.042) as having a negative impact on prognosis. On multivariate analysis, male gender (P=0.046) remained an independent predictor of mortality, as well as an older age (P<0.001) and the presence of distant metastases (P=0.012). CONCLUSIONS: Male gender independently predicted worse survival in MTC patients even after adjusting for age and disease stage. The few older studies on the topic pointed to a behavioural explanation regarding medical care seeking patterns by men, but our study and newer genetic and basic-science oriented publications raise the possibility of a true biological difference between genders in the tumourigenesis of MTC that should me further investigated.