Pharmacogenetics in Italy: current landscape and future prospects.

Pharmacogenetics investigates sequence of genes that affect drug response, enabling personalized medication. This approach reduces drug-induced adverse reactions and improves clinical effectiveness, making it a crucial consideration for personalized medical care. Numerous guidelines, drawn by global consortia and scientific organizations, codify genotype-driven administration for over 120 active substances. As the scientific community acknowledges the benefits of genotype-tailored therapy over traditionally agnostic drug administration, the push for its implementation into Italian healthcare system is gaining momentum. This evolution is influenced by several factors, including the improved access to patient genotypes, the sequencing costs decrease, the growing of large-scale genetic studies, the rising popularity of direct-to-consumer pharmacogenetic tests, and the continuous improvement of pharmacogenetic guidelines. Since EMA (European Medicines Agency) and AIFA (Italian Medicines Agency) provide genotype information on drug leaflet without clear and explicit clinical indications for gene testing, the regulation of pharmacogenetic testing is a pressing matter in Italy. In this manuscript, we have reviewed how to overcome the obstacles in implementing pharmacogenetic testing in the clinical practice of the Italian healthcare system. Our particular emphasis has been on germline testing, given the absence of well-defined national directives in contrast to somatic pharmacogenetics.

Parents' and patients' perspectives, experiences, and preferences for germline genetic or genomic testing of children with cancer: A systematic review.

PURPOSE: Germline testing in pediatric cancer presents opportunities and challenges. Understanding family perspectives, experiences, and preferences will optimize integration into routine care. METHODS: Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we searched 4 databases for studies exploring perspectives, experiences, and preferences of parents/caregivers and/or patients regarding germline testing of children with cancer. Qualitative and quantitative data were extracted, organized, and summarized by research question and themes. RESULTS: We identified 2286 unique articles, of which 24 were included. Interest in and uptake of testing was high. Families were motivated by altruism and a desire for inheritance/causation information. Testing barriers included psychological concerns, timing of the testing approach if offered at diagnosis or in a high-risk cancer setting and privacy/discrimination. Testing experiences highlighted challenges yet also positive impacts, with results providing psychological relief and informing proactive decision making. Timing preferences varied; however, allowing time to adjust to a new diagnosis was a common theme. Most wanted to receive as many germline sequencing-related results as possible. CONCLUSION: Findings underscore the importance of integrating germline analyses into pediatric cancer care with flexibility and support for families facing challenges. Where possible, consent should be provided at a time that suits each family's situation with access to information aligning with their needs and preferences. PROSPERO: CRD42023444890.

Germline and somatic testing for ovarian Cancer: An SGO clinical practice statement.

Germline and somatic genetic testing have become critical components of care for people with ovarian cancer. The identification of germline and somatic pathogenic variants as well as homologous recombination deficiency can contribute to the prediction of treatment response, prognostic outcome, and suitability for targeted agents (e.g. poly (ADP-ribose) polymerase (PARP) inhibitors). Furthermore, identifying germline pathogenic variants can prompt cascade genetic testing for at-risk relatives. Despite the clinical benefits and consensus recommendations from several organizations calling for universal genetic testing in ovarian cancer, only about one third of patients complete germline or somatic genetic testing. The members of the Society of Gynecologic Oncology (SGO) Clinical Practice Committee have composed this statement to provide an overview of germline and somatic genetic testing for patients with epithelial ovarian cancer, focusing on available testing modalities and options for care delivery.

Predictors of germline genetic testing referral and completion in ovarian cancer patients at a Comprehensive Cancer Center.

OBJECTIVES: To identify predictors of referral and completion of germline genetic testing among newly diagnosed ovarian cancer patients, with a focus on geographic social deprivation, oncologist-level practices, and time between diagnosis and completion of testing. METHODS: Clinical and sociodemographic data were abstracted from medical records of patients newly diagnosed with ovarian cancer between 2014 and 2019 in the University of North Carolina Health System. Factors associated with referral for genetic counseling, completion of germline testing, and time between diagnosis and test results were identified using multivariable regression. RESULTS: 307/459 (67%) patients were referred for genetic counseling and 285/459 (62%) completed testing. The predicted probability of test completion was 0.83 (95% CI: 0.77-0.88) for patients with a referral compared to 0.27 (95% CI: 0.18-0.35) for patients without a referral. The predicted probability of referral was 0.75 (95% CI: 0.69-0.82) for patients at the 25th percentile of ZIP code-level Social Deprivation Index (SDI) and 0.67 (0.60-0.74) for patients at the 75th percentile of SDI. Referral varied by oncologist, with predicted probabilities ranging from 0.47 (95% CI: 0.32-0.62) to 0.93 (95% CI: 0.85-1.00) across oncologists. The median time between diagnosis and test results was 137 days (IQR: 55-248 days). This interval decreased by a predicted 24.46 days per year (95% CI: 37.75-11.16). CONCLUSIONS: We report relatively high germline testing and a promising trend in time from diagnosis to results, with variation by oncologist and patient factors. Automated referral, remote genetic counseling and sample collection, reduced out-of-pocket costs, and educational interventions should be explored.

The Cost-Effectiveness of Germline BReast CAncer Gene Testing in Metastatic Prostate Cancer Followed by Cascade Testing of First-Degree Relatives of Mutation Carriers.

OBJECTIVES: Patients with metastatic prostate cancer (mPCa) with BReast CAncer gene (BRCA) mutations benefit from targeted treatments (eg, olaparib). In addition, family members of affected patients have increased risk of hereditary cancers and benefit from early detection and prevention. International guidelines recommend genetic testing in mPCa; however, the value for money of testing patients with mPCa and cascade testing of blood-related family members has not been assessed. In this context, we evaluated the cost-effectiveness of germline BRCA testing in patients with mPCa followed by cascade testing of first-degree relatives (FDRs) of mutation carriers. METHODS: We conducted a cost-utility analysis of germline BRCA testing using 2 scenarios: (1) testing patients with mPCa only and (2) testing patients with mPCa and FDRs of those who test positive. A semi-Markov multi-health-state transition model was constructed using a lifetime time horizon. The analyses were performed from an Australian payer perspective. Decision uncertainty was characterized using probabilistic analyses. RESULTS: Compared with no testing, BRCA testing in mPCa was associated with an incremental cost of AU$3731 and a gain of 0.014 quality-adjusted life-years (QALYs), resulting in an incremental cost-effectiveness ratio of AU$265 942/QALY. Extending testing to FDRs of variant-positive patients resulted in an incremental cost-effectiveness ratio of AU$16 392/QALY. Probability of cost-effectiveness at a willingness-to-pay of AU$75 000/QALY was 0% in the standalone mPCa analysis and 100% in the cascade testing analysis. CONCLUSION: BRCA testing when performed as a standalone strategy in patients with mPCa may not be cost-effective but demonstrates significant value for money after the inclusion of cascade testing of FDRs of mutation carriers.

Isolated subependymal giant cell astrocytoma (SEGA) in the absence of clinical tuberous sclerosis: two case reports and literature review.

PURPOSE: Subependymal giant cell astrocytoma (SEGA) is a WHO grade I pediatric glioma arising in 5-15% of patients with tuberous sclerosis (TSC). Rare cases of isolated SEGA without TSC have been described. The etiology, genetic mechanisms, natural history, and response to treatment of these lesions are currently unknown. We describe two such cases of isolated SEGA with follow-up. METHODS: Retrospective review was performed at a single institution to describe the clinical course of pathology-confirmed SEGA in patients with germline testing negative for TSC mutations. RESULTS: Two cases of isolated SEGA were identified. Genetic analysis of the tumor specimen was available for one, which revealed an 18 base pair deletion in TSC1. Both cases were managed with surgical resection, one with preoperative embolization. In spite of a gross total resection, one patient experienced recurrence after three years. Treatment with an mTOR inhibitor led to a significant interval reduction of the mass on follow-up MRI. The patient tolerated the medication well for 6 years and is now off of treatment for 2 years with a stable lesion. CONCLUSION: Cases of SEGA outside of the context of TSC are exceedingly rare, with only 48 cases previously described. The genetic mechanisms and treatment response of these lesions are poorly understood. To date, these lesions appear to respond well to mTOR inhibitors and may behave similarly to SEGAs associated with TSC. However, given that experience is extremely limited, these cases should be followed long term to better understand their natural history and treatment response.

The cost-effectiveness of germline BRCA testing-guided olaparib treatment in metastatic castration resistant prostate cancer.

BACKGROUND: Olaparib targets the DNA repair pathways and has revolutionized the management of metastatic castration resistant prostate cancer (mCRPC). Treatment with the drug should be guided by genetic testing; however, published economic evaluations did not consider olaparib and genetic testing as codependent technologies. This study aims to assess the cost-effectiveness of BRCA germline testing to inform olaparib treatment in mCRPC. METHODS: We conducted a cost-utility analysis of germline BRCA testing-guided olaparib treatment compared to standard care without testing from an Australian health payer perspective. The analysis applied a decision tree to indicate the germline testing or no testing strategy. A Markov multi-state transition approach was used for patients within each strategy. The model had a time horizon of 5 years. Costs and outcomes were discounted at an annual rate of 5 percent. Decision uncertainty was characterized using probabilistic and scenario analyses. RESULTS: Compared to standard care, BRCA testing-guided olaparib treatment was associated with an incremental cost of AU$7,841 and a gain of 0.06 quality-adjusted life-years (QALYs). The incremental cost-effectiveness ratio (ICER) was AU$143,613 per QALY. The probability of BRCA testing-guided treatment being cost effective at a willingness-to-pay threshold of AU$100,000 per QALY was around 2 percent; however, the likelihood for cost-effectiveness increased to 66 percent if the price of olaparib was reduced by 30 percent. CONCLUSION: This is the first study to evaluate germline genetic testing and olaparib treatment as codependent technologies in mCRPC. Genetic testing-guided olaparib treatment may be cost-effective with significant discounts on olaparib pricing.

Evaluating Germline Testing Panels in Southern African Males With Advanced Prostate Cancer.

BACKGROUND: Germline testing for prostate cancer is on the increase, with clinical implications for risk assessment, treatment, and management. Regardless of family history, NCCN recommends germline testing for patients with metastatic, regional, very-high-risk localized, and high-risk localized prostate cancer. Although African ancestry is a significant risk factor for aggressive prostate cancer, due to a lack of available data no testing criteria have been established for ethnic minorities. PATIENTS AND METHODS: Through deep sequencing, we interrogated the 20 most common germline testing panel genes in 113 Black South African males presenting with largely advanced prostate cancer. Bioinformatic tools were then used to identify the pathogenicity of the variants. RESULTS: After we identified 39 predicted deleterious variants (16 genes), further computational annotation classified 17 variants as potentially oncogenic (12 genes; 17.7% of patients). Rare pathogenic variants included CHEK2 Arg95Ter, BRCA2 Trp31Arg, ATM Arg3047Ter (2 patients), and TP53 Arg282Trp. Notable oncogenic variants of unknown pathogenicity included novel BRCA2 Leu3038Ile in a patient with early-onset disease, whereas patients with FANCA Arg504Cys and RAD51C Arg260Gln reported a family history of prostate cancer. Overall, rare pathogenic and early-onset or familial-associated oncogenic variants were identified in 6.9% (5/72) and 9.2% (8/87) of patients presenting with a Gleason score ≥8 or ≥4 + 3 prostate cancer, respectively. CONCLUSIONS: In this first-of-its-kind study of southern African males, we provide support of African inclusion for advanced, early-onset, and familial prostate cancer genetic testing, indicating clinical value for 30% of current gene panels. Recognizing current panel limitations highlights an urgent need to establish testing guidelines for men of African ancestry. We provide a rationale for considering lowering the pathologic diagnostic inclusion criteria and call for further genome-wide interrogation to ensure the best possible African-relevant prostate cancer gene panel.

Germline genomic findings in children and young adults with melanocytic tumors.

In this retrospective study, we examined the prevalence and spectrum of germline variants in selected cancer predisposition genes in 38 children and young adults with melanocytic lesions at St. Jude Children's Research Hospital. Diagnoses included malignant melanoma (n = 16; 42%), spitzoid melanoma (n = 16; 42%), uveal melanoma (n = 5; 13%), and malignant melanoma arising in a giant congenital melanocytic nevus (n = 1; 3%). Six patients (15.8%) harbored pathogenic germline variants: one with bi-allelic PMS2 variants, one with a heterozygous 17q21.31 deletion, and one each with a pathogenic variant in TP53, BRIP1, ATM, or AXIN2. Overall, 15.8% of patients harbored a cancer-predisposing genetic variant.

Germline Pathogenic Variants in Squamous Cell Carcinoma of the Head and Neck.

Head and neck squamous cell carcinoma (HNSCC) presents a significant global health problem with variable geographic distribution and risk factors, including tobacco and alcohol abuse, human papillomavirus infections, and genetic predisposition. While the majority of cases are sporadic, several well-defined hereditary syndromes have been associated with a higher risk of developing HNSCC including Li-Fraumeni syndrome, Fanconi anaemia, Bloom syndrome, familial atypical multiple mole melanoma, and dyskeratosis congenita. There is also evidence of familial clusters of HNSCC, suggesting a genetic component in the development of the disease. Germ-line genetic testing in HNSCC using next-generation sequencing has revealed a wide range of germline variants, some of which were not anticipated based on standard guidelines. These variants may influence treatment decisions and have the potential to be targeted with precision medicine in the future. Despite these advances, routine germline genetic testing for HNSCC is not currently recommended and remains reserved for HNSCC cases with early onset or strong family cancer history. However, the increasing availability of germline genetic testing warrants development of more comprehensive and standardized testing protocols. Germline genetic testing also has the potential to influence precision-guided treatment in HNSCC patients carrying germline pathogenic variants.

The prevalence of mismatch repair deficiency in ovarian cancer: A systematic review and meta-analysis.

Ovarian cancer (OC) is the least survivable gynecological malignancy and presents late. Five-year survival for OC is around 45% increasing the need for innovative treatments. Checkpoint inhibitors have shown significant clinical efficacy in mismatch repair deficient (MMRd) cancers and could be a powerful treatment in OC. However, their application in OC is limited due to the lack of data on the prevalence of MMRd. The aim of our study was to conduct a systematic review of the literature and meta-analysis to provide an accurate estimate of the prevalence of MMRd in OC. We followed PRISMA guidelines throughout. Studies were identified by electronic searches of Medline, Embase, Cochrane CENTRAL and Web of Science followed by citation searching. Studies not written in English were excluded. All studies were reviewed by at least two independent reviewers. Proportions of test positivity were calculated by random and fixed-effects meta-analysis models. I2 score was used to assess heterogeneity across studies. In total 54 studies were included with 17 532 analyzed for MMRd. The overall proportions of MMRd by immunohistochemistry and microsatellite instability analysis were 6.7% and 10.4%, respectively. MMRd was reported in all histotypes of epithelial OC but was most common in endometrioid OC. We estimate that on average 46.7% (95% CI: 28.8-65.4) of ovarian carcinomas showing MMRd by IHC had a germline path_MMR variant identified. OC in those with Lynch syndrome seems to present at an earlier age and stage. Studies however were generally of low quality and there was a high degree of heterogeneity. A significant minority (up to 16%) of OC displays MMRd and, therefore, could be amenable to checkpoint inhibition therapy. However, the current literature base is of limited quality and therefore high-quality prospective studies exploring MMRd in OC with the use of multimodal testing are required. In addition, trials researching efficacy of checkpoint inhibition in MMRd OC are needed.

Germline Cancer Susceptibility Gene Testing in Unselected Patients With Colorectal Adenocarcinoma: A Multicenter Prospective Study.

BACKGROUND & AIMS: Hereditary factors play a role in the development of colorectal cancer (CRC). Identification of germline predisposition can have implications on treatment and cancer prevention. This study aimed to determine the prevalence of pathogenic germline variants (PGVs) in CRC patients using a universal testing approach, association with clinical outcomes, and the uptake of family variant testing. METHODS: We performed a prospective multisite study of germline sequencing using a more than 80-gene next-generation sequencing platform among CRC patients (not selected for age or family history) receiving care at Mayo Clinic Cancer Centers between April 1, 2018, and March 31, 2020. RESULTS: Of 361 patients, the median age was 57 years (SD, 12.4 y), 43.5% were female, 82% were white, and 38.2% had stage IV disease. PGVs were found in 15.5% (n = 56) of patients, including 44 in moderate- and high-penetrance cancer susceptibility genes. Thirty-four (9.4%) patients had incremental clinically actionable findings that would not have been detected by practice guideline criteria or a CRC-specific gene panel. Only younger age at diagnosis was associated with the presence of PGVs (odds ratio, 1.99; 95% CI, 1.12-3.56). After a median follow-up period of 20.7 months, no differences in overall survival were seen between those with or without a PGV (P = .2). Eleven percent of patients had modifications in their treatment based on genetic findings. Family cascade testing was low (16%). CONCLUSIONS: Universal multigene panel testing in CRC was associated with a modest, but significant, detection of heritable mutations over guideline-based testing. One in 10 patients had changes in their management based on test results. Uptake of cascade family testing was low, which is a concerning observation that warrants further study.

Comprehensive assessment of germline pathogenic variant detection in tumor-only sequencing.

BACKGROUND: Tumor-only sequencing, implemented for the identification of somatic variants, is oftentimes used for the detection of actionable germline variants. We sought to determine whether tumor-only sequencing assays are suitable for detection of actionable germline variants, given their importance for the delivery of targeted therapies and risk-reducing measures. PATIENTS AND METHODS: The detection of germline variants affecting moderate- and high-penetrance cancer susceptibility genes (CSGs) by tumor-only sequencing was compared to clinical germline testing in 21 333 cancer patients who underwent tumor and germline testing using the Food and Drug Administration (FDA)-authorized Memorial Sloan Kettering-Integrated Mutation Profiling of Actionable Targets (MSK-IMPACT) assay. Seven homologous recombination deficiency (HRD), two DNA damage response (DDR) and four mismatch repair (MMR) genes, as well as NF1, RB1 and TP53 were included in the analysis. FDA-authorized and New York State Department of Health-approved sequencing methods for germline, tumor/normal and tumor-only sequencing assays and analytical pipelines were employed. RESULTS: In patients who underwent tumor and germline sequencing, as compared to clinical genetic testing, tumor-only sequencing failed to detect 10.5% of clinically actionable pathogenic germline variants in CSGs, including 18.8%, 12.8% and 7.3% of germline variants in MMR, DDR and HRD genes, respectively. The sensitivity for detection of pathogenic germline variants by tumor-only sequencing was 89.5%. Whilst the vast majority of pathogenic germline exonic single-nucleotide variants (SNVs) and small indels were detected by tumor-only sequencing, large percentages of germline copy number variants, intronic variants and repetitive element insertions were not detected. CONCLUSIONS: Tumor-only sequencing is adequate for the detection of clinically actionable germline variants, particularly for SNVs and small indels; however, a small subset of alterations affecting HRD, DDR and MMR genes may not be detected optimally. Therefore, for high-risk patients with negative tumor-only sequencing results, clinical genetic testing could be considered given the impact of these variants on therapy and genetic counseling.

Germline Cancer Testing in Unselected Patients with Gastric and Esophageal Cancers: A Multi-center Prospective Study.

BACKGROUND AND AIMS: To determine prevalence and clinical utility of pathogenic germline variants (PGV) in gastric and esophageal cancer patients using universal genetic testing approach. METHODS: We undertook a prospective study of germline sequencing using an > 80 gene next-generation sequencing platform among patients with gastric and esophageal cancers receiving care at Mayo Clinic Cancer Center between April 1, 2018, and March 31, 2020. Patients were not selected based on cancer stage, family history of cancer, ethnicity, or age. Family cascade testing was offered at no cost. RESULTS: A total of 96 patients were evaluated. Median age was 66 years, 80.2% were male, 89.6% were white. Nearly 39% of the cohort had esophageal cancer, 35.4% gastric cancer and 26% gastroesophageal junction cancers. Approximately half (52%) of the patients had metastatic disease. Pathogenic germline variants (PGV) were detected in 15.6% (n = 15) patients. The prevalence of PGV was 10.8% in esophageal cancer, 17.6% in gastric cancer and 20% in gastroesophageal cancer. Eighty percent of patients with a positive result would not have been detected by screening with standard guidelines for genetic testing. Most PGV detected included genes with high and moderate penetrance related to DNA damage response including BRCA1, BRCA2, PALB2 and ATM. CONCLUSIONS: Universal multi-gene panel testing in gastric and esophageal cancers was associated with detection of heritable mutations in 15% of patients. The majority of PGV would not be detected with current screening guidelines and are related to DNA damage response.

Germline sequencing for presumed germline pathogenic variants via tumor-only comprehensive genomic profiling.

BACKGROUND: The European Society for Medical Oncology Precision Medicine Working Group (ESMO-PMWG) published recommendations regarding confirmatory germline testing for presumed germline pathogenic variants (PGPVs) in tumor-only comprehensive genomic profiling (CGP). However, the clinical validity of these recommendations has not been investigated in a real-world practice. METHODS: Medical records of 180 consecutive patients who obtained the results of a tumor-only CGP (FoundationOne® CDx, Foundation Medicine, Inc, Cambridge, MA, USA) between October 2018 and March 2020, were retrospectively reviewed. After excluding patients with no reported variants in 45 actionable genes (n = 6), or no archived germline DNA samples (n = 31), 143 patients were investigated. The PGPVs were selected from the CGP report and germline sequencing were performed using DNA samples archived in Clinical Bioresource Center in Kyoto University Hospital (Kyoto, Japan). RESULTS: A total of 195 variants were classified as PGPV based on the conventional criteria. Germline sequencing disclosed that 12 variants (6.2%) were of germline origin. In contrast, after filtering these 195 variants through the ESMO-PMWG recommendation criteria for confirmatory germline testing, following seven PGPVs, BRCA2 (n = 2), BRIP1 (n = 1), BAP1 (n = 1), PMS2 (n = 1), MSH2 (n = 1), and SDHB (n = 1) remained and six variants (85.7%) were confirmed to be of germline origin. CONCLUSION: Our current data suggested that the application of ESMO-PMWG criteria is helpful in selecting PGPVs with a high likelihood of germline origin in a tumor-only CGP in daily clinical practice.

Risk assessment and genetic counseling for Lynch syndrome - Practice resource of the National Society of Genetic Counselors and the Collaborative Group of the Americas on Inherited Gastrointestinal Cancer.

Identifying individuals who have Lynch syndrome involves a complex diagnostic workup that includes taking a detailed family history and a combination of various tests such as immunohistochemistry and/or molecular which may be germline and/or somatic. The National Society of Genetic Counselors and the Collaborative Group of the Americas on Inherited Gastrointestinal Cancer have come together to publish this practice resource for the evaluation of Lynch syndrome. The purpose of this practice resource was to provide guidance and a testing algorithm for Lynch syndrome as well as recommendations on when to offer testing. This practice resource does not replace a consultation with a genetics professional. This practice resource includes explanations in support of this and a summary of background data. While this practice resource is not intended to serve as a review of Lynch syndrome, it includes a discussion of background information and cites a number of key publications which should be reviewed for a more in-depth understanding. This practice resource is intended for genetic counselors, geneticists, gastroenterologists, surgeons, medical oncologists, obstetricians and gynecologists, nurses, and other healthcare providers who evaluate patients for Lynch syndrome.

Cancer Predisposition Sequencing Reporter (CPSR): A flexible variant report engine for high-throughput germline screening in cancer.

The value of high-throughput germline genetic testing is increasingly recognized in clinical cancer care. Disease-associated germline variants in cancer patients are important for risk management and surveillance, surgical decisions and can also have major implications for treatment strategies since many are in DNA repair genes. With the increasing availability of high-throughput DNA sequencing in cancer clinics and research, there is thus a need to provide clinically oriented sequencing reports for germline variants and their potential therapeutic relevance on a per-patient basis. To meet this need, we have developed the Cancer Predisposition Sequencing Reporter (CPSR), an open-source computational workflow that generates a structured report of germline variants identified in known cancer predisposition genes, highlighting markers of therapeutic, prognostic and diagnostic relevance. A fully automated variant classification procedure based on more than 30 refined American College of Medical Genetics and Genomics (ACMG) criteria represents an integral part of the workflow. Importantly, the set of cancer predisposition genes profiled in the report can be flexibly chosen from more than 40 virtual gene panels established by scientific experts, enabling customization of the report for different screening purposes and clinical contexts. The report can be configured to also list actionable secondary variant findings, as recommended by ACMG. CPSR demonstrates comparable sensitivity and specificity for the detection of pathogenic variants when compared to other algorithms in the field. Technically, the tool is implemented in Python/R, and is freely available through Docker technology. Source code, documentation, example reports and installation instructions are accessible via the project GitHub page: https://github.com/sigven/cpsr.

Germline BLM mutations and metastatic prostate cancer.

BACKGROUND: Biallelic loss-of-function BLM mutations result in Bloom syndrome: a genetic disorder characterized by growth deficiencies, photosensitivity, and multiple cancer susceptibilities. There are conflicting reports about whether or not heterozygous BLM carriers are at a higher risk of various cancers. Without BLM protein functionality, there is evidence of increased sister chromatid exchange and chromosomal instability. METHODS: Metastatic prostate cancer patients (N = 796) underwent germline genetic testing as part of routine care at three academic centers. Patients with heterozygous BLM mutations were identified. Tumor tissue was analyzed for somatic alterations in those patients who had a germline pathogenic mutation. Control data using a population sample were extracted from the Genome Aggregation Database. RESULTS: Heterozygous BLM germline mutations in 5 of 796 patients (prevalence, 0.63%). All mutations were loss-of-function truncating alterations. None of the mutations were BLMAsh . The control population (gnomAD) frequency of pathogenic or likely pathogenic BLM mutations was 0.18% (212 of 116 653). The relative risk (RR) of BLM mutations in metastatic prostate cancer patients was 3.4 (95% CI, 1.42-8.33; P < .0062) compared to gnomAD controls. Tumor DNA sequencing in the BLM carriers showed no evidence of somatic BLM mutations. Interestingly, 3 of 5 BLM germline carriers had bi-allelic BRCA2 inactivation evident on tumor sequencing. One patient had both germline and somatic mutations in BRCA2. Excluding the patient with the germline BRCA2 mutation (BLM prevalence, 4 of 796: 0.50%) still yielded a statistically significant finding vs the gnomAD controls (RR, 2.8; 95% CI, 1.02-7.39; P < .04). CONCLUSION: Truncating BLM germline mutations occur at a higher frequency in patients with advanced prostate cancer as compared to control populations. Though no biallelic loss of BLM was no noted in cancers, a surprising number of the BLM germline heterozygotes had pathogenic BRCA2 mutations in their tumor.

Genetic Testing in Prostate Cancer.

PURPOSE OF REVIEW: This review summarizes recent advances in prostate cancer (PCa) genetics. RECENT FINDINGS: Upwards of 20% of metastatic castration-resistant prostate tumors (mCRPC) carry homologous recombination (HR) repair gene mutations, of which ~ 10% are germline (inherited). Another ~ 5% exhibit microsatellite instability (MSI-H) and/or mismatch repair deficiency (MMRd). Pembrolizumab is approved for tumors with MMRd, thus patients with mCRPC and MMRd are candidates for pembrolizumab. Emerging data indicate that platinum chemotherapy and poly ADP-ribose polymerase inhibitors (PARPi) are effective in PCa exhibiting HR deficiency. NCCN guidelines now recommend germline and somatic tumor testing in specific clinical scenarios due to treatment and family implications. Genetic testing in PCa patients may inform prognosis, treatment options, and have implications for family counseling. PARPi, platinum chemotherapy, and immune checkpoint inhibitors are promising targeted therapies for PCa with specific molecular features. Therapeutic advances, along with importance to relatives, are driving genetic testing in prostate cancer.

Canadian cost-effectiveness model of BRCA-driven surgical prevention of breast/ovarian cancers compared to treatment if cancer develops.

OBJECTIVES: To assess the cost effectiveness from a Canadian perspective of index patient germline BRCA testing and then, if positive, family members with subsequent risk-reducing surgery (RRS) in as yet unaffected mutation carriers compared with no testing and treatment of cancer when it develops. METHODS: A patient level simulation was developed comparing outcomes between two groups using Canadian data. Group 1: no mutation testing with treatment if cancer developed. Group 2: cascade testing (index patient BRCA tested and first-/second-degree relatives tested if index patient/first-degree relative is positive) with RRS in carriers. End points were the incremental cost-effectiveness ratio (ICER) and budget impact. RESULTS: There were 29,102 index patients: 2,786 ovarian cancer and 26,316 breast cancer (BC). Using the base-case assumption of 44 percent and 21 percent of women with a BRCA mutation receiving risk-reducing bilateral salpingo-oophorectomy and risk-reducing mastectomy, respectively, testing was cost effective versus no testing and treatment on cancer development, with an ICER of CAD 14,942 (USD 10,555) per quality-adjusted life-year (QALY), 127 and 104 fewer cases of ovarian and BC, respectively, and twenty-one fewer all-cause deaths. Testing remained cost effective versus no testing at the commonly accepted North American threshold of approximately CAD 100,000 (or USD 100,000) per QALY gained in all scenario analyses, and cost effectiveness improved as RRS uptake rates increased. CONCLUSIONS: Prevention via testing and RRS is cost effective at current RRS uptake rates; however, optimization of uptake rates and RRS will increase cost effectiveness and can provide cost savings.