Early Cancer Detection in Li-Fraumeni Syndrome with Cell-Free DNA.

People with Li-Fraumeni syndrome (LFS) harbor a germline pathogenic variant in the TP53 tumor suppressor gene, face a near 100% lifetime risk of cancer, and routinely undergo intensive surveillance protocols. Liquid biopsy has become an attractive tool for a range of clinical applications, including early cancer detection. Here, we provide a proof-of-principle for a multimodal liquid biopsy assay that integrates a targeted gene panel, shallow whole-genome, and cell-free methylated DNA immunoprecipitation sequencing for the early detection of cancer in a longitudinal cohort of 89 LFS patients. Multimodal analysis increased our detection rate in patients with an active cancer diagnosis over uni-modal analysis and was able to detect cancer-associated signal(s) in carriers prior to diagnosis with conventional screening (positive predictive value = 67.6%, negative predictive value = 96.5%). Although adoption of liquid biopsy into current surveillance will require further clinical validation, this study provides a framework for individuals with LFS. SIGNIFICANCE: By utilizing an integrated cell-free DNA approach, liquid biopsy shows earlier detection of cancer in patients with LFS compared with current clinical surveillance methods such as imaging. Liquid biopsy provides improved accessibility and sensitivity, complementing current clinical surveillance methods to provide better care for these patients. See related commentary by Latham et al., p. 23. This article is featured in Selected Articles from This Issue, p. 5.

"I just wanted more": Hereditary cancer syndromes patients' perspectives on the utility of circulating tumour DNA testing for cancer screening.

Hereditary cancer syndromes (HCS) predispose individuals to a higher risk of developing multiple cancers. However, current screening strategies have limited ability to screen for all cancer risks. Circulating tumour DNA (ctDNA) detects DNA fragments shed by tumour cells in the bloodstream and can potentially detect cancers early. This study aimed to explore patients' perspectives on ctDNA's utility to help inform its clinical adoption and implementation. We conducted a qualitative interpretive description study using semi-structured phone interviews. Participants were purposively sampled adult HCS patients recruited from a Canadian HCS research consortium. Thirty HCS patients were interviewed (n = 19 women, age range 20s-70s, n = 25 were white). Participants were highly concerned about developing cancers, particularly those without reliable screening options for early detection. They "just wanted more" than their current screening strategies. Participants were enthusiastic about ctDNA's potential to be comprehensive (detect multiple cancers), predictive (detect cancers early) and tailored (lead to personalized clinical management). Participants also acknowledged ctDNA's potential limitations, including false positives/negatives risks and experiencing additional anxiety. However, they saw ctDNA's potential benefits outweighing its limitations. In conclusion, participants' belief in ctDNA's potential to improve their care overshadowed its limitations, indicating patients' support for using ctDNA in HCS care.

Comprehensive molecular assessment of mismatch repair deficiency in Lynch associated ovarian cancers using next generation sequencing panel.

OBJECTIVES: Abnormalities in mismatch repair have been described in ovarian cancer, but few studies have examined the causes of mismatch repair deficiency (MMRd). To address this, we completed targeted mutational and methylation sequencing on MMRd ovarian cancer cases. The objective of this study was to explore the molecular mechanism of MMRd using our targeted next generation sequencing panel. METHODS: Newly diagnosed non-serous/mucinous ovarian cancers (n=215) were prospectively recruited from three cancer centers in Ontario, Canada, between 2015 and 2018. Tumors were reflexively assessed for mismatch repair protein by immunohistochemistry. Matched tumor-normal MMRd cases were analyzed on a custom next generation sequencing panel to identify germline and somatic mutations, copy number variants, rearrangements, and promoter methylation in mismatch repair and associated genes. RESULTS: Of 215 cases, 28 (13%) were MMRd. The MMRd cohort had a median age of 52.3 years (range 33.6-62.2), with mostly stage I (50%) and grade 1 or 2 endometrioid histotype (57%). Of the 28 cases, 22 were available for molecular analysis, and Lynch syndrome was detected in 50% of MMRd cases (11/22; seven ovarian cancer and four synchronous ovarian and endometrial cancer: seven MSH6, two MLH1, one PMS2, and one MSH2). An explanation for the observed mismatch repair phenotype was available for 22/22 deficient cases, including 12 MLH1/PMS2 deficient (nine somatic methylation, one bi-allelic somatic deletion, and two pathogenic germline variant), one PMS2 deficient (one pathogenic germline variant), seven MSH6 deficient (seven pathogenic germline variant), and two MSH2/MSH6 deficient (one pathogenic germline variant and one bi-allelic somatic mutation). Concordance between clinical germline testing and panel sequencing results was 100%. CONCLUSIONS: Use of our custom next generation sequencing panel allowed for the streamlined assessment of hereditary and somatic causes of MMRd in ovarian cancers.

Current and new frontiers in hereditary cancer surveillance: Opportunities for liquid biopsy.

At least 5% of cancer diagnoses are attributed to a causal pathogenic or likely pathogenic germline genetic variant (hereditary cancer syndrome-HCS). These individuals are burdened with lifelong surveillance monitoring organs for a wide spectrum of cancers. This is associated with substantial uncertainty and anxiety in the time between screening tests and while the individuals are awaiting results. Cell-free DNA (cfDNA) sequencing has recently shown potential as a non-invasive strategy for monitoring cancer. There is an opportunity for high-yield cancer early detection in HCS. To assess clinical validity of cfDNA in individuals with HCS, representatives from eight genetics centers from across Canada founded the CHARM (cfDNA in Hereditary and High-Risk Malignancies) Consortium in 2017. In this perspective, we discuss operationalization of this consortium and early data emerging from the most common and well-characterized HCSs: hereditary breast and ovarian cancer, Lynch syndrome, Li-Fraumeni syndrome, and Neurofibromatosis type 1. We identify opportunities for the incorporation of cfDNA sequencing into surveillance protocols; these opportunities are backed by examples of earlier cancer detection efficacy in HCSs from the CHARM Consortium. We seek to establish a paradigm shift in early cancer surveillance in individuals with HCSs, away from highly centralized, regimented medical screening visits and toward more accessible, frequent, and proactive care for these high-risk individuals.

Identifying Mechanisms of Resistance by Circulating Tumor DNA in EVOLVE, a Phase II Trial of Cediranib Plus Olaparib for Ovarian Cancer at Time of PARP Inhibitor Progression.

PURPOSE: To evaluate the use of blood cell-free DNA (cfDNA) to identify emerging mechanisms of resistance to PARP inhibitors (PARPi) in high-grade serous ovarian cancer (HGSOC). EXPERIMENTAL DESIGN: We used targeted sequencing (TS) to analyze 78 longitudinal cfDNA samples collected from 30 patients with HGSOC enrolled in a phase II clinical trial evaluating cediranib (VEGF inhibitor) plus olaparib (PARPi) after progression on PARPi alone. cfDNA was collected at baseline, before treatment cycle 2, and at end of treatment. These were compared with whole-exome sequencing (WES) of baseline tumor tissues. RESULTS: At baseline (time of initial PARPi progression), cfDNA tumor fractions were 0.2% to 67% (median, 3.25%), and patients with high ctDNA levels (>15%) had a higher tumor burden (sum of target lesions; P = 0.043). Across all timepoints, cfDNA detected 74.4% of mutations known from prior tumor WES, including three of five expected BRCA1/2 reversion mutations. In addition, cfDNA identified 10 novel mutations not detected by WES, including seven TP53 mutations annotated as pathogenic by ClinVar. cfDNA fragmentation analysis attributed five of these novel TP53 mutations to clonal hematopoiesis of indeterminate potential (CHIP). At baseline, samples with significant differences in mutant fragment size distribution had shorter time to progression (P = 0.001). CONCLUSIONS: Longitudinal testing of cfDNA by TS provides a noninvasive tool for detection of tumor-derived mutations and mechanisms of PARPi resistance that may aid in directing patients to appropriate therapeutic strategies. With cfDNA fragmentation analyses, CHIP was identified in several patients and warrants further investigation.

Synthesis of Existent Oncology Curricula for Primary Care Providers: A Scoping Review With a Global Equity Lens.

PURPOSE: Global increases in cancer, coupled with a shortage of cancer specialists, has led to an increasing role for primary care providers (PCP) in cancer care. This review aimed to examine all extant cancer curricula for PCPs and to analyze the motivations for curriculum development. METHODS: A comprehensive literature search was conducted from inception to October 13, 2021, with no language restrictions. The initial search yielded 11,162 articles and 10,902 articles underwent title and abstract review. After full-text review, 139 articles were included. Numeric and thematic analyses were conducted and education programs were evaluated using Bloom's taxonomy. RESULTS: Most curricula were developed in high-income countries (HICs), with 58% in the United States. Cancer-specific curricula focused on HIC priority cancers, such as skin/melanoma, and did not represent the global cancer burden. Most (80%) curricula were developed for staff physicians and 73% focused on cancer screening. More than half (57%) of programs were delivered in person, with a shift toward online delivery over time. Less than half (46%) of programs were codeveloped with PCPs and 34% did not involve PCPs in the program design and development. Curricula were primarily developed to improve cancer knowledge, and 72 studies assessed multiple outcome measures. No studies included the top two levels of Bloom's taxonomy of learning (evaluating; creating). CONCLUSION: To our knowledge, this is the first review to assess the current state of cancer curricula for PCPs with a global focus. This review shows that extant curricula are primarily developed in HICs, do not represent the global cancer burden, and focus on cancer screening. This review lays a foundation to advance the cocreation of curricula that are aligned to the global cancer burden.

"Game Changer": Health Professionals' Views on the Clinical Utility of Circulating Tumor DNA Testing in Hereditary Cancer Syndrome Management.

BACKGROUND: We explored health professionals' views on the utility of circulating tumor DNA (ctDNA) testing in hereditary cancer syndrome (HCS) management. MATERIALS AND METHODS: A qualitative interpretive description study was conducted, using semi-structured interviews with professionals across Canada. Thematic analysis employing constant comparison was used for analysis. 2 investigators coded each transcript. Differences were reconciled through discussion and the codebook was modified as new codes and themes emerged from the data. RESULTS: Thirty-five professionals participated and included genetic counselors (n = 12), geneticists (n = 9), oncologists (n = 4), family doctors (n = 3), lab directors and scientists (n = 3), a health-system decision maker, a surgeon, a pathologist, and a nurse. Professionals described ctDNA as "transformative" and a "game-changer". However, they were divided on its use in HCS management, with some being optimistic (optimists) while others were hesitant (pessimists). Differences were driven by views on 3 factors: (1) clinical utility, (2) ctDNA's role in cancer screening, and (3) ctDNA's invasiveness. Optimists anticipated ctDNA testing would have clinical utility for HCS patients, its role would be akin to a diagnostic test and would be less invasive than standard screening (eg imaging). Pessimistic participants felt ctDNA testing would add limited utility; it would effectively be another screening test in the pathway, likely triggering additional investigations downstream, thereby increasing invasiveness. CONCLUSIONS: Providers anticipated ctDNA testing will transform early cancer detection for HCS families. However, the contrasting positions on ctDNA's role in the care pathway raise potential practice variations, highlighting a need to develop evidence to support clinical implementation and guidelines to standardize adoption.

VHL mosaicism: the added value of multi-tissue analysis.

Von Hippel-Lindau disease (VHL) is an autosomal dominant, inherited syndrome with variants in the VHL gene causing predisposition to multi-organ benign and malignant neoplasms. A germline VHL variant is identified in 95-100% of individuals with a clinical diagnosis of VHL. Here, we present the case of an individual with a clinical diagnosis of VHL disease where peripheral blood DNA analysis did not detect a VHL variant. Sequencing of four tumor tissues (ccRCC, pheochromocytoma, lung via sputum, liver) revealed a VHL c.593 T > C (p.Leu198Pro) variant at varying allele fractions (range: 10-55%) in all tissues. Re-examination of the peripheral blood sequencing data identified this variant at 6% allele fraction. Tumor analysis revealed characteristic cytomorphological, immunohistochemical reactivity for alpha-inhibin, and CAIX, and reduced pVHL reactivity supported VHL-related pseudohypoxia. This report of a rare case of VHL mosaicism highlights the value of tissue testing in VHL variant negative cases.

Brief family history questionnaire to screen for Lynch syndrome in women with newly diagnosed non-serous, non-mucinous ovarian cancers.

OBJECTIVES: While ovarian cancer is the third most common Lynch syndrome-associated cancer in women, there is no established screening strategy to identify Lynch syndrome in this population. The objective of this study was to assess whether the 4-item brief Family History Questionnaire can be used as a screening tool to identify women with ovarian cancer at risk of Lynch syndrome. METHODS: In this prospective cohort study, participants with newly diagnosed non-serous, non-mucinous ovarian cancer completed the brief Family History Questionnaire, extended Family History Questionnaire, and had tumors assessed with immunohistochemistry for mismatch repair proteins, MLH1 methylation, and microsatellite instability testing. All underwent universal germline testing for Lynch syndrome. Performance characteristics were compared between the brief Family History Questionnaire, extended Family History Questionnaire, immunohistochemistry±MLH1 methylation, and microsatellite instability testing. RESULTS: Of 215 participants, 169 (79%) were evaluable with both the brief Family History Questionnaire and germline mutation status; 12 of these 169 were confirmed to have Lynch syndrome (7%). 10 of 12 patients (83%) with Lynch syndrome were correctly identified by the brief Family History Questionnaire, compared with 6 of 11 (55%) by the extended Family History Questionnaire, 11 of 13 (85%) by immunohistochemistry±MLH1 methylation, and 9 of 11 (82%) by microsatellite instability testing. The sensitivity, specificity, positive predictive values, and negative predictive values of the brief Family History Questionnaire were 83%, 65%, 15%, and 98%, respectively. A combined approach with immunohistochemistry and the brief Family History Questionnaire correctly identified all 12 patients with Lynch syndrome. The brief Family History Questionnaire was more sensitive than the extended Family History Questionnaire and took <10 min for each patient to complete. CONCLUSIONS: The brief Family History Questionnaire alone or combined with immunohistochemistry may serve as an adequate screening strategy, especially in centers without access to universal tumor testing.

Mutations in Noncoding Cis-Regulatory Elements Reveal Cancer Driver Cistromes in Luminal Breast Cancer.

Whole-genome sequencing of primary breast tumors enabled the identification of cancer driver genes and noncoding cancer driver plexuses from somatic mutations. However, differentiating driver from passenger events among noncoding genetic variants remains a challenge. Herein, we reveal cancer-driver cis-regulatory elements linked to transcription factors previously shown to be involved in development of luminal breast cancers by defining a tumor-enriched catalogue of approximately 100,000 unique cis-regulatory elements from 26 primary luminal estrogen receptor (ER)+ progesterone receptor (PR)+ breast tumors. Integrating this catalog with somatic mutations from 350 publicly available breast tumor whole genomes, we uncovered cancer driver cistromes, defined as the sum of binding sites for a transcription factor, for ten transcription factors in luminal breast cancer such as FOXA1 and ER, nine of which are essential for growth in breast cancer with four exclusive to the luminal subtype. Collectively, we present a strategy to find cancer driver cistromes relying on quantifying the enrichment of noncoding mutations over cis-regulatory elements concatenated into a functional unit. IMPLICATIONS: Mapping the accessible chromatin of luminal breast cancer led to discovery of an accumulation of mutations within cistromes of transcription factors essential to luminal breast cancer. This demonstrates coopting of regulatory networks to drive cancer and provides a framework to derive insight into the noncoding space of cancer.

Identifying Core Domains to Assess the "Quality of Death": A Scoping Review.

CONTEXT: There is growing recognition of the value to patients, families, society, and health systems in providing healthcare, including end-of-life care, that is consistent with both patient preferences and clinical guidelines. OBJECTIVES: Identify the core domains and subdomains that can be used to evaluate the performance of end-of-life care within and across health systems. METHODS: PubMed/MEDLINE (NCBI), PsycINFO (ProQuest), and CINAHL (EBSCO) databases were searched for peer-reviewed journal articles published prior to February 22, 2020. The SPIDER tool was used to determine search terms. A priori criteria were followed with independent review to identify relevant articles. RESULTS: A total of 309 eligible articles were identified out of 2728 discrete results. The articles represent perspectives from the broader health system (11), patients (70), family and informal caregivers (65), healthcare professionals (43), multiple viewpoints (110), and others (10). The most common condition of focus was cancer (103) and the majority (245) of the studies concentrated on high-income country contexts. The review identified five domains and 11 subdomains focused on structural factors relevant to end-of-life care at the broader health system level, and two domains and 22 subdomains focused on experiential aspects of end-of-life care from the patient and family perspectives. The structural health system domains were: 1) stewardship and governance, 2) resource generation, 3) financing and financial protection, 4) service provision, and 5) access to care. The experiential domains were: 1) quality of care, and 2) quality of communication. CONCLUSION: The review affirms the need for a people-centered approach to managing the delicate process and period of accepting and preparing for the end of life. The identified structural and experiential factors pertinent to the "quality of death" will prove invaluable for future efforts aimed to quantify health system performance in the end-of-life period.

Maximizing cancer prevention through genetic navigation for Lynch syndrome detection in women with newly diagnosed endometrial and nonserous/nonmucinous epithelial ovarian cancer.

BACKGROUND: Despite recommendations for reflex immunohistochemistry (IHC) for mismatch repair (MMR) proteins to identify Lynch syndrome (LS), the uptake of genetic assessment by those who meet referral criteria is low. The authors implemented a comprehensive genetic navigation program to increase the uptake of genetic testing for LS in patients with endometrial cancer (EC) or nonserous/nonmucinous ovarian cancer (OC). METHODS: Participants with newly diagnosed EC or OC were prospectively recruited from 3 cancer centers in Ontario, Canada. Family history questionnaires were used to assess LS-specific family history. Reflex IHC for MMR proteins was performed with the inclusion of clinical directives in pathology reports. A trained genetic navigator initiated a genetic referral on behalf of the treating physician and facilitated genetic referrals to the closest genetics center. RESULTS: A total of 841 participants (642 with EC, 172 with OC, and 27 with synchronous EC/OC) consented to the study; 194 (23%) were MMR-deficient by IHC. Overall, 170 women (20%) were eligible for a genetic assessment for LS: 35 on the basis of their family history alone, 24 on the basis of their family history and IHC, 82 on the basis of IHC alone, and 29 on the basis of clinical discretion. After adjustments for participants who died (n = 6), 149 of 164 patients (91%) completed a genetic assessment, and 111 were offered and completed genetic testing. Thirty-four women (4.0% of the total cohort and 30.6% of those with genetic testing) were diagnosed with LS: 5 with mutL homolog 1 (MLH1), 9 with mutS homolog 2 (MSH2), 15 with mutS homolog 6 (MSH6), and 5 with PMS2. CONCLUSIONS: The introduction of a navigated genetic program resulted in a high rate of genetic assessment (>90%) in patients with gynecologic cancer at risk for LS.

Understanding the clinical implication of mismatch repair deficiency in endometrioid endometrial cancer through a prospective study.

OBJECTIVES: Findings on impact of mismatch repair deficiency (MMRd) on patient outcomes in endometrial cancer (EC) have been inconsistent to date. The objective of this study was to compare the oncologic outcomes and recurrence patterns between MMRd and MMR-intact (MMRi) endometrioid EC (EEC). METHODS: Between 2015 and 2018, we prospectively recruited 492 EEC cases from three cancer centers in Ontario, Canada. Tumors were reflexively assessed for MMR protein expression by immunohistochemistry (IHC). Clinicopathological, survival and recurrence patterns were compared between MMRd and MMRi cases. RESULTS: Of 492 EEC, 348 were MMRi (71%) and 144 were MMRd (29%) with median follow-up of 16.8 months (0-69.6). MMRd tumors tended to be grade 2 or 3 (56% vs. 29%, p < 0.001), with propensity for lymphovascular space invasion (28% vs. 18%, p = 0.024), lymph node involvement (7% vs. 5%, p < 0.001) and received more adjuvant treatment (46% vs. 33%, p = 0.027). This group also had significantly lower 3-year recurrence-free survival (78% vs. 90%, p = 0.014) although there was no difference in OS (p = 0.603). MMRd cases were more likely to recur in retroperitoneal lymph nodes (p = 0.045). Upon subgroup analysis, MLH1 methylated tumors had the worst prognostic features and survival outcomes. CONCLUSIONS: MLH1 methylated EECs exhibit more aggressive features compared to other MMRd and MMRi EECs. This may indicate an inherent difference in tumor biology, suggesting the importance of individualized management based on EC molecular phenotype.

Effect of genetics clinical decision support tools on health-care providers' decision making: a mixed-methods systematic review.

PURPOSE: Patient care involving genetics is challenging for nongenetics health-care providers. Clinical decision support (CDS) tools are a potential solution because they provide patient-specific risk assessments and/or management recommendations. This systematic review synthesized evidence on whether using CDS tools resulted in appropriate changes in genetics-related patient management made by nongenetics health-care providers. METHODS: A comprehensive search in MEDLINE, Embase, and CINAHL yielded 2,239 unique articles. Two independent reviewers screened abstracts and full texts for quantitative, qualitative, and mixed-methods articles on management changes by nongenetics clinicians using a CDS tool as part of patient care. Effect sizes were calculated for quantitative studies and all articles were analyzed together using narrative synthesis. Twenty articles were included. RESULTS: In 12/16 quantitative studies, CDS tools slightly increased appropriate changes in management, but study design appeared to affect the statistical significance of the effect. The qualitative data in the four remaining studies reaffirmed that CDS tools facilitated management decisions but raised questions about their effect on patient outcomes. CONCLUSION: Our review assessed clinical utility of CDS tools, finding that they slightly increase appropriate management changes by nongenetics providers. Future studies on CDS tools should explicitly evaluate decision making and patient outcomes.

An Integrative DNA Sequencing and Methylation Panel to Assess Mismatch Repair Deficiency.

Clinical testing for mismatch repair (MMR) deficiency often entails serial testing of tumor and constitutional DNA using multiple assays. To minimize cost and specimen requirements of MMR testing, we developed an integrated targeted sequencing protocol (termed MultiMMR) that tests for promoter methylation, mutations, copy number alterations, copy neutral loss of heterozygosity, and microsatellite instability from a single aliquot of DNA. Hybrid capture of DNA-sequencing libraries constructed with methylated adapters was performed on 142 samples (60 tumors and 82 constitutional samples) from 82 patients with MMR-associated colorectal, endometrial, and brain cancers as well as a synthetic DNA mix with 11 known mutations. The captured material was split to enable parallel bisulfite and conventional sequence analysis. The panel targeted microsatellite regions and 13 genes associated with MMR, hypermutation, and hereditary colorectal cancer. MultiMMR recapitulated clinical testing results in 23 of 24 cases, was able to explain MMR loss in an additional 29 of 48 patients with incomplete or inconclusive testing, and identified all 11 MMR variants within the synthetic DNA mix. Promoter methylation and microsatellite instability analysis found 95% and 97% concordance with clinical testing, respectively. We report the feasibility for amalgamation of the current stepwise and complex clinical testing workflow into an integrated test for hereditary and somatic causes of MMR deficiency.

Tumor site discordance in mismatch repair deficiency in synchronous endometrial and ovarian cancers.

OBJECTIVES: For synchronous endometrial and ovarian cancers, most centers rely on mismatch repair testing of the endometrial cancer to identify Lynch syndrome, and neglect the ovarian tumor site completely. We examined the mismatch repair immunohistochemistry and microsatellite instability results from the endometrium and ovary to assess discordance between the tumor sites and between tests. METHODS: 30 women with newly diagnosed synchronous endometrial and ovarian cancer were prospectively recruited from three cancer centers in Ontario, Canada. Both tumor sites were assessed for mismatch repair deficiency by immunohistochemistry and microsatellite instability test; discordance in results between tumor sites and discordance between test results at each site was examined. Cases with discordant results had tumors sequenced with a targeted panel in order to reconcile the findings. All women underwent mismatch repair gene germline testing. RESULTS: Of 30 patients, 11 (37%) were mismatch repair deficient or microsatellite instable at either tumor site, with 5 (17%) testing positive for Lynch syndrome. Mismatch repair immunohistochemistry expression was discordant between endometrial and ovarian tumor sites in 2 of 27 patients (7%) while microsatellite instability results were discordant in 2 of 25 patients (8%). Relying on immunohistochemistry or microsatellite instability alone on the endometrial tumor would have missed one and three cases of Lynch syndrome, respectively. One patient with Lynch syndrome with a PMS2 pathogenic variant was not detected by either immunohistochemistry or microsatellite instability testing. The rate of discordance between immunohistochemistry and microsatellite instability test was 3.8% in the ovary and 12% in the endometrium. CONCLUSIONS: There was discordance in immunohistochemistry and microsatellite instability results between tumor sites and between tests within each site. Endometrial tumor testing with mismatch repair immunohistochemistry performed well, but missed one case of Lynch syndrome. Given the high incidence of Lynch syndrome (17%), consideration may be given to germline testing in all patients with synchronous endometrial and ovarian cancers.

Performance characteristics of screening strategies to identify Lynch syndrome in women with ovarian cancer.

BACKGROUND: For women with ovarian cancer (OC), the optimal screening strategy to identify Lynch syndrome (LS) has not been determined. In the current study, the authors compared the performance characteristics of various strategies combining mismatch repair (MMR) immunohistochemistry (IHC), microsatellite instability testing (MSI), and family history for the detection of LS. METHODS: Women with nonserous and/or nonmucinous ovarian cancer were recruited prospectively from 3 cancer centers in Ontario, Canada. All underwent germline testing for LS and completed a family history assessment. Tumors were assessed using MMR IHC and MSI. The sensitivity, specificity, and positive and negative predictive values of screening strategies were compared with the gold standard of a germline result. RESULTS: Of 215 women, germline data were available for 189 (88%); 13 women (7%) had pathogenic germline variants with 7 women with mutS homolog 6 (MSH6); 3 women with mutL homolog 1 (MLH1); 2 women with PMS1 homolog 2, mismatch repair system component (PMS2); and 1 woman with mutS homolog 2 (MSH2). A total of 28 women had MMR-deficient tumors (13%); of these, 11 had pathogenic variants (39%). Sequential IHC (with MLH1 promoter methylation analysis on MLH1-deficient tumors) followed by MSI for nonmethylated and/or MMR-intact patients was the most sensitive (92.3%; 95% confidence interval, 64%-99.8%) and specific (97.7%; 95% confidence interval, 94.2%-99.4%) approach, missing 1 case of LS. IHC with MLH1 promoter methylation analysis missed 2 patients of LS. Family history was found to have the lowest sensitivity at 55%. CONCLUSIONS: Sequential IHC (with MLH1 promoter methylation analysis) followed by MSI was found to be most sensitive. However, IHC with MLH1 promoter methylation analysis also performed well and is likely more cost-effective and efficient in the clinical setting. The pretest probability of LS is high in patients with MMR deficiency and warrants universal screening for LS.

Molecular Events in the Natural History of Pancreatic Cancer.

Pancreatic ductal adenocarcinoma (PDAC) is among the deadliest epithelial malignancies. Improvements in our understanding of PDAC carcinogenesis will hopefully improve its detection, management, and outcomes, as has been achieved with other malignancies. Here we review the literature on the natural history of PDAC, including its cell of origin, the initiating somatic mutational events, pathways deranged in the mature tumor, its biological heterogeneity, and the relationship of the primary tumor with metastases. We also suggest areas for further research and highlight translatable findings that are beginning to make clinical inroads.