Lost in translation: returning germline genetic results in genome-scale cancer research

Recontact to return new or updated PALB2 genetic results in the clinical laboratory setting

OBJECTIVE

The purpose of this study was to recontact individuals with clinically actionable test results identified through a retrospective research study and to provide a framework for laboratories to recontact patients.

METHODS

Genetic testing was conducted on 2977 individuals originally referred for BRCA1 and BRCA2 hereditary breast and ovarian cancer testing that had a negative genetic test result. A gene panel was used to identify pathogenic variants in known or newly discovered genes that could explain the underlying cause of disease; however, analysis was restricted to PALB2 for the purposes of this study. A patient recontact decision tree was developed to assist in the returning of updated genetic test results to clinics and patients.

RESULTS

Novel clinically actionable pathogenic variants were identified in the PALB2 gene in 18 participants (0.6%), the majority of whom were recontacted with their new or updated genetic test results. Eight individuals were unable to be recontacted; five individuals had already learnt about their new or updated findings from genetic testing outside the context of this study; three individuals prompted cascade testing in family members; two individuals were deceased.

CONCLUSION

Novel pathogenic variants in PALB2 were identified in 18 individuals through retrospective gene panel testing. Recontacting these individuals regarding these new or updated findings had a range of outcomes. The process of conveying genomic results within this framework can be effectively accomplished while upholding patient autonomy, potentially leading to advantageous outcomes for patients and their families.

Understanding the Genetic Landscape of Pancreatic Ductal Adenocarcinoma to Support Personalized Medicine: A Systematic Review

Pancreatic ductal adenocarcinoma (PDAC) is one of the most fatal malignancies worldwide. While population-wide screening recommendations for PDAC in asymptomatic individuals are not achievable due to its relatively low incidence, pancreatic cancer surveillance programs are recommended for patients with germline causative variants in PDAC susceptibility genes or a strong family history. In this study, we sought to determine the prevalence and significance of germline alterations in major genes (ATM, BRCA1, BRCA2, CDKN2A, EPCAM, MLH1, MSH2, MSH6, PALB2, PMS2, STK11, TP53) involved in PDAC susceptibility. We performed a systematic review of PubMed publications reporting germline variants identified in these genes in PDAC patients. Overall, the retrieved articles included 1493 PDAC patients. A high proportion of these patients (n = 1225/1493, 82%) were found to harbor alterations in genes (ATM, BRCA1, BRCA2, PALB2) involved in the homologous recombination repair (HRR) pathway. Specifically, the remaining PDAC patients were reported to carry alterations in genes playing a role in other cancer pathways (CDKN2A, STK11, TP53; n = 181/1493, 12.1%) or in the mismatch repair (MMR) pathway (MLH1, MSH2, MSH6, PMS2; n = 87/1493, 5.8%). Our findings highlight the importance of germline genetic characterization in PDAC patients for better personalized targeted therapies, clinical management, and surveillance.

Evaluation of inherited germline mutations in cancer susceptibility genes among pancreatic cancer patients: a single-center study

BACKGROUND

Germline mutations in cancer susceptibility genes were identified in pancreatic cancer (PanC) patients with a sporadic disease and in those unselected for family cancer history.

METHODS

With the aim to determine the prevalence of germline predisposition genes mutations in PanC, and to evaluate whether they were associated with the presence of PanC, we profiled a custom AmpliSeq panel of 27 cancer susceptibility genes in 47 PanC patients and 51 control subjects by using the Ion Torrent PGM system.

RESULTS

Multigene panel testing identified a total of 31 variants in 27 PanC (57.4%), including variants with pathogenic/likely pathogenic effect, those of uncertain significance, and variants whose clinical significance remains currently undefined. Five patients carried more than one variant in the same gene or in different genes. Eight patients (17.0%) had at least one pathogenic/likely pathogenic variant in four main genes: CFTR (10.6%), BRCA2 (8.5%), ATM and CHEK2 (2.1%). Pathogenic/likely pathogenic mutation were identified in patients with positive PanC family history (20%) or in patients without first-degree relatives affected by PanC (13.6%). All the BRCA2 mutation carriers were unselected PanC patients. The presence of mutations in BRCA2 was significantly associated with an increased occurrence of PanC and with positive family history for endometrial cancer (p = 0.018).

CONCLUSIONS

This study confirmed the potential remarkable contribution of BRCA2 in assessing the presence of PanC. Overall our findings supported the recommendation of offering the germline testing to all the PanC patients with the intent to reduce the number of underdiagnosed carriers of mutations in predisposition genes, and not to preclude their relatives from the opportunity to benefit from surveillance programs.

Transforming Diagnosis and Therapeutics Using Cancer Genomics

In past quarter of the century, much has been understood about the genetic variation and abnormal genes that activate cancer in humans. All the cancers somehow possess alterations in the DNA sequence of cancer cell's genome. In present, we are heading toward the era where it is possible to obtain complete genome of the cancer cells for their better diagnosis, categorization and to explore treatment options.

Half of germline pathogenic and likely pathogenic variants found on panel tests do not fulfil NHS testing criteria

Genetic testing for cancer predisposition has been curtailed by the cost of sequencing, and testing has been restricted by eligibility criteria. As the cost of sequencing decreases, the question of expanding multi-gene cancer panels to a broader population arises. We evaluated how many additional actionable genetic variants are returned by unrestricted panel testing in the private sector compared to those which would be returned by adhering to current NHS eligibility criteria. We reviewed 152 patients referred for multi-gene cancer panels in the private sector between 2014 and 2016. Genetic counselling and disclosure of all results was standard of care provided by the Consultant. Every panel conducted was compared to current eligibility criteria. A germline pathogenic / likely pathogenic variant (P/LP), in a gene relevant to the personal or family history of cancer, was detected in 15 patients (detection rate of 10%). 46.7% of those found to have the P/LP variants (7 of 15), or 4.6% of the entire set (7 of 152), did not fulfil NHS eligibility criteria. 46.7% of P/LP variants in this study would have been missed by national testing guidelines, all of which were actionable. However, patients who do not fulfil eligibility criteria have a higher Variant of Uncertain Significance (VUS) burden. We demonstrated that the current England NHS threshold for genetic testing is missing pathogenic variants which would alter management in 4.6%, nearly 1 in 20 individuals. However, the clinical service burden that would ensue is a detection of VUS of 34%.

Molecular Targeting of a BRAF Mutation in Pancreatic Ductal Adenocarcinoma: Case Report and Literature Review

Current standard-of-care treatment for advanced pancreatic ductal adenocarcinoma is mainly based on conventional cytotoxic chemotherapy. Until recently, no randomized clinical trials had shown any clinically meaningful outcome benefit from targeted therapy in this indication. This is in contrast to many other tumor types. The majority of pancreatic tumors are driven by KRAS mutations, which are generally not amenable to targeted therapy. Driving mutations in the BRAF oncogene have proven to be an interesting molecular target in the management of advanced melanoma and colorectal adenocarcinoma and can be found in 3% of patients with advanced pancreatic ductal adenocarcinoma. Here, we report objective tumor response to treatment with the combination of the BRAF inhibitor vemurafenib and the MEK inhibitor cobimetinib in a patient with poorly differentiated, V600E mutant, advanced pancreatic ductal adenocarcinoma.

Artificial Intelligence and Early Detection of Pancreatic Cancer: 2020 Summative Review

ABSTRACT

Despite considerable research efforts, pancreatic cancer is associated with a dire prognosis and a 5-year survival rate of only 10%. Early symptoms of the disease are mostly nonspecific. The premise of improved survival through early detection is that more individuals will benefit from potentially curative treatment. Artificial intelligence (AI) methodology has emerged as a successful tool for risk stratification and identification in general health care. In response to the maturity of AI, Kenner Family Research Fund conducted the 2020 AI and Early Detection of Pancreatic Cancer Virtual Summit (www.pdac-virtualsummit.org) in conjunction with the American Pancreatic Association, with a focus on the potential of AI to advance early detection efforts in this disease. This comprehensive presummit article was prepared based on information provided by each of the interdisciplinary participants on one of the 5 following topics: Progress, Problems, and Prospects for Early Detection; AI and Machine Learning; AI and Pancreatic Cancer-Current Efforts; Collaborative Opportunities; and Moving Forward-Reflections from Government, Industry, and Advocacy. The outcome from the robust Summit conversations, to be presented in a future white paper, indicate that significant progress must be the result of strategic collaboration among investigators and institutions from multidisciplinary backgrounds, supported by committed funders.

Implementing Systematic Genetic Counseling and Multigene Germline Testing for Individuals With Pancreatic Cancer

PURPOSE

National guidelines recommend genetic counseling and multigene germline testing (GC/MGT) for all patients with pancreatic ductal adenocarcinoma (PDAC). This study's aim was to assess real-world effectiveness of implementing systematic GC/MGT for all patients with PDAC at a high-volume academic institution.

METHODS

An iterative process for systematizing GC/MGT was developed in which gastrointestinal oncology providers at the Dana-Farber Cancer Institute were recommended to refer all patients with PDAC for GC/MGT (clinician-directed referral). Workflows were subsequently changed such that patients with PDAC were automatically offered GC/MGT when scheduling their initial oncology consultation (automated referral). Clinical and germline data were collected on a consecutive cohort of patients with PDAC undergoing GC/MGT during a 25-month enrollment period (19-month clinician-directed referrals; 6-month automated referrals).

RESULTS

One thousand two hundred fourteen patients with PDAC were seen for initial oncologic evaluation, 266 (21.9%) of whom underwent GC/MGT. Compared with baseline clinician-directed referrals, implementation of automated referrals led to a significant increase in patients with PDAC undergoing GC/MGT (16.5% v 38.0%, P < .001), including those undergoing multigene germline testing (MGT) ≤ 7 days of initial oncology evaluation (14.7% v 60.3%, P < .001), with preserved pathogenic variant detection rates (10.0% v 11.2%, P = 0.84). 16 of 28 (57.1%) pathogenic variant carriers had relatives who pursued cascade germline testing, and 13 of 26 (50.0%) carriers with incurable disease received targeted therapy based on MGT results.

CONCLUSION

Implementation of systematic GC/MGT in patients with PDAC is feasible and leads to management changes for patients with PDAC and their families. GC/MGT workflows that bypass the need for clinician referral result in superior uptake and time to testing. Further investigation is needed to identify other barriers and facilitators of universal GC/MGT.

Discovery through clinical sequencing in oncology

The molecular characterization of tumors now informs clinical cancer care for many patients. This advent of molecular oncology is driven by the expanding number of therapeutic biomarkers that can predict sensitivity to both approved and investigational agents. Beyond its role in driving clinical trial enrollments and guiding therapy in individual patients, large-scale clinical genomics in oncology also represents a rapidly expanding research resource for translational scientific discovery. Here, we review the progress, opportunities, and challenges of scientific and translational discovery from prospective clinical genomic screening programs now routinely conducted in cancer patients.

Perspectives regarding family disclosure of genetic research results in three racial and ethnic minority populations

The lack of data on perspectives of racial and ethnic minority populations regarding family disclosure of individual research results (IRR) hinders the development of return of IRR policies and practices that are meaningful and culturally appropriate in diverse populations. This research aims to uncover preferences regarding family disclosure of IRR and identify factors that may shape the preferences in three minority populations. Nine focus groups with 68 adult African American, Hispanic/Latinx, and American Indian/Alaska Native individuals were conducted. Data were analyzed using thematic analysis. Participants were willing to share IRR with relatives who elected to know and preferred a participant-driven (vs. researcher-driven) decision-making process. Privacy of personal information was deemed important, as were anticipated familial benefits from genetic information, except when improper use of the information was suspected. Factors influencing family disclosure decisions included the family's biological and emotional closeness, and participants' perceived mental preparedness of the relative. Family disclosure of IRR among racial and ethnic minority individuals is a complex decision-making process wherein issues of individual privacy are entangled with family dynamic and familial benefit considerations. These data suggest that policies surrounding family disclosure of IRR should carefully consider participant preferences and adopt a participant-driven approach.

MCL-1 antagonism enhances the anti-invasive effects of dasatinib in pancreatic adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) remains one of the deadliest malignancies. It is phenotypically heterogeneous with a highly unstable genome and provides few common therapeutic targets. We found that MCL1, Cofilin1 (CFL1) and SRC mRNA were highly expressed by a wide range of these cancers, suggesting that a strategy of dual MCL-1 and SRC inhibition might be efficacious for many patients. Immunohistochemistry revealed that MCL-1 protein was present at high levels in 94.7% of patients in a cohort of PDACs from Australian Pancreatic Genome Initiative (APGI). High MCL1 and Cofilin1 mRNA expression was also strongly predictive of poor outcome in the TCGA dataset and in the APGI cohort. In culture, MCL-1 antagonism reduced the level of the cytoskeletal remodeling protein Cofilin1 and phosphorylated SRC on the active Y416 residue, suggestive of reduced invasive capacity. The MCL-1 antagonist S63845 synergized with the SRC kinase inhibitor dasatinib to reduce cell viability and invasiveness through 3D-organotypic matrices. In preclinical murine models, this combination reduced primary tumor growth and liver metastasis of pancreatic cancer xenografts. These data suggest that MCL-1 antagonism, while reducing cell viability, may have an additional benefit in increasing the antimetastatic efficacy of dasatinib for the treatment of PDAC.

Genetic counselling and personalised risk assessment in the Australian pancreatic cancer screening program

Background

Pancreatic cancer (PC) is an aggressive disease with a dismal 5-year survival rate. Surveillance of high-risk individuals is hoped to improve survival outcomes by detection of precursor lesions or early-stage malignancy.

Methods

Since 2011, a national high-risk cohort recruited through St Vincent’s Hospital, Sydney, has undergone prospective PC screening incorporating annual endoscopic ultrasound, formal genetic counselling and mutation analysis as appropriate. PancPRO, a Bayesian PC risk assessment model, was used to estimate 5-year and lifetime PC risks for familial pancreatic cancer (FPC) participants and this was compared to their perceived chance of pancreatic and other cancers. Genetic counselling guidelines were developed to improve consistency. Follow-up questionnaires were used to assess the role of genetic counselling and testing.

Results

We describe the Australian PC screening program design and recruitment strategy and the results of the first 102 individuals who have completed at least one-year of follow-up. Seventy-nine participants met the FPC criteria (≥ two first-degree relatives affected), 22 individuals had both a BRCA2 pathogenic variant and a close relative with PC and one had a clinical diagnosis of Peutz-Jeghers syndrome. Participants reported a high perceived chance of developing PC regardless of their genetic testing status. PancPRO reported FPC participants’ mean 5-year and lifetime PC risks as 1.81% (range 0.2–3.2%) and 10.17% (range 2.4–14.4%), respectively. Participants’ perceived PC chance did not correlate with their PancPRO 5-year (r = − 0.17, p = 0.128) and lifetime PC risks (r = 0.19, p = 0.091). Two-thirds felt that current genetic testing would help them, and 91% of tested participants were glad to have undergone genetic testing. Overall, 79% of participants found genetic counselling to be helpful, and 88% reported they would recommend counselling to their relatives.

Conclusions

Participants reported multiple benefits of genetic counselling and testing but continue to seek greater clarification about their individual PC risk. Extension of PancPRO is required to enable personalised PC risk assessment for all high-risk sub-groups. More detailed discussion of PC risk for BRCA2 pathogenic variant carriers, providing a written summary in all cases and a plan for genetics review were identified as areas for improvement.

Men's experiences of recontact about a potential increased risk of prostate cancer due to Lynch Syndrome: "Just another straw on the stack"

The practice of recontacting patients to provide new health information is becoming increasingly common in clinical genetics, despite the limited research to evidence the patient experience. We explored how men with Lynch Syndrome (LS) understand and experience being recontacted about a potential increased risk of prostate cancer. Sixteen men with LS (Meanage 51 years) were recruited from an Australian screening study to undergo a semi-structured interview. A modified grounded theory approach was used to guide data collection and thematic analysis. Qualitative coding was shared by the research team to triangulate analysis. The practice of recontact was viewed by participants as acceptable and was associated with minimal emotional distress. The majority of men understood that they may be above population risk of prostate cancer, although evidence was still emerging. Men reported high engagement with personal and familial health, including regular screening practices and familial risk communication. Findings suggest that men's carrier status and beliefs about the actionability of the new cancer risk information influence their response to recontact. Recontact practices that include the offer of risk management strategies may lead to improved patient outcomes (e.g., reduced cancer worry and increased health engagement), if perceived as valuable by recipients.

Evaluating Susceptibility to Pancreatic Cancer: ASCO Provisional Clinical Opinion

Purpose

An ASCO provisional clinical opinion (PCO) offers timely clinical direction to ASCO’s membership and other health care providers. This PCO addresses identification and management of patients and family members with possible predisposition to pancreatic adenocarcinoma.

Methods

ASCO convened an Expert Panel and conducted a systematic review of the literature published from January 1998 to June 2018. Results of the databases searched were supplemented with hand searching of the bibliographies of systematic reviews and selected seminal articles and contributions from Expert Panel members’ curated files.

Provisional Clinical Opinion

All patients diagnosed with pancreatic adenocarcinoma should undergo assessment of risk for hereditary syndromes known to be associated with an increased risk for pancreatic adenocarcinoma. Assessment of risk should include a comprehensive review of family history of cancer. Individuals with a family history of pancreatic cancer affecting two first-degree relatives meet criteria for familial pancreatic cancer (FPC). Individuals (cancer affected or unaffected) with a family history of pancreatic cancer meeting criteria for FPC, those with three or more diagnoses of pancreatic cancer in same side of the family, and individuals meeting criteria for other genetic syndromes associated with increased risk for pancreatic cancer have an increased risk for pancreatic cancer and are candidates for genetic testing. Germline genetic testing for cancer susceptibility may be discussed with individuals diagnosed with pancreatic cancer, even if family history is unremarkable. Benefits and limitations of pancreatic cancer screening should be discussed with individuals whose family history meets criteria for FPC and/or genetic susceptibility to pancreatic cancer. Additional information is available at www.asco.org/gastrointestinal-cancer-guidelines .

Germline cancer susceptibility gene variants, somatic second hits, and survival outcomes in patients with resected pancreatic cancer

PURPOSE

Germline variants in double-strand DNA damage repair (dsDDR) genes (e.g., BRCA1/2) predispose to pancreatic adenocarcinoma (PDAC) and may predict sensitivity to platinum-based chemotherapy and poly(ADP) ribose polymerase (PARP) inhibitors. We sought to determine the prevalence and significance of germline cancer susceptibility gene variants in PDAC with paired somatic and survival analyses.

METHODS

Using a customized next-generation sequencing panel, germline/somatic DNA was analyzed from 289 patients with resected PDAC ascertained without preselection for high-risk features (e.g., young age, personal/family history). All identified variants were assessed for pathogenicity. Outcomes were analyzed using multivariable-adjusted Cox proportional hazards regression.

RESULTS

We found that 28/289 (9.7%; 95% confidence interval [CI] 6.5-13.7%) patients carried pathogenic/likely pathogenic germline variants, including 21 (7.3%) dsDDR gene variants (3 BRCA1, 4 BRCA2, 14 other dsDDR genes [ATM, BRIP1, CHEK2, NBN, PALB2, RAD50, RAD51C]), 3 Lynch syndrome, and 4 other genes (APC p.I1307K, CDKN2A, TP53). Somatic sequencing and immunohistochemistry identified second hits in the tumor in 12/27 (44.4%) patients with germline variants (1 failed sequencing). Compared with noncarriers, patients with germline dsDDR gene variants had superior overall survival (hazard ratio [HR] 0.54; 95% CI 0.30-0.99; P = 0.05).

CONCLUSION

Nearly 10% of PDAC patients harbor germline variants, although the majority lack somatic second hits, the therapeutic significance of which warrants further study.

Should Researchers Offer Results to Family Members of Cancer Biobank Participants? A Mixed-Methods Study of Proband and Family Preferences

BACKGROUND

Genomic analysis may reveal both primary and secondary findings with direct relevance to the health of probands' biological relatives. Researchers question their obligations to return findings not only to participants but also to family members. Given the social value of privacy protection, should researchers offer a proband's results to family members, including after the proband's death?

METHODS

Preferences were elicited using interviews and a survey. Respondents included probands from two pancreatic cancer research resources, plus biological and nonbiological family members. Hypothetical scenarios based on actual research findings from the two cancer research resources were presented; participants were asked return of results preferences and justifications. Interview transcripts were coded and analyzed; survey data were analyzed descriptively.

RESULTS

Fifty-one individuals (17 probands, 21 biological relatives, 13 spouses/partners) were interviewed. Subsequently, a mailed survey was returned by 464 probands, 1,040 biological family members, and 399 spouses/partners. This analysis highlights the interviews, augmented by survey findings. Probands and family members attribute great predictive power and lifesaving potential to genomic information. A majority hold that a proband's genomic results relevant to family members' health ought to be offered. While informants endorse each individual's choice whether to learn results, most express a strong moral responsibility to know and to share, particularly with the younger generation. Most have few concerns about sharing genetic information within the family; rather, their concerns focus on the health consequences of not sharing.

CONCLUSIONS

Although additional studies in diverse populations are needed, policies governing return of genomic results should consider how families understand genomic data, how they value confidentiality within the family, and whether they endorse an ethics of sharing. A focus on respect for individual privacy-without attention to how the broad social and cultural context shapes preferences within families-cannot be the sole foundation of policy.

Prevalence of pathogenic/likely pathogenic variants in the 24 cancer genes of the ACMG Secondary Findings v2.0 list in a large cancer cohort and ethnicity-matched controls

Background

Prior research has established that the prevalence of pathogenic/likely pathogenic (P/LP) variants across all of the American College of Medical Genetics (ACMG) Secondary Findings (SF) genes is approximately 0.8–5%. We investigated the prevalence of P/LP variants in the 24 ACMG SF v2.0 cancer genes in a family-based cancer research cohort (n = 1173) and in cancer-free ethnicity-matched controls (n = 982).

Methods

We used InterVar to classify variants and subsequently conducted a manual review to further examine variants of unknown significance (VUS).

Results

In the 24 genes on the ACMG SF v2.0 list associated with a cancer phenotype, we observed 8 P/LP unique variants (8 individuals; 0.8%) in controls and 11 P/LP unique variants (14 individuals; 1.2%) in cases, a non-significant difference. We reviewed 115 VUS. The median estimated per-variant review time required was 30 min; the first variant within a gene took significantly (p = 0.0009) longer to review (median = 60 min) compared with subsequent variants (median = 30 min). The concordance rate was 83.3% for the variants examined by two reviewers.

Conclusion

The 115 VUS required database and literature review, a time- and labor-intensive process hampered by the difficulty in interpreting conflicting P/LP determinations. By rigorously investigating the 24 ACMG SF v2.0 cancer genes, our work establishes a benchmark P/LP variant prevalence rate in a familial cancer cohort and controls.

Electronic supplementary material

The online version of this article (10.1186/s13073-018-0607-5) contains supplementary material, which is available to authorized users.

Returning Individual Genetic Research Results to Research Participants: Uptake and Outcomes Among Patients With Breast Cancer

Purpose

Understanding the outcomes of returning individual genetic research results to participants is critical because some genetic variants are found to be associated with health outcomes and have become available for clinical testing.

Materials and Methods

BRCA1/2-negative women with early-onset breast cancer, multiple primary cancers, or a family history of breast cancer who participated in a gene discovery cancer registry were offered the opportunity to learn their individual genetic research results of 24 breast cancer susceptibility genes with a genetic counselor after predisclosure genetic counseling. Outcomes included uptake of research results, knowledge, informed choice, psychosocial adjustment, uncertainty, satisfaction, and uptake of clinical confirmation testing.

Results

Four hundred two potential participants were contacted. One hundred ninety-four participants (48%) did not respond despite multiple attempts, and 85 participants (21%) actively or passively declined. One hundred seven participants (27%) elected for predisclosure counseling and were more likely to be younger, married, and white. Ninety percent of participants who had predisclosure counseling elected to receive their genetic research results, and 89% made an informed choice. Knowledge increased significantly after predisclosure counseling, and anxiety, intrusive cancer-specific distress, uncertainty, and depression declined significantly after receipt of results. General anxiety and intrusive cancer-specific distress declined significantly for both participants with a positive result and those with a negative result. Sixty-four percent of participants had clinical confirmation testing when recommended, including all participants with a mutation in a high-penetrance gene.

Conclusion

Uptake of genetic research results may be lower than anticipated by hypothetical reports and small select studies. Participants who elected to receive research results with genetic providers did not experience increases in distress or uncertainty, but not all patients return for confirmation testing.

Advances in Molecular Profiling and Categorisation of Pancreatic Adenocarcinoma and the Implications for Therapy

Pancreatic ductal adenocarcinoma (PDAC) continues to be a disease with poor outcomes and short-lived treatment responses. New information is emerging from genome sequencing identifying potential subgroups based on somatic and germline mutations. A variety of different mutations and mutational signatures have been identified; the driver mutation in around 93% of PDAC is KRAS, with other recorded alterations being SMAD4 and CDKN2A. Mutations in the deoxyribonucleic acid (DNA) damage repair pathway have also been investigated in PDAC and multiple clinical trials are ongoing with DNA-damaging agents. Rare mutations in BRAF and microsatellite instability (MSI) have been reported in about 1-3% of patients with PDAC, and agents used in other cancers to target these have also shown some promise. Immunotherapy is a developing field, but has failed to demonstrate benefits in PDAC to date. While many trials have failed to improve outcomes in this deadly disease, there is optimism that by developing a better understanding of the translational aspects of this cancer, future informed therapeutic strategies may prove more successful.

Considering the Benefits and Risks of Research Participants' Access to Sequence Data

The use of sequencing technologies has greatly expanded in both research and clinical settings. The generation of voluminous datasets has raised several issues regarding data sharing and access. Current regulations require clinical laboratories and some research laboratories to provide access to test data, including sequencing data, directly to patients upon request. There is some controversy over whether this access right may be somewhat broader, encompassing research data as well-a question beyond the scope of this article. It is clear that in the research setting, deposition of sequencing data into public or private databases often occurs, although little information exists about the return of data files to research participants (in contrast to the extensive deliberations regarding return of results). Thus, further consideration of the issue of access to data files is warranted as well as more effort to understand both patients' and research participants' use of the data.