Referral frequency, attrition rate, and outcomes of germline testing in patients with pancreatic adenocarcinoma

Expanding access to genetic testing for pancreatic cancer

Among individuals with pancreatic ductal adenocarcinoma (PDAC) 5-10% have a pathogenic germline variant (PGV) in a PDAC susceptibility gene. Guidelines recommend genetic testing among all individuals with PDAC. Additionally, at-risk relatives of PDAC patients benefit from their own genetic education, risk assessment, and testing. Multigene panel testing (MGPT) can identify individuals with inherited cancer risk who can benefit from early cancer surveillance and risk reduction strategies. This manuscript discusses various healthcare delivery models for MGPT including traditional in-person genetic counseling, novel integrated in-person infrastructures, telemedicine genetics care via telephone- or video-visits and direct-to-consumer testing. Barriers and facilitators to care on the individual, provider, and system level are also outlined including specific considerations for historically marginalized communities.

A Randomized Trial of Two Remote Health Care Delivery Models on the Uptake of Genetic Testing and Impact on Patient-Reported Psychological Outcomes in Families With Pancreatic Cancer: The Genetic Education, Risk Assessment, and Testing (GENERATE) Study

BACKGROUND & AIMS

Genetic testing uptake for cancer susceptibility in family members of patients with cancer is suboptimal. Among relatives of patients with pancreatic ductal adenocarcinoma (PDAC), The GENetic Education, Risk Assessment, and TEsting (GENERATE) study evaluated 2 online genetic education/testing delivery models and their impact on patient-reported psychological outcomes.

METHODS

Eligible participants had ≥1 first-degree relative with PDAC, or ≥1 first-/second-degree relative with PDAC with a known pathogenic germline variant in 1 of 13 PDAC predisposition genes. Participants were randomized by family, between May 8, 2019, and June 1, 2021. Arm 1 participants underwent a remote interactive telemedicine session and online genetic education. Arm 2 participants were offered online genetic education only. All participants were offered germline testing. The primary outcome was genetic testing uptake, compared by permutation tests and mixed-effects logistic regression models. We hypothesized that Arm 1 participants would have a higher genetic testing uptake than Arm 2. Validated surveys were administered to assess patient-reported anxiety, depression, and cancer worry at baseline and 3 months postintervention.

RESULTS

A total of 424 families were randomized, including 601 participants (n = 296 Arm 1; n = 305 Arm 2), 90% of whom completed genetic testing (Arm 1 [87%]; Arm 2 [93%], P = .014). Arm 1 participants were significantly less likely to complete genetic testing compared with Arm 2 participants (adjusted ratio [Arm1/Arm2] 0.90, 95% confidence interval 0.78-0.98). Among participants who completed patient-reported psychological outcomes questionnaires (Arm 1 [n = 194]; Arm 2 [n = 206]), the intervention did not affect mean anxiety, depression, or cancer worry scores.

CONCLUSIONS

Remote genetic education and testing can be a successful and complementary option for delivering genetics care. (Clinicaltrials.gov, number NCT03762590).

Genetic Testing Utilization: Discrepancies Between Somatic and Germline Results in Patients With Cancer Reviewed at the UW Health Precision Medicine Molecular Tumor Board

PURPOSE

Somatic and germline testing are increasingly used to estimate risks for patients with cancer. Although both germline testing and somatic testing can identify genetic variants that could change a patient's care and eligible treatments, the aims of these tests and their technologies are fundamentally different and cannot be used interchangeably. This study examines the timing and results of somatic and germline genetic testing for patients with cancer at UW Health.

METHODS

Eight hundred and seventy-seven participants underwent somatic genetic testing, which was reviewed by the Precision Medicine Molecular Tumor Board (PMMTB). Patients were diagnosed with cancers, including breast, colorectal, endometrial, pancreatic, or ovarian cancer, and met National Comprehensive Cancer Network criteria for germline genetic testing. Germline testing details were collected by medical record review.

RESULTS

The results of this study found that only 310 patients (35%) had germline evaluation before PMMTB review. The percent of germline pathogenic/likely pathogenic variants identified in actionable genes was 28%. Most germline variants were identified in the BRCA1 (26%) and BRCA2 (28%) genes. In total, 65% (54/83) of germline variants were detected with both germline testing and somatic testing; however, 35% (29/83) of germline variants were not identified on somatic results. These results demonstrate the importance of combination germline and somatic testing.

CONCLUSION

This study highlights the differences in genetic testing types and demonstrates that conducting germline testing at earlier stages of diagnoses is necessary to identify potentially actionable and treatment-specific variants in patients with cancer.

Tumor-Only Sequencing: A Story Only Half Told

Germline testing and tumor sequencing are often both necessary for optimal cancer treatment and management.

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.

Germline BRCA testing in pancreatic cancer: improving awareness, timing, turnaround, and uptake

Prognosis is generally poor for patients with pancreatic ductal adenocarcinoma. However, patients with germline BRCA1 or BRCA2 mutations (gBRCAm) may benefit from first-line platinum-based chemotherapy and maintenance therapy with the poly(adenosine diphosphate-ribose) polymerase inhibitor olaparib following at least 16 weeks of first-line platinum-based chemotherapy without disease progression. Germline breast cancer gene (BRCA) testing is therefore important to ensure that patients receive the most effective treatment. In addition, testing for other DNA damage response gene mutations beyond gBRCAm may also guide treatment decisions. However, clinical pathways for genetic testing are often suboptimal, leading to delays in treatment initiation or missed opportunities for personalized therapy. Barriers to testing include low rates of referral and uptake, delays to referral and slow result turnaround times, cost, and biopsy and assay limitations if somatic testing is performed, leading to the requirement for subsequent dedicated germline testing. Low rates of referral may result from lack of awareness among physicians of the clinical value of testing, coupled with low confidence in interpreting test results and poor availability of genetic counseling services. Among patients, barriers to uptake may include similar lack of awareness of the clinical value of testing, anxiety regarding the implications of test results, lack of insurance coverage, fear of negative insurance implications, and socioeconomic factors. Potential solutions include innovative approaches to testing pathways, including 'mainstreaming' of testing in which BRCA tests are routinely arranged by the treating oncologist, with the involvement of genetic counselors if a patient is found to have a gBRCAm. More recently, the utility of multigene panel analyses has also been explored. Access to genetic counseling may also be improved through initiatives such as having a genetic counseling appointment for all new patient visits and telemedicine approaches, including the use of telephone consultations or DVD-assisted counseling. Educational programs will also be beneficial, and cost effectiveness is likely to improve as the number of targeted treatments increases and when the earlier detection of tumors in family members following cascade testing is considered.

Genetic counselling referral practices for patients with pancreatic adenocarcinoma: A French retrospective multicentre observational cohort study (CAPANCOGEN)

BACKGROUND/OBJECTIVES

Genetic counselling (GC) is a key step in the identification of inherited germline mutations. However, the oncogenetic practices are poorly described for pancreatic adenocarcinoma (PA) in Europe. The CAPANCOGEN study aimed to describe the GC referral practices in France and assess the implementation of international guidelines in patients with PA.

METHODS

Information about GC referrals with PA was collected in 13 French centres from September 2019 to October 2021. In the 5 largest centres, personal and familial histories of cancers and diseases associated with a higher risk of germline mutations were collected in 460 patients, according to international, American, European and French GC referral guidelines. Univariate and multivariate logistic regression analysis were performed to identify the factors influencing GC referral.

RESULTS

Among 833 patients, a total of 100 patients (12%) had an indication of GC according to local multidisciplinary tumour board meetings (MTBM). Among these patients, 41% did not undergo GC. The median time between MTBM and GC was 55 days (IQR: 14.5-112). Among 460 patients with collected personal and familial history, 31.5% were not referred to a GC despite an existing indication. In multivariate logistic regression analysis, suspected CDKN2A (p = 0.032) or BRCA mutation (p < 0.001), familial pancreatic cancer history (p < 0.001) and controlled disease with first-line platinum-based chemotherapy (p < 0.001) increased the referral rate. Conversely, older age (p = 0.002) and a locally advanced PA (p = 0.045) decreased the risk of GC referral.

CONCLUSIONS

GC referral is inadequate despite valuable information in patients' medical files.

Psychosocial factors impacting barriers and motivators to cancer genetic testing

BACKGROUND

Only a small proportion of patients who qualify for clinical genetic testing for cancer susceptibility get testing. Many patient-level barriers contribute to low uptake. In this study, we examined self-reported patient barriers and motivators for cancer genetic testing.

METHODS

A survey comprised of both new and existing measures related to barriers and motivators to genetic testing was emailed to patients with a diagnosis of cancer at a large academic medical center. Patients who self-reported receiving a genetic test were included in these analyses (n = 376). Responses about emotions following testing as well as barriers and motivators prior to getting testing were examined. Group differences in barriers and motivators by patient demographic characteristics were examined.

RESULTS

Being assigned female at birth was associated with increased emotional, insurance, and family concerns as well as increased health benefits compared to patients assigned male at birth. Younger respondents had significantly higher emotional and family concerns compared to older respondents. Recently diagnosed respondents expressed fewer concerns about insurance implications and emotional concerns. Those with a BRCA-related cancer had higher scores on social and interpersonal concerns scale than those with other cancers. Participants with higher depression scores indicated increased emotional, social and interpersonal, and family concerns.

CONCLUSIONS

Self-reported depression emerged as the most consistent factor influencing report of barriers to genetic testing. By incorporating mental health resources into clinical practice, oncologists may better identify those patients who might need more assistance following through with a referral for genetic testing and the response afterwards.

Compliance with the Current NCCN Guidelines and Its Critical Role in Pancreatic Adenocarcinoma

OBJECTIVES

Since 2019, the National Comprehensive Cancer Network (NCCN) has recommended genetic testing for patients diagnosed with pancreatic adenocarcinoma that includes universal germline testing and tumor gene profiling for metastatic, locally advanced, or recurrent disease. However, testing compliance with this guideline has not yet been published in the English literature.

METHODS

A quality assurance/quality improvement retrospective review was done to identify patients diagnosed with pancreatic adenocarcinoma from January 2019 to February 2021 to include the patient's clinical status and genetic test results.

RESULTS

There were 20 patient cases identified with pancreatic adenocarcinoma. A total of 11 cases had molecular tumor gene profiling and microsatellite instability/mismatch repair (MSI/MMR) testing performed and 1 case had only MSI/MMR testing by immunohistochemistry performed. Only 3 patients of the 20 in total received germline testing.

CONCLUSION

There was a significant number of patients for whom tumor gene profiling or germline testing had never been attempted as per recommended NCCN guidelines.

Mainstreaming germline genetic testing for patients with pancreatic cancer increases uptake

Germline genetic testing is recommended for all patients with pancreatic cancer (PC) but uptake rates are low. We implemented a mainstreaming program in oncology clinics to increase testing for PC patients. Genetic counselors trained oncology providers to offer a standardized multigene panel and obtain informed consent using an educational video. Pre-test genetic counseling was available upon request. Otherwise, patients with identified pathogenic variants, strong family history, or questions regarding their results were referred for post-test genetic counseling. We measured rates of testing and genetic counseling visits. From September 2019 to April 2021, 245 patients with PC underwent genetic testing. This represents a 6.5-fold increase in germline testing volume (95% confidence interval 5.2-8.1) compared to previous years. At least one pathogenic or likely pathogenic variant (PV/LPV) was found in 34 (13.9%) patients, including 17 (6.9%) PV/LPVs in high or moderate risk genes and 18 (7.3%) in low risk or recessive genes. Five (2.0%) PVs had implications on treatment selection. 22 of the positive patients (64.7%) and an additional 8 PC patients (1 negative, 3 VUS, and 4 pre-test) underwent genetic counseling during the study period. Genetic counselors saw 2.0 PC patients/month prior to this project, 1.6 PC patients/month during this project, and would have seen 2.2 PC patients/month if all patients with pathogenic variants attended post-test counseling. Conclusions Mainstreaming genetic testing expands access for PC patients without overwhelming genetic counseling resources.

Therapeutic advances in metastatic pancreatic cancer: a focus on targeted therapies

Mortality from pancreatic ductal adenocarcinoma (PDAC) is increasing worldwide and effective new treatments are urgently needed. The current treatment of metastatic PDAC in fit patients is based on two chemotherapy combinations (FOLFIRINOX and gemcitabine plus nab-paclitaxel) which were validated more than 8 years ago. Although almost all treatments targeting specific molecular alterations have failed so far when administered to unselected patients, encouraging results were observed in the small subpopulations of patients with germline BRCA 1/2 mutations, and somatic gene fusions (neurotrophic tyrosine receptor kinase, Neuregulin 1, which are enriched in KRAS wild-type PDAC), KRAS G12C mutations, or microsatellite instability. While targeted tumor metabolism therapies and immunotherapy have been disappointing, they are still under investigation in combination with other drugs. Optimizing pharmacokinetics and adapting available chemotherapies based on molecular signatures are other promising avenues of research. This review evaluates the current expectations and limits of available treatments and analyses the existing trials. A permanent search for actionable vulnerabilities in PDAC tumor cells and microenvironments will probably result in a more personalized therapeutic approach, keeping in mind that supportive care must also play a major role if real clinical efficacy is to be achieved in these patients.

Impact of comprehensive family history and genetic analysis in the multidisciplinary pancreatic tumor clinic setting

BACKGROUND

Genetic testing is recommended for all pancreatic ductal adenocarcinoma (PDAC) patients. Prior research demonstrates that multidisciplinary pancreatic cancer clinics (MDPCs) improve treatment- and survival-related outcomes for PDAC patients. However, limited information exists regarding the utility of integrated genetics in the MDPC setting. We hypothesized that incorporating genetics in an MDPC serving both PDAC patients and high-risk individuals (HRI) could: (1) improve compliance with guideline-based genetic testing for PDAC patients, and (2) optimize HRI identification and PDAC surveillance participation to improve early detection and survival.

METHODS

Demographics, genetic testing results, and pedigrees were reviewed for PDAC patients and HRI at one institution over 45 months. Genetic testing analyzed 16 PDAC-associated genes at minimum.

RESULTS

Overall, 969 MDPC subjects were evaluated during the study period; another 56 PDAC patients were seen outside the MDPC. Among 425 MDPC PDAC patients, 333 (78.4%) completed genetic testing; 29 (8.7%) carried a PDAC-related pathogenic germline variant (PGV). Additionally, 32 (9.6%) met familial pancreatic cancer (FPC) criteria. These PDAC patients had 191 relatives eligible for surveillance or genetic testing. Only 2/56 (3.6%) non-MDPC PDAC patients completed genetic testing (p < 0.01). Among 544 HRI, 253 (46.5%) had a known PGV or a designation of FPC, and were eligible for surveillance at baseline; of the remainder, 15/291 (5.2%) were eligible following genetic testing and PGV identification.

CONCLUSION

Integrating genetics into the multidisciplinary setting significantly improved genetic testing compliance by reducing logistical barriers for PDAC patients, and clarified cancer risks for their relatives while conserving clinical resources. Overall, we identified 206 individuals newly eligible for surveillance or genetic testing (191 relatives of MDPC PDAC patients, and 15 HRI from this cohort), enabling continuity of care for PDAC patients and at-risk relatives in one clinic.

Interventions to improve delivery of cancer genetics services in the United States: A scoping review

PURPOSE

Interventions that decrease barriers and improve clinical processes can increase patient access to guideline-recommended cancer genetics services. We sought to identify and describe interventions to improve patient receipt of guideline-recommended cancer genetics services in the United States.

METHODS

We performed a comprehensive search in Ovid MEDLINE and Embase, Scopus, and Web of Science from January 1, 2000 to February 12, 2020. Eligible articles reported interventions to improve the identification, referral, genetic counseling (GC), and genetic testing (GT) of patients in the United States. We independently screened titles and abstracts and reviewed full-text articles. Data were synthesized by grouping articles by clinical process.

RESULTS

Of 44 included articles, 17 targeted identification of eligible patients, 14 targeted referral, 15 targeted GC, and 16 targeted GT. Patient identification interventions included universal tumor testing and screening of medical/family history. Referral interventions included medical record system adaptations, standardizing processes, and provider notifications. GC interventions included supplemental patient education, integrated GC within oncology clinics, appointment coordination, and alternative service delivery models. One article directly targeted the GT process by implementing provider-coordinated testing.

CONCLUSION

This scoping review identified and described interventions to improve US patients' access to and receipt of guideline-recommended cancer genetics services.

Implementation of an Embedded In-Clinic Genetic Testing Station to Optimize Germline Testing for Patients with Pancreatic Adenocarcinoma

BACKGROUND

Germline genetic testing is universally recommended for patients with pancreatic cancer, but testing remains infrequent. In May 2018, we implemented a systematic patient intake workflow featuring an in-clinic genetic testing station (GTS) at the University of California San Francisco (UCSF) to expedite genetic counseling and facilitate sample collection. We sought to determine the impact of this innovation on rates of genetic counseling and testing.

METHODS

Medical records, patient intake records, and genetic test reports were retrospectively reviewed for new patients with pancreatic cancer eligible for germline testing at UCSF from May 2018 to May 2019. Primary outcomes included the rate of offered genetic counseling and confirmed germline testing. Data were compared for periods before and after GTS implementation. Associations between demographic characteristics and testing rates were assessed.

RESULTS

Genetic counseling/testing was offered to 209 (94%) of 223 eligible patients, and 158 (71%) completed testing (135 at UCSF, 23 elsewhere). Compared with a traditional referral-based genetic counseling model, confirmed testing increased from 19% to 71%, patient attrition between referral and genetics appointment decreased from 36% to 3%, and rate of pathogenic variant detection increased from 20% to 33%. Patients who were younger, identified as non-Hispanic White, and spoke English as a primary language were more likely to complete testing.

CONCLUSIONS

Implementation of a systematic patient intake workflow and in-clinic GTS resulted in the highest reported real-world rate of germline testing for patients with pancreatic cancer. Health care disparities were identified and will guide future innovation. This report provides a model for other centers to create a similar testing infrastructure.

IMPLICATIONS FOR PRACTICE

This study demonstrates that a systematic patient intake workflow and associated in-clinic genetic testing station improve delivery of genetic counseling and completion of germline testing for patients with pancreatic cancer. This study achieved, to the authors' knowledge, the highest real-world rate of confirmed genetic testing in this patient population. This article describes this innovation in detail to guide replication at other medical centers and facilitate guideline-concordant care for patients with pancreatic cancer. This infrastructure can also be applied to other cancers for which germline testing is recommended.

Significant detection of new germline pathogenic variants in Australian Pancreatic Cancer Screening Program participants

BACKGROUND

The Australian Pancreatic Cancer Screening Program (APCSP) offers endoscopic ultrasound surveillance for individuals at increased risk of pancreatic ductal adenocarcinoma (PDAC) with all participants requiring assessment by a Familial Cancer Service before or after study enrolment.

METHODS

Individuals aged 40-80 years (or 10 years younger than the earliest PDAC diagnosis) were eligible for APCSP study entry if they had 1) ≥ two blood relatives with PDAC (at least one of first-degree association); 2) a clinical or genetic diagnosis of Hereditary Pancreatitis or Peutz-Jeghers syndrome irrespective of PDAC family history; or 3) a known PDAC predisposition germline pathogenic variant (BRCA2, PALB2, CDKN2A, or Lynch syndrome) with ≥one PDAC-affected first- or second-degree relative. Retrospective medical record review was conducted for APCSP participants enrolled at the participating Australian hospitals from January 2011 to December 2019. We audited the genetic investigations offered by multiple Familial Cancer Services who assessed APCSP participants according to national guidelines, local clinical protocol and/or the availability of external research-funded testing, and the subsequent findings. Descriptive statistical analysis was performed using Microsoft Excel.

RESULTS

Of 189 kindreds (285 participants), 50 kindreds (71 participants) had a known germline pathogenic variant at enrolment (BRCA2 n = 35, PALB2 n = 6, CDKN2A n = 3, STK11 n = 3, PRSS1 n = 2, MLH1 n = 1). Forty-eight of 136 (35%) kindreds with no known germline pathogenic variant were offered mutation analysis; 89% was clinic-funded, with increasing self-funded testing since 2016. The relatively low rates of genetic testing performed reflects initial strict criteria for clinic-funded genetic testing. New germline pathogenic variants were detected in five kindreds (10.4%) after study enrolment (BRCA2 n = 3 kindreds, PALB2 n = 1, CDKN2A n = 1). Of note, only eight kindreds were reassessed by a Familial Cancer Service since enrolment, with a further 21 kindreds identified as being suitable for reassessment.

CONCLUSION

Germline pathogenic variants associated with PDAC were seen in 29.1% of our high-risk cohort (55/189 kindreds; 82/285 participants). Importantly, 10.4% of kindreds offered genetic testing were newly identified as having germline pathogenic variants, with majority being BRCA2. As genetic testing standards evolve rapidly in PDAC, 5-yearly reassessment of high-risk individuals by Familial Cancer Services is warranted.

Dilemma and Challenge of Immunotherapy for Pancreatic Cancer

Pancreatic cancer is a tumor with a high degree of malignancy, morbidity, and mortality. Immunotherapy is another important treatment for pancreatic cancer in addition to surgery and chemotherapy, but its application in pancreatic cancer is very limited, which is related to the unique biological behavior of pancreatic cancer and the tumor microenvironment. The immunosuppressive microenvironment of pancreatic cancer is highly heterogeneous and presents challenges for immunotherapy. The transformation of tumor immunosuppressive microenvironment contributes to the response to tumor immunotherapy, such that the tumor undergoes functional reprogramming to change from immunologically "cold" to immunologically "hot." In this review, we summarized the research and progress in immunotherapy for pancreatic cancer, including immune checkpoint inhibitors, vaccines, adoptive T cell therapy, oncolytic viruses, and immunomodulators, and suggest that individualized, combination, and precise therapy should be the main direction of future immunotherapy in pancreatic cancer.

Genetic evaluation of patients and families with concern for hereditary endocrine tumor syndromes

Hereditary endocrine tumor syndromes are rare conditions with overlapping features. It is imperative that healthcare providers differentiate between these syndromes for proper patient care. Advances in genetic testing technologies have increased utilization of genetic counseling and testing in this field; however, few endocrine cancer genetics clinics exist. Two years ago, a genetic counselor (GC) specializing in endocrine cancer genetics was added to the multidisciplinary team of the James Neuroendocrine/Thyroid Clinic at The Ohio State University. Here, we report on this experience. In total, 358 patients were seen. The majority were referred by medical oncology (n = 204; 57%) for a personal history of disease (n = 249; 81%). The most common referral indications were pancreatic neuroendocrine tumors (n = 44; 17%), multiple primary tumors (n = 37; 14%), and pheochromocytoma/paraganglioma (n = 35; 14%). Most patients completed genetic testing after genetic counseling (n = 200; 65%). Targeted gene panel testing was the most common testing ordered (n = 98; 32%). Thirty-one patients (15.5%) had ≥ one likely pathogenic variant (LPV) or pathogenic variant (PV) identified. Approximately 37% (n = 11) did not meet genetic testing guidelines for the gene they tested positive for. The most common genes with LPV/PVs were the SDH genes (n = 8) and MEN1 (n = 7). Referral indications with the highest likelihood of LPV/PVs were paraganglioma, medullary thyroid carcinoma, and multiple primary tumors. We believe this data can provide valuable guidance to healthcare providers who see patients with endocrine neoplasia or who are seeking to establish hereditary endocrine cancer clinics.

Burden of hereditary cancer susceptibility in unselected patients with pancreatic ductal adenocarcinoma referred for germline screening

BACKGROUND

Recent guidelines recommend consideration of germline testing for all newly diagnosed pancreatic ductal adenocarcinoma (PDAC). The primary aim of this study was to determine the burden of hereditary cancer susceptibility in PDAC. A secondary aim was to compare genetic testing uptake rates across different modes of genetic counselling.

PATIENTS AND METHODS

All patients diagnosed with PDAC in the province of British Columbia, Canada referred to a population-based hereditary cancer program were eligible for multi-gene panel testing, irrespective of cancer family history. Any healthcare provider or patients themselves could refer.

RESULTS

A total of 305 patients with PDAC were referred between July 2016 and January 2019. Two hundred thirty-five patients attended a consultation and 177 completed index germline genetic testing. 25/177 (14.1%) of unrelated patients had a pathogenic variant (PV); 19/25 PV were in known PDAC susceptibility genes with cancer screening or risk-reduction implications. PDAC was significantly associated with PV in ATM (OR, 7.73; 95% CI, 3.10 to 19.33, P = 6.14E-05) when comparing age and gender and ethnicity-matched controls tested on the same platform. The overall uptake rate for index testing was 59.2% and was significantly higher with 1-on-1 consultations and group consultations compared to telehealth consultations (88.9% vs 82.9% vs 61.8%, P < .001).

CONCLUSION

In a prospective clinic-based cohort of patients with PDAC referred for testing irrespective of family history, germline PV were detected in 14.1%. PV in ATM accounted for half of all PVs and were significantly associated with PDAC. These findings support recent guidelines and will guide future service planning in this population.