Point/Counterpoint: Is It Time for Universal Germline Genetic Testing for all GI Cancers?

Use of germline genetic testing among patients with cancer is increasing because of (1) the availability of multigene panel tests that include multiple cancer susceptibility genes in a single test, (2) decreased costs of these tests and improvements in insurance coverage, and (3) US Food and Drug Administration-approval of genotype-directed therapies such as poly(ADP-ribose) polymerase inhibitors for individuals with certain cancers and pathogenic germline variants in BRCA1 and BRCA2 (with possible benefits with other genes in the homologous repair deficiency pathway). In addition, National Comprehensive Cancer Network guidelines have already endorsed germline genetic testing for all patients with certain cancer types (epithelial ovarian cancer, exocrine pancreatic cancer, and high-grade/metastatic prostate cancer), regardless of age or personal/family history of cancer. Herein, we debate the pros and cons of offering germline multigene panel testing to all patients diagnosed with any GI cancer. The authors agree that it may just be a matter of time before germline multigene panel testing is offered to all patients with cancer; however, this article will highlight some of the benefits, risks, and limitations of this approach so that research can help fill some of the gaps to ensure that genetic medicine continues to be implemented in ways that improve real-world patient care and outcomes.

Identification and Management of Pathogenic Variants in BRCA1, BRCA2, and PALB2 in a Tumor-Only Genomic Testing Program

PURPOSE

Tumor-only genomic testing can uncover somatic and germline pathogenic variants (P/LPs) in cancer predisposition genes. We describe the prevalence of P/LPs in BRCA1/2 and PALB2 (B1B2P2) across malignancies and the frequency of clinical germline testing (CGT) in patients with P/LPs in B1B2P2 identified on tumor-only testing.

EXPERIMENTAL DESIGN

Among 7,575 patients tested between 2016-2018 with the OncoPanel tumor-only sequencing assay, we characterized P/LP frequencies by tumor type, receipt of CGT prior to or within 12 months (m) after OncoPanel, and factors associated with CGT.

RESULTS

272 (3.6%) had OncoPanel-detected P/LPs in B1B2P2: 37.5% of P/LPs were in BRCA-related cancers; the remainder were in non-BRCA tumors. P/LPs were detected in {greater than or equal to}5% of breast, pancreatic, prostate, ovarian, non-melanoma skin, endometrial, small-cell lung and colorectal cancers. 37.9% of patients with P/LPs received GCT prior to OncoPanel; an additional 10.7% underwent CGT within 12m of OncoPanel. Among 132 with CGT, 88.6% had {greater than or equal to}1 clinical factor for CGT compared to 47.1% who did not undergo CGT. Patients with BRCA-tumors were more likely to have CGT compared to those without (81.4% vs. 29.0%, p<0.0001). Among patients with CGT, 70.5% (93/132) of P/LPs were germline.

CONCLUSION

Tumor-only genomic testing identified P/LPs in B1B2P2 in 3.6% of patients. 52.9% of patients with tumor-detected P/LPs and without CGT did not meet personal or family history criteria for CGT. Additionally, some patients with tumor-detected P/LPs were not referred for CGT, especially those with non-BRCA tumors. Given implications for treatment selection and familial cancer risk, processes to reliably trigger CGT from tumor-genomic findings are needed.

Cetuximab and Irinotecan With or Without Bevacizumab in Refractory Metastatic Colorectal Cancer: BOND-3, an ACCRU Network Randomized Clinical Trial

Background

Combination irinotecan and cetuximab is approved for irinotecan-refractory metastatic colorectal cancer (mCRC). It is unknown if adding bevacizumab improves outcomes.

Patients and Methods

In this multicenter, randomized, double-blind, placebo-controlled phase II trial, patients with irinotecan-refractory RAS-wildtype mCRC and no prior anti-EGFR therapy were randomized to cetuximab 500 mg/m², bevacizumab 5 mg/kg, and irinotecan 180 mg/m² (or previously tolerated dose) (CBI) versus cetuximab, irinotecan, and placebo (CI) every 2 weeks until disease progression or intolerable toxicity. The primary endpoint was progression-free survival (PFS). Secondary endpoints included overall survival (OS), objective response rate (ORR), and adverse events (AEs).

Results

The study closed early after the accrual of 36 out of a planned 120 patients due to changes in funding. Nineteen patients were randomized to CBI and 17 to CI. Baseline characteristics were similar between arms. Median PFS was 9.7 versus 5.5 months for CBI and CI, respectively (1-sided log-rank P = .38; adjusted hazard ratio [HR] = 0.64; 95% confidence interval [CI], 0.25-1.66). Median OS was 19.7 versus 10.2 months for CBI and CI (1-sided log-rank P = .02; adjusted HR = 0.41; 95% CI, 0.15-1.09). ORR was 36.8% for CBI versus 11.8% for CI (P = .13). Grade 3 or higher AEs occurred in 47% of patients receiving CBI versus 35% for CI (P = .46).

Conclusion

In this prematurely discontinued trial, there was no significant difference in the primary endpoint of PFS between CBI and CI. There was a statistically significant improvement in OS in favor of CBI compared with CI. Further investigation of CBI for the treatment of irinotecan-refractory mCRC is warranted.

Clinical Trial Registration: NCT02292758

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

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

Clinical Implications of Pathogenic Germline Variants in Small Intestine Neuroendocrine Tumors (SI-NETs)

PURPOSE

An inherited basis for presumed sporadic neuroendocrine tumor (NET) has been suggested by evidence of familial clustering of NET and a higher incidence of second malignancies in patients and families with NET. To further investigate a potential heritable basis for sporadic neuroendocrine tumors, we performed multigene platform germline analysis to determine the frequency of hereditary susceptibility gene variants in a cohort of patients with sporadic small intestine NET (SI-NET).

METHODS

We performed a multigene platform germline analysis with Invitae's 83-gene, next-generation sequencing panel using DNA from 88 individuals with SI-NET from a clinically annotated database of patients with NET evaluated at Dana-Farber Cancer Institute (DFCI) who are considered high risk for inherited variants. Additionally, we evaluated the prevalence of pathogenic variants in an unselected cohort of patients with SI-NET who underwent testing with Invitae.

RESULTS

Of the 88 patients in the DFCI cohort, a pathogenic germline variant was identified in eight (9%) patients. In an independent cohort of 120 patients with SI-NET, a pathogenic germline variant was identified in 13 (11%) patients. Pathogenic variants were identified in more than one patient in the following genes: ATM, RAD51C, MUTYH, and BLM. Somatic testing of tumors from the DFCI cohort was suboptimal because of insufficient coverage of all targeted exons, and therefore, analysis was limited.

CONCLUSION

We demonstrate a 9%-11% incidence of pathogenic germline variants in genes associated with inherited susceptibility for malignancy not previously described in association with SI-NET. The association of these germline variants with neuroendocrine carcinogenesis and risk is uncertain but warrants further characterization.

Lynch Syndrome-Associated Cancers Beyond Colorectal Cancer

Lynch syndrome (LS) is a common form of inherited cancer susceptibility, which predisposes to colorectal cancer (CRC) along with a wide array of other extracolonic malignancies, including other gastrointestinal cancers, cancers of the gynecologic and genitourinary tracts, and other organ sites. Recent data have provided novel insights into patient-specific factors that can help clinicians understand an individual LS carrier's risk of extracolonic cancers, including sex, specific LS gene, age, family history of cancer, and other factors. This summary seeks to provide an update on extracolonic cancer risks in LS and provide recommendations for surveillance and risk reduction.

A Case of Microsatellite Instability-High Colon Cancer in a Young Woman With Familial Adenomatous Polyposis

Two major molecular pathways of colorectal carcinogenesis, chromosomal instability (CIN) and microsatellite instability (MSI), are considered to be mutually exclusive. Distinguishing CIN from MSI-high tumors has considerable therapeutic implications, because patients with MSI-high tumors can derive considerable benefit from immune checkpoint inhibitors, and tumors that evolved through the CIN pathway do not respond to these agents. Familial adenomatous polyposis (FAP) is a genetic syndrome that is defined by a mutation in the APC gene and is thought to lead to carcinogenesis through the CIN pathway. Here, we report a case of a young woman with FAP who was treated for medulloblastoma as a child and developed advanced MSI-high colon cancer as a young adult. Her response to second-line immunotherapy enabled resection of her colon cancer, and she is free of disease >10 months after surgery. This case highlights the potential for overlap between the CIN and MSI carcinogenic pathways and associated therapeutic implications.

Durable clinical benefit from PARP inhibition in a platinum-sensitive, BRCA2-mutated pancreatic cancer patient after earlier progression on placebo treatment on the POLO trial: a case report

Metastatic pancreatic adenocarcinoma is a deadly malignancy with limited treatment options. Based on the results of the phase 3 POLO trial, the PARP inhibitor olaparib was approved by the Food and Drug Administration as a maintenance therapy in germline BRCA1- and BRCA2-mutated metastatic pancreatic cancer patients whose cancers had not progressed on first-line platinum-based chemotherapy. While this approval was a step forward, there have been criticisms of the POLO study leaving doubts in the field about the effectiveness of PARP inhibition in pancreatic cancer. Here, we describe a patient with a germline BRCA2-mutated, metastatic pancreatic cancer who was randomized to the placebo-arm of the POLO trial. After progressing on the placebo-arm of the POLO study, her cancer again responded to platinum-based chemotherapy and has since been successfully treated for 4 years with off-protocol maintenance olaparib. The presence of placebo treatment in this case serves as an internal control demonstrating the efficacy of PARP inhibition in this patient. This case highlights the potential of PARP inhibitor maintenance therapy in appropriately selected metastatic pancreatic cancer patients.

Abstract PO-013: Comparison of novel healthcare delivery models on the uptake of genetic education and testing in families with a history of pancreatic cancer: The GENetic Education, Risk Assessment and TEsting (GENERATE) study

Background: Roughly 7–10% of patients with pancreatic ductal adenocarcinoma (PDAC) have a deleterious germline variant. Although identification of germline variants in family members has implications for cancer surveillance and can lead to early cancer detection and interception for PDAC, as well as other cancers, cascade genetic testing rates are low. The GENetic Education, Risk Assessment and TEsting (GENERATE) study evaluates novel methods of providing genetic education and testing for individuals at risk for hereditary PDAC. Methods: Eligible participants had: (1) a first- or second-degree relative with a diagnosis of PDAC and a known familial germline variant in APC, ATM, BRCA1, BRCA2, CDKN2A, EPCAM, MLH1, MSH2, MSH6, PALB2, PMS2, STK11, or TP53 (Known Familial Mutation (KFM)), (2) or were first-degree relatives of PDAC patients (no KFM). Participants were recruited through six academic centers, patient advocacy organizations and online outreach. Enrollment occurred through the study website (www.GENERATEstudy.org). All study participation, including genetic testing via a at home saliva sample kit, was done remotely. Participants were cluster randomized at the family level into one of two arms. Arm 1 (Doxy.me plus Color Genomics) included remote genetic education and testing through a video-based telemedicine platform (Doxy.me) and physician-mediated testing through Color Genomics. Arm 2 included remote genetic education and testing through Color Genomics only. Results: Between 5/8/2019–6/01/2021, 423 families were randomized, comprising 595 participants. Recruitment occurred through patient invitation via healthcare providers (n=128, 21.5%), family members (n=271, 45.5%), friends, advocacy groups, and online outreach (n=223, 37.5%). Participants were referred from the six GENERATE academic centers (n=270, 45.4%) and other institutions (n=325, 54.6%). Study participants were 52.5 years on average, primarily identified as White (n=577, 97%) and from the Northeast (n=184, 30.9%), Midwest (n=154, 25.9%), South (n=158, 26.6%) and West (n=99, 16.6%). Participants were randomized into each arm (n=296 Doxy.me plus Color Genomics; n=299 Color Genomics only). To date, 527 (88.6%) participants have ordered genetic testing. The uptake of genetic testing was 253/296 (85.5%) in the Doxy.me plus Color Genomics arm and 274/299 (91.6%) in the Color Genomics only arm (p=0.049, generalized mixed-effects model). A total of 82 PDAC associated pathogenic variants were identified. The most frequently detected variants were BRCA2 (n=32), ATM (n=25) and PALB2 (n=6). Additionally, 13 non-PDAC associated pathogenic variants and 20 low penetrance variants were detected. Conclusions: Remote methods of genetic education and testing are successful alternatives to traditional cascade testing, with genetic testing rates nearly 90%. Participant follow up will assess if satisfaction with decision making, cancer-risk distress, knowledge gained, family communication, and uptake of surveillance were impacted by the mode of delivery of pre-test genetic education.

Citation Format: Nicolette J. Rodriguez, Constance S. Furniss, Matthew B. Yurgelun, Chinedu Ukaegbu, Pamela E. Constantinou, Alison N. Schwartz, Jill Stopfer, Meghan Underhill-Blazey, Barbara Kenner, Scott Nelson, Sydney Okumura, Sherman Law, Alicia Y. Zhou, Tara B. Coffin, Hajime Uno, Allyson Ocean, Florencia McAllister, Andrew M. Lowy, Scott M. Lippman, Alison P. Klein, Lisa Madlensky, Gloria M. Petersen, Judy E. Garber, Michael G. Goggins, Anirban Maitra, Sapna Syngal. Comparison of novel healthcare delivery models on the uptake of genetic education and testing in families with a history of pancreatic cancer: The GENetic Education, Risk Assessment and TEsting (GENERATE) study [abstract]. In: Proceedings of the AACR Virtual Special Conference on Pancreatic Cancer; 2021 Sep 29-30. Philadelphia (PA): AACR; Cancer Res 2021;81(22 Suppl):Abstract nr PO-013.

Novel Models of Genetic Education and Testing for Pancreatic Cancer Interception: Preliminary Results from the GENERATE Study

Up to 10% of patients with pancreatic ductal adenocarcinoma (PDAC) carry underlying germline pathogenic variants in cancer susceptibility genes. The GENetic Education Risk Assessment and TEsting (GENERATE) study aimed to evaluate novel methods of genetic education and testing in relatives of patients with PDAC. Eligible individuals had a family history of PDAC and a relative with a germline pathogenic variant in APC, ATM, BRCA1, BRCA2, CDKN2A, EPCAM, MLH1, MSH2, MSH6, PALB2, PMS2, STK11, or TP53 genes. Participants were recruited at six academic cancer centers and through social media campaigns and patient advocacy efforts. Enrollment occurred via the study website (https://GENERATEstudy.org) and all participation, including collecting a saliva sample for genetic testing, could be done from home. Participants were randomized to one of two remote methods that delivered genetic education about the risks of inherited PDAC and strategies for surveillance. The primary outcome of the study was uptake of genetic testing. From 5/8/2019 to 5/6/2020, 49 participants were randomized to each of the intervention arms. Overall, 90 of 98 (92%) of randomized participants completed genetic testing. The most frequently detected pathogenic variants included those in BRCA2 (N = 15, 17%), ATM (N = 11, 12%), and CDKN2A (N = 4, 4%). Participation in the study remained steady throughout the onset of the Coronavirus disease (COVID-19) pandemic. Preliminary data from the GENERATE study indicate success of remote alternatives to traditional cascade testing, with genetic testing rates over 90% and a high rate of identification of germline pathogenic variant carriers who would be ideal candidates for PDAC interception approaches. PREVENTION RELEVANCE: Preliminary data from the GENERATE study indicate success of remote alternatives for pancreatic cancer genetic testing and education, with genetic testing uptake rates over 90% and a high rate of identification of germline pathogenic variant carriers who would be ideal candidates for pancreatic cancer interception.

NCCN Guidelines® Insights: Genetic/Familial High-Risk Assessment: Colorectal, Version 1.2021

Identifying individuals with hereditary syndromes allows for timely cancer surveillance, opportunities for risk reduction, and syndrome-specific management. Establishing criteria for hereditary cancer risk assessment allows for the identification of individuals who are carriers of pathogenic genetic variants. The NCCN Guidelines for Genetic/Familial High-Risk Assessment: Colorectal provides recommendations for the assessment and management of patients at risk for or diagnosed with high-risk colorectal cancer syndromes. The NCCN Genetic/Familial High-Risk Assessment: Colorectal panel meets annually to evaluate and update their recommendations based on their clinical expertise and new scientific data. These NCCN Guidelines Insights focus on familial adenomatous polyposis (FAP)/attenuated familial adenomatous polyposis (AFAP) syndrome and considerations for management of duodenal neoplasia.

Familial Burden and Other Clinical Factors Associated With Various Types of Cancer in Individuals With Lynch Syndrome

BACKGROUND & AIMS

Lynch syndrome (LS) is associated with increased risks of various gastrointestinal, gynecologic, genitourinary, and other cancers. Many clinical practice guidelines recommend that LS carriers' screening strategies be devised based on their family history of various cancers, in addition to age-, sex-, and gene-specific considerations. The aim of this study was to examine the association between family history and other clinical factors with LS carriers' histories of various cancers.

METHODS

Two cohorts of LS carriers were analyzed: a laboratory-based cohort of consecutively ascertained individuals undergoing germline LS testing and a clinic-based cohort of LS carriers undergoing clinical care at an academic medical center. Multivariable logistic regression was performed to assess clinical factors associated with LS carriers' histories of various cancers/neoplasms. Familial burden was defined as LS carriers' aggregate number of first-/second-degree relatives with a history of a given malignancy.

RESULTS

Multivariable analysis of the laboratory-based cohort (3828 LS carriers) identified familial burden as being incrementally associated with LS carriers' personal history of endometrial (odds ratio [OR], 1.37 per affected first-/second-degree relative; 95% confidence interval [CI], 1.21-1.56), urinary tract (OR, 2.72; 95% CI, 2.02-3.67), small bowel (OR, 3.17; 95% CI, 1.65-6.12), gastric (OR, 1.93; 95% CI, 1.24-3.02), and pancreaticobiliary cancers (OR, 2.10; 95% CI, 1.21-3.65) and sebaceous neoplasms (OR, 7.39; 95% CI, 2.71-20.15). Multivariable analysis of the clinic-based cohort (607 LS carriers) confirmed a significant association of familial burden of endometrial and urinary tract cancers.

CONCLUSIONS

Familial burden - in addition to age, sex, and specific LS gene - should be used to assess LS carriers' risks of specific cancers and guide decision-making about organ-specific surveillance.

A Case-Based Approach to Understanding Complex Genetic Information in an Evolving Landscape

The rapid integration of highly sensitive next-generation sequencing technologies into clinical oncology care has led to unparalleled progress, and yet these technological advances have also made genetic information considerably more complex. For instance, accurate interpretation of genetic testing for germline/inherited cancer predisposition syndromes and somatic/acquired pathogenic variants now requires a more nuanced understanding of the presence and incidence of clonal hematopoiesis and circulating tumor cells, with careful evaluation of pathogenic variants occurring at low variant allele frequency required. The interplay between somatic and germline pathogenic variants and awareness of distinct genotype-phenotype manifestations in various inherited cancer syndromes are now increasingly appreciated and can impact patient management. Through a case-based approach, we focus on three areas of particular relevance to the treating clinician oncologist: (1) understanding clonal hematopoiesis and somatic mosaicism, which can be detected on germline sequencing and lead to considerable confusion in clinical interpretation; (2) implications of the detection of a potentially germline pathogenic variant in a high-penetrance cancer susceptibility gene during routine tumor testing; and (3) a review of gene-specific risks and surveillance recommendations in Lynch syndrome. A discussion on the availability and difficulties often associated with direct-to-consumer genetic testing is also provided.

Collaborative Group of the Americas on Inherited Gastrointestinal Cancer Position statement on multigene panel testing for patients with colorectal cancer and/or polyposis

Multigene panel tests for hereditary cancer syndromes are increasingly utilized in the care of colorectal cancer (CRC) and polyposis patients. However, widespread availability of panels raises a number of questions including which patients should undergo testing, which genes should be included on panels, and the settings in which panels should be ordered and interpreted. To address this knowledge gap, key questions regarding the major issues encountered in clinical evaluation of hereditary CRC and polyposis were designed by the Collaborative Group of the Americas on Inherited Gastrointestinal Cancer Position Statement Committee and leadership. A literature search was conducted to address these questions. Recommendations were based on the best available evidence and expert opinion. This position statement addresses which genes should be included on a multigene panel for a patient with a suspected hereditary CRC or polyposis syndrome, proposes updated genetic testing criteria, discusses testing approaches for patients with mismatch repair proficient or deficient CRC, and outlines the essential elements for ordering and disclosing multigene panel test results. We acknowledge that critical gaps in access, insurance coverage, resources, and education remain barriers to high-quality, equitable care for individuals and their families at increased risk of hereditary CRC.

Characterizing germline APC and MUTYH variants in Ashkenazi Jews compared to other individuals

Germline variants in the APC and MUTYH genes contribute to colorectal cancer (CRC) and adenoma risk, though may occur with varying frequencies in individuals of different ancestries. The aim of this study was to evaluate the prevalence of APC, monoallelic MUTYH and biallelic MUTYH germline variants in Ashkenazi Jewish (AJ) and Other Ancestry (OA) individuals with colorectal adenomas. We studied 7225 individuals with colorectal adenomas who had germline APC and MUTYH testing at a commercial laboratory. Cross-sectional medical history data were extracted from provider-completed test requisition forms. We performed bivariate analysis to compare the frequency of APC and MUTYH variants between AJ and OA, and examined APC p.I1307K and monoallelic MUTYH carrier phenotypes using logistic regression. Pathogenic APC variants occurred in 38/285 AJ (13%) and 1342/6940 OA (19%; P = 0.09); biallelic MUTYH variants in 2/285 (1%) AJ and 399/6940 (6%) OA (P < 0.0001); APC p.I1307K in 35/285 (12%) AJ and 29/6940 (1%) OA (P < 0.0001); and monoallelic MUTYH in 2/285 (1%) AJ and 133/6940 (2%) OA (P = 0.06). Monoallelic MUTYH variants were significantly associated with having a personal history of CRC, regardless of ancestry (OR 1.78; 95% CI 1.21-2.49; P < 0.01), but no significant association was found between APC p.I1307K variants and personal history of CRC (OR 1.38; 95% CI 0.79-2.44; P = 0.26). Ashkenazim with colorectal adenomas rarely have monoallelic or biallelic MUTYH variants, suggesting different genetic etiologies for polyposis in AJ compared to OA individuals. AJ ancestry assessment may be important in clinical evaluation for polyposis.

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.

Genetic/Familial High-Risk Assessment: Breast, Ovarian, and Pancreatic, Version 2.2021, NCCN Clinical Practice Guidelines in Oncology

The NCCN Guidelines for Genetic/Familial High-Risk Assessment: Breast, Ovarian, and Pancreatic focus primarily on assessment of pathogenic or likely pathogenic variants associated with increased risk of breast, ovarian, and pancreatic cancer and recommended approaches to genetic testing/counseling and management strategies in individuals with these pathogenic or likely pathogenic variants. This manuscript focuses on cancer risk and risk management for BRCA-related breast/ovarian cancer syndrome and Li-Fraumeni syndrome. Carriers of a BRCA1/2 pathogenic or likely pathogenic variant have an excessive risk for both breast and ovarian cancer that warrants consideration of more intensive screening and preventive strategies. There is also evidence that risks of prostate cancer and pancreatic cancer are elevated in these carriers. Li-Fraumeni syndrome is a highly penetrant cancer syndrome associated with a high lifetime risk for cancer, including soft tissue sarcomas, osteosarcomas, premenopausal breast cancer, colon cancer, gastric cancer, adrenocortical carcinoma, and brain tumors.

Comparison of Colorectal and Endometrial Microsatellite Instability Tumor Analysis and Premm5 Risk Assessment for Predicting Pathogenic Germline Variants on Multigene Panel Testing

PURPOSE

Tumor testing for microsatellite instability and/or mismatch repair-deficiency (MSI/IHC) and clinical prediction models effectively screen for Lynch syndrome (LS)-associated colorectal cancer (CRC) and endometrial cancer (EC), but they have not been assessed for their ability to identify non-LS forms of inherited risk. The aim of this study was to compare MSI/IHC and the PREMM5 prediction model to identify carriers of LS and non-LS pathogenic variants (PVs) among patients with CRC and EC.

PATIENTS AND METHODS

Data were retrospectively analyzed from two single-institution cohorts: 706 patients with CRC and/or EC referred for genetic evaluation/testing (high-risk cohort) and 1,058 consecutively ascertained patients with CRC (oncology clinic cohort), unselected for familial risk. All participants underwent germline multigene panel testing. PREMM5 scores were calculated from personal/family cancer history. The primary outcome was the proportion of individuals with germline PVs (LS PVs, high-penetrance PVs, and any PVs) who had abnormal MSI/IHC testing and/or PREMM5 score ≥ 2.5%.

RESULTS

MSI/IHC and PREMM5 had comparable sensitivity for identifying LS carriers in high-risk (89.3% v 85.7%; P = .712) and oncology clinic patients (96.6% v 96.6%; P = 1.000), although MSI/IHC had significantly superior specificity for LS (81.3% v 20.1%; P < .001; 92.3% v 24.3%; P < .001). In both cohorts, PREMM5 had superior sensitivity to MSI/IHC at identifying patients with any high-penetrance PVs and any low-, moderate-, and high-penetrance PVs. Among patients with normal MSI/IHC, PREMM5 identified 84.2% and 83.3% of high-risk patients with CRC/EC and oncology clinic CRC patients with high-penetrance PVs, respectively.

CONCLUSION

MSI/IHC and PREMM5 effectively identify patients with CRC and/or EC with LS, although MSI/IHC has better specificity for LS. Because PREMM5 identifies non-LS, high-penetrance germline PVs, patients with CRC and/or EC with PREMM5 score ≥ 2.5%, including those with normal MSI/IHC, should be offered multigene panel testing.

Effect of High-Dose vs Standard-Dose Vitamin D3 Supplementation on Body Composition among Patients with Advanced or Metastatic Colorectal Cancer: A Randomized Trial

Simple Summary

Skeletal muscle and adipose tissue express the vitamin D receptor and may be a mechanism through which vitamin D supplementation slows cancer progression and reduces cancer death. It is unknown if high-dose vitamin D₃ impacts skeletal muscle and adipose tissue, as compared with standard-dose vitamin D₃, in patients with advanced or metastatic colorectal cancer. In this exploratory analysis of a phase II randomized trial, high-dose vitamin D₃ did not lead to changes of body weight, body mass index, muscle area, muscle attenuation, visceral adipose tissue area, or subcutaneous adipose tissue area, as compared with standard-dose vitamin D₃. High-dose vitamin D₃ did not change body composition in patients receiving chemotherapy for advanced or metastatic colorectal cancer.

Abstract

Skeletal muscle and adipose tissue express the vitamin D receptor and may be a mechanism through which vitamin D supplementation slows cancer progression and reduces cancer death. In this exploratory analysis of a double-blind, multicenter, randomized phase II clinical trial, 105 patients with advanced or metastatic colorectal cancer who were receiving chemotherapy were randomized to either high-dose vitamin D₃ (4000 IU) or standard-dose (400 IU) vitamin D₃. Body composition was measured with abdominal computed tomography at enrollment (baseline) and after cycle 8 of chemotherapy (16 weeks). As compared with standard-dose vitamin D₃, high-dose vitamin D₃ did not significantly change body weight [−0.7 kg; (95% CI: −3.5, 2.0)], body mass index [−0.2 kg/m²; (95% CI: −1.2, 0.7)], muscle area [−1.7 cm²; (95% CI: −9.6, 6.3)], muscle attenuation [−0.4 HU; (95% CI: −4.2, 3.2)], visceral adipose tissue area [−7.5 cm²; (95% CI: −24.5, 9.6)], or subcutaneous adipose tissue area [−8.3 cm²; (95% CI: −35.5, 18.9)] over the first 8 cycles of chemotherapy. Among patients with advanced or metastatic colorectal cancer, the addition of high-dose vitamin D₃, vs standard-dose vitamin D₃, to standard chemotherapy did not result in any changes in body composition.