Universal tumor screening in a population with MSH6- and PMS2-associated Lynch syndrome.

PURPOSE: Universal screening for Lynch syndrome (LS) on resected colorectal carcinomas (CRCs) and endometrial carcinomas (ECs) was implemented in Iceland in 2017 using immunohistochemistry (IHC) for mismatch repair (MMR) proteins. We examined the efficacy of the universal screening algorithm to detect LS and the diagnostic accuracy of MMR IHC by comparing results with a population-based genotype database. METHODS: All patients diagnosed with CRC or EC per the Icelandic Cancer Registry from 2017 to 2019 who had tumor MMR IHC performed were included. Pathology reports and patient charts were reviewed. MMR IHC stains were crossmatched with genotyping results obtained from the deCODE database. RESULTS: IHC staining was done on 404 patients with CRC and 74 patients with EC. A total of 61 (15.1%) patients with CRC and 15 (20.3%) patients with EC were MMR-deficient. MMR IHC had 88.9% sensitivity in identifying patients with LS and a positive predictive value of 10.7%. Only 50% of individuals were appropriately referred for genetic testing, leading to underdiagnosis of LS. CONCLUSION: Universal screening for LS using MMR protein IHC in CRC and EC accurately identified patients appropriate for genetic testing in a population with MSH6 and PMS2 LS predominance. Because of lack of referral to genetic counseling, only 50% of patients with LS were identified through the screening algorithm.

Mismatch Repair (MMR) Gene Alteration and BRAF V600E Mutation Are Potential Predictive Biomarkers of Immune Checkpoint Inhibitors in MMR-Deficient Colorectal Cancer.

BACKGROUND: Immune checkpoint inhibitor (ICI) therapy is highly effective in metastatic mismatch repair-deficient (MMR-D) colorectal cancer (CRC). In this study, we evaluated molecular and clinical predictors of ICI response in MMR-D CRC. MATERIALS AND METHODS: Patient databases at four cancer institutions were queried. The Fisher exact test was performed to test the association of clinical and molecular markers. The Kaplan-Meier method was used to estimate progression-free survival (PFS) and compared by the log-rank test. Twelve- and 24-month PFS rates were compared by the Z test. RESULTS: A total of 60 patients with CRC with MMR-D/microsatellite instability-high who previously received ICIs were identified. Patients with liver metastasis had a lower overall response rate as compared with other sites of metastasis (36.4% vs. 68.7%; p = .081). Patients with MLH1/PMS2 loss had worse 1-year and 2-year PFS rates compared with patients with MSH2/MSH6 loss (84.2% vs. 57.8% and 78.2% vs. 54.2%, respectively; p < .001). There were improved 1-year and 2-year PFS rates in patients with wild-type BRAF when compared with patients with BRAF V600E mutation (73.3% vs. 40%, and 73.3% vs. 26.7%; respectively; p < .001). Patients aged >65 had significantly worse PFS rates as compared with patients aged ≤65 (p < .001). CONCLUSION: BRAF V600E mutation, MLH1 and/or PMS2 loss, as well as age >65 years and liver metastasis, may be predictive of duration of ICI response in patients with MMR-D CRC. Larger cohorts are needed to confirm our findings. IMPLICATIONS FOR PRACTICE: The results of this study reveal clinically important biomarkers that potentially predict immune checkpoint inhibitor response in patients with mismatch repair-deficient colorectal cancer.

Immune-Related Adverse Events and Immune Checkpoint Inhibitor Efficacy in Patients with Gastrointestinal Cancer with Food and Drug Administration-Approved Indications for Immunotherapy.

INTRODUCTION: Immune-related adverse event (IRAE) onset may represent a clinical biomarker for anti-programmed cell death protein 1 (PD-1) antibody response based on emerging evidence from patients with various advanced malignancies. This phenomenon has not been previously reported in a multidisease cohort of patients with gastrointestinal (GI) cancer with Food and Drug Administration (FDA)-approved indications to receive immune checkpoint inhibitor therapy. MATERIALS AND METHODS: The study was a multicenter retrospective cohort analysis of 76 patients with GI cancer who had received anti-PD-1 antibodies for FDA-approved indications. The primary and secondary outcomes of the study were progression-free survival (PFS) and overall survival (OS) in patients based upon IRAE presence, respectively. PFS and OS were estimated by the Kaplan-Meier method; a Cox proportional-hazards model adjusted for IRAE onset, patient age, and enrolling institution was used to analyze outcomes. RESULTS: Median PFS and OS were prolonged in patients who experienced IRAEs compared with those who did not experience them (PFS: not reached [NR] vs. 3.9 months [hazard ratio (HR) 0.13, 95% confidence interval (CI) 0.05-0.3, p < .001]; OS: NR vs. 7.4 months [HR 0.11, 95% CI 0.03-0.36, p < .001]). Among patients who experienced IRAEs, there were no significant differences in PFS and OS by either initial IRAE severity, management, or time to onset. CONCLUSION: Patients with gastrointestinal cancer who experienced IRAEs while on anti-PD-1 antibodies demonstrated significant improvements in PFS and OS compared with their counterparts who did not develop IRAEs. Although these findings add to results from studies in other tumor types, larger prospective studies are needed prior to clinical adoption of IRAE onset as a biomarker for immune checkpoint inhibitor response. IMPLICATIONS FOR PRACTICE: Predictive clinical biomarkers for immune checkpoint inhibitor response have been understudied in the field of immuno-oncology. Immune-related adverse event onset appears to be one such biomarker. Across tumor types, immune-related adverse event onset has been associated with response to anti-programmed cell death protein 1 (PD-1) antibodies. The results of this study demonstrate this for the first time in patients with gastrointestinal cancer receiving anti-PD-1 antibodies. Before immune-related adverse event onset can be adopted clinically as a predictive biomarker for immune checkpoint inhibitor response, however, larger prospective studies are needed to better understand the nuances between immune-related adverse event characteristics (severity, site, management, timing of onset) and immune checkpoint inhibitor effectiveness.

Clinical characteristics of patients with colorectal cancer with double somatic mismatch repair mutations compared with Lynch syndrome.

BACKGROUND: Patients with colorectal cancer (CRC) with mismatch repair-deficient (dMMR) tumours without MLH1 methylation or germline MMR pathogenic variants (PV) were previously thought to have Lynch syndrome (LS). It is now appreciated that they can have double somatic (DS) MMR PVs. We explored the clinical characteristics between patients with DS tumours and LS in two population-based cohorts. METHODS: We included patients with CRC from Ohio 2013-2016 and Iceland 2000-2009. All had microsatellite instability testing and/or immunohistochemistry (IHC) of MMR proteins, and MLH1 methylation testing when indicated. Germline next-generation sequencing was performed for all with dMMR tumours; tumour sequencing followed for patients with unexplained dMMR. Clinical characteristics of DS patients and patients with LS were compared. RESULTS: Of the 232 and 51 patients with non-methylated dMMR tumours in the Ohio and Iceland cohorts, respectively, 57.8% (n=134) and 45.1% (n=23) had LS, 32.8% (n=76) and 31.4% (n=16) had DS PVs, 6% (n=14) and 9.8% (n=5) were unexplained and 4.3% (n=10) and 13.7% (n=7) had incorrect IHC. Age of diagnosis for DS patients was older than patients with LS (p=3.73×10-4) in the two cohorts. Patients with LS were more likely to meet Amsterdam II criteria (OR=15.81, p=8.47×10-6) and have multiple LS-associated tumours (OR=6.67, p=3.31×10-5). Absence of MLH1/PMS2 was predictive of DS PVs; isolated MSH6 and PMS2 absence was predictive of LS in both cohorts. CONCLUSIONS: Individuals with LS are 15× more likely to meet Amsterdam II criteria and >5× more likely to have multiple cancers as compared with those with DS tumours. Furthermore, isolated loss of MSH6 or PMS2 protein predicts LS.

NCCN Guidelines Insights: Genetic/Familial High-Risk Assessment: Colorectal, Version 2.2019.

Identifying individuals with hereditary syndromes allows for improved cancer surveillance, risk reduction, and optimized management. Establishing criteria for assessment allows for the identification of individuals who are carriers of pathogenic genetic variants. The NCCN Guidelines for Genetic/Familial High-Risk Assessment: Colorectal provide recommendations for the assessment and management of patients with high-risk colorectal cancer syndromes. These NCCN Guidelines Insights focus on criteria for the evaluation of Lynch syndrome and considerations for use of multigene testing in the assessment of hereditary colorectal cancer syndromes.

Tumor Molecular Testing Guides Anti-PD-1 Therapy and Provides Evidence for Pathogenicity of Mismatch Repair Variants.

Lynch syndrome is characterized by germline abnormalities in mismatch repair (MMR) genes, leading to predisposition to multiple cancers [1]. A second hit to the unaffected allele is required for tumorigenesis. MMR proteins repair incorrectly paired nucleotides and prevent generation of insertions and deletions at microsatellites [2]. Aberrancies in these MMR proteins can be a result of germline mutations or somatic alterations. Defective MMR results in microsatellite instability (MSI) and a high mutational burden [3].The clinical implications of MSI are becoming readily apparent, as presence of MSI leads to the generation of neoantigens, stimulating tumor-associated lymphocytes [4], [5]. This has led to the use of programmed cell death protein 1 blockade for MMR-deficient tumors [6]. The U.S. Food and Drug Administration recently approved pembrolizumab for any advanced solid tumor demonstrating MSI and nivolumab for metastatic MSI colorectal cancer. However, the clinical significance of numerous MMR gene variants remains uncertain. The International Society for Gastrointestinal Hereditary Tumors classification system categorizes 2,360 MMR variants, which can be used to gauge pathogenicity [7]. There are many variants of uncertain significance (VUS; or class 3) for which clinicians are unable to provide recommendations. In this study, we employed the combination of germline testing and tumor mutational assessment to help discern the clinical relevance of VUS and guide immunotherapeutic decisions. KEY POINTS: A clinical dilemma arises when genomic testing yields variants of uncertain significance (VUS).Germline VUS were identified in two patients with gastrointestinal malignancies, but only one patient had a second-hit mutation in a mismatch repair gene leading to mismatch repair deficiency that conferred response to immunotherapy.The combination of germline testing along with tumor mutational assessment can help discern the clinical relevance of VUS and can help guide therapeutic decision-making toward individualized patient care.

Targeting BRAF Mutations in High-Grade Neuroendocrine Carcinoma of the Colon.

Mutations in the RAS/RAF/MEK/ERK pathway leading to constitutive activation and uncontrolled cellular growth have been identified in various human malignancies, making this pathway a target for potential therapeutics. The activating BRAFV600E mutation is one well-characterized oncogenic mutation that has been described and targeted with clinical success in various malignancies, including melanoma and hairy cell leukemia. Although BRAF-directed treatments have yielded clinical benefit in a subset of tumor types, such as melanoma, thyroid cancer, and lung cancer, BRAF inhibition fails to confer a clinical benefit in colon cancer. Identification of patients for whom BRAF inhibition may produce clinically meaningful outcomes is imperative. The incidence of BRAF mutations in neuroendocrine carcinoma (NEC) is estimated to be 5% to 10%. A recent case series demonstrated benefit in targeting the BRAFV600E mutation in metastatic high-grade rectal NECs. Combination BRAF and MEK inhibition is known to yield improved outcomes compared with BRAF inhibition alone in melanoma. This report presents 2 patients with high-grade colorectal NECs who had different responses to treatment with combined BRAF/MEK inhibition after experiencing disease progression through first-line platinum-based chemotherapy. One patient experienced an excellent initial response to therapy before ultimately experiencing progression, and in the other patient initially had stable disease before eventually experiencing progression. These cases highlight the complicated role BRAF mutations play in gastrointestinal NECs, and the need for further research to identify not only patients who may benefit from BRAF-directed therapies but also strategies to avoid development of resistance.

The risk of developing a mismatch repair deficient colorectal cancer after undergoing cholecystectomy.

OBJECTIVES: Mismatch repair deficient (dMMR) colorectal cancer (CRC) is caused by inactivation of the MMR DNA repair system, most commonly via epigenetic inactivation of the MLH1 gene, and these tumors occur most frequently in the right colon. The objective was to determine whether cholecystectomy (CCY) increases the risk of a dMMR CRC by comparing CCY incidence in patients with dMMR CRC and proficient MMR (pMMR) CRC to unaffected controls. MATERIALS AND METHODS: All patients diagnosed with CRC in Iceland from 2000 to 2009 (n = 1171) were included. They had previously been screened for dMMR by immunohistochemistry (n = 129 were dMMR). Unaffected age- and sex-matched controls (n = 17,460) were obtained from large Icelandic cohort studies. Subjects were cross-referenced with all pathology databases in Iceland to establish who had undergone CCY. Odds ratios were calculated using unconditional logistic regression. RESULTS: Eighteen (13.7%) dMMR CRC cases and 90 (8.7%) pMMR CRC cases had undergone CCY compared to 1532 (8.8%) controls. CCY-related odds ratios (OR) were 1.06 (95% CI 0.90-1.26, p = .577) for all CRC, 1.16 (95% CI 0.66-2.05 p = .602) for dMMR CRCand 1.04 (95% CI 0.83-1.29, p = .744) for pMMR CRC. Furthermore, OR for dMMR CRC was 0.51 (95% CI 0.16-1.67, p = .266), 2.04 (95% CI 0.92-4.50, p = .080) and 1.08 (95% CI 0.40-2.89, p = .875) <10 years, 10-20 years and >20 years after a CCY, respectively. CONCLUSIONS: There was no evidence of increased risk of developing dMMR CRC after CCY although a borderline significantly increased 2-fold risk was observed 10-20 years after CCY. Larger studies are warranted to examine this further.

Promising New Agents for Colorectal Cancer.

OPINION STATEMENT: Choosing the optimal treatment approach for patients with metastatic colorectal cancer (mCRC) demands that oncologists assess both clinical and genomic variables and individualize care based upon the findings. Clinically, choices depend on assessing the side of the colon in which the primary tumor originates, the sites and burden of metastatic disease, the patient's performance status, and their individual comorbidities. Genomic assessment of the tumor to discern the mutational status of genes such as RAS/RAF, HER2, and TRK, as well as assessing whether tumors have defective mismatch repair (dMMR) or high microsatellite instability (MSI-H), all factor in to potential treatment options and can determine clinical trial eligibility. Metastasectomy may be an option for patients with a low burden of disease and accessible liver- or lung-limited metastases. In some unresectable cases, systemic therapy with a FOLFOX- or FOLFIRI-based regimen with or without a biologic agent can lead to sufficient disease reduction to make a patient eligible for resection of metastatic disease. Tumor sidedness and RAS mutational status guide which biologic we add to the initial chemotherapy backbone, with patients with left-sided, RAS wild-type (WT) tumors receiving anti-epidermal growth factor receptor (EGFR)-directed therapy and patients with right-sided tumors or those with RAS mutations receiving bevacizumab. In patients with tumors that manifest microsatellite instability or deficient mismatch repair, we typically administer checkpoint inhibitors such as pembrolizumab or nivolumab after progression on irinotecan- or oxaliplatin-based therapies. In patients with progressive disease, we routinely send tumor tissue for next generation sequencing (NGS) to assess for the presence of actionable genomic alterations such as HER2, BRAF, and TRK fusions and offer them the option of enrollment on clinical trials with agents targeting those or other identified alterations.

Frequent PIK3CA Mutations in Colorectal and Endometrial Tumors With 2 or More Somatic Mutations in Mismatch Repair Genes.

BACKGROUND & AIMS: Some colorectal and endometrial tumors with microsatellite instability not attributable to MLH1 hypermethylation or germline mutations contain 2 or more somatic mutations in genes encoding mismatch repair (MMR) proteins. We sought to define the molecular phenotype of this newly recognized tumor subtype. METHODS: From 2 prospective studies of the efficacy of screening for Lynch syndrome, we identified patients with colorectal and endometrial tumors who had 2 or more somatic (but not germline) mutations in genes encoding MMR proteins (double somatic). We determined the frequencies of tumor mutations in PIK3CA, BRAF, KRAS, NRAS, and PTEN by targeted next-generation sequencing and used logistic-regression models to compare them with those from patients with Lynch syndrome, MLH1-hypermethylated, or microsatellite-stable tumors. We validated our findings using independent data sets from The Cancer Genome Atlas. RESULTS: Among colorectal cancer cases, we found that 14 of 21 (67%) patients with double somatic tumors also had PIK3CA mutations, compared with 4 of 18 (22%) tumors from patients with Lynch syndrome, 2 of 10 (20%) tumors with MLH1 hypermethylation, and 12 of 78 (15%) tumors with microsatellite stability (P < .0001 for patients with double somatic tumors vs other subgroups). Mutations in PIK3CA were detected in all 13 patients with double somatic endometrial cancers (P = .04 compared with other subgroups). We did not detect BRAF mutations in patients with double somatic colorectal tumors or Lynch syndrome. We found highly similar results in a validation cohort from The Cancer Genome Atlas (113 patients with colorectal tumors, 178 endometrial tumors); 100% of double somatic cases had a somatic mutation in PIK3CA (P < .0001 compared with other subgroups). CONCLUSIONS: Most patients with colorectal or endometrial tumors with 2 or more somatic (but not germline) mutations in MMR proteins also have mutations in PIK3CA; mutations in PIK3CA are detected at substantially higher frequencies in these double somatic tumors than in other microsatellite-instability subgroups. PIK3CA mutation status might be used to identify a specific group of colorectal tumors, and to select treatment or determine prognosis.

Patients with colorectal cancer associated with Lynch syndrome and MLH1 promoter hypermethylation have similar prognoses.

PURPOSE: Mismatch repair-deficient (dMMR) colorectal cancer (CRC) is caused by Lynch syndrome (LS) in 3% and sporadic inactivation of MLH1 by hypermethylation (MLH1-hm) in 12% of cases. It is not clear whether outcomes between LS-associated and MLH1-hm CRC differ. The objective of this study was to explore differences in clinical factors and outcomes in these two groups. METHODS: Patients with dMMR CRC identified by immunohistochemistry staining and treated at a single institution from 1998 to 2012 were included. MLH1-hm was established with BRAF mutational analysis or hypermethylation testing. Patients' charts were accessed for information on pathology, germ-line MMR mutation testing, and clinical course. RESULTS: A total of 143 patients had CRC associated with LS (37 patients, 26%) or MLH1-hm (106 patients, 74%). Patients with LS were younger, more often male, presented more often with stage III disease, and had more metachronous disease than patients with MLH1-hm tumors. There was no difference in cancer-specific survival (CSS) between the groups; overall survival was longer in patients with LS, but this difference was minimal after adjusting for age and stage at diagnosis. CONCLUSION: CSS did not differ in LS-associated CRC compared with MLH1-hm CRC, suggesting that they carry a similar prognosis.Genet Med 18 9, 863-868.

Colon and endometrial cancers with mismatch repair deficiency can arise from somatic, rather than germline, mutations.

BACKGROUND & AIMS: Patients with Lynch syndrome carry germline mutations in single alleles of genes encoding the mismatch repair (MMR) proteins MLH1, MSH2, MSH6, and PMS2; when the second allele becomes mutated, cancer can develop. Increased screening for Lynch syndrome has identified patients with tumors that have deficiency in MMR, but no germline mutations in genes encoding MMR proteins. We investigated whether tumors with deficient MMR had acquired somatic mutations in patients without germline mutations in MMR genes using next-generation sequencing. METHODS: We analyzed blood and tumor samples from 32 patients with colorectal or endometrial cancer who participated in Lynch syndrome screening studies in Ohio and were found to have tumors with MMR deficiency (based on microsatellite instability and/or absence of MMR proteins in immunohistochemical analysis, without hypermethylation of MLH1), but no germline mutations in MMR genes. Tumor DNA was sequenced for MLH1, MSH2, MSH6, PMS2, EPCAM, POLE, and POLD1 with ColoSeq and mutation frequencies were established. RESULTS: Twenty-two of 32 patients (69%) were found to have 2 somatic (tumor) mutations in MMR genes encoding proteins that were lost from tumor samples, based on immunohistochemistry. Of the 10 remaining tumors 3 had one somatic mutation in a MMR gene, with possible loss of heterozygosity that could lead to MMR deficiency, 6 were found to be false-positive results (19%), and 1 had only one mutation in a MMR gene and remained unexplained. All of the tumors found to have somatic MMR mutations were of the hypermutated phenotype (>12 mutations/megabase); 6 had mutation frequencies >200/megabase, and 5 of these had somatic mutations in POLE, which encodes a DNA polymerase. CONCLUSIONS: Some patients are found to have tumors with MMR defects during screening for Lynch syndrome, yet have no identifiable germline mutations in MMR genes. We found that almost 70% of these patients acquire somatic mutations in MMR genes, leading to a hypermutated phenotype of tumor cells. Patients with colon or endometrial cancers with MMR deficiency not explained by germline mutations might undergo analysis for tumor mutations in MMR genes to guide future surveillance guidelines.

An update on clinical trials of targeted therapies in thyroid cancer.

PURPOSE OF REVIEW: Several new targeted therapies with multikinase inhibitors targeting vascular endothelial growth factor (VEGF), rearranged during transfection and v-raf murine sarcoma viral oncogene homolog B1 pathways have been tested in clinical trials for radioiodine-refractory differentiated thyroid cancer (DTC) and medullary thyroid cancer (MTC) in the past 10 years. RECENT FINDINGS: Results of the first phase III trial of VEGF-targeted therapy (sorafenib) in DTC were presented in June 2013, and two phase III trials with VEGF and rearranged during transfection-targeted therapies (vandetanib and cabozantinib) in MTC have led to approval by US Food and Drug Administration in the past 2 years. Whereas such therapies increase median progression-free survival compared to placebo, there is no therapy proven to improve overall survival yet. Significant potential adverse event risks associated with such therapies need to be recognized. Dissemination of knowledge about targeted therapies is critical for various medical specialists as patient care for thyroid cancers is best delivered in a multidisciplinary setting. SUMMARY: Successful development of targeted systemic therapies in DTC and MTC in the past 5 years is incredibly exciting in the field and patients with advanced DTC/MTC now have new standard-of-care therapy options.

Prostate cancer incidence in males with Lynch syndrome.

PURPOSE: An increased risk of prostate cancer is currently not considered a part of the Lynch syndrome spectrum. The purpose of this study was to retrospectively examine prostate cancer incidence in the Lynch syndrome cohort at the Ohio State University in comparison with that in the general population. METHODS: We included all males diagnosed with Lynch syndrome from June 1998 to June 2012 at the Ohio State University and obtained baseline information including cancer history. If patients had not been seen in the 12 months before June 2012, they were contacted to document changes in their cancer history. We compared prostate cancer incidence among the Lynch syndrome families with that of the general population by using the Surveillance, Epidemiology, and End RESULTS registry 1999-2009. RESULTS: Of the 188 males identified with Lynch syndrome, 11 males were diagnosed with prostate cancer during the study period. The ratio of observed to expected numbers of prostate cancer cases resulted in a standardized rate ratio of 4.87 (95% confidence interval: 2.43-8.71). Impaired mismatch repair expression and microsatellite instability were seen in one out of two prostate cancer specimens available for testing. CONCLUSION: Males with Lynch syndrome had a nearly fivefold increased risk of developing prostate cancer but did not appear to have earlier onset or a more aggressive phenotype.

Germline Testing for Individuals with Pancreatic Adenocarcinoma and Novel Genetic Risk Factors.

Germline genetic variants implicated in increasing lifetime risk of pancreatic cancer (PDAC) have been identified in ∼4% to 10% of cases. Clinical features such as family history have poor sensitivity in identifying carriers of these risk variants. Genetic testing for these germline variants has potential to guide risk assessment and surveillance recommendations in high-risk individuals to promote prevention and early detection measures. Furthermore, identification of novel germline variants can offer important insights into pathogenesis that may inform precision medicine approaches. This article reviews current understanding of germline mutations associated with PDAC risk and implications of genetic testing.

Large Cancer Pedigree Involving Multiple Cancer Genes including Likely Digenic MSH2 and MSH6 Lynch Syndrome (LS) and an Instance of Recombinational Rescue from LS.

Lynch syndrome (LS), caused by heterozygous pathogenic variants affecting one of the mismatch repair (MMR) genes (MSH2, MLH1, MSH6, PMS2), confers moderate to high risks for colorectal, endometrial, and other cancers. We describe a four-generation, 13-branched pedigree in which multiple LS branches carry the MSH2 pathogenic variant c.2006G>T (p.Gly669Val), one branch has this and an additional novel MSH6 variant c.3936_4001+8dup (intronic), and other non-LS branches carry variants within other cancer-relevant genes (NBN, MC1R, PTPRJ). Both MSH2 c.2006G>T and MSH6 c.3936_4001+8dup caused aberrant RNA splicing in carriers, including out-of-frame exon-skipping, providing functional evidence of their pathogenicity. MSH2 and MSH6 are co-located on Chr2p21, but the two variants segregated independently (mapped in trans) within the digenic branch, with carriers of either or both variants. Thus, MSH2 c.2006G>T and MSH6 c.3936_4001+8dup independently confer LS with differing cancer risks among family members in the same branch. Carriers of both variants have near 100% risk of transmitting either one to offspring. Nevertheless, a female carrier of both variants did not transmit either to one son, due to a germline recombination within the intervening region. Genetic diagnosis, risk stratification, and counseling for cancer and inheritance were highly individualized in this family. The finding of multiple cancer-associated variants in this pedigree illustrates a need to consider offering multicancer gene panel testing, as opposed to targeted cascade testing, as additional cancer variants may be uncovered in relatives.

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.

Profiling diverse sequence tandem repeats in colorectal cancer reveals co-occurrence of microsatellite and chromosomal instability involving Chromosome 8.

We developed a sensitive sequencing approach that simultaneously profiles microsatellite instability, chromosomal instability, and subclonal structure in cancer. We assessed diverse repeat motifs across 225 microsatellites on colorectal carcinomas. Our study identified elevated alterations at both selected tetranucleotide and conventional mononucleotide repeats. Many colorectal carcinomas had a mix of genomic instability states that are normally considered exclusive. An MSH3 mutation may have contributed to the mixed states. Increased copy number of chromosome arm 8q was most prevalent among tumors with microsatellite instability, including a case of translocation involving 8q. Subclonal analysis identified co-occurring driver mutations previously known to be exclusive.

Implementation of a cloud-based electronic patient-reported outcome (ePRO) platform in patients with advanced cancer.

BACKGROUND: Patient reported outcomes (PROs) have been associated with improved symptom management and quality of life in patients with cancer. However, the implementation of PROs in an academic clinical practice has not been thoroughly described. Here we report on the execution, feasibility and healthcare utilization outcomes of an electronic PRO (ePRO) application for cancer patients at an academic medical center. METHODS: We conducted a randomized trial comparing an experimental ePRO arm to standard of care in patients with advanced cancer in the thoracic, gastrointestinal, and genitourinary oncology groups at Stanford Cancer Center from March 2018 to November 2019. We describe the pre-implementation, implementation, and post-implementation phases of the ePRO arm, technological barriers, electronic health record (EHR) integration, clinician burden, and patient data privacy and security. Feasibility was pre-specified to be at least 70% completion of all questionnaires. Acceptability was based on patient and clinician feedback. Ambulatory healthcare utilization was assessed by reviewing numbers of phone messages, electronic portal messages, and referrals for supportive care. RESULTS: Of 617 ePRO questionnaires sent to 72 patients, 445 (72%) were completed. Most clinicians (87.5%) and patients (93%) felt neutral or positive about the ePRO tool's ease of use. Exposure to ePRO did not cause a measurable change in ambulatory healthcare utilization, with a median of less than two phone messages and supportive care referrals, and 5-6 portal messages. CONCLUSIONS: Web-based ePRO tools for patients with advanced cancer are feasible and acceptable without increasing clinical burden. Key lessons include the importance of pilot testing, engagement of stakeholders at all levels, and the need for customization by disease group. Future directions for this work include completion of EHR integration, expansion to other centers, and development of integrated workflows for routine clinical practice.