Kasi, Pashtoon Murtaza

PURPOSE EGFR alterations occur in a subset of biliary tract cancers (BTCs) and are often linked to disease progression and poor prognosis, yet targeted approaches remain underexplored. ERRFI1 , encoding the epidermal growth factor receptor (EGFR) inhibitor MIG6, is mutated in various cancers, including BTC, representing a potential predictive biomarker. We investigated whether loss of ERRFI1 function may enhance sensitivity to EGFR-targeted tyrosine kinase inhibitors (TKIs), presenting a potential therapeutic opportunity. METHODS This is a retrospective multicenter study of patients with BTC harboring ERRFI1 alterations. Data were extracted from electronic health records following institutional approval. ERRFI1 alterations were classified based on the alteration type, variant allele frequencies were documented, and coalterations were analyzed. Treatment outcomes including response, time to progression (TTP), overall survival (OS), safety profiles, and tumor marker kinetics were noted. RESULTS Fourteen BTC patients with ERRFI1 mutations were identified in our database; the median age was 50 years, 64% were males; all cases were intrahepatic cholangiocarcinomas. Common coalterations included IDH1 (36%), TP53 (29%), and ARID1A (29%). All patients received gemcitabine-cisplatin as first-line treatment, and 79% received immune checkpoint inhibitors. Eight patients (57%) received EGFR TKIs. Best responses to EGFR therapy included three partial responses (2 responses lasting >20 months), four stable diseases, and one progressive disease. The median TTP was 7 months (95% CI, 6 to 21 months). Treatment was well-tolerated: toxicities included rash (n = 2), transaminitis (n = 1), and diarrhea (n = 1). The median OS was 20 months (95% CI: 8-36 months); 50% remained alive at last follow-up. CONCLUSION ERRFI1 mutations represent actionable biomarkers in BTC, with EGFR-targeted therapy demonstrating meaningful clinical benefit in this heavily pretreated population. These findings support integration of ERRFI1 testing into routine molecular profiling of BTC and other EGFR-driven malignancies.

PURPOSE Cancer of unknown primary (CUP) is a syndrome comprising metastatic cancers without a clinically identified primary site. Although patients with CUP have an unfavorable prognosis, treatment with site-specific therapies guided by clinical features, standard pathology, and molecular assays can improve overall survival. The 92-gene assay (CancerTYPE ID) is a gene expression–based classifier that helps identify the tissue of origin for metastatic cancers with unknown or uncertain diagnoses. This study reports the frequency of selected molecular aberrations of oncogenes, including KRAS, IDH1/2, BRCA1/2, and BRAF, in patients with CUP in the MOSAIC database to highlight potential treatment options. METHODS MOSAIC is a database of patients with CUP submitted for CancerTYPE ID testing and NeoTYPE biomarker testing. Tumor biopsy samples were analyzed by CancerTYPE ID for tumor type identification and further tested for molecular aberrations of oncogenes, including KRAS, IDH1/2, BRCA1/2, and BRAF. RESULTS CancerTYPE ID identified a specific tumor type in 92.5% (2,929 of 3,168) of CUP cases in the MOSAIC database. The most commonly identified histological type was adenocarcinoma (75.4%), with pancreaticobiliary being the most common molecularly diagnosed cancer (24.9%). Aberrations in KRAS, IDH1/2, BRCA, and BRAF genes were identified in 18.8% (n = 597) of biopsies. A cancer-specific US Food and Drug Administration (FDA)–approved or investigational targeted therapy was potentially available for 24.6% (n = 147) of these patients. CONCLUSION This retrospective analysis supports incorporating CancerTYPE ID into the evaluation for patients with CUP to help determine the tissue of origin and identify actionable genetic alterations. This approach may allow more patients with CUP to benefit from site-specific FDA-approved targeted therapies or enrollment into clinical trials.

Abstract Colorectal cancer is the third most common cancer worldwide, and incidence is rising in younger individuals. Anti-EGFR antibodies, including cetuximab and panitumumab, have been incorporated into standard-of-care practice for patients with advanced disease. Herein, we review the molecular characteristics of these agents and the trials that lead to their approvals. Further, we discuss clinical implications of data regarding biomarkers that dictate treatment selection, different dosing strategies, and side effect management. Finally, we look towards the future and describe contexts in which these agents are currently being investigated clinically with a focus on combinations with MAPK-targeted therapies and immunotherapy. Overall, this review provides historical context, current clinical usage, and future directions for anti-EGFR antibodies in advanced colorectal cancer.

AbstractPurpose:To analytically and clinically validate microsatellite instability (MSI) detection using cell-free DNA (cfDNA) sequencing.Experimental Design:Pan-cancer MSI detection using Guardant360 was analytically validated according to established guidelines and clinically validated using 1,145 cfDNA samples for which tissue MSI status based on standard-of-care tissue testing was available. The landscape of cfDNA-based MSI across solid tumor types was investigated in a cohort of 28,459 clinical plasma samples. Clinical outcomes for 16 patients with cfDNA MSI-H gastric cancer treated with immunotherapy were evaluated.Results:cfDNA MSI evaluation was shown to have high specificity, precision, and sensitivity, with a limit of detection of 0.1% tumor content. In evaluable patients, cfDNA testing accurately detected 87% (71/82) of tissue MSI-H and 99.5% of tissue microsatellite stable (863/867) for an overall accuracy of 98.4% (934/949) and a positive predictive value of 95% (71/75). Concordance of cfDNA MSI with tissue PCR and next-generation sequencing was significantly higher than IHC. Prevalence of cfDNA MSI for major cancer types was consistent with those reported for tissue. Finally, robust clinical activity of immunotherapy treatment was seen in patients with advanced gastric cancer positive for MSI by cfDNA, with 63% (10/16) of patients achieving complete or partial remission with sustained clinical benefit.Conclusions:cfDNA-based MSI detection using Guardant360 is highly concordant with tissue-based testing, enabling highly accurate detection of MSI status concurrent with comprehensive genomic profiling and expanding access to immunotherapy for patients with advanced cancer for whom current testing practices are inadequate.See related commentary by Wang and Ajani, p. 6887

Abstract Purpose: To compare the clinical characteristics and overall survival (OS) of germline mutation carriers in homologous recombination repair (HRR) genes and noncarriers with pancreatic ductal adenocarcinoma (PDAC). Experimental Design: Germline DNA from 3,078 patients with PDAC enrolled in a prospective registry at Mayo Clinic between 2000 and 2017 was analyzed for mutations in 37 cancer predisposition genes. Characteristics and OS of patients with mutations in eight genes (ATM, BARD1, BRCA1, BRCA2, BRIP1, PALB2, RAD51C, and RAD51D) involved in HRR were compared with patients testing negative for mutations in all 37 genes. Results: The 175 HRR mutation carriers and 2,730 noncarriers in the study had a median duration of follow-up of 9.9 years. HRR mutation carriers were younger (median age at diagnosis: 63 vs. 66 years, P < 0.001) and more likely to have metastatic disease at diagnosis (46% vs. 36%, P = 0.004). In a multivariable model adjusting for sex, age at diagnosis, and tumor staging, patients with germline HRR mutations had a significantly longer OS compared with noncarriers [HR, 0.83; 95% confidence interval (CI), 0.70–0.97; P = 0.02]. Further gene-level analysis demonstrated that germline ATM mutation carriers had longer OS compared with patients without germline mutations in any of the 37 genes (HR, 0.72; 95% CI, 0.55–0.94; P = 0.01). Conclusions: This study demonstrates that germline mutation carrier status in PDAC is associated with longer OS compared with noncarriers. Further research into tumor biology and response to platinum-based chemotherapy in germline mutation carriers with PDAC are needed to better understand the association with longer OS.

Introduction: Pharmacogenomics is about selecting the “right drug in the right amount for the right patient.” In metastatic colorectal cancer, germline pharmacogenomics testing presents a unique opportunity to improve outcomes, since the genes dihydropyrimidine dehydrogenase and UDP-glucuronosyltransferase metabolizing the chemotherapy drugs, 5-fluorouracil, and irinotecan are already well known. In a retrospective analysis of the landmark TRIBE clinical trial [(TRIBE - TRIplet plus BEvacizumab multicenter, phase III trial by the Italian Cooperative GONO (Gruppo Oncologico Nord Ovest) group (NCT00719797)], the proportion of patients with serious adverse events was higher in those with dihydropyrimidine dehydrogenase/UDP-glucuronosyltransferase aberrations and was dose dependent. We aimed to report on the feasibility and the results of incorporating pharmacogenomics testing into clinical practice. Methods: As a quality improvement initiative and a center of individualized medicine grant, we integrated the use of OneOme RightMed comprehensive test, which reports on 27 genes related to pharmacogenomics and over 300 medications of interest. We limited initial testing to patients with colorectal cancer. Pharmacists provided dosage recommendations based on test results in real-time. Results: At our cancer center, 155 patients underwent pharmacogenomics testing from November 2017 to January 2019. Results were available within 3 to 5 days of testing for most patients and were integrated into treatment decision-making. Of 155 sampled participants, a total of 89 (57.4%) participants had an UGT1A1 variant genotype, NM_000463.2: c.-53_-52[8] *1/*28, n = 74 (47.7%); *28/*28, n = 15 (9.7%). Additionally, 4 (2.6%) participants were heterozygous for dihydropyrimidine dehydrogenase. Two (1.3%) individuals were heterozygous for both UDP-glucuronosyltransferase and dihydropyrimidine dehydrogenase genes. All (100%) the patients had at least 1 actionable aberration related to supportive care medications ( CYP-family) of all the possible medications listed on their pharmacogenomics report. Conclusion: Preemptive comprehensive pharmacogenomics testing can be integrated into clinical practice in real-time for patients with cancer given faster turnaround and low cost. Pharmacist-driven, patient-specific medication management consults add further value given the number of genes/drugs. This sets the stage for a prospective randomized clinical trial to demonstrate the amount of benefit this can result in these patients.

Abstract Doublet chemotherapies are the mainstay in the management of metastatic anal cancer. Immunotherapy has been incorporated into guidelines in a refractory setting. Treatment options remain limited with tumor progression beyond immunotherapy. Modified docetaxel, cisplatin, and fluorouracil (mDCF) chemotherapy, after progression postimmunotherapy, has shown a near‐complete response in our patient with metastatic anal cancer. This likely is secondary to the sequence of immunotherapy followed by chemotherapy that is yielding greater than historical responses.

Abstract Background: Patients with DNA-damage response genes (DDR)-related pancreas cancer (BRCA1/2 or other DNA-damage related genes) may have improved outcomes secondary to increased sensitivity to DNA-damaging drugs (platinum chemotherapy/ poly ADP ribose polymerase (PARP)-inhibitors). However, data is scarce pertaining to outcomes in this subset of patients. Our objective was to retrospectively identify DDR-related pancreas cancer patients and report on clinical outcomes. Methods: Pancreas cancer patients with either a somatic or germline BRCA1/2 or other DDR genes were identified retrospectively through review of medical records (medical genetics/oncology), germline and tumor-based genetic testing results at our institution. Data regarding clinical outcomes, therapy received, and survival was subsequently extracted. Results: A total of 11 patients with pancreas cancer were identified. Pathogenic DDR-variants detected were within BRCA1 (3), ATM (4), BRCA2 (2), PALB2 (1) and FANCC (1). Five of these individuals had prior history of other cancers. Clinically these tumors were localized (4), locally advanced (3), and metastatic (4) at diagnosis. Seven out of 11 patients were still alive at time of data review. Survival in the 3 patients who had died in the metastatic/advanced cohort was 23.5, 25.8 and 111.5 months. All patients with advanced disease had exposure to platinum chemotherapy. Conclusions: Historical survival in patients with advanced and metastatic pancreas cancer is poor. Results of this DDR-subset of patients do show significantly superior outcomes, likely secondary to exposure to platinum drugs. This data, alongside other similar cohorts, would favor the DDR-genes being a predictive marker with improved survival if exposed to these drugs and the new class of drugs, PARP-inhibitors.

PURPOSE Recent advances in molecular diagnostic technologies have allowed for the evaluation of solid tumor malignancies via noninvasive blood sampling, including circulating tumor DNA (ctDNA) profiling. We sought to characterize the ctDNA genomic alteration landscape in patients with biliary tract cancers (BTCs). PATIENTS AND METHODS From January 2015 to February 2018, 124 patients with BTC at the Mayo Clinic Comprehensive Cancer Center underwent ctDNA testing using a clinically available assay. The majority of samples (n = 122) were tested using the 73-gene panel that includes somatic genomic targets, including complete or critical exon coverage in 30 and 40 genes, respectively, and in some, amplifications, fusions, and indels. RESULTS A total of 138 samples were included, with approximately 70% of patients having intrahepatic BTC. All patients had locally advanced or metastatic BTC. Samples with one or more alterations, when variants of unknown significance were excluded, numbered 105 (76%). Each sample contained, on average, three alterations with a median allelic fraction of 0.52%. The overall landscape of alterations is summarized in Figures 1 and 2. After excluding variants of unknown significance, therapeutically relevant alterations were observed in 76 patients (55%), including BRAF mutations, ERBB2 amplifications, FGFR2 fusions, FGFR2 mutations, and IDH1 mutations seen in 21% of patients. A different spectrum of alterations was observed in patients with early-onset BTC (younger than age 50 years) compared with older patients (older than age 50 years). CONCLUSION Data on ctDNA in BTC is currently limited. Our study, the largest cohort reported to date to our knowledge, demonstrates the feasibility of ctDNA testing in this disease. We provide a foundation upon which the field can continue to grow.