Synthetic Lethality Beyond BRCA: A Phase I Study of Rucaparib and Irinotecan in Metastatic Solid Tumors With Homologous Recombination-Deficiency Mutations Beyond BRCA1/2.

PURPOSE: Combining poly ADP-ribose polymerase (PARP) and topoisomerase I inhibitors has demonstrated synergistic effects in in vivo models. This phase I trial evaluated rucaparib and irinotecan in metastatic solid tumors with homologous recombination deficiency. METHODS: This study enrolled patients in three cohorts to determine the tolerability and preliminary efficacy of (1) rucaparib 400 mg PO twice a day (days 1-7, 15-21) and irinotecan 65 mg/m2 intravenously once every 2 weeks; (2) rucaparib 400 mg PO twice a day (D1-7, 15-21) and irinotecan 100 mg/m2 once every 2 weeks; and (3) rucaparib 400 mg per os twice a day (D1-7) and irinotecan 100 mg/m2 once every 3 weeks. RESULTS: Twenty patients were enrolled: 95% with previous platinum, 40% with previous irinotecan, and 20% with previous PARP inhibitor. The maximally tolerated was determined as rucaparib 400 mg twice a day days 1-7 and irinotecan 100 mg/m2 once every 3 weeks. Four dose-limiting toxicities (all grade 3-4 neutropenia) occurred during dose escalation with only neutropenia as other grade 3-4 toxicities (25%; grade 3 [n = 3], grade 4 [n = 2]). Treatment-related grade 1-2 adverse events included neutropenia (45%), diarrhea (45%), nausea (40%), and fatigue (30%). Of 17 patients with evaluable disease, six patients (35%) derived clinical benefit (n = 2 with PR, n = 4 with stable disease for over 6 months). Three patients remained on study >1 year: two with ATM mutations (small bowel carcinoma and pancreatic neuroendocrine tumor) and one patient with a PALB2 mutation (primary peritoneal cancer). CONCLUSION: Pulse dosing of rucaparib and once every 3 weeks irinotecan was well tolerated for up to 18 months with durable responses in BRCA-, PALB2-, and ATM-mutated cancers despite progression on previous platinum.

Pancreatic Cancer Action Network's SPARK: A Cloud-Based Patient Health Data and Analytics Platform for Pancreatic Cancer.

PURPOSE: Pancreatic cancer currently holds the position of third deadliest cancer in the United States and the 5-year survival rate is among the lowest for major cancers at just 12%. Thus, continued research efforts to better understand the clinical and molecular underpinnings of pancreatic cancer are critical to developing both early detection methodologies as well as improved therapeutic options. This study introduces Pancreatic Cancer Action Network's (PanCAN's) SPARK, a cloud-based data and analytics platform that integrates patient health data from the PanCAN's research initiatives and aims to accelerate pancreatic cancer research by making real-world patient health data and analysis tools easier to access and use. MATERIALS AND METHODS: The SPARK platform integrates clinical, molecular, multiomic, imaging, and patient-reported data generated from PanCAN's research initiatives. The platform is built on a cloud-based infrastructure powered by Velsera. Cohort exploration and browser capabilities are built using Velsera ARIA, a specialized product for leveraging clinicogenomic data to build cohorts, query variant information, and drive downstream association analyses. Data science and analytic capabilities are also built into the platform allowing researchers to perform simple to complex analysis. RESULTS: Version 1 of the SPARK platform was released to pilot users, who represented diverse end users, including molecular biologists, clinicians, and bioinformaticians. Included in the pilot release of SPARK are deidentified clinical (including treatment and outcomes data), molecular, multiomic, and whole-slide pathology images for over 600 patients enrolled in PanCAN's Know Your Tumor molecular profiling service. CONCLUSION: The pilot release of the SPARK platform introduces qualified researchers to PanCAN real-world patient health data and analytical resources in a centralized location.

In vivo bioluminescence imaging of labile iron in xenograft models and liver using FeAL-1, an iron-activatable form of D-luciferin.

Dysregulated iron homeostasis underlies diverse pathologies, from ischemia-reperfusion injury to epithelial-mesenchymal transition and drug-tolerant "persister" cancer cell states. Here, we introduce ferrous iron-activatable luciferin-1 (FeAL-1), a small-molecule probe for bioluminescent imaging of the labile iron pool (LIP) in luciferase-expressing cells and animals. We find that FeAL-1 detects LIP fluctuations in cells after iron supplementation, depletion, or treatment with hepcidin, the master regulator of systemic iron in mammalian physiology. Utilizing FeAL-1 and a dual-luciferase reporter system, we quantify LIP in mouse liver and three different orthotopic pancreatic ductal adenocarcinoma tumors. We observed up to a 10-fold increase in FeAL-1 bioluminescent signal in xenograft tumors as compared to healthy liver, the major organ of iron storage in mammals. Treating mice with hepcidin further elevated hepatic LIP, as predicted. These studies reveal a therapeutic index between tumoral and hepatic LIP and suggest an approach to sensitize tumors toward LIP-activated therapeutics.

Conserved regulatory motifs in the juxtamembrane domain and kinase N-lobe revealed through deep mutational scanning of the MET receptor tyrosine kinase domain.

MET is a receptor tyrosine kinase (RTK) responsible for initiating signaling pathways involved in development and wound repair. MET activation relies on ligand binding to the extracellular receptor, which prompts dimerization, intracellular phosphorylation, and recruitment of associated signaling proteins. Mutations, which are predominantly observed clinically in the intracellular juxtamembrane and kinase domains, can disrupt typical MET regulatory mechanisms. Understanding how juxtamembrane variants, such as exon 14 skipping (METΔEx14), and rare kinase domain mutations can increase signaling, often leading to cancer, remains a challenge. Here, we perform a parallel deep mutational scan (DMS) of MET intracellular kinase domain in two fusion protein backgrounds: wild type and METΔEx14. Our comparative approach has revealed a critical hydrophobic interaction between a juxtamembrane segment and the kinase αC helix, pointing to differences in regulatory mechanisms between MET and other RTKs. Additionally, we have uncovered a ß5 motif that acts as a structural pivot for kinase domain activation in MET and other TAM family of kinases. We also describe a number of previously unknown activating mutations, aiding the effort to annotate driver, passenger, and drug resistance mutations in the MET kinase domain.

A Genomic Analysis of Esophageal Squamous Cell Carcinoma in Eastern Africa.

BACKGROUND: Esophageal squamous cell carcinoma (ESCC) comprises 90% of all esophageal cancer cases globally and is the most common histology in low-resource settings. Eastern Africa has a disproportionately high incidence of ESCC. METHODS: We describe the genomic profiles of 61 ESCC cases from Tanzania and compare them to profiles from an existing cohort of ESCC cases from Malawi. We also provide a comparison to ESCC tumors in The Cancer Genome Atlas (TCGA). RESULTS: We observed substantial transcriptional overlap with other squamous histologies via comparison with TCGA PanCan dataset. DNA analysis revealed known mutational patterns, both genome-wide as well as in genes known to be commonly mutated in ESCC. TP53 mutations were the most common somatic mutation in tumors from both Tanzania and Malawi but were detected at lower frequencies than previously reported in ESCC cases from other settings. In a combined analysis, two unique transcriptional clusters were identified: a proliferative/epithelial cluster and an invasive/migrative/mesenchymal cluster. Mutational signature analysis of the Tanzanian cohort revealed common signatures associated with aging and cytidine deaminase activity (APOBEC) and an absence of signature 29, which was previously reported in the Malawi cohort. CONCLUSIONS: This study defines the molecular characteristics of ESCC in Tanzania, and enriches the Eastern African dataset, with findings of overall similarities but also some heterogeneity across two unique sites. IMPACT: Despite a high burden of ESCC in Eastern Africa, investigations into the genomics in this region are nascent. This represents the largest comprehensive genomic analysis ESCC from sub-Saharan Africa to date.

RAS and Other Molecular Targets in Pancreatic Cancer: The Next Wave Is Coming.

OPINION STATEMENT: Since the discovery of oncogenes in the 1970s, cancer doctors and researchers alike have understood the promise of discovering drugs to block the dominantly acting function of mutated signaling proteins in cancer. This promise was delivered, first slowly, with early signals inhibiting HER2 and BCR-Abl in the 1990s and 2000s, and then quickly, with kinase inhibitors being approved hand over fist in non-small cell lung cancer, melanoma, and many other malignancies. The RAS proteins, however, remained recalcitrant to chemical inhibition for decades, despite being, by far, the most frequently mutated oncogenes in cancers of all types. Nowhere was this deficit more palpable than in pancreatic ductal adenocarcinoma (PDA), where > 90% of cases are driven by single nucleotide substitutions at a single codon of the KRAS gene. The ice began to crack in 2012 when Ostrem and colleagues (Nature 503(7477): 548-551, 2013) synthesized the first KRAS G12C inhibitors, which covalently bind to GDP-bound G12C-mutated KRAS and lock the oncoprotein in its inactive state. In the last decade, the scientific community has established a new foundation on this and other druggable pockets in mutant KRAS. Here we provide an up-to-date overview of drugs targeting KRAS and other molecular targets in pancreatic cancer.

Development of an artificial intelligence-derived histologic signature associated with adjuvant gemcitabine treatment outcomes in pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) has been left behind in the evolution of personalized medicine. Predictive markers of response to therapy are lacking in PDAC despite various histological and transcriptional classification schemes. We report an artificial intelligence (AI) approach to histologic feature examination that extracts a signature predictive of disease-specific survival (DSS) in patients with PDAC receiving adjuvant gemcitabine. We demonstrate that this AI-generated histologic signature is associated with outcomes following adjuvant gemcitabine, while three previously developed transcriptomic classification systems are not (n = 47). We externally validate this signature in an independent cohort of patients treated with adjuvant gemcitabine (n = 46). Finally, we demonstrate that the signature does not stratify survival outcomes in a third cohort of untreated patients (n = 161), suggesting that the signature is specifically predictive of treatment-related outcomes but is not generally prognostic. This imaging analysis pipeline has promise in the development of actionable markers in other clinical settings where few biomarkers currently exist.

An international report on bacterial communities in esophageal squamous cell carcinoma.

The incidence of esophageal squamous cell carcinoma (ESCC) is disproportionately high in the eastern corridor of Africa and parts of Asia. Emerging research has identified a potential association between poor oral health and ESCC. One possible link between poor oral health and ESCC involves the alteration of the microbiome. We performed an integrated analysis of four independent sequencing efforts of ESCC tumors from patients from high- and low-incidence regions of the world. Using whole genome sequencing (WGS) and RNA sequencing (RNAseq) of ESCC tumors from 61 patients in Tanzania, we identified a community of bacteria, including members of the genera Fusobacterium, Selenomonas, Prevotella, Streptococcus, Porphyromonas, Veillonella and Campylobacter, present at high abundance in ESCC tumors. We then characterized the microbiome of 238 ESCC tumor specimens collected in two additional independent sequencing efforts consisting of patients from other high-ESCC incidence regions (Tanzania, Malawi, Kenya, Iran, China). This analysis revealed similar ESCC-associated bacterial communities in these cancers. Because these genera are traditionally considered members of the oral microbiota, we next explored whether there was a relationship between the synchronous saliva and tumor microbiomes of ESCC patients in Tanzania. Comparative analyses revealed that paired saliva and tumor microbiomes were significantly similar with a specific enrichment of Fusobacterium and Prevotella in the tumor microbiome. Together, these data indicate that cancer-associated oral bacteria are associated with ESCC tumors at the time of diagnosis and support a model in which oral bacteria are present in high abundance in both saliva and tumors of some ESCC patients.

Mutant KRAS regulates transposable element RNA and innate immunity via KRAB zinc-finger genes.

RAS genes are the most frequently mutated oncogenes in cancer, yet the effects of oncogenic RAS signaling on the noncoding transcriptome remain unclear. We analyzed the transcriptomes of human airway and bronchial epithelial cells transformed with mutant KRAS to define the landscape of KRAS-regulated noncoding RNAs. We find that oncogenic KRAS signaling upregulates noncoding transcripts throughout the genome, many of which arise from transposable elements (TEs). These TE RNAs exhibit differential expression, are preferentially released in extracellular vesicles, and are regulated by KRAB zinc-finger (KZNF) genes, which are broadly downregulated in mutant KRAS cells and lung adenocarcinomas in vivo. Moreover, mutant KRAS induces an intrinsic IFN-stimulated gene (ISG) signature that is often seen across many different cancers. Our results indicate that mutant KRAS remodels the repetitive noncoding transcriptome, demonstrating the broad scope of intracellular and extracellular RNAs regulated by this oncogenic signaling pathway.

Efficacy of Preoperative mFOLFIRINOX vs mFOLFIRINOX Plus Hypofractionated Radiotherapy for Borderline Resectable Adenocarcinoma of the Pancreas: The A021501 Phase 2 Randomized Clinical Trial.

Importance: National guidelines endorse treatment with neoadjuvant therapy for borderline resectable pancreatic ductal adenocarcinoma (PDAC), but the optimal strategy remains unclear. Objective: To compare treatment with neoadjuvant modified FOLFIRINOX (mFOLFIRINOX) with or without hypofractionated radiation therapy with historical data and establish standards for therapy in borderline resectable PDAC. Design, Setting, and Participants: This prospective, multicenter, randomized phase 2 clinical trial conducted from February 2017 to January 2019 among member institutions of National Clinical Trials Network cooperative groups used standardized quality control measures and included 126 patients, of whom 70 (55.6%) were registered to arm 1 (systemic therapy; 54 randomized, 16 following closure of arm 2 at interim analysis) and 56 (44.4%) to arm 2 (systemic therapy and sequential hypofractionated radiotherapy; all randomized before closure). Data were analyzed by the Alliance Statistics and Data Management Center during September 2021. Interventions: Arm 1: 8 treatment cycles of mFOLFIRINOX (oxaliplatin, 85 mg/m2; irinotecan, 180 mg/m2; leucovorin, 400 mg/m2; and infusional fluorouracil, 2400 mg/m2) over 46 hours, administered every 2 weeks. Arm 2: 7 treatment cycles of mFOLFIRINOX followed by stereotactic body radiotherapy (33-40 Gy in 5 fractions) or hypofractionated image-guided radiotherapy (25 Gy in 5 fractions). Patients without disease progression underwent pancreatectomy, which was followed by 4 cycles of treatment with postoperative FOLFOX6 (oxaliplatin, 85 mg/m2; leucovorin, 400 mg/m2; bolus fluorouracil, 400 mg/m2; and infusional fluorouracil, 2400 mg/m2 over 46 hours). Main Outcomes and Measures: Each treatment arm's 18-month overall survival (OS) rate was compared with a historical control rate of 50%. A planned interim analysis mandated closure of either arm for which 11 or fewer of the first 30 accrued patients underwent margin-negative (R0) resection. Results: Of 126 patients, 62 (49%) were women, and the median (range) age was 64 (37-83) years. Among the first 30 evaluable patients enrolled to each arm, 17 patients in arm 1 (57%) and 10 patients in arm 2 (33%) had undergone R0 resection, leading to closure of arm 2 but continuation to full enrollment in arm 1. The 18-month OS rate of evaluable patients was 66.7% (95% CI, 56.1%-79.4%) in arm 1 and 47.3% (95% CI 35.8%-62.5%) in arm 2. The median OS of evaluable patients in arm 1 and arm 2 was 29.8 (95% CI, 21.1-36.6) months and 17.1 (95% CI, 12.8-24.4) months, respectively. Conclusions and Relevance: This randomized clinical trial found that treatment with neoadjuvant mFOLFIRINOX alone was associated with favorable OS in patients with borderline resectable PDAC compared with mFOLFIRINOX treatment plus hypofractionated radiotherapy; thus, mFOLFIRINOX represents a reference regimen in this setting. Trial Registration: ClinicalTrials.gov Identifier: NCT02839343.

The Additional Diagnostic Benefit of Pancreatic Cancer Molecular Profiling After Germline Testing.

OBJECTIVES: Germline genetic testing is universally recommended for patients with pancreatic cancer to guide therapeutic selection, but tumor molecular profiling (TMP) is not. We aimed to determine the real-world additional diagnostic benefit of TMP after germline testing for detecting therapeutically actionable alterations. METHODS: Medical records and genetic test reports were reviewed for all patients who underwent germline testing and TMP at the University of California San Francisco during January 2016-January 2020. The detection rate of actionable alterations with germline testing alone was compared to that with both germline testing and TMP. RESULTS: Among 738 eligible patients, 144 (20%) met study criteria. Germline testing detected 10 actionable alterations in 10 patients. Tumor molecular profiling identified 3 new therapeutic targets among these 10 patients and 45 targets in 41 additional patients, increasing the number of patients with actionable findings from 10 (7%) to 51 (35%). Most actionable alterations (35/58, 60%) involved genes associated with the Homologous Recombination DNA Damage Repair pathway. CONCLUSIONS: Tumor molecular profiling after germline testing increased the detection of actionable alterations by 5-fold. Tumor molecular profiling is a necessary complement to germline genetic testing to fully inform therapeutic decision making for all patients with pancreatic cancer.

Comparison of FOLFIRINOX vs Gemcitabine Plus Nab-Paclitaxel as First-Line Chemotherapy for Metastatic Pancreatic Ductal Adenocarcinoma.

Importance: FOLFIRINOX (leucovorin calcium [folinic acid], fluorouracil, irinotecan hydrochloride, and oxaliplatin) and gemcitabine plus nab-paclitaxel are the 2 common first-line therapies for metastatic adenocarcinoma of the pancreas (mPC), but they have not been directly compared in a clinical trial, and comparative clinical data analyses on their effectiveness are limited. Objective: To compare the FOLFIRINOX and gemcitabine plus nab-paclitaxel treatments of mPC in clinical data and evaluate whether there are differences in overall survival and posttreatment complications between them. Design, Setting, and Participants: This retrospective, nonrandomized comparative effectiveness study used data from the AIM Specialty Health-Anthem Cancer Care Quality Program and from administrative claims of commercially insured patients, spanning 388 outpatient centers and clinics for medical oncology located in 44 states across the US. Effectiveness and safety of the treatments were analyzed by matching or adjusting for age, Charlson Comorbidity Index, ECOG performance status (PS) score, Social Deprivation Index (SDI), liver and lymph node metastasis, prior radiotherapy or surgical procedures, and year of treatment. Patients with mPC treated between January 1, 2016, and December 31, 2019, and followed up until June 30, 2020, were included in the analysis. Interventions: Initiation of treatment with FOLFIRINOX or gemcitabine plus nab-paclitaxel. Main Outcomes and Measures: Outcomes were overall survival and posttreatment costs and hospitalization. Median survival time was calculated using Kaplan-Meier estimates adjusted with inverse probability of treatment weighting and 1:1 matching. Results: Among the 1102 patients included in the analysis (618 men [56.1%]; median age, 60.0 [IQR, 55.5-63.7] years), those treated with FOLFIRINOX were younger (median age, 59.1 [IQR, 53.9-63.3] vs 61.2 [IQR, 57.2-64.3] years; P < .001), with better PS scores (226 [39.9%] with PS of 0 in the FOLFIRINOX group vs 176 [32.8%] in the gemcitabine plus nab-paclitaxel group; P = .02), fewer comorbidities (median Charlson Comorbidity Index, 0.0 [IQR, 0.0-1.0] vs 1.0 [IQR, 0.0-1.0]), and lower SDI (median, 36.0 [IQR, 16.2-61.0] vs 42.0 [IQR, 23.8-66.2]). After adjustments, the median overall survival was 9.27 (IQR, 8.74-9.76) and 6.87 (IQR, 6.41-7.66) months for patients treated with FOLFIRINOX and gemcitabine plus nab-paclitaxel, respectively (P < .001). This survival benefit was observed among all subgroups, including different ECOG PS scores, ages, SDIs, and metastatic sites. FOLFIRINOX-treated patients also had 17.3% fewer posttreatment hospitalizations (P = .03) and 20% lower posttreatment costs (P < .001). Conclusions and Relevance: In this comparative effectiveness cohort study, FOLFIRINOX was associated with improved survival of approximately 2 months compared with gemcitabine plus nab-paclitaxel and was also associated with fewer posttreatment complications. A randomized clinical trial comparing these first-line treatments is warranted to test the survival and posttreatment hospitalization (or complications) benefit of FOLFIRINOX compared with gemcitabine plus nab-paclitaxel.

Ferrous iron-activatable drug conjugate achieves potent MAPK blockade in KRAS-driven tumors.

KRAS mutations drive a quarter of cancer mortality, and most are undruggable. Several inhibitors of the MAPK pathway are FDA approved but poorly tolerated at the doses needed to adequately extinguish RAS/RAF/MAPK signaling in the tumor cell. We found that oncogenic KRAS signaling induced ferrous iron (Fe2+) accumulation early in and throughout mutant KRAS-mediated transformation. We converted an FDA-approved MEK inhibitor into a ferrous iron-activatable drug conjugate (FeADC) and achieved potent MAPK blockade in tumor cells while sparing normal tissues. This innovation allowed sustainable, effective treatment of tumor-bearing animals, with tumor-selective drug activation, producing superior systemic tolerability. Ferrous iron accumulation is an exploitable feature of KRAS transformation, and FeADCs hold promise for improving the treatment of KRAS-driven solid tumors.

Discovering dominant tumor immune archetypes in a pan-cancer census.

Cancers display significant heterogeneity with respect to tissue of origin, driver mutations, and other features of the surrounding tissue. It is likely that individual tumors engage common patterns of the immune system-here "archetypes"-creating prototypical non-destructive tumor immune microenvironments (TMEs) and modulating tumor-targeting. To discover the dominant immune system archetypes, the University of California, San Francisco (UCSF) Immunoprofiler Initiative (IPI) processed 364 individual tumors across 12 cancer types using standardized protocols. Computational clustering of flow cytometry and transcriptomic data obtained from cell sub-compartments uncovered dominant patterns of immune composition across cancers. These archetypes were profound insofar as they also differentiated tumors based upon unique immune and tumor gene-expression patterns. They also partitioned well-established classifications of tumor biology. The IPI resource provides a template for understanding cancer immunity as a collection of dominant patterns of immune organization and provides a rational path forward to learn how to modulate these to improve therapy.

Activating Immune Recognition in Pancreatic Ductal Adenocarcinoma via Autophagy Inhibition, MEK Blockade, and CD40 Agonism.

BACKGROUND AND AIMS: Patients with pancreatic ductal adenocarcinoma (PDA) have not yet benefitted from the revolution in cancer immunotherapy due in large part to a dominantly immunosuppressive tumor microenvironment. MEK inhibition combined with autophagy inhibition leads to transient tumor responses in some patients with PDA. We examined the functional effects of combined MEK and autophagy inhibition on the PDA immune microenvironment and the synergy of combined inhibition of MEK and autophagy with CD40 agonism (aCD40) against PDA using immunocompetent model systems. METHODS: We implanted immunologically "cold" murine PDA cells orthotopically in wide type C57BL/6J mice. We administered combinations of inhibitors of MEK1/2, inhibitors of autophagy, and aCD40 and measured anticancer efficacy and immune sequelae using mass cytometry and multiplexed immunofluorescence imaging analysis to characterize the tumor microenvironment. We also used human and mouse PDA cell lines and human macrophages in vitro to perform functional assays to elucidate the cellular effects induced by the treatments. RESULTS: We find that coinhibition of MEK (using cobimetinib) and autophagy (using mefloquine), but not either treatment alone, activates the STING/type I interferon pathway in tumor cells that in turn activates paracrine tumor associated macrophages toward an immunogenic M1-like phenotype. This switch is further augmented by aCD40. Triple therapy (cobimetinib + mefloquine + aCD40) achieved cytotoxic T-cell activation in an immunologically "cold" mouse PDA model, leading to enhanced antitumor immunity. CONCLUSIONS: MEK and autophagy coinhibition coupled with aCD40 invokes immune repolarization and is an attractive therapeutic approach for PDA immunotherapy development.

Retrospective Case Series Analysis of RAF Family Alterations in Pancreatic Cancer: Real-World Outcomes From Targeted and Standard Therapies.

PURPOSE: In pancreatic cancer (PC), the RAF family alterations define a rare subset of patients that may predict response to inhibition of the BRAF/MEK/ERK signaling pathway. A comprehensive understanding of the molecular and clinical characteristics of RAF-mutated PC may support future development of RAF-directed strategies. METHODS: Clinical outcomes were assessed across a multi-institutional case series of 81 patients with RAF family-mutated PC. Mutational subgroups were defined on the basis of RAF alteration hotspots and therapeutic implications. RESULTS: The frequency of RAF alterations in PC was 2.2% (84 of 3,781) within a prevalence cohort derived from large molecular databases where BRAF V600E (Exon 15), BRAF ΔNVTAP (Exon 11), and SND1-BRAF fusions were the most common variants. In our retrospective case series, we identified 17 of 81 (21.0%) molecular profiles with a BRAF V600/Exon 15 mutation without any confounding drivers, 25 of 81 (30.9%) with BRAF or RAF1 fusions, and 18 of 81 (22.2%) with Exon 11 mutations. The remaining 21 of 81 (25.9%) profiles had atypical RAF variants and/or multiple oncogenic drivers. Clinical benefit from BRAF/MEK/ERK inhibitors was observed in 3 of 3 subjects within the V600 subgroup (two partial responses), 4 of 6 with fusions (two partial responses), 2 of 6 with Exon 11 mutations (one partial response), and 0 of 3 with confounding drivers. Outcomes analyses also suggested a trend favoring fluorouracil-based regimens over gemcitabine/nab-paclitaxel within the fusion subgroup (P = .027). CONCLUSION: Prospective evaluation of RAF-directed therapies is warranted in RAF-mutated PC; however, differential responses to targeted agents or standard regimens for each mutational subgroup should be a consideration when designing clinical trials.

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.

Single-cell transcriptome analysis defines heterogeneity of the murine pancreatic ductal tree.

To study disease development, an inventory of an organ's cell types and understanding of physiologic function is paramount. Here, we performed single-cell RNA-sequencing to examine heterogeneity of murine pancreatic duct cells, pancreatobiliary cells, and intrapancreatic bile duct cells. We describe an epithelial-mesenchymal transitory axis in our three pancreatic duct subpopulations and identify osteopontin as a regulator of this fate decision as well as human duct cell dedifferentiation. Our results further identify functional heterogeneity within pancreatic duct subpopulations by elucidating a role for geminin in accumulation of DNA damage in the setting of chronic pancreatitis. Our findings implicate diverse functional roles for subpopulations of pancreatic duct cells in maintenance of duct cell identity and disease progression and establish a comprehensive road map of murine pancreatic duct cell, pancreatobiliary cell, and intrapancreatic bile duct cell homeostasis.