Genomic alterations and transcriptional phenotypes in circulating tumor DNA and matched metastatic tumor.

Background: Profiling circulating cell-free DNA (cfDNA) has become a fundamental practice in cancer medicine, but the effectiveness of cfDNA at elucidating tumor-derived molecular features has not been systematically compared to standard single-lesion tumor biopsies in prospective cohorts of patients. The use of plasma instead of tissue to guide therapy is particularly attractive for patients with small cell lung cancer (SCLC), a cancer whose aggressive clinical course making it exceedingly challenging to obtain tumor biopsies. Methods: Here, a prospective cohort of 49 plasma samples obtained before, during, and after treatment from 20 patients with recurrent SCLC, we study cfDNA low pass whole genome (0.1X coverage) and exome (130X) sequencing in comparison with time-point matched tumor, characterized using exome and transcriptome sequencing. Results: Direct comparison of cfDNA versus tumor biopsy reveals that cfDNA not only mirrors the mutation and copy number landscape of the corresponding tumor but also identifies clinically relevant resistance mechanisms and cancer driver alterations not found in matched tumor biopsies. Longitudinal cfDNA analysis reliably tracks tumor response, progression, and clonal evolution. Genomic sequencing coverage of plasma DNA fragments around transcription start sites shows distinct treatment-related changes and captures the expression of key transcription factors such as NEUROD1 and REST in the corresponding SCLC tumors, allowing prediction of SCLC neuroendocrine phenotypes and treatment responses. Conclusions: These findings have important implications for non-invasive stratification and subtype-specific therapies for patients with SCLC, now treated as a single disease.

Berzosertib Plus Topotecan vs Topotecan Alone in Patients With Relapsed Small Cell Lung Cancer: A Randomized Clinical Trial.

Importance: Patients with relapsed small cell lung cancer (SCLC), a high replication stress tumor, have poor prognoses and few therapeutic options. A phase 2 study showed antitumor activity with the addition of the ataxia telangiectasia and Rad3-related kinase inhibitor berzosertib to topotecan. Objective: To investigate whether the addition of berzosertib to topotecan improves clinical outcomes for patients with relapsed SCLC. Design, Setting, and Participants: Between December 1, 2019, and December 31, 2022, this open-label phase 2 randomized clinical trial recruited 60 patients with SCLC and relapse after 1 or more prior therapies from 16 US cancer centers. Patients previously treated with topotecan were not eligible. Interventions: Eligible patients were randomly assigned to receive topotecan alone (group 1), 1.25 mg/m2 intravenously on days 1 through 5, or with berzosertib (group 2), 210 mg/m2 intravenously on days 2 and 5, in 21-day cycles. Randomization was stratified by tumor sensitivity to first-line platinum-based chemotherapy. Main Outcomes and Measures: The primary end point was progression-free survival (PFS) in the intention-to-treat population. Secondary end points included overall survival (OS) in the overall population and among patients with platinum-sensitive or platinum-resistant tumors. The PFS and OS for each treatment group were estimated using the Kaplan-Meier method. The log-rank test was used to compare PFS and OS between the 2 groups, and Cox proportional hazards models were used to estimate the treatment hazard ratios (HRs) and the corresponding 2-sided 95% CI. Results: Of 60 patients (median [range] age, 59 [34-79] years; 33 [55%] male) included in this study, 20 were randomly assigned to receive topotecan alone and 40 to receive a combination of topotecan with berzosertib. After a median (IQR) follow-up of 21.3 (18.1-28.3) months, there was no difference in PFS between the 2 groups (median, 3.0 [95% CI, 1.2-5.1] months for group 1 vs 3.9 [95% CI, 2.8-4.6] months for group 2; HR, 0.80 [95% CI, 0.46-1.41]; P = .44). Overall survival was significantly longer with the combination therapy (5.4 [95% CI, 3.2-6.8] months vs 8.9 [95% CI, 4.8-11.4] months; HR, 0.53 [95% CI, 0.29-0.96], P = .03). Adverse event profiles were similar between the 2 groups (eg, grade 3 or 4 thrombocytopenia, 11 of 20 [55%] vs 20 of 40 [50%], and any grade nausea, 9 of 20 [45%] vs 14 of 40 [35%]). Conclusions and Relevance: In this randomized clinical trial, treatment with berzosertib plus topotecan did not improve PFS compared with topotecan therapy alone among patients with relapsed SCLC. However, the combination treatment significantly improved OS. Trial Registration: ClinicalTrials.gov Identifier: NCT03896503.

Repurposing the FDA-approved anthelmintic pyrvinium pamoate for pancreatic cancer treatment: study protocol for a phase I clinical trial in early-stage pancreatic ductal adenocarcinoma.

BACKGROUND: Recent reports of the utilisation of pyrvinium pamoate (PP), an FDA-approved anti-helminth, have shown that it inhibits pancreatic ductal adenocarcinoma (PDAC) cell growth and proliferation in-vitro and in-vivo in preclinical models. Here, we report about an ongoing phase I open-label, single-arm, dose escalation clinical trial to determine the safety and tolerability of PP in PDAC surgical candidates. METHODS AND ANALYSIS: In a 3+3 dose design, PP is initiated 3 days prior to surgery. The first three patients will be treated with the initial dose of PP at 5 mg/kg orally for 3 days prior to surgery. Dose doubling will be continued to a reach a maximum of 20 mg/kg orally for 3 days, if the previous two dosages (5 mg/kg and 10 mg/kg) were tolerated. Dose-limiting toxicity grade≥3 is used as the primary endpoint. The pharmacokinetic and pharmacodynamic (PK/PD) profile of PP and bioavailability in humans will be used as the secondary objective. Each participant will be monitored weekly for a total of 30 days from the final dose of PP for any side effects. The purpose of this clinical trial is to examine whether PP is safe and tolerable in patients with pancreatic cancer, as well as assess the drug's PK/PD profile in plasma and fatty tissue. Potential implications include the utilisation of PP in a synergistic manner with chemotherapeutics for the treatment of pancreatic cancer. ETHICS AND DISSEMINATION: This study was approved by the Thomas Jefferson Institutional Review Board. The protocol number for this study is 20F.041 (Version 3.1 as of 27 October 2021). The data collected and analysed from this study will be used to present at local and national conferences, as well as, written into peer-reviewed manuscript publications. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov: NCT05055323.

ATR inhibition augments the efficacy of lurbinectedin in small-cell lung cancer.

Small-cell lung cancer (SCLC) is the most lethal type of lung cancer. Specifically, MYC-driven non-neuroendocrine SCLC is particularly resistant to standard therapies. Lurbinectedin was recently approved for the treatment of relapsed SCLC, but combinatorial approaches are needed to increase the depth and duration of responses to lurbinectedin. Using high-throughput screens, we found inhibitors of ataxia telangiectasia mutated and rad3 related (ATR) as the most effective agents for augmenting lurbinectedin efficacy. First-in-class ATR inhibitor berzosertib synergized with lurbinectedin in multiple SCLC cell lines, organoid, and in vivo models. Mechanistically, ATR inhibition abrogated S-phase arrest induced by lurbinectedin and forced cell cycle progression causing mitotic catastrophe and cell death. High CDKN1A/p21 expression was associated with decreased synergy due to G1 arrest, while increased levels of ERCC5/XPG were predictive of increased combination efficacy. Importantly, MYC-driven non-neuroendocrine tumors which are resistant to first-line therapies show reduced CDKN1A/p21 expression and increased ERCC5/XPG indicating they are primed for response to lurbinectedin-berzosertib combination. The combination is being assessed in a clinical trial NCT04802174.

Targeting Replication Stress and Chemotherapy Resistance with a Combination of Sacituzumab Govitecan and Berzosertib: A Phase I Clinical Trial.

PURPOSE: Despite promising preclinical studies, toxicities have precluded combinations of chemotherapy and DNA damage response (DDR) inhibitors. We hypothesized that tumor-targeted chemotherapy delivery might enable clinical translation of such combinations. PATIENTS AND METHODS: In a phase I trial, we combined sacituzumab govitecan, antibody-drug conjugate (ADC) that delivers topoisomerase-1 inhibitor SN-38 to tumors expressing Trop-2, with ataxia telangiectasia and Rad3-related (ATR) inhibitor berzosertib. Twelve patients were enrolled across three dose levels. RESULTS: Treatment was well tolerated, with improved safety over conventional chemotherapy-based combinations, allowing escalation to the highest dose. No dose-limiting toxicities or clinically relevant ≥grade 4 adverse events occurred. Tumor regressions were observed in 2 patients with neuroendocrine prostate cancer, and a patient with small cell lung cancer transformed from EGFR-mutant non-small cell lung cancer. CONCLUSIONS: ADC-based delivery of cytotoxic payloads represents a new paradigm to increase efficacy of DDR inhibitors. See related commentary by Berg and Choudhury, p. 3557.

A Novel 3DNA® Nanocarrier effectively delivers payloads to pancreatic tumors.

INTRODUCTION: Standard-of-care systemic chemotherapies for pancreatic ductal adenocarcinoma (PDAC) currently have limited clinical benefits, in addition to causing adverse side effects in many patients. One factor known to contribute to the poor chemotherapy response is the poor drug diffusion into PDAC tumors. Novel treatment methods are therefore drastically needed to improve targeted delivery of treatments. Here, we evaluated the efficacy of the 3DNA® Nanocarrier (3DNA) platform to direct delivery of therapeutics to PDAC tumors in vivo. MATERIALS AND METHODS: A panel of PDAC cell lines and a patient tissue microarray were screened for established tumor-specific proteins to identify targeting moieties for active targeting of the 3DNA. NRG mice with or without orthotopic MIA PaCa-2-luciferase PDAC tumors were treated intraperitoneally with 100 µl of fluorescently labeled 3DNA. RESULTS: Folic acid and transferrin receptors were significantly elevated in PDAC compared to normal pancreas. Accordingly, both folic acid- and transferrin-conjugated 3DNA treatments significantly increased delivery of 3DNA specifically to tumors in comparison to unconjugated 3DNA treatment. In the absence of tumors, there was an increased clearance of both folic acid-conjugated 3DNA and unconjugated 3DNA, compared to the clearance rate in tumor-bearing mice. Lastly, delivery of siLuciferase by folic acid-conjugated 3DNA in an orthotopic model of luciferase-expressing PDAC showed significant and prolonged suppression of luciferase protein expression and activity. CONCLUSION: Our study progresses the 3DNA technology as a reliable and effective treatment delivery platform for targeted therapeutic approaches in PDAC.

Extrachromosomal DNA Amplification Contributes to Small Cell Lung Cancer Heterogeneity and Is Associated with Worse Outcomes.

Small-cell lung cancer (SCLC) is an aggressive neuroendocrine lung cancer. Oncogenic MYC amplifications drive SCLC heterogeneity, but the genetic mechanisms of MYC amplification and phenotypic plasticity, characterized by neuroendocrine and nonneuroendocrine cell states, are not known. Here, we integrate whole-genome sequencing, long-range optical mapping, single-cell DNA sequencing, and fluorescence in situ hybridization to find extrachromosomal DNA (ecDNA) as a primary source of SCLC oncogene amplifications and driver fusions. ecDNAs bring to proximity enhancer elements and oncogenes, creating SCLC transcription-amplifying units, driving exceptionally high MYC gene dosage. We demonstrate that cell-free nucleosome profiling can noninvasively detect ecDNA amplifications in plasma, facilitating its genome-wide interrogation in SCLC and other cancers. Altogether, our work provides the first comprehensive map of SCLC ecDNA and describes a new mechanism that governs MYC-driven SCLC heterogeneity. ecDNA-enabled transcriptional flexibility may explain the significantly worse survival outcomes of SCLC harboring complex ecDNA amplifications. SIGNIFICANCE: MYC drives SCLC progression, but the genetic basis of MYC-driven SCLC evolution is unknown. Using SCLC as a paradigm, we report how ecDNA amplifications function as MYC-amplifying units, fostering tumor plasticity and a high degree of tumor heterogeneity. This article is highlighted in the In This Issue feature, p. 799.

Pyrvinium Pamoate: Past, Present, and Future as an Anti-Cancer Drug.

Pyrvinium, a lipophilic cation belonging to the cyanine dye family, has been used in the clinic as a safe and effective anthelminthic for over 70 years. Its structure, similar to some polyaminopyrimidines and mitochondrial-targeting peptoids, has been linked with mitochondrial localization and targeting. Over the past two decades, increasing evidence has emerged showing pyrvinium to be a strong anti-cancer molecule in various human cancers in vitro and in vivo. This efficacy against cancers has been attributed to diverse mechanisms of action, with the weight of evidence supporting the inhibition of mitochondrial function, the WNT pathway, and cancer stem cell renewal. Despite the overwhelming evidence demonstrating the efficacy of pyrvinium for the treatment of human cancers, pyrvinium has not yet been repurposed for the treatment of cancers. This review provides an in-depth analysis of the history of pyrvinium as a therapeutic, the rationale and data supporting its use as an anticancer agent, and the challenges associated with repurposing pyrvinium as an anti-cancer agent.

Replication stress defines distinct molecular subtypes across cancers.

Endogenous replication stress is a major driver of genomic instability. Current assessments of replication stress are low throughput precluding its comprehensive assessment across tumors. Here we develop and validate a transcriptional profile of replication stress by leveraging established cellular characteristics that portend replication stress. The repstress gene signature defines a subset of tumors across lineages characterized by activated oncogenes, aneuploidy, extrachromosomal DNA amplification, immune evasion, high genomic instability, and poor survival, and importantly predicts response to agents targeting replication stress more robustly than previously reported transcriptomic measures of replication stress. Repstress score profiles the dual roles of replication stress during tumorigenesis and in established cancers and defines distinct molecular subtypes within cancers that may be more vulnerable to drugs targeting this dependency. Altogether, our study provides a molecular profile of replication stress, providing novel biological insights of the replication stress phenotype, with clinical implications.

CDK7 Inhibition Synergizes with Topoisomerase I Inhibition in Small Cell Lung Cancer Cells by Inducing Ubiquitin-Mediated Proteolysis of RNA Polymerase II.

Small cell lung cancers (SCLC) are highly aggressive, and currently there are no available targeted therapies. To identify clinically actionable drug combinations, we analyzed our previously reported chemogenomics screens and identified a synergistically cytotoxic combination of the topoisomerase I (TOP1) inhibitor topotecan and cycle-dependent kinase 7 (CDK7) inhibitor THZ1. Topotecan causes cell death by generating TOP1-induced DNA breaks and DNA-protein cross-links (TOP1-DPC) that require proteolysis by the ubiquitin-proteasome pathway for their repair. We find that inhibition of the transcriptional kinase CDK7 by THZ1 induces ubiquitin-mediated proteasomal degradation of RNA polymerase II and prevents the proteasomal degradation of TOP1-DPCs. We provide a mechanistic basis for combinatorial targeting of transcription using selective inhibitors of CDK7 and TOP1 in clinical trials to advance SCLC therapeutics.

The RNA-Binding Protein HuR Posttranscriptionally Regulates the Protumorigenic Activator YAP1 in Pancreatic Ductal Adenocarcinoma.

Yes-associated protein 1 (YAP1) is indispensable for the development of mutant KRAS-driven pancreatic ductal adenocarcinoma (PDAC). High YAP1 mRNA is a prognostic marker for worse overall survival in patient samples; however, the regulatory mechanisms that mediate its overexpression are not well understood. YAP1 genetic alterations are rare in PDAC, suggesting that its dysregulation is likely not due to genetic events. HuR is an RNA-binding protein whose inhibition impacts many cancer-associated pathways, including the "conserved YAP1 signature" as demonstrated by gene set enrichment analysis. Screening publicly available and internal ribonucleoprotein immunoprecipitation (RNP-IP) RNA sequencing (RNA-Seq) data sets, we discovered that YAP1 is a high-confidence target, which was validated in vitro with independent RNP-IPs and 3' untranslated region (UTR) binding assays. In accordance with our RNA sequencing analysis, transient inhibition (e.g., small interfering RNA [siRNA] and small-molecular inhibition) and CRISPR knockout of HuR significantly reduced expression of YAP1 and its transcriptional targets. We used these data to develop a HuR activity signature (HAS), in which high expression predicts significantly worse overall and disease-free survival in patient samples. Importantly, the signature strongly correlates with YAP1 mRNA expression. These findings highlight a novel mechanism of YAP1 regulation, which may explain how tumor cells maintain YAP1 mRNA expression at dynamic times during pancreatic tumorigenesis.

Heterogeneity of neuroendocrine transcriptional states in metastatic small cell lung cancers and patient-derived models.

Molecular subtypes of small cell lung cancer (SCLC) defined by the expression of key transcription regulators have recently been proposed in cell lines and limited number of primary tumors. The clinical and biological implications of neuroendocrine (NE) subtypes in metastatic SCLC, and the extent to which they vary within and between patient tumors and in patient-derived models is not known. We integrate histology, transcriptome, exome, and treatment outcomes of SCLC from a range of metastatic sites, revealing complex intra- and intertumoral heterogeneity of NE differentiation. Transcriptomic analysis confirms previously described subtypes based on ASCL1, NEUROD1, POU2F3, YAP1, and ATOH1 expression, and reveal a clinical subtype with hybrid NE and non-NE phenotypes, marked by chemotherapy-resistance and exceedingly poor outcomes. NE tumors are more likely to have RB1, NOTCH, and chromatin modifier gene mutations, upregulation of DNA damage response genes, and are more likely to respond to replication stress targeted therapies. In contrast, patients preferentially benefited from immunotherapy if their tumors were non-NE. Transcriptional phenotypes strongly skew towards the NE state in patient-derived model systems, an observation that was confirmed in paired patient-matched tumors and xenografts. We provide a framework that unifies transcriptomic and genomic dimensions of metastatic SCLC. The marked differences in transcriptional diversity between patient tumors and model systems are likely to have implications in development of novel therapeutic agents.

The FDA-Approved Anthelmintic Pyrvinium Pamoate Inhibits Pancreatic Cancer Cells in Nutrient-Depleted Conditions by Targeting the Mitochondria.

Pancreatic ductal adenocarcinoma (PDAC) is a lethal aggressive cancer, in part due to elements of the microenvironment (hypoxia, hypoglycemia) that cause metabolic network alterations. The FDA-approved antihelminthic pyrvinium pamoate (PP) has previously been shown to cause PDAC cell death, although the mechanism has not been fully determined. We demonstrated that PP effectively inhibited PDAC cell viability with nanomolar IC50 values (9-93 nmol/L) against a panel of PDAC, patient-derived, and murine organoid cell lines. In vivo, we demonstrated that PP inhibited PDAC xenograft tumor growth with both intraperitoneal (IP; P < 0.0001) and oral administration (PO; P = 0.0023) of human-grade drug. Metabolomic and phosphoproteomic data identified that PP potently inhibited PDAC mitochondrial pathways including oxidative phosphorylation and fatty acid metabolism. As PP treatment reduced oxidative phosphorylation (P < 0.001), leading to an increase in glycolysis (P < 0.001), PP was 16.2-fold more effective in hypoglycemic conditions similar to those seen in PDAC tumors. RNA sequencing demonstrated that PP caused a decrease in mitochondrial RNA expression, an effect that was not observed with established mitochondrial inhibitors rotenone and oligomycin. Mechanistically, we determined that PP selectively bound mitochondrial G-quadruplexes and inhibited mitochondrial RNA transcription in a G-quadruplex-dependent manner. This subsequently led to a 90% reduction in mitochondrial encoded gene expression. We are preparing to evaluate the efficacy of PP in PDAC in an IRB-approved window-of-opportunity trial (IND:144822).

Splenic-vasculature involvement is associated with poor prognosis in resected distal pancreatic cancer.

BACKGROUND: Distal pancreatic carcinoma is one of the most lethal cancers largely due to its high incidence of distant metastasis. This study aims to assess the prognostic value of splenic-vasculature involvement in resected distal pancreatic carcinoma. METHODS: In this retrospective study, we collected the clinicopathologic information of 454 patients with pancreatic cancer and performed univariate and multivariate analyses to identify factors associated with progression-free survival (PFS) and overall survival (OS), with an emphasis on the prognostic value of splenic-artery and -vein involvement. RESULTS: Univariate analysis revealed that larger tumor size, non-intraductal papillary mucinous neoplasm (non-IPMN)-associated adenocarcinoma, poor differentiation, stage pT3, nodal metastasis, lymphovascular invasion, perineural invasion, and pathologic and radiographic evidence of splenic-vein invasion were significantly associated with shorter PFS and OS (all P < 0.05). Multivariate analysis confirmed non-IPMN-associated adenocarcinoma, stage pT3, stage pN1-2, and post-operative adjuvant chemotherapy as independent risk factors for both PFS and OS, and larger tumor size and radiographic evidence of splenic-artery invasion as predictors of PFS only. CONCLUSION: Guidelines should be developed for a uniform approach with regard to the examination and reporting of the status of the splenic vasculature when dealing with distal-pancreatic-cancer specimens.

Novel and Highly Potent ATR Inhibitor M4344 Kills Cancer Cells With Replication Stress, and Enhances the Chemotherapeutic Activity of Widely Used DNA Damaging Agents.

Although several ATR inhibitors are in development, there are unresolved questions regarding their differential potency, molecular signatures of patients with cancer for predicting activity, and most effective therapeutic combinations. Here, we elucidate how to improve ATR-based chemotherapy with the newly developed ATR inhibitor, M4344 using in vitro and in vivo models. The potency of M4344 was compared with the clinically developed ATR inhibitors BAY1895344, berzosertib, and ceralasertib. The anticancer activity of M4344 was investigated as monotherapy and combination with clinical DNA damaging agents in multiple cancer cell lines, patient-derived tumor organoids, and mouse xenograft models. We also elucidated the anticancer mechanisms and potential biomarkers for M4344. We demonstrate that M4344 is highly potent among the clinically developed ATR inhibitors. Replication stress (RepStress) and neuroendocrine (NE) gene expression signatures are significantly associated with a response to M4344 treatment. M4344 kills cancer cells by inducing cellular catastrophe and DNA damage. M4344 is highly synergistic with a broad range of DNA-targeting anticancer agents. It significantly synergizes with topotecan and irinotecan in patient-derived tumor organoids and xenograft models. Taken together, M4344 is a promising and highly potent ATR inhibitor. It enhances the activity of clinical DNA damaging agents commonly used in cancer treatment including topoisomerase inhibitors, gemcitabine, cisplatin, and talazoparib. RepStress and NE gene expression signatures can be exploited as predictive markers for M4344.

Therapeutic targeting of ATR yields durable regressions in small cell lung cancers with high replication stress.

Small cell neuroendocrine cancers (SCNCs) are recalcitrant cancers arising from diverse primary sites that lack effective treatments. Using chemical genetic screens, we identified inhibition of ataxia telangiectasia and rad3 related (ATR), the primary activator of the replication stress response, and topoisomerase I (TOP1), nuclear enzyme that suppresses genomic instability, as synergistically cytotoxic in small cell lung cancer (SCLC). In a proof-of-concept study, we combined M6620 (berzosertib), first-in-class ATR inhibitor, and TOP1 inhibitor topotecan in patients with relapsed SCNCs. Objective response rate among patients with SCLC was 36% (9/25), achieving the primary efficacy endpoint. Durable tumor regressions were observed in patients with platinum-resistant SCNCs, typically fatal within weeks of recurrence. SCNCs with high neuroendocrine differentiation, characterized by enhanced replication stress, were more likely to respond. These findings highlight replication stress as a potentially transformative vulnerability of SCNCs, paving the way for rational patient selection in these cancers, now treated as a single disease.

Selecting the optimal parameters for sonoporation of pancreatic cancer in a pre-clinical model.

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers in the modern world, in part due to poor delivery of chemotherapeutics. Sonoporation can be used to enhance the efficacy of standard of care therapies for PDAC. Using xenograft models of PDAC we investigate sonoporation using four ifferent ultrasound contrast agents (UCAs) and two ultrasound regimens to identify the ideal parameters to increase therapeutic efficacy. MIA-PaCa2 xenografts in over 175 immunodeficient mice were treated with gemcitabine and paclitaxel and subjected to low or high power ultrasound (60 and 200 mW/cm2 respectively) in conjunction with one of four different UCAs. The UCAs investigated were Definity®, SonoVue®, Optison™ or Sonazoid™. Tumor volumes, vascularity, hemoglobin, and oxygenation were measured and compared to controls. High power treatment in conjunction with Sonazoid sonoporation led to significantly smaller tumors when started early (tumors ~50mm3; p = .0105), while no UCAs significantly increased efficacy in the low power cohort. This trend was also found in larger tumors (~250mm3) where all four UCA agents significantly increased therapeutic efficacy in the high power group (p < .01), while only Definity and SonoVue increased efficacy in the low power cohort (p < .03). Overall, the higher power ultrasound treatment modality was more consistently effective at decreasing tumor volume and increasing vascularity characteristics. In conclusion, Sonazoid was the most consistently effective UCA at decreasing tumor volume and increasing vascularity. Thus, we are pursuing a larger phase II clinical trial to validate the increased efficacy of sonoporation in conjunction with chemotherapy in PDAC patients.

Margin-Positive Pancreatic Ductal Adenocarcinoma during Pancreaticoduodenectomy: Additional Resection Does Not Improve Survival.

BACKGROUND: The impact of resecting positive margins during pancreaticoduodenectomy (PD) for pancreatic ductal adenocarcinoma (PDA) remains debated. Additionally, the survival benefit of resecting multiple positive margins is unknown. METHODS: We identified patients with PDA who underwent PD from 2006 to 2015. Pancreatic neck, bile duct, and uncinate frozen section margins were assessed before and after resection of positive margins. Survival curves were compared with log-rank tests. Multivariable Cox regression assessed the effect of margin status on overall survival. RESULTS: Of 501 patients identified, 17.3%, 5.3%, and 19.7% had an initially positive uncinate, bile duct, or neck margin, respectively. Among initially positive bile duct and neck margins, 77.8% and 67.0% were resected, respectively. Although median survival was decreased among patients with any positive margins (15.6 vs. 20.9 months; p = 0.006), it was similar among patients with positive bile duct or neck margins with or without R1 to R0 resection (17.0 vs. 15.6 months; p = 0.20). Median survival with and without positive uncinate margins was 13.8 vs. 19.7 months (p = 0.04). Uncinate margins were never resected. Resection of additional margins when the uncinate was concurrently positive was not associated with improved survival (p = 0.37). Patients with positive margins who received adjuvant therapy had improved survival, regardless of margin resection (p = 0.03). Adjuvant therapy was independently protective against death (hazard ratio 0.6, 95% CI 0.5-0.7). CONCLUSIONS: Positive PD margins at any position are associated with reduced overall survival; however, resection of additional margins may not improve survival, particularly with concurrently positive uncinate margins. Adjuvant chemotherapy improves survival with positive margins, regardless of resection.