Combined MEK and STAT3 Inhibition Uncovers Stromal Plasticity by Enriching for Cancer-Associated Fibroblasts With Mesenchymal Stem Cell-Like Features to Overcome Immunotherapy Resistance in Pancreatic Cancer.

BACKGROUND & AIMS: We have shown that reciprocally activated rat sarcoma (RAS)/mitogen-activated protein kinase/extracellular signal-regulated kinase (MEK) and Janus kinase/signal transducer and activator of transcription 3 (STAT3) pathways mediate therapeutic resistance in pancreatic ductal adenocarcinoma (PDAC), while combined MEK and STAT3 inhibition (MEKi+STAT3i) overcomes such resistance and alters stromal architecture. We now determine whether MEKi+STAT3i reprograms the cancer-associated fibroblast (CAF) and immune microenvironment to overcome resistance to immune checkpoint inhibition in PDAC. METHODS: CAF and immune cell transcriptomes in MEKi (trametinib)+STAT3i (ruxolitinib)-treated vs vehicle-treated Ptf1aCre/+;LSL-KrasG12D/+;Tgfbr2flox/flox (PKT) tumors were examined via single-cell RNA sequencing (scRNAseq). Clustered regularly interspaced short palindromic repeats/clustered regularly interspaced short palindromic repeats associated protein 9 silencing of CAF-restricted Map2k1/Mek1 or Stat3, or both, enabled interrogation of CAF-dependent effects on immunologic remodeling in orthotopic models. Tumor growth, survival, and immune profiling via mass cytometry by time-of-flight were examined in PKT mice treated with vehicle, anti-programmed cell death protein 1 (PD-1) monotherapy, and MEKi+STAT3i combined with anti-PD1. RESULTS: MEKi+STAT3i attenuates Il6/Cxcl1-expressing proinflammatory and Lrrc15-expressing myofibroblastic CAF phenotypes while enriching for Ly6a/Cd34-expressing CAFs exhibiting mesenchymal stem cell-like features via scRNAseq in PKT mice. This CAF plasticity is associated with M2-to-M1 reprogramming of tumor-associated macrophages, and enhanced trafficking of cluster of differentiation 8+ T cells, which exhibit distinct effector transcriptional programs. These MEKi+STAT3i-induced effects appear CAF-dependent, because CAF-restricted Mek1/Stat3 silencing mitigates inflammatory-CAF polarization and myeloid infiltration in vivo. Addition of MEKi+STAT3i to PD-1 blockade not only dramatically improves antitumor responses and survival in PKT mice but also augments recruitment of activated/memory T cells while improving their degranulating and cytotoxic capacity compared with anti-PD-1 monotherapy. Importantly, treatment of a patient who has chemotherapy-refractory metastatic PDAC with MEKi (trametinib), STAT3i (ruxolitinib), and PD-1 inhibitor (nivolumab) yielded clinical benefit. CONCLUSIONS: Combined MEKi+STAT3i mitigates stromal inflammation and enriches for CAF phenotypes with mesenchymal stem cell-like properties to overcome immunotherapy resistance in PDAC.

Multicenter randomized controlled trial and registry study to assess the safety and efficacy of the NanoKnife® system for the ablation of stage 3 pancreatic adenocarcinoma: overview of study protocols.

BACKGROUND: Irreversible electroporation (IRE) is a local ablation technique utilizing high voltage, low energy direct current to create nanopores in cell membrane which disrupt homeostasis and leads to cell death. Previous reports have suggested IRE may have a role in treating borderline resectable and unresectable Stage 3 pancreatic tumors. METHODS: Patients with Stage 3 pancreatic ductal adenocarcinoma (PDAC) will be enrolled in either a randomized, controlled, multicenter trial (RCT) or a multicenter registry study. Subjects enrolled in the RCT must have no evidence of disease progression after 3 months of modified FOLFIRINOX (mFOLFIRINOX) treatment prior to being randomization to either a control or IRE arm. Post-induction and post-IRE treatment for the control and IRE arms, respectively, will be left to the discretion of the treating physician. The RCT will enroll 528 subjects with 264 per arm and include up to 15 sites. All subjects will be followed for at least 24 months or until death. The registry study will include two cohorts of patients with Stage 3 PDAC, patients who received institutional standard of care (SOC) alone and those treated with IRE in addition to SOC. Both cohorts will be required to have undergone at least 3 months of SOC without progression prior to enrollment. The registry study will enroll 532 patients with 266 patients in each arm. All patients will be followed for at least 24 months or until death. The primary efficacy endpoint for both studies will be overall survival (OS). Co-primary safety endpoints will be 1) time from randomization or enrollment in the registry to death or new onset of Grade 4 adverse event (AE), and (2 high-grade complications defined as any AE or serious AE (SAE) with a CTCAE v5.0 grade of 3 or higher. Secondary endpoints will include progression-free survival, cancer-related pain, quality of life, and procedure-related pain for the IRE arm only. DISCUSSION: These studies are intended to provide Level 1 clinical evidence and real-world data demonstrating the clinical utility and safety of the use of IRE in combination with chemotherapy in patients with Stage 3 PDAC. TRIAL REGISTRATION: Clinicaltrials.gov NCT03899636 and NCT03899649. Registered April 2, 2019. Food and Drug Administration (FDA) Investigational Device Exemption (IDE) trial G180278 approved on May 3, 2019.

Phase 2 study of pembrolizumab and circulating biomarkers to predict anticancer response in advanced, unresectable hepatocellular carcinoma.

BACKGROUND: Checkpoint inhibitors have shown modest activity in patients with advanced hepatocellular carcinoma (HCC). Herein, the authors report a prospective single-institution clinical/translational phase 2 study of pembrolizumab in patients with advanced HCC and circulating biomarkers closely related to response. METHODS: Pembrolizumab was administered at a dose of 200 mg intravenously every 3 weeks among patients who may have developed disease progression while receiving, were intolerant of, or refused sorafenib. The circulating levels of cytokines, chemokines, programmed cell death protein 1 (PD-1), programmed death-ligand 1 (PD-L1), and PD-L2 were correlated with response, tumor PD-L1 expression, and other clinicopathological features. RESULTS: A total of 29 patients were treated and 28 patients were evaluable for response. The most common laboratory grade 3/4 adverse events were increases in aspartate aminotransferase and/or alanine aminotransferase and serum bilirubin, which for the most part were reversible. In terms of efficacy, one patient achieved a complete response and 8 patients achieved partial responses for an overall response rate of 32%. Four other patients had stable disease. The median progression-free survival was 4.5 months and the median overall survival was 13 months. Response did not correlate with prior sorafenib therapy, PD-L1 tumor staining, or a prior history of hepatitis. Correlative studies revealed that high baseline plasma TGF-ß levels (≥200 pg/mL) significantly correlated with poor treatment outcomes after pembrolizumab. Tumor PD-L1 and plasma PD-L1/PD-1 levels were associated with plasma IFN-γ or IL-10. CONCLUSIONS: Pembrolizumab was found to demonstrate activity in patients with advanced HCC. Toxicity generally was tolerable and reversible. A set of immunological markers in blood plasma as well as PD-L1 staining indicated that baseline TGF-ß could be a predictive biomarker for response to pembrolizumab.

Comprehensive genomic profiling in routine clinical practice leads to a low rate of benefit from genotype-directed therapy.

BACKGROUND: Describe a single-center real-world experience with comprehensive genomic profiling (CGP) to identify genotype directed therapy (GDT) options for patients with malignancies refractory to standard treatment options. METHODS: Patients who had CGP by a CLIA-certified laboratory between November 2012 and December 2015 were included. The medical records were analyzed retrospectively after Institutional Review Board (IRB) approval. The treating oncologist made the decision to obtain the assay to provide potential therapeutic options. The objectives of this study were to determine the proportion of patients who benefited from GDT, and to identify barriers to receiving GDT. RESULTS: A total of 125 pediatric and adult patients with a histologically confirmed diagnosis of malignancy were included. Among these, 106 samples were from adult patients, and 19 samples were from pediatric patients. The median age was 54 years for adults. The majority had stage IV malignancy (53%) and were pretreated with 2-3 lines of therapy (45%). The median age was 8 years for pediatric patients. The majority had brain tumors (47%) and had received none or 1 line of therapy (58%) when the profiling was requested. A total of 111 (92%) patients had genomic alterations and were candidates for GDT either via on/off-label use or a clinical trial (phase 1 through 3). Fifteen patients (12%) received GDT based on these results including two patients who were referred for genomically matched phase 1 clinical trials. Three patients (2%) derived benefit from their GDT that ranged from 2 to 6 months of stable disease. CONCLUSIONS: CGP revealed potential treatment options in the majority of patients profiled. However, multiple barriers to therapy were identified, and only a small minority of the patients derived benefit from GDT.

Effect of complications on oncologic outcomes after pancreaticoduodenectomy for pancreatic cancer.

BACKGROUND: Although adjuvant therapy (AT) is a necessary component of multimodality therapy for pancreatic ductal adenocarcinoma (PDAC), its application can be hindered by post-pancreaticoduodenectomy (PD) complications. The primary aim of this study was to evaluate the impact of post-PD complications on AT utilization and overall survival (OS). METHODS: Patients undergoing PD without neoadjuvant therapy for stages I-III PDAC at a single institution (2007-2015) were evaluated. Ninety-day postoperative major complications (PMCs) were defined as grade ≥3. Records were linked to the Kentucky Cancer Registry for AT/OS data. Early AT was given <8 wk; late 8-16 wk. Initiation >16 wk was not considered to be AT. Complication effects on AT timing/utilization and OS were evaluated. RESULTS: Of 93 consecutive patients treated with surgery upfront with AT data, 64 (69%) received AT (41 [44%] early; 23 [25%] late). There were 32 patients (34%) with low-grade complications and 24 (26%) with PMC. With PMC, only six of 24 patients (25%) received early AT and 13 of 24 (54%) received any (early/late) AT versus 35 of 69 (51%) early AT and 51 of 69 (74%) any AT without PMC. PMCs were associated with worse median OS (7.1 versus 24.6 mo, without PMC, P < 0.001). Independent predictors of OS included AT (hazard ratio [HR]: 0.48), tumor >2 cm (HR: 3.39), node-positivity (HR: 2.16), and PMC (HR: 3.69, all P < 0.02). CONCLUSIONS: Independent of AT utilization and biologic factors, PMC negatively impacted OS in patients treated with surgery first. These data suggest that strategies to decrease PMC and treatment sequencing alternatives to increase multimodality therapy rates may improve oncologic outcomes for PDAC.

Percutaneous Image-Guided Irreversible Electroporation for the Treatment of Unresectable, Locally Advanced Pancreatic Adenocarcinoma.

PURPOSE: To describe safety and effectiveness of percutaneous irreversible electroporation (IRE) for treatment of unresectable, locally advanced pancreatic adenocarcinoma (LAPC). MATERIALS AND METHODS: This retrospective study included 50 patients (23 women, 27 men; age range, 46-91 y; median age, 62.5 y) with biopsy-proven, unresectable LAPC who received percutaneous computed tomography (CT)-guided IRE. The primary objective was to assess the safety profile of the procedure; the secondary objective was to determine overall survival (OS). All patients had prior chemotherapy (1-5 lines, median 2), and 30 (60%) of 50 patients had prior radiation therapy. Follow-up included CT at 1 month and at 3-month intervals thereafter. RESULTS: There were no treatment-related deaths and no 30-day mortality. Serious adverse events occurred in 10 (20%) of 50 patients (abdominal pain [n = 7], pancreatitis [n = 1], sepsis [n = 1], gastric leak [n = 1]). Median OS was 27.0 months (95% confidence interval [CI], 22.7-32.5 months) from time of diagnosis and 14.2 months (95% CI, 9.7-16.2 months) from time of IRE. Patients with tumors ≤ 3 cm (n = 24) had significantly longer median OS than patients with tumors > 3 cm (n = 26): 33.8 vs 22.7 months from time of diagnosis (P = .002) and 16.2 vs 9.9 months from time of IRE (P = .031). Tumor size was confirmed as the only independent predictor of OS at multivariate analysis. CONCLUSIONS: Percutaneous image-guided IRE of unresectable LAPC is associated with an acceptable safety profile.

FOLFIRINOX for locally advanced pancreatic cancer: a systematic review and patient-level meta-analysis.

BACKGROUND: 35% of patients with pancreatic cancer have unresectable locally advanced disease at diagnosis. Several studies have examined systemic chemotherapy with FOLFIRINOX (leucovorin and fluorouracil plus irinotecan and oxaliplatin) in patients with locally advanced pancreatic cancer. We aimed to assess the effectiveness of FOLFIRINOX as first-line treatment in this patient population. METHODS: We systematically searched Embase, MEDLINE (OvidSP), Web of Science, Scopus, PubMed Publisher, Cochrane, and Google Scholar from July 1, 1994, to July 2, 2015, for studies of treatment-naive patients of any age who received FOLFIRINOX as first-line treatment of locally advanced pancreatic cancer. Our primary outcome was overall survival. Secondary outcomes were progression-free survival; rates of grade 3 or 4 adverse events; and the proportion of patients who underwent radiotherapy or chemoradiotherapy, surgical resection after FOLFIRINOX, and R0 resection. We evaluated survival outcomes with the Kaplan-Meier method with patient-level data. Grade 3 or 4 adverse events, and the proportion of patients who underwent subsequent radiotherapy or chemoradiotherapy or resection, were pooled in a random-effects model. FINDINGS: We included 13 studies comprising 689 patients, of whom 355 (52%) patients had locally advanced pancreatic cancer. 11 studies, comprising 315 patients with locally advanced disease, reported survival outcomes and were eligible for patient-level meta-analysis. Median overall survival from the start of FOLFIRINOX ranged from 10·0 months (95% CI 4·0-16·0) to 32·7 months (23·1-42·3) across studies with a pooled patient-level median overall survival of 24·2 months (95% CI 21·7-26·8). Median progression-free survival ranged from 3·0 months (95% CI not calculable) to 20·4 months (6·5-34·3) across studies with a patient-level median progression-free survival of 15·0 months (95% 13·8-16·2). In ten studies comprising 490 patients, 296 grade 3 or 4 adverse events were reported (60·4 events per 100 patients). No deaths were attributed to FOLFIRINOX toxicity. The proportion of patients who underwent radiotherapy or chemoradiotherapy ranged from 31% to 100% across studies. In eight studies, 154 (57%) of 271 patients received radiotherapy or chemoradiotherapy after FOLFIRINOX. The pooled proportion of patients who received any radiotherapy treatment was 63·5% (95% CI 43·3-81·6, I(2) 90%). The proportion of patients who underwent surgical resection for locally advanced pancreatic cancer ranged from 0% to 43%. The proportion of patients who had R0 resection of those who underwent resection ranged from 50% to 100% across studies. In 12 studies, 91 (28%) of 325 patients underwent resection after FOLFIRINOX. The pooled proportion of patients who had resection was 25·9% (95% CI 20·2-31·9, I(2) 24%). R0 resection was reported in 60 (74%) of 81 patients. The pooled proportion of patients who had R0 resection was 78·4% (95% CI 60·2-92·2, I(2) 64%). INTERPRETATION: Patients with locally advanced pancreatic cancer treated with FOLFIRINOX had a median overall survival of 24·2 months-longer than that reported with gemcitabine (6-13 months). Future research should assess these promising results in a randomised controlled trial, and should establish which patients might benefit from radiotherapy or chemoradiotherapy or resection after FOLFIRINOX. FUNDING: None.

Colorectal Tumors From Different Racial and Ethnic Minorities Have Similar Rates of Mismatch Repair Deficiency.

BACKGROUND & AIMS: Microsatellite instability (MSI) in colorectal cancer cells results from deficient mismatch repair (MMR) protein function, either acquired or from germline alterations such as in patients with Lynch syndrome. Universal screening initiatives for Lynch syndrome have been encouraged. However, little is known about the true prevalence of MMR deficiency and MSI in colorectal tumors among individuals from different racial and ethnic subgroups or their clinical effects in these populations. METHODS: We performed a retrospective analysis of 253 surgically resected, primary colorectal adenocarcinoma specimens identified from the University of Miami tumor registry from 2005 through 2010. We collected clinical data, including overall survival (OS), the proportion of patients alive at specific intervals, from non-Hispanic white, Hispanic, and black patients matched by stage. We performed immunohistochemical staining to detect MMR proteins in all specimens and polymerase chain reaction analysis of 51 tumors to detect MSI. RESULTS: We detected MMR deficiency in 28 of 253 cases (11.1%), evenly distributed among blacks (9.6%), non-Hispanic whites (10.4%), and Hispanics (12.6%) (P = .79). Combined deficiencies in MLH1 and PMS2 were found in 23 of 28 MMR-deficient samples (82.1%); MSH2 and MSH6 were most frequently absent in tumor samples from Hispanics (P = .03). Eleven of 51 tumor samples (21.6%) had high levels of MSI, and we observed a high level of concordance between MMR and MSI (κ = .81). OS was significantly better in patients whose tumors had deficient MMR (hazard ratio for patients with MMR-deficient tumors vs MMR proteins intact = 0.37; 95% confidence interval, 0.15-0.91; P = .03). Race and ethnicity were not significant predictors of OS. CONCLUSIONS: MMR deficiency in colorectal tumors occurs with similar rates among patients of different racial and ethnic groups, which is based on immunohistochemical analysis of 253 primary tumor specimens. This finding indicates the potential value of universal testing of colorectal cancer by immunohistochemistry in minority populations and confirms the benefit of MMR deficiency to OS.

Defining the optimal timing of adjuvant therapy for resected pancreatic adenocarcinoma: A statewide cancer registry analysis.

BACKGROUND: Long-term results of the ESPAC-3 trial suggest that while completing adjuvant therapy (AT) is necessary after resection of pancreatic ductal adenocarcinoma (PDAC), early initiation (within 8 weeks) may not be associated with improved overall survival (OS). The primary aim of this study was to evaluate the OS impact of early versus late AT in a statewide analysis. METHODS: Patients with stages I-III PDAC in the Kentucky Cancer Registry (KCR) from 2004 to 2013, were evaluated. Those undergoing pancreatectomy were stratified into two groups ("early," <8 weeks, vs. "late," 8-16 weeks). RESULTS: Of 2,221 diagnosed patients with stages I-III, 831 (37.4%) underwent pancreatectomy upfront. Of these, only 420 (50.5%) received AT. Initiation date of AT was not associated with OS (median OS: early, 20.2 vs. late, 19.0 months, P = 0.97). On multivariate analysis, factors that affected OS included stage (II, HR-1.82, P = 0.017; III, HR-3.77, P < 0.001), node positivity (HR-1.51, P = 0.004), poorly/undifferentiated grade (HR-1.34; P = 0.011), but not AT initiation date. CONCLUSIONS: In this statewide analysis, there was no difference in OS between early and late AT initiation for resected PDAC. The ideal window for AT initiation remains unknown as tumor biology continues to trump regimens from the past decade. J. Surg. Oncol. 2016;114:451-455. © 2016 Wiley Periodicals, Inc.

Long-term outcome of patients undergoing liver transplantation for mixed hepatocellular carcinoma and cholangiocarcinoma: an analysis of the UNOS database.

BACKGROUND: Mixed hepatocellular and cholangiocarcinoma (HCC-CC) have been associated with a poor prognosis after liver transplantation (LT). We aimed to evaluate long-term outcomes in patients undergoing LT for HCC-CC versus patients with hepatocellular carcinoma (HCC) or cholangiocarcinoma (CC). METHODS: Retrospective analysis of the United Network for Organ Sharing (UNOS) database from 1994-2013. Overall survival (OS) in patients with HCC-CC, HCC, and CC, were compared. RESULTS: We identified 4049 patients transplanted for primary malignancy (94 HCC-CC; 3515 HCC; 440 CC). Mean age of patients with HCC-CC was 57 ± 10 years, and 77% were male. MELD score did not differ among the groups (p = 0.637). Hepatitis C virus was the most common secondary diagnosis within the HCC-CC (44%) and HCC (36%) cohorts, with primary sclerosing cholangitis in the CC (16%) cohort. OS rates at 1, 3 and 5 years for HCC-CC (82%, 47%, 40%) were similar to CC (79%, 58%, 47%), but significantly worse than HCC (86%, 72%, and 62% p = 0.002). DISCUSSION: Patients undergoing LT for HCC had significantly better survival compared to those transplanted for HCC-CC and CC. LT for mixed HCC-CC confers a survival rate similar to selected patients with CC. Efforts should be made to identify HCC-CC patients preoperatively.

Full dose neoadjuvant FOLFIRINOX is associated with prolonged survival in patients with locally advanced pancreatic adenocarcinoma.

BACKGROUND: The efficacy of FOLFIRINOX for metastatic pancreatic cancer has led to its use in patients with earlier stages of disease. This study retrospectively analyzed a cohort of patients with locally-advanced pancreatic cancer (LAPC) treated with FOLFIRINOX. METHODS: Between 2008 and 2013, 51 treatment-naïve patients with LAPC at a single institution received first-line FOLFIRINOX with neoadjuvant intent, at the full dose as described in the PRODIGE 4/ACCORD 11 study. Combined chemoradiation was administered for those who remained unresectable after maximum response to chemotherapy. The primary outcome measure was overall survival (OS), and secondary outcomes were progression-free survival (PFS) and margin-negative (R0) resection rate, and toxicity profile. RESULTS: A total of 429 cycles of FOLFIRINOX were given with a median of 8 cycles (range 2-29) per patient; 66% of cycles were full dose. After chemotherapy, 27 (53%) received chemoradiation. The median OS was 35.4 months (95% CI 25.8-45). Ten (4 borderline resectable and 6 unresectable) patients had successful R0 resections; those who had R0 resections had a significantly longer survival than those who did not (3-year OS rate 67% versus 21%, log rank p = 0.042). Increasing number of full-dose cycles was significantly associated with increased survival. The toxicity profile was similar to previous reports of this regimen. CONCLUSIONS: FOLFIRINOX is feasible as neoadjuvant therapy for LAPC. Although the R0 resection rate was only 20%, the median OS of almost 3 years appears promising. Dose intensity and duration were associated with increased survival in this study, arguing against dose attenuated versions of this regimen.

Updated survival analysis of two sequential prospective trials of R-MACLO-IVAM followed by maintenance for newly diagnosed mantle cell lymphoma.

A phase II trial of R-MACLO-IVAM followed by thalidomide maintenance for mantle cell lymphoma (MCL) demonstrated promising progression-free survival (PFS) and overall survival (OS) rates. Thalidomide maintenance was associated with significant toxicity and was subsequently modified to rituximab maintenance. Herein, we present updated results and follow-up. Two sequential phase II trials included chemotherapy-naïve patients with MCL up to 75 years old. Four cycles of R-MACLO-IVAM chemotherapy were delivered as previously described. Patients who achieved complete responses (CR) were eligible for thalidomide or rituximab maintenance therapy. Among 36 patients enrolled, the MCL International Prognostic Index (MIPI) was low in 53%, intermediate in 36% and high in 11%. Thirty-five patients completed at least 2 cycles of chemotherapy; 34 (94%) achieved a CR. After a median follow-up of 74.4 months, the 5-year PFS was 51% (95% CI 33-68%) and the 5-year OS was 85% (95% CI 73-97%). Two deaths occurred during the chemotherapy phase due to disease progression and neutropenic sepsis, respectively. One patient developed secondary acute myeloid leukemia after 7 years. R-MACLO-IVAM chemotherapy is effective for patients with newly diagnosed MCL.

LMO2 and BCL6 are associated with improved survival in primary central nervous system lymphoma.

Primary central nervous system lymphoma (PCNSL) is an aggressive sub-variant of non-Hodgkin lymphoma (NHL) with morphological similarities to diffuse large B-cell lymphoma (DLBCL). While methotrexate (MTX)-based therapies have improved patient survival, the disease remains incurable in most cases and its pathogenesis is poorly understood. We evaluated 69 cases of PCNSL for the expression of HGAL (also known as GCSAM), LMO2 and BCL6 - genes associated with DLBCL prognosis and pathobiology, and analysed their correlation to survival in 49 PCNSL patients receiving MTX-based therapy. We demonstrate that PCNSL expresses LMO2, HGAL(also known as GCSAM) and BCL6 proteins in 52%, 65% and 56% of tumours, respectively. BCL6 protein expression was associated with longer progression-free survival (P = 0·006) and overall survival (OS, P = 0·05), while expression of LMO2 protein was associated with longer OS (P = 0·027). Further research is needed to elucidate the function of BCL6 and LMO2 in PCNSL.

A multicentre study of primary breast diffuse large B-cell lymphoma in the rituximab era.

Primary breast diffuse large B-cell lymphoma (DLBCL) is a rare subtype of non-Hodgkin lymphoma (NHL) with limited data on pathology and outcome. A multicentre retrospective study was undertaken to determine prognostic factors and the incidence of central nervous system (CNS) relapses. Data was retrospectively collected on patients from 8 US academic centres. Only patients with stage I/II disease (involvement of breast and localized lymph nodes) were included. Histologies apart from primary DLBCL were excluded. Between 1992 and 2012, 76 patients met the eligibility criteria. Most patients (86%) received chemotherapy, and 69% received immunochemotherapy with rituximab; 65% received radiation therapy and 9% received prophylactic CNS chemotherapy. After a median follow-up of 4·5 years (range 0·6-20·6 years), the Kaplan-Meier estimated median progression-free survival was 10·4 years (95% confidence interval [CI] 5·8-14·9 years), and the median overall survival was 14·6 years (95% CI 10·2-19 years). Twelve patients (16%) had CNS relapse. A low stage-modified International Prognostic Index (IPI) was associated with longer overall survival. Rituximab use was not associated with a survival advantage. Primary breast DLBCL has a high rate of CNS relapse. The stage-modified IPI score is associated with survival.

Percutaneous irreversible electroporation for the treatment of colorectal cancer liver metastases with a proposal for a new response evaluation system.

PURPOSE: To describe an initial experience with irreversible electroporation (IRE) in patients with colorectal liver metastasis (CLM). MATERIALS AND METHODS: A retrospective analysis of patients undergoing IRE for the management of CLM was performed. Procedures were done percutaneously under general anesthesia. Patients were then followed for adverse events, tumor response, and survival. RESULTS: Between March 2010 and February 2013, 29 patients underwent percutaneous ablation of 58 tumors in 36 IRE sessions. Most patients (89%) had an absolute or relative contraindication to thermal ablation. The median age was 62 years, and the median time from diagnosis to IRE was 28 months. The median number of lesions treated per patient was two, and the median tumor size was 2.7 cm. Patients had received previous chemotherapy regimens (range, 1-5 per patient). A new Metabolic Imaging And Marker Integration response evaluation criteria was used for response assessment, and was a predictor of progression-free and overall survival. The 2-year progression-free survival rate was 18% (95% confidence interval, 0%-35%), and the 2-year overall survival rate was 62% (95% confidence interval, 37%-87%). Complications included arrhythmias (n = 1) and postprocedure pain (n = 1). Both patients recovered without sequelae. CONCLUSIONS: Percutaneous IRE of CLM is feasible and safe. A new response evaluation system for colorectal cancer appears to be prognostic.

Transmembrane TNF-TNFR2 signaling as a critical immunoregulatory node in pancreatic cancer.

Pancreatic cancer is characterized by extreme therapeutic resistance. In pancreatic cancers harboring high-risk genomes, we describe that cancer cell-neutrophil signaling circuitry provokes neutrophil-derived transmembrane (tm)TNF-TNFR2 interactions that dictate inflammatory polarization in cancer-associated fibroblasts and T-cell dysfunction - two hallmarks of therapeutic resistance. Targeting tmTNF-TNFR2 signaling may sensitize pancreatic cancer to chemo±immunotherapy.

Genomic Profiling of Rare Undifferentiated Sarcomatoid Subtypes of Pancreatic Carcinomas: In Search of Therapeutic Targets.

PURPOSE: The highly aggressive undifferentiated sarcomatoid carcinoma (USC) subtype of pancreatic ductal adenocarcinoma (PDAC) remains poorly characterized because of its rarity. Previous case reports suggest that immune checkpoint inhibitors could be a promising treatment strategy, but the prevalence of established predictive biomarkers of response is largely unknown. The objective of this study was to leverage comprehensive genomic profiling of USC PDAC tumors to determine the prevalence of biomarkers associated with potential response to targeted therapies. METHODS: USC tumors (n = 20) underwent central pathology review by a board-certified gastrointestinal pathologist to confirm the diagnosis. These samples were compared with non-USC PDAC tumors (N = 5,562). Retrospective analysis of DNA and RNA next-generation sequencing data was performed. RESULTS: USC PDACs were more frequently PD-L1+ by immunohistochemistry than non-USC PDAC (63% v 16%, respectively, P < .001). Furthermore, USC PDAC had an increase in neutrophils (8.99% v 5.55%, P = .005) and dendritic cells (1.08% v 0.00%, q = 0.022) and an increased expression of PDCD1LG2 (4.6% v 1.3%, q = 0.001), PDCD1 (2.0% v 0.8%, q = 0.060), and HAVCR2 (45.9% v 21.7%, q = 0.107) than non-USC PDAC. Similar to non-USC PDAC, KRAS was the most commonly mutated gene (86% v 90%, respectively, P = 1). CONCLUSION: To our knowledge, this work represents the largest molecular analysis of USC tumors to date and showed an increased expression of immune checkpoint genes in USC tumors. These findings provide evidence for further investigation into immune checkpoint inhibitors in USC tumors.

Detection and therapeutic implications of homologous recombination repair deficiency in pancreatic cancer: a narrative review.

Background and Objective: Pancreatic ductal adenocarcinoma (PDAC) remains one of the most lethal cancers. A major recent advance has been the identification of a subset of patients with PDAC who harbor inherited or somatic genetic alterations that result in homologous recombination deficiency (HRD) in tumor cells. These patients often respond favorably to drugs that can exploit this vulnerability. This review outlines the biomarkers that have been developed to predict HRD and their performance related specifically to PDAC, as well as novel HRD-targeted therapies for PDAC. Methods: We conducted a narrative review of the HRD in PDAC based on PubMed, Google Scholar, website and citation searches. Key Content and Findings: Germline mutations in BRCA1 and BRCA2 remains the only validated biomarker for the HRD state but various platforms are now available to define HRD beyond BRCA1/2 alterations. Currently, the available evidence supports the use of platinum-based chemotherapy as well as PARP inhibitors, and there is also emerging data that immune checkpoint inhibitors can produce some durable responses in these patients. Conclusions: Consistently detecting clinically significant the HRD status in PDAC has remained challenging with current commercially available platforms. Multiple novel HRD-targeted therapies for PDAC are currently in development and clinical trials, offering new opportunities for these patients.

Comparative Genomic Analysis of Pancreatic Acinar Cell Carcinoma (PACC) and Pancreatic Ductal Adenocarcinoma (PDAC) Unveils New Actionable Genomic Aberrations in PACC.

PURPOSE: Pure pancreatic acinar cell carcinomas (PACC) are rare malignancies with no established treatment. PACC demonstrates significant genetic intertumoral heterogeneity with multiple pathways involved, suggesting using targeted cancer therapeutics to treat this disease. We aggregated one of the largest datasets of pure PACC to examine the genomic variability and explore patient-specific therapeutic targets. EXPERIMENTAL DESIGN: PACC specimens (n = 51) underwent next-generation sequencing of DNA (n = 29) or whole exome (n = 22) and RNA (whole transcriptome, n = 29) at a commercial laboratory. We performed comparative analyses of a genomic cohort of pancreatic ductal adenocarcinomas (PDAC; n = 4,205). In parallel, we conducted a retrospective review of patients with PACC treated at Huntsman Cancer Institute (HCI). RESULTS: The real-world dataset included samples from 51 patients with PACC. We found key molecular differences between pure PACC and PDAC, highlighting the unique characteristics of pure PACC. Major differences in PACC include lower MAPK signaling and less stromal cell abundance compared with PDAC. Pure PACC showed genomic loss-of-heterozygosity to largely coincide with mutations in BRCA1, BRCA2, and PALB2. Of the 7 patients treated at HCI, one had a tumor that harbored a BRAF-V600E mutation. Leveraging precision oncology, this patient is being treated with encorafenib plus binimetinib, achieving an exceptionally durable and ongoing complete response of more than 3 years. CONCLUSIONS: There are major differences between PACC and PDAC, including downregulation of the MAPK signaling pathway, and less stromal cell abundance. In addition, genomic characterization of pure PACC revealed frequent targetable alterations, which can guide patient treatment.