Trends in the Care of Locally Advanced Pancreatic Cancer in the Modern Era of Chemotherapy.

INTRODUCTION: Current guidelines for treatment for locally advanced pancreatic cancer recommend chemotherapy ± radiation, or radiation alone when multimodal therapy is contraindicated. In a subset of patients, guideline-recommended treatment (GRT) achieves sufficient response to qualify for potentially curative resection. This study evaluated trends in treatment utilization and aimed to identify barriers to GRT. METHODS: Patients with clinical T4M0 disease in the National Cancer Database from 2010 to 2017 were included. Potential predictors were assessed by relative risk regression with Poisson distribution and compared by log-link function. RESULTS: In total, 28 056 patients met the criteria. Among 17 059 (67.67%) patients treated primarily with chemotherapy, 41.19% also had radiation and 8.89% went onto resection. Many received no cancer-directed treatment or failed to receive GRT. Another 710 patients had radiation (±surgery) without chemotherapy despite few contraindications to chemotherapy. Over time, patients were more likely to undergo resection after chemotherapy (aRR = 1.58; p < 0.0001) and less likely to have chemoradiation (aRR = 0.78; p < 0.0001) or go untreated (aRR = 0.90; p < 0.0001). Socioeconomic factors (race, education, income, and insurance status) affected the likelihood of receiving chemotherapy and surgery. Median overall survival (OS) was significantly improved for patients treated with chemotherapy and particularly in those patients who went on to receive RT or undergo surgical resection. OS was also longer for patients treated at high-volume academic centers. Patients insured by Medicaid, Medicare, or those without insurance had worse OS. CONCLUSIONS: Despite improvement over time, many patients go untreated. Clinical factors were influential, but the impact of vulnerable social standing suggests persistent inequity in access to care.

Perioperative and persistent opioid utilization following pancreatectomy in the United States.

BACKGROUND: Opioids are central to analgesia for pancreatic diseases. Individuals undergoing pancreatectomy have largely been excluded from studies of opioid use, because of malignancy or chronic use. Surgeons need to understand usage patterns, and practices that may incline patients toward persistent post-operative use. METHODS: A retrospective study using IBM Watson Health MarketScan database examined patterns of peri-pancreatectomy opioid use between 2009 and 2017. Patients were grouped by opioid use 12 months to 31 days prior to pancreatectomy and followed for persistent use (refills 90-180 days postoperatively). Morphine milligram equivalents (MME) were calculated. Multivariable models explored associations between clinical characteristics, perioperative use and persistent use. RESULTS: Opioids were used within the year prior to surgery by 35.6% of 8325 patients. The median MME for opioid naïve patients (400 mg) was a fraction of the 1800 mg prescribed to chronic opioid users for peri-operative analgesia. The rate of persistent opioid use was 15.1% among naïve, 27.2% among intermittent and 77.3% among chronic opioid users. Multivariable models demonstrated naïve and intermittent users who filled a prescription within 30 days prior to pancreatectomy, those who were prescribed total MME ≥1500 mg, and a ≥14 day supply were most at risk of persistent opioid use. Almost 23% of chronic users stopped using opioids post-operatively, suggesting surgery can provide relief. CONCLUSION: Preoperative and persistent opioid use after pancreatectomy is substantially greater than expected based on other operations. Providers may mitigate this by recognizing the issue, managing expectations, and altering the timing and quantities of opioids prescribed.

Hyaluronan-binding peptide for targeting peritoneal carcinomatosis.

Peritoneal carcinomatosis results from dissemination of solid tumors in the peritoneal cavity, and is a common site of metastasis in patients with carcinomas of gastrointestinal or gynecological origin. Peritoneal carcinomatosis treatment is challenging as poorly vascularized, disseminated peritoneal micro-tumors are shielded from systemic anticancer drugs and drive tumor regrowth. Here, we describe the identification and validation of a tumor homing peptide CKRDLSRRC (IP3), which upon intraperitoneal administration delivers payloads to peritoneal metastases. IP3 peptide was identified by in vivo phage display on a mouse model of peritoneal carcinomatosis of gastric origin (MKN-45P), using high-throughput sequencing of the peptide-encoding region of phage genome as a readout. The IP3 peptide contains a hyaluronan-binding motif, and fluorescein-labeled IP3 peptide bound to immobilized hyaluronan in vitro. After intraperitoneal administration in mice bearing peritoneal metastases of gastric and colon origin, IP3 peptide homed robustly to macrophage-rich regions in peritoneal tumors, including poorly vascularized micro-tumors. Finally, we show that IP3 functionalization conferred silver nanoparticles the ability to home to peritoneal tumors of gastric and colonic origin, suggesting that it could facilitate targeted delivery of nanoscale payloads to peritoneal tumors. Collectively, our study suggests that the IP3 peptide has potential applications for targeting drugs, nanoparticles, and imaging agents to peritoneal tumors.

Tumor-Targeted Multimodal Optical Imaging with Versatile Cadmium-Free Quantum Dots.

The rapid development of fluorescence imaging technologies requires concurrent improvements in the performance of fluorescent probes. Quantum dots have been extensively used as an imaging probe in various research areas because of their inherent advantages based on unique optical and electronic properties. However, their clinical translation has been limited by the potential toxicity especially from cadmium. Here, a versatile bioimaging probe is developed by using highly luminescent cadmium-free CuInSe2/ZnS core/shell quantum dots conjugated with CGKRK (Cys-Gly-Lys-Arg-Lys) tumor-targeting peptides. This probe exhibits excellent photostability, reasonably long circulation time, minimal toxicity, and strong tumor-specific homing property. The most important feature of this probe is that it shows distinctive versatility in tumor-targeted multimodal imaging including near-infrared, time-gated, and two-photon imaging in different tumor models. In a glioblastoma mouse model, the targeted probe clearly denotes tumor boundaries and positively labels a population of diffusely infiltrating tumor cells, suggesting its utility in precise tumor detection during surgery. This work lays a foundation for potential clinical translation of the probe.

New p32/gC1qR Ligands for Targeted Tumor Drug Delivery.

Cell surface p32, the target of LyP-1 homing peptide, is upregulated in tumors and atherosclerotic plaques and has been widely used as a receptor for systemic delivery of payloads. Here, we identified an improved LyP-1-mimicking peptide (TT1, CKRGARSTC). We used this peptide in a fluorescence polarization-based high-throughput screening of a 50,000-compound chemical library and identified a panel of compounds that bind p32 with low micromolar affinity. Among the hits identified in the screen, two compounds were shown to specifically bind to p32 in multiple assays. One of these compounds was chosen for an in vivo study. Nanoparticles surface-functionalized with this compound specifically adhered to surfaces coated with recombinant p32 and, when injected intravenously, homed to p32-expressing breast tumors in mice. This compound provides a lead for the development of p32-targeted affinity ligands that circumvent some of the limitations of peptide-based probes in guided drug delivery.

Proteasome activator complex PA28 identified as an accessible target in prostate cancer by in vivo selection of human antibodies.

Antibody cancer therapies rely on systemically accessible targets and suitable antibodies that exert a functional activity or deliver a payload to the tumor site. Here, we present proof-of-principle of in vivo selection of human antibodies in tumor-bearing mice that identified a tumor-specific antibody able to deliver a payload and unveils the target antigen. By using an ex vivo enrichment process against freshly disaggregated tumors to purge the repertoire, in combination with in vivo biopanning at optimized phage circulation time, we have identified a human domain antibody capable of mediating selective localization of phage to human prostate cancer xenografts. Affinity chromatography followed by mass spectrometry analysis showed that the antibody recognizes the proteasome activator complex PA28. The specificity of soluble antibody was confirmed by demonstrating its binding to the active human PA28αß complex. Whereas systemically administered control phage was confined in the lumen of blood vessels of both normal tissues and tumors, the selected phage spread from tumor vessels into the perivascular tumor parenchyma. In these areas, the selected phage partially colocalized with PA28 complex. Furthermore, we found that the expression of the α subunit of PA28 [proteasome activator complex subunit 1 (PSME1)] is elevated in primary and metastatic human prostate cancer and used anti-PSME1 antibodies to show that PSME1 is an accessible marker in mouse xenograft tumors. These results support the use of PA28 as a tumor marker and a potential target for therapeutic intervention in prostate cancer.

Etchable plasmonic nanoparticle probes to image and quantify cellular internalization.

There is considerable interest in using nanoparticles as labels or to deliver drugs and other bioactive compounds to cells in vitro and in vivo. Fluorescent imaging, commonly used to study internalization and subcellular localization of nanoparticles, does not allow unequivocal distinction between cell surface-bound and internalized particles, as there is no methodology to turn particles 'off'. We have developed a simple technique to rapidly remove silver nanoparticles outside living cells, leaving only the internalized pool for imaging or quantification. The silver nanoparticle (AgNP) etching is based on the sensitivity of Ag to a hexacyanoferrate-thiosulphate redox-based destain solution. In demonstration of the technique we present a class of multicoloured plasmonic nanoprobes comprising dye-labelled AgNPs that are exceptionally bright and photostable, carry peptides as model targeting ligands, can be etched rapidly and with minimal toxicity in mice, and that show tumour uptake in vivo.

Proapoptotic peptide-mediated cancer therapy targeted to cell surface p32.

Antiangiogenic therapy is a promising new treatment modality for cancer, but it generally produces only transient tumor regression. We have previously devised a tumor-targeted nanosystem, in which a pentapeptide, CGKRK, delivers a proapoptotic peptide into the mitochondria of tumor blood vessel endothelial cells and tumor cells. The treatment was highly effective in glioblastoma mouse models completely refractory to other antiangiogenic treatments. Here, we identify p32/gC1qR/HABP, a mitochondrial protein that is also expressed at the cell surface of activated (angiogenic) endothelial cells and tumor cells, as a receptor for the CGKRK peptide. The results demonstrate the ability of p32 to cause internalization of a payload bound to p32 into the cytoplasm. We also show that nardilysin, a protease capable of cleaving CGKRK, plays a role in the internalization of a p32-bound payload. As p32 is overexpressed and surface displayed in breast cancers, we studied the efficacy of the nanosystem in this cancer. We show highly significant treatment results in an orthotopic model of breast cancer. The specificity of cell surface p32 for tumor-associated cells, its ability to carry payloads to mitochondria, and the efficacy of the system in important types of cancer make the nanosystem a promising candidate for further development.

Targeted nanoparticle enhanced proapoptotic peptide as potential therapy for glioblastoma.

Antiangiogenic therapy can produce transient tumor regression in glioblastoma (GBM), but no prolongation in patient survival has been achieved. We have constructed a nanosystem targeted to tumor vasculature that incorporates three elements: (i) a tumor-homing peptide that specifically delivers its payload to the mitochondria of tumor endothelial cells and tumor cells, (ii) conjugation of this homing peptide with a proapoptotic peptide that acts on mitochondria, and (iii) multivalent presentation on iron oxide nanoparticles, which enhances the proapoptotic activity. The iron oxide component of the nanoparticles enabled imaging of GBM tumors in mice. Systemic treatment of GBM-bearing mice with the nanoparticles eradicated most tumors in one GBM mouse model and significantly delayed tumor development in another. Coinjecting the nanoparticles with a tumor-penetrating peptide further enhanced the therapeutic effect. Both models used have proven completely resistant to other therapies, suggesting clinical potential of our nanosystem.

Selection of phage-displayed peptides on live adherent cells in microfluidic channels.

Affinity reagents that bind to specific molecular targets are an essential tool for both diagnostics and targeted therapeutics. There is a particular need for advanced technologies for the generation of reagents that specifically target cell-surface markers, because transmembrane proteins are notoriously difficult to express in recombinant form. We have previously shown that microfluidics offers many advantages for generating affinity reagents against purified protein targets, and we have now significantly extended this approach to achieve successful in vitro selection of T7 phage-displayed peptides that recognize markers expressed on live, adherent cells within a microfluidic channel. As a model, we have targeted neuropilin-1 (NRP-1), a membrane-bound receptor expressed at the surface of human prostate carcinoma cells that plays central roles in angiogenesis, cell migration, and invasion. We show that, compared to conventional biopanning methods, microfluidic selection enables more efficient discovery of peptides with higher affinity and specificity by providing controllable and reproducible means for applying stringent selection conditions against minimal amounts of target cells without loss. Using our microfluidic system, we isolate peptide sequences with superior binding affinity and specificity relative to the well known NRP-1-binding RPARPAR peptide. As such microfluidic systems can be used with a wide range of biocombinatorial libraries and tissue types, we believe that our method represents an effective approach toward efficient biomarker discovery from patient samples.

Targeting vascular disrupting agent-treated tumor microenvironment with tissue-penetrating nanotherapy.

Cancer treatment with vascular disrupting agents (VDAs) causes rapid and extensive necrosis in solid tumors. However, these agents fall short in eliminating all malignant cells, ultimately leading to tumor regrowth. Here, we investigated whether the molecular changes in the tumor microenvironment induced by VDA treatment sensitize the tumors for secondary nanotherapy enhanced by clinical-stage tumor penetrating peptide iRGD. Treatment of peritoneal carcinomatosis (PC) and breast cancer mice with VDA combretastatin A-4 phosphate (CA4P) resulted in upregulation of the iRGD receptors αv-integrins and NRP-1, particularly in the peripheral tumor tissue. In PC mice treated with CA4P, coadministration of iRGD resulted in an approximately threefold increase in tumor accumulation and a more homogenous distribution of intraperitoneally administered nanoparticles. Notably, treatment with a combination of CA4P, iRGD, and polymersomes loaded with a novel anthracycline Utorubicin (UTO-PS) resulted in a significant decrease in the overall tumor burden in PC-bearing mice, while avoiding overt toxicities. Our results indicate that VDA-treated tumors can be targeted therapeutically using iRGD-potentiated nanotherapy and warrant further studies on the sequential targeting of VDA-induced molecular signatures.

Sequence dependence of C-end rule peptides in binding and activation of neuropilin-1 receptor.

Neuropilin-1 (NRP-1) is a hub receptor that plays an essential role in angiogenesis and vascular permeability. It is over-expressed in the new blood vessels grown by tumor cells and is a target for anti-tumor treatments. Peptides that expose the consensus sequence R/K/XXR/K at the C-terminus (C-end rule or CendR peptides) bind to NRP-1 and are internalized into the cell. We used peptide phage display binding assays and molecular dynamics (MD) simulations to study the potential role of the central residues of CendR peptides in binding and activation of the NRP-1 receptor. The high stability of RPAR-receptor domain complex stems from the formation of a characteristic pattern of three hydrogen bonds between the peptide C-terminus and the residues in the NRP-1 loop III. Any changes in the peptide structure that fail to preserve this triad result in a less-stable complex. We performed a systematic study of RXXR mutants, where X=A/D/S/R/P, in order to test the effect of replacement of A or P on the binding capabilities. Our results, both experimental and computational, show that RRAR, RDAR, RPDR, RPRR and RPPR are capable of binding NRP-1. However, only RPPR and RPRR segments form an optimal organization around loop III with low potential energy. In other analogs, the absence of these stabilizing interactions always results in higher potential energy of the complexes. The binding of RPAR analogs does not guarantee receptor activation; only stable complexes that are properly stabilized via loop III appear able to trigger NRP-1 activation.

A pancreatic cancer mouse model with human immunity.

Pancreatic ductal adenocarcinoma (PDAC) is characterized by a tumor immune microenvironment (TIME) that promotes resistance to immunotherapy. A preclinical model system that facilitates studies of the TIME and its impact on the responsiveness of human PDAC to immunotherapies remains an unmet need. We report a novel mouse model, which develops metastatic human PDAC that becomes infiltrated by human immune cells recapitulating the TIME of human PDAC. The model may serve as a versatile platform to study the nature of human PDAC TIME and its response to various treatments.

Associations Between Patient Characteristics and Whipple Procedure Outcomes Before and After Implementation of an Enhanced Recovery After Surgery Protocol.

PURPOSE: The Enhanced Recovery After Surgery (ERAS) protocol is a multimodal perioperative care bundle aimed to improve pancreatic surgery outcomes. This work evaluates whether a Whipple ERAS protocol can be safely implemented at a quaternary care center. We also aimed to assess if race and socioeconomic factors are associated with disparities in outcomes in patients undergoing a Whipple ERAS protocol. METHODS: A retrospective review identified demographic and clinical data for 458 patients undergoing pancreaticoduodenectomies (PDs) at a single institution from October 2017 to May 2022. Patients were split into two cohorts: pre-ERAS (treated before implementation) and ERAS (treated after). Outcomes included length of stay (LOS), 30-day readmission and mortality rates, and major complications. RESULTS: There were 213 pre-ERAS PD patients, and 245 were managed with an ERAS protocol. More ERAS patients had a BMI > 30 (15.5% vs. 8.0%; p = 0.01) and received neoadjuvant chemotherapy (15.5% vs. 4.2%; p < 0.001). ERAS patients had a higher rate of major complications (57.6% vs. 37.6%; p < 0.001). Medicaid patients did not have more complications or longer LOS compared to non-Medicaid patients. On univariate analysis, race/ethnicity or gender was not significantly associated with a higher rate of major complications or prolonged LOS. CONCLUSION: A Whipple ERAS protocol did not significantly change LOS, readmissions, or 30-day mortality. Rate of overall complications did not significantly change after implementation, but rate of major complications increased. These outcomes were not significantly impacted by race/ethnicity, gender, tumor staging, or insurance status.

Tumor-resident regulatory T cells in pancreatic cancer express the αvß5 integrin as a targetable activation marker.

Pancreatic ductal adenocarcinoma (PDAC) has abundant immunosuppressive regulatory T cells (Tregs), which contribute to a microenvironment resistant to immunotherapy. Here, we report that Tregs in the PDAC tissue, but not those in the spleen, express the αvß5 integrin in addition to neuropilin-1 (NRP-1), which makes them susceptible to the iRGD tumor-penetrating peptide, which targets cells positive for αv integrin- and NRP-1. As a result, long-term treatment of PDAC mice with iRGD leads to tumor-specific depletion of Tregs and improved efficacy of immune checkpoint blockade. αvß5 integrin + Tregs are induced from both naïve CD4 + T cells and natural Tregs upon T cell receptor stimulation, and represent a highly immunosuppressive subpopulation of CCR8 + Tregs. This study identifies the αvß5 integrin as a marker for activated tumor-resident Tregs, which can be targeted to achieve tumor-specific Treg depletion and thereby augment anti-tumor immunity for PDAC therapy.

Nanoparticle-induced vascular blockade in human prostate cancer.

The tumor-homing pentapeptide CREKA (Cys-Arg-Glu-Lys-Ala) specifically homes to tumors by binding to fibrin and fibrin-associated clotted plasma proteins in tumor vessels. Previous results show that CREKA-coated superparamagnetic iron oxide particles can cause additional clotting in tumor vessels, which creates more binding sites for the peptide. We have used this self-amplifying homing system to develop theranostic nanoparticles that simultaneously serve as an imaging agent and inhibit tumor growth by obstructing tumor circulation through blood clotting. The CREKA nanoparticles were combined with nanoparticles coated with another tumor-homing peptide, CRKDKC, and nanoparticles with an elongated shape (nanoworms) were used for improved binding efficacy. The efficacy of the CREKA peptide was then increased by replacing some residues with nonproteinogenic counterparts, which increased the stability of the peptide in the circulation. Treatment of mice bearing orthotopic human prostate cancer tumors with the targeted nanoworms caused extensive clotting in tumor vessels, whereas no clotting was observed in the vessels of normal tissues. Optical and magnetic resonance imaging confirmed tumor-specific targeting of the nanoworms, and ultrasound imaging showed reduced blood flow in tumor vessels. Treatment of mice with prostate cancer with multiple doses of the nanoworms induced tumor necrosis and a highly significant reduction in tumor growth.

C-end rule peptides mediate neuropilin-1-dependent cell, vascular, and tissue penetration.

Screening of phage libraries expressing random peptides for binding to prostate cancer cells primarily yielded peptides that had a C-terminal arginine (or rarely lysine) residue, usually in a consensus context R/KXXR/K. Phage expressing these sequences and synthetic nanoparticles coated with them bound to and were internalized into cells. The C-terminal arginine (or lysine) was essential to the activity; adding another amino acid, or even blocking the free carboxyl group of this arginine residue by amidation, eliminated the binding and internalizing activity. An internal R/KXXR/K can be exposed and switched on by a cleavage by a protease. The strict requirement for C-terminal exposure of the motif prompted us to term the phenomenon the C-end rule (CendR). Affinity chromatography showed that the CendR peptides bind to neuropilin-1 (NRP-1) on the target cells. NRP-1 is a cell-surface receptor that plays an essential role in angiogenesis, regulation of vascular permeability, and the development of the nervous system. VEGF-A165 and other ligands of NRP-1 possess a C-terminal CendR sequence that interacts with the b1 domain of NRP-1 and causes cellular internalization and vascular leakage. Our CendR peptides have similar effects, particularly when made multivalent through coupling to a particle. We also noted a unique and important activity of these peptides: penetration and transportation through tissues. The peptides were able to take payloads up to the nanoparticle size scale deep into extravascular tissue. Our observations have implications in drug delivery and penetration of tissue barriers and tumors.

Socioeconomic Predictors of Access to Care for Patients with Operatively Managed Pancreatic Cancer in New York State.

PURPOSE: We evaluated how race and socioeconomic factors impact access to high-volume surgical centers, treatment initiation, and postoperative care for pancreatic cancer in a state with robust safety net insurance coverage and healthcare infrastructure. METHODS: The New York Statewide Planning and Research Cooperative System was analyzed. Patients with pancreatic cancer resected from 2007 to 2017 were identified by ICD and CPT codes. Primary outcomes included surgery at low-volume facilities (< 20 pancreatectomies/year), time to therapy initiation, and time to postoperative surveillance imaging (within 60-180 days after surgery). RESULTS: In total, 3312 patients underwent pancreatectomy across 124 facilities. Median age was 67 years (IQR 59, 75) and 55% of patients were male. Most (72.7%) had surgery at high-volume centers. On multivariable analysis, odds ratios for surgery at low-volume centers were increased for Black race (2.21 (95% CI 1.69-2.88)), Asian race (1.64 (95% CI 1.09-2.43)), Hispanic ethnicity (1.68 (95% CI 1.24-2.28)), Medicaid insurance (2.52 (95% CI 1.79-3.56)), no insurance (2.24 (95% CI 1.38-3.61)), lowest income quartile (3.31 (95% CI 2.14-5.32)), and rural zip code (2.49 (95% CI 1.69-3.65)). Patients treated at low-volume centers waited longer to initiate treatment (hazard ratio (HR) 0.91 (95% CI 0.81-1.01)). Black patients underwent the least surveillance imaging (50.4%; p < 0.0001), while Asian (HR 2.04, 95% CI 1.40-2.98)) and Hispanic patients (HR 1.36 (95% CI 1.00-1.84)) were more likely to have surveillance imaging. CONCLUSIONS: Race independently affected access to high-volume facilities and surveillance imaging. When considered in light of other accumulating evidence, future efforts might investigate the perceptions and logistical considerations noted by providers and patients alike to identify the etiology of these disparities and then institute corrective measures.

Tumor-penetrating therapy for ß5 integrin-rich pancreas cancer.

Pancreatic ductal adenocarcinoma (PDAC) is characterized by marked desmoplasia and drug resistance due, in part, to poor drug delivery to extravascular tumor tissue. Here, we report that carcinoma-associated fibroblasts (CAFs) induce ß5 integrin expression in tumor cells in a TGF-ß dependent manner, making them an efficient drug delivery target for the tumor-penetrating peptide iRGD. The capacity of iRGD to deliver conjugated and co-injected payloads is markedly suppressed when ß5 integrins are knocked out in the tumor cells. Of note, ß5 integrin knock-out in tumor cells leads to reduced disease burden and prolonged survival of the mice, demonstrating its contribution to PDAC progression. iRGD significantly potentiates co-injected chemotherapy in KPC mice with high ß5 integrin expression and may be a powerful strategy to target an aggressive PDAC subpopulation.