Multicenter phase II trial of adjuvant therapy for resected pancreatic cancer using cisplatin, 5-fluorouracil, and interferon-alfa-2b-based chemoradiation: ACOSOG Trial Z05031

Efficacy of Cisplatin-Containing Chemotherapy Regimens in Patients of Pancreatic Ductal Adenocarcinoma: A Systematic Review and Meta-analysis

BACKGROUND

The relative success of cisplatin-based chemotherapy regimens for PDAC in clinical trials warrants a review of the literature to assess the cumulative results. This study aims to assess the efficacy of cisplatin-containing regimens for PDAC in terms of survival and response outcomes using a systematic review and proportional meta-analysis.

METHODS

In this study, an electronic search was conducted on PubMed, Cochrane Library, Scopus, and Google Scholar to find relevant literature. The random effects model was used to assess pooled overall response rate, stable disease rate, progressive disease rate, 1-year overall survival rate, and their 95% CIs. Publication bias was assessed using funnel plot symmetry and the one-tailed Eggers' test. In all cases, p-value < 0.05 was indicative of significant results. The review is registered with PROSPERO: CRD42023459243.

RESULTS

A total of 34 studies consisting of 1599 patients were included in this review. All the included studies were of good quality. In total, 906 patients were male, and the median age of the patients was 58-69 years. Overall, 599 patients had cancer of the pancreatic head, 139 had cancer of the pancreatic body, and 102 patients had cancer of the pancreatic tail. The pooled risk ratios (RRs) revealed an overall response rate of 19.2% (95% CI, 14.6-24.2%), a stable disease rate of 42.3% (95% CI, 36.6-48.8), a 1-year overall survival rate of 40% (95% CI, 34.3-45.8), and progressive disease rate of 24.7% (95% CI, 18.8-31.2). Commonly reported adverse events were anemia, thrombocytopenia, abdominal adverse events, neutropenia, fatigue, leukopenia, alopecia, anorexia, mucositis, stomatitis, and hepatobiliary adverse events.

CONCLUSION

Cisplatin-containing regimens have shown moderate efficacy with significant improvement in overall survival at 1 year, stable disease rate, and progressive disease rate; however, only a small percentage of patients achieved an overall response rate.

Immune modulation during anti-cancer radio(immuno)therapy

Cancer can affect all human organs and tissues and ranks as a prominent cause of death as well as an obstruction to increasing life expectancy. A notable breakthrough in oncology has been the inclusion of the immune system in fighting cancer, potentially prolonging life and providing long-term benefits. The concept of "immunotherapy" has been discussed from the 19th and early 20th centuries by Wilhelm Busch, William B. Coley and Paul Ehrlich. This involves distinct approaches, including vaccines, non-specific cytokines and adoptive cell therapies. However, despite the advances made in recent years, questions on how to select the best therapeutic options or how to select the best combinations to improve clinical outcomes are still relevant for scientists and clinicians. More than half of cancer patients receive radiotherapy (RT) as part of their treatment. With the advances in RT and immunotherapy approaches, it is reasonable to consider how to enhance immunotherapy with radiation and vice versa, and to investigate whether combinations of these therapies would be beneficial. In this chapter, we will discuss how the immune system responds to cancer cells and different cancer therapies with a focus on combination of RT and immunotherapy (radioimmunotherapy, RIT).

The immunogenic radiation and new players in immunotherapy and targeted therapy for head and neck cancer

Although treatment modalities for head and neck cancer have evolved considerably over the past decades, survival rates have plateaued. The treatment options remained limited to definitive surgery, surgery followed by fractionated radiotherapy with optional chemotherapy, and a definitive combination of fractionated radiotherapy and chemotherapy. Lately, immunotherapy has been introduced as the fourth modality of treatment, mainly administered as a single checkpoint inhibitor for recurrent or metastatic disease. While other regimens and combinations of immunotherapy and targeted therapy are being tested in clinical trials, adapting the appropriate regimens to patients and predicting their outcomes have yet to reach the clinical setting. Radiotherapy is mainly regarded as a means to target cancer cells while minimizing the unwanted peripheral effect. Radiotherapy regimens and fractionation are designed to serve this purpose, while the systemic effect of radiation on the immune response is rarely considered a factor while designing treatment. To bridge this gap, this review will highlight the effect of radiotherapy on the tumor microenvironment locally, and the immune response systemically. We will review the methodology to identify potential targets for therapy in the tumor microenvironment and the scientific basis for combining targeted therapy and radiotherapy. We will describe a current experience in preclinical models to test these combinations and propose how challenges in this realm may be faced. We will review new players in targeted therapy and their utilization to drive immunogenic response against head and neck cancer. We will outline the factors contributing to head and neck cancer heterogeneity and their effect on the response to radiotherapy. We will review in-silico methods to decipher intertumoral and intratumoral heterogeneity and how these algorithms can predict treatment outcomes. We propose that (a) the sequence of surgery, radiotherapy, chemotherapy, and targeted therapy should be designed not only to annul cancer directly, but to prime the immune response. (b) Fractionation of radiotherapy and the extent of the irradiated field should facilitate systemic immunity to develop. (c) New players in targeted therapy should be evaluated in translational studies toward clinical trials. (d) Head and neck cancer treatment should be personalized according to patients and tumor-specific factors.

Combination, Modulation and Interplay of Modern Radiotherapy with the Tumor Microenvironment and Targeted Therapies in Pancreatic Cancer: Which Candidates to Boost Radiotherapy?

Pancreatic ductal adenocarcinoma cancer (PDAC) is a highly diverse disease with low tumor immunogenicity. PDAC is also one of the deadliest solid tumor and will remain a common cause of cancer death in the future. Treatment options are limited, and tumors frequently develop resistance to current treatment modalities. Since PDAC patients do not respond well to immune checkpoint inhibitors (ICIs), novel methods for overcoming resistance are being explored. Compared to other solid tumors, the PDAC's tumor microenvironment (TME) is unique and complex and prevents systemic agents from effectively penetrating and killing tumor cells. Radiotherapy (RT) has the potential to modulate the TME (e.g., by exposing tumor-specific antigens, recruiting, and infiltrating immune cells) and, therefore, enhance the effectiveness of targeted systemic therapies. Interestingly, combining ICI with RT and/or chemotherapy has yielded promising preclinical results which were not successful when translated into clinical trials. In this context, current standards of care need to be challenged and transformed with modern treatment techniques and novel therapeutic combinations. One way to reconcile these findings is to abandon the concept that the TME is a well-compartmented population with spatial, temporal, physical, and chemical elements acting independently. This review will focus on the most interesting advancements of RT and describe the main components of the TME and their known modulation after RT in PDAC. Furthermore, we will provide a summary of current clinical data for combinations of RT/targeted therapy (tRT) and give an overview of the most promising future directions.

C9orf16 represents the aberrant genetic programs and drives the progression of PDAC

Background

Pancreatic ductal adenocarcinoma (PDAC), constituting 90% of pancreatic cancers, is the fourth leading cause of cancer-related deaths in the world. Lack of early detection of PDAC contributes to its poor prognosis as patients are often diagnosed at an advanced stage of disease. This is mostly due to the lack of promising diagnostic and therapeutic targets and corresponding drugs.

Methods and results

Here, by bioinformatic analysis of single cell RNA-sequencing data on normal pancreas tissues, primary and metastatic PDAC tumors, we identified a promising PDAC biomarker, C9orf16. The expression of C9orf16, rarely detectable in normal epithelial cells, was upregulated in primary PDAC cancer cells and was further elevated in metastatic PDAC cancer cells. Gain or loss of function of C9orf16 demonstrated its critical functions in regulating the cell proliferation, invasion and chemotherapy resistance of cancer cells. Pathway analysis and functional studies identified MYC signaling pathways as the most activated pathways in regulating C9orf16 expression and in mediating the development and progression of PDAC.

Conclusions

These data suggested a crucial gene regulation system, MYC-C9orf16, which is actively involved in PDAC development and progression, and targeting this system should be a novel diagnostic and therapeutic target for PDAC.

Current clinical landscape of oncolytic viruses as novel cancer immunotherapeutic and recent preclinical advancements

Oncolytic viruses (OVs) have been gaining attention in the pharmaceutical industry as a novel immunotherapeutic and therapeutic adjuvant due to their ability to induce and boost antitumor immunity through multiple mechanisms. First, intrinsic mechanisms of OVs that enable exploitation of the host immune system (e.g., evading immune detection) can nullify the immune escape mechanism of tumors. Second, many types of OVs have been shown to cause direct lysis of tumor cells, resulting in an induction of tumor-specific T cell response mediated by release of tumor-associated antigens and danger signal molecules. Third, armed OV-expressing immune stimulatory therapeutic genes could be highly expressed in tumor tissues to further improve antitumor immunity. Last, these OVs can inflame cold tumors and their microenvironment to be more immunologically favorable for other immunotherapeutics. Due to these unique characteristics, OVs have been tested as an adjuvant of choice in a variety of therapeutics. In light of these promising attributes of OVs in the immune-oncology field, the present review will examine OVs in clinical development and discuss various strategies that are being explored in preclinical stages for the next generation of OVs that are optimized for immunotherapy applications.

Systemic therapy and perioperative management improve the prognosis of pancreatic ductal adenocarcinoma: A retrospective cohort study of 2000 consecutive cases

OBJECTIVE

This study aimed to explore patterns of the treatment strategies of pancreatic ductal adenocarcinoma based on 2000 consecutive cases of a prospective database since 2012 to obtain new insights for future directions.

METHODS

Among 2000 patients enrolled in this study, 210 patients were excluded, and 710, 521, and 559 patients were treated between 2012 and 2015 (group 1), between 2016 and 2017 (group 2), and between 2018 and 2019 (group 3), respectively. Patient clinicopathologic and biological factors, and perioperative outcomes were used to assess the prognostic factors.

RESULTS

The median survival for all patients with pancreatic ductal adenocarcinoma was 21.7 months (1-year survival, 75.0%; 2-year survival, 43.7%; 5-year survival, 19.7%). Group 3 had a better survival outcome than groups 1 and 2 (median survival time: 23 versus 20.5 and 21.1 months). The proportion of patients younger than 65 gradually increased over time, as did the use of systemic chemotherapy and postoperative adjuvant radiotherapy. The tendency for early diagnosis (lower CA19-9 and CEA levels, smaller size, and earlier N stage), use of chemotherapy and radiotherapy, early recovery (lesser hospital stay and Clavien-Dindo grade <3), absence of abdominal pain, younger age, length of operation ≤3 h, and pathological factors (absence of lymphovascular invasion, peripancreatic fat infiltration and neural invasion, higher differentiation) were related to patients' survival. Multivariable analysis for prognosis revealed that tumor biological factors (increased preoperative serum CA19-9 level, tumor size, tumor differentiation, N stage, and presence of lymphovascular invasion and neural invasion), chemotherapy, radiotherapy, abdomen pain, operation period, length of stay, and length of operation correlated with patients' survival.

CONCLUSIONS

Systemic therapy, including chemotherapy and radiotherapy, has gradually improved the prognosis after operative resection for pancreatic ductal adenocarcinoma. Neoadjuvant therapy is also beneficial to improve the prognosis to a certain extent. The enhanced recovery after surgery (ERAS) policies and the specific assessment of postoperative pancreatic fistula (POPF) risk may be related to reduced hospital stays and the reduction of serious complications. These advancements show that the concept of systemic therapy has been accepted and actively applied by Chinese medical institutions.

Pancreas cancer trials for early stage disease: Surgeons leading therapeutic cooperative group trials

Surgeon-led clinical trials have defined the standard of care for locoregional pancreatic cancer to date. The infrastructure and collaborative nature of cooperative oncology groups offer many advantages, such as providing an ideal mechanism through which multidisciplinary pancreatic cancer trials are performed. As key members of the treatment team, surgeons bring experience and expertise to the design of surgical and multidisciplinary trials and are uniquely poised to be leaders of future pancreatic cancer trials.

Seminars in surgical oncology-Pancreas cancer adjuvant therapy trials

Adjuvant therapy for pancreatic cancer has undergone a paradigm shift in the last 30 years. Before the 1990s, surgery was the main treatment with high morbidity and minimal long-term survival. In the mid-1980s, GITSG showed a doubling of overall survival from 11 to 20 months with 5-fluorouracil-based chemoradiation and now the PRODIGE trial showed the benefit of FOLFIRINOX with the longest overall survival to date approaching 5 years. Further investigation on the agents, duration and sequencing of therapy remains ongoing.

Landmark Series: Immunotherapy and Targeted Therapy for Pancreatic Cancer

Pancreatic cancer is one of the most aggressive gastrointestinal malignancies despite multimodality therapy. In the last several years, genomic studies have revealed that carcinogenesis is driven largely by key driver mutations that can be targeted for oncologic therapy. In addition, advances in cancer immunology have identified receptors and monoclonal antibodies that can be manipulated into harnessing the power of the host's immune system for antitumor treatment. These strategies have generated a paradigm shift in the management of several cancer types, including those in the gastrointestinal tract. However, there are several complicating factors when translating the results to pancreatic cancer, including the dense, fibrotic stroma unique to this disease that may shield the cancer cells from both cytotoxic and immunologic agents. Although the majority of trials have been performed in the metastatic setting, this review will focus on both the historic studies that have defined this field as well as the emerging data arising from ongoing efforts to exploit newly discovered mutations and their druggable targets.

Type I interferons in pancreatic cancer and development of new therapeutic approaches

Immunotherapy has emerged as a new treatment strategy for cancer. However, its promise in pancreatic cancer has not yet been realized. Understanding the immunosuppressive tumor microenvironment of pancreatic cancer, and identifying new therapeutic targets to increase tumor-specific immune responses, is necessary in order to improve clinical outcomes. Type I interferons, e.g. IFN-α and -β, are considered as an important bridge between the innate and adaptive immune system. Thereby, type I IFNs induce a broad spectrum of anti-tumor effects, including immunologic, vascular, as well as direct anti-tumor effects. While IFN therapies have been around for a while, new insights into exogenous and endogenous activation of the IFN pathway have resulted in new IFN-related cancer treatment strategies. Here, we focus on the pre-clinical and clinical evidence of novel ways to take advantage of the type I IFN pathway, such as IFN based conjugates and activation of the STING and RIG-I pathways.

APOBEC3 enzymes mediate efficacy of cisplatin and are epistatic with base excision repair and mismatch repair in platinum response

Identifying the mechanisms mediating cisplatin response is essential for improving patient response. Previous research has identified base excision repair (BER) and mismatch repair (MMR) activity in sensitizing cells to cisplatin. Cisplatin forms DNA adducts including interstrand cross-links (ICLs) that distort the DNA helix, forcing adjacent cytosines to become extrahelical. These extrahelical cytosines provide a substrate for cytosine deaminases. Herein, we show that APOBEC3 (A3) enzymes are capable of deaminating the extrahelical cytosines to uracils and sensitizing breast cancer cells to cisplatin. Knockdown of A3s results in resistance to cisplatin and induction of A3 expression in cells with low A3 expression increases sensitivity to cisplatin. We show that the actions of A3s are epistatic with BER and MMR. We propose that A3-induced cytosine deamination to uracil at cisplatin ICLs results in repair of uracils by BER, which blocks ICL DNA repair and enhances cisplatin efficacy and improves breast cancer outcomes.

Clinical Trials for the Surgical Oncologist: Opportunities and Hurdles

Advancements in clinical practice usually require level one evidence from clinical trials that directly compare new approaches to standard of care. While clinical trials have provided data to guide advances in practices across surgical oncology, all too often accrual to clinical trials is slower than anticipated, and once results are presented and published, adoption in clinical practice is slow. Why and how can surgeons be successfully involved with clinical trials? An expert panel discusses the basic infrastructure of clinical trials, investigator-initiated trials, the National Clinical Trials Network, and opportunities for surgeon involvement. Two national clinical trials, NSABP B-51/RTOG 1304 and PROSPECT N1048, are discussed to highlight the role of the surgical oncologist.

Comparative Age-Based Prospective Multi-Institutional Observations of 12,367 Patients Enrolled to the American College of Surgeons Oncology Group (ACOSOG) Z901101 Trials (Alliance)

BACKGROUND

The risk of surgery, particularly for older cancer patients with serious, extensive comorbidities, can make this otherwise curative modality precarious. Leveraging data from the American College of Surgeons Oncology Group, this study sought to characterize age-based comparative demographics, adverse event rates, and study completion rates to define how best to conduct research in older cancer patients.

METHODS

This study relied on clinical data from 21 completed studies to assess whether older patients experienced more grade 3 or worse adverse events and were more likely to discontinue study participation prematurely than their younger counterparts.

RESULTS

The study enrolled 12,367 patients. The median age was 60 years, and 36% of the patients were 65 years of age or older. Among 4008 patients with adverse event data, 1067 (27%) had experienced a grade 3 or worse event. The patients 65 years or older had higher rates of grade 3 or worse adverse events compared to younger patients [32% vs. 24%; odds ratio (OR), 1.5; 95% confidence interval (CI), 1.3-1.7; p < 0.0001]. This association was not observed in multivariate analyses. The study protocol was completed by 97% of the patients. No association was observed between age and trial completion (OR 0.8; 95% CI 0.7-1.1; p = 0.14). Only the older gastrointestinal cancer trial patients were less likely to complete their studies compared to younger patients (OR 0.50; 95% CI 0.30-0.70; p < 0.0001).

CONCLUSION

Despite higher rates of adverse events, the older patients typically completed the study protocol, thereby contributing relevant data on how best to render care to older cancer patients and affirming the important role of enrolling these patients to surgical trials.

Radiotherapy in Combination With Cytokine Treatment

Radiotherapy (RT) plays an important role in the management of cancer patients. RT is used in more than 50% of patients during the course of their disease in a curative or palliative setting. In the past decades it became apparent that the abscopal effect induced by RT might be dependent on the activation of immune system, and that the induction of immunogenic cancer cell death and production of danger-associated molecular patterns from dying cells play a major role in the radiotherapy-mediated anti-tumor efficacy. Therefore, the combination of RT and immunotherapy is of a particular interest that is reflected in designing clinical trials to treat patients with various malignancies. The use of cytokines as immunoadjuvants in combination with RT has been explored over the last decades as one of the immunotherapeutic combinations to enhance the clinical response to anti-cancer treatment. Here we review mainly the data on the efficacy of IFN-α, IL-2, IL-2-based immunocytokines, GM-CSF, and TNF-α used in combinations with various radiotherapeutic techniques in clinical trials. Moreover, we discuss the potential of IL-15 and its analogs and IL-12 cytokines in combination with RT based on the efficacy in preclinical mouse tumor models.

The Development of Oncolytic Adenovirus Therapy in the Past and Future - For the Case of Pancreatic Cancer

Pancreatic cancer is an aggressive malignant disease and the efficacy of current treatments for unresectable diseases is quite limited despite recent advances. Gene therapy /virotherapy strategies may provide new options for the treatment of various cancers including pancreatic cancer. Oncolytic adenovirus shows an antitumoral effect via its intratumoral amplification and strong cytocidal effect in a variety of cancers and it has been employed for the development of potent oncolytic virotherapy agents for pancreatic cancer. Our ultimate goal is to develop an oncolytic adenovirus enabling the treatment of patients with advanced or spread diseases by systemic injection. Systemic application of oncolytic therapy mandates more efficient and selective gene delivery and needs to embody sufficient antitumor effect even with limited initial delivery to the tumor location. In this review, the current status of oncolytic adenoviruses from the viewpoints of vector design and potential strategies to overcome current obstacles for its clinical application will be described. We will also discuss the efforts to improve the antitumor activity of oncolytic adenovirus, in in vivo animal models, and the combination therapy of oncolytic adenovirus with radiation and chemotherapy.

Novel Approaches to Improve the Efficacy of Immuno-Radiotherapy

Radiotherapy (RT) has been applied for decades as a treatment modality in the management of various types of cancer. Ionizing radiation induces tumor cell death, which in turn can either elicit protective anti-tumor immune responses or immunosuppression in the tumor micromilieu that contributes to local tumor recurrence. Immunosuppression is frequently accompanied by the attraction of immunosuppressive cells such as myeloid-derived suppressor cells (MDSCs), M2 tumor-associated macrophages (TAMs), T regulatory cells (Tregs), N2 neutrophils, and by the release of immunosuppressive cytokines (TGF-β, IL-10) and chemokines. Immune checkpoint pathways, particularly of the PD-1/PD-L1 axis, have been determined as key regulators of cancer immune escape. While IFN-dependent upregulation of PD-L1 has been extensively investigated, up-to-date studies indicated the importance of DNA damage signaling in the regulation of PD-L1 expression following RT. DNA damage dependent PD-L1 expression is upregulated by ATM/ATR/Chk1 kinase activities and cGAS/STING-dependent pathway, proving the role of DNA damage signaling in PD-L1 induced expression. Checkpoint blockade immunotherapies (i.e., application of anti-PD-1 and anti-PD-L1 antibodies) combined with RT were shown to significantly improve the objective response rates in therapy of various primary and metastatic malignancies. Further improvements in the therapeutic potential of RT are based on combinations of RT with other immunotherapeutic approaches including vaccines, cytokines and cytokine inducers, and an adoptive immune cell transfer (DCs, NK cells, T cells). In the current review we provide immunological rationale for a combination of RT with various immunotherapies as well as analysis of the emerging preclinical evidences for these therapies.

Radiotherapy as a New Player in Immuno-Oncology

Recent development in radiation biology has revealed potent immunogenic properties of radiotherapy in cancer treatments. However, antitumor immune effects of radiotherapy are limited by the concomitant induction of radiation-dependent immunosuppressive effects. In the growing era of immunotherapy, combining radiotherapy with immunomodulating agents has demonstrated enhancement of radiation-induced antitumor immune activation that correlated with improved treatment outcomes. Yet, how to optimally deliver combination therapy regarding dose-fractionation and timing of radiotherapy is largely unknown. Future prospective testing to fine-tune this promising combination of radiotherapy and immunotherapy is warranted.

Novel nano-drug combination therapeutic regimen demonstrates significant efficacy in the transgenic mouse model of pancreatic ductal adenocarcinoma

The current work studied the chemopreventive efficacy of orally administered chitosan coated solid-lipid nanoparticle (c-SLN) encapsulated aspirin (ASP), curcumin (CUR) and free sulforaphane (SFN), ACS-cSLN, in the LSL-Kras ^G12D/+; Pdx-1 ^Cre/+ transgenic mouse model of pancreatic ductal adenocarcinoma (PDAC). In vitro uptake study and intracellular localization of ODA-FITC labeled ASP and CUR c-SLNs were performed in Panc-1 and MIA PaCa-2 cells by fluorescence microscopy. LSL-Kras ^G12D/+; Pdx-1 ^Cre/+ transgenic mice (n = 30) were randomly divided into 5 groups. Treatment groups were orally gavaged with ACS c-SLNs in three doses: low (2 + 4.5 + 0.16 mg/kg), medium (20 + 45 + 1.6 mg/kg) and high (60 + 135 + 4.8 mg/kg), respectively. After 20 weeks of treatment, mice pancreas were harvested, stained with dye and scored according to various pancreatic intraepithelial neoplasms (PanIN) categories by an independent observer. In vitro, cellular uptake evaluated on Panc-1 and MIA PaCa-2 cells resulted in higher fluorescence intensities, indicating increased cellular uptake of ASP and CUR c-SLNs. For further evidence, the addition of lysoID (red fluorescence) demonstrated location and uptake of ASP and CUR c-SLNs into the lysosome. In vivo, treatment with ACS c-SLN for 20-weeks did not cause obvious adverse effects on growth and no statistically significant differences in body weight were observed between groups. However, the weight (mean ± SEM) of pancreas at the end of the study was higher in blank c-SLN group (223.6 ± 42.2 mg) compared to low (138.0 ± 26.0 mg; not significant [NS]), medium (145.0 ± 9.0 mg; NS), and high (133.8 ± 20.3 mg; NS) ACS c-SLN treated groups, demonstrating the efficacy of ACS c-SLN nanoformulations. The low, medium and high dose of ACS c-SLN combinations exhibited a reduction in tumor incidence (PanIN count) by 16.6% (P < 0.01), 66.8% (P < 0.01), and 83.4% (P < 0.01), respectively. These studies provide further proof for the use of an oral, low dose nanotechnology-based combinatorial regimen for the chemoprevention of PDAC.

Differentiation therapy and the mechanisms that terminate cancer cell proliferation without harming normal cells

Chemotherapeutic drugs have a common intent to activate apoptosis in tumor cells. However, master regulators of apoptosis (e.g., p53, p16/CDKN2A) are frequently genetically inactivated in cancers, resulting in multidrug resistance. An alternative, p53-independent method for terminating malignant proliferation is to engage terminal-differentiation. Normally, the exponential proliferation of lineage-committed progenitors, coordinated by the master transcription factor (TF) MYC, is self-limited by forward-differentiation to terminal lineage-fates. In cancers, however, this exponential proliferation is disengaged from terminal-differentiation. The mechanisms underlying this decoupling are mostly unknown. We performed a systematic review of published literature (January 2007-June 2018) to identify gene pathways linked to differentiation-failure in three treatment-recalcitrant cancers: hepatocellular carcinoma (HCC), ovarian cancer (OVC), and pancreatic ductal adenocarcinoma (PDAC). We analyzed key gene alterations in various apoptosis, proliferation and differentiation pathways to determine whether it is possible to predict treatment outcomes and suggest novel therapies. Poorly differentiated tumors were linked to poorer survival across histologies. Our analyses suggested loss-of-function events to master TF drivers of lineage-fates and their cofactors as being linked to differentiation-failure: genomic data in TCGA and ICGC databases demonstrated frequent haploinsufficiency of lineage master TFs (e.g., GATA4/6) in poorly differentiated tumors; the coactivators that these TFs use to activate genes (e.g. ARID1A, PBRM1) were also frequently inactivated by genetic mutation and/or deletion. By contrast, corepressor components (e.g., DNMT1, EED, UHRF1, and BAZ1A/B), that oppose coactivators to repress or turn off genes, were frequently amplified instead, and the level of amplification was highest in poorly differentiated lesions. This selection by neoplastic evolution towards unbalanced activity of transcriptional corepressors suggests these enzymes as candidate targets for inhibition aiming to re-engage forward-differentiation. This notion is supported by both pre-clinical and clinical trial literature.

Turn Back the TIMe: Targeting Tumor Infiltrating Myeloid Cells to Revert Cancer Progression

Tumor cells frequently produce soluble factors that favor myelopoiesis and recruitment of myeloid cells to the tumor microenvironment (TME). Consequently, the TME of many cancer types is characterized by high infiltration of monocytes, macrophages, dendritic cells and granulocytes. Experimental and clinical studies show that most myeloid cells are kept in an immature state in the TME. These studies further show that tumor-derived factors mold these myeloid cells into cells that support cancer initiation and progression, amongst others by enabling immune evasion, tumor cell survival, proliferation, migration and metastasis. The key role of myeloid cells in cancer is further evidenced by the fact that they negatively impact on virtually all types of cancer therapy. Therefore, tumor-associated myeloid cells have been designated as the culprits in cancer. We review myeloid cells in the TME with a focus on the mechanisms they exploit to support cancer cells. In addition, we provide an overview of approaches that are under investigation to deplete myeloid cells or redirect their function, as these hold promise to overcome resistance to current cancer therapies.

Altering the response to radiation: radiosensitizers and targeted therapies in pancreatic ductal adenocarcinoma: preclinical and emerging clinical evidence

Radiation therapy continues to have an evolving role in pancreatic ductal adenocarcinoma. While metastatic failure likely contributes to the majority of patient mortality, achieving local control through surgery and/or radiation appears to be important as certain studies suggest that mortality is contributed by local failure. Many studies support that pancreatic cancer is a relatively radiation resistant tumor type. In addition, the ability to further improve radiation through dose escalation strategies in the non-metastatic setting is hampered by closeness of normal organs, including small bowel and stomach, to the tumor. Thus subverting molecular pathways that promote radiation resistance will be critical to further success of radiation in this disease. There is a wealth of preclinical data supporting the targeting of various molecular pathways in combination with radiation therapy, including DNA repair, cell cycle checkpoint proteins, receptor tyrosine kinases, oncoproteins, stem cells, and immunomodulation. A number of clinical trials have been completed or are on-going with novel molecular inhibitors. In this review, we summarize existing preclinical and clinical molecular strategies for improving the efficacy of radiation in pancreatic cancer, and highlight recent and ongoing clinical trials combining radiation and various targeted therapies.

Resectable pancreatic adenocarcinoma neo-adjuvant FOLF(IRIN)OX-based chemotherapy - a multicenter, non-comparative, randomized, phase II trial (PANACHE01-PRODIGE48 study)

BACKGROUND

At time of diagnosis, less than 10% of patients with pancreatic adenocarcinomas (PDAC) are considered to be immediately operable (i.e. resectable). Considering their poor overall survival (OS), only tumours without vascular invasion (NCCN 2017) should be considered for resection, i.e. those for which resection with disease-free margins (R0) is theoretically possible in absence of presurgery treatment. With regard to high R1 rates and undetectable locoregional and/or metastatic spreading prior to surgery explain (at least in part) the observed 1-year relapse and mortality rates of 50 and 25%, respectively. Today, upfront surgery followed by adjuvant chemotherapy is the reference treatment in Europe. The main limitation of the adjuvant approach is the low rate of completion of the full therapeutic sequence. Indeed, only 47 to 60% patients received any adjuvant therapy after resection compared to more than 75% for neoadjuvant therapy. No previous prospective study has compared this approach to a neoadjuvant FOLFIRINOX or FOLFOX chemotherapy for resectable PDAC.

METHODS

PANACHE01-PRODIGE48 is a prospective multicentre controlled randomized non comparative Phase II trial, evaluating the safety and efficacy of two regimens of neo-adjuvant chemotherapy (4 cycles of mFOLFIRINOX or FOLFOX) relative to the current reference treatment (surgery and then adjuvant chemotherapy) in patients with resectable PDAC. The main co-primary endpoints are OS rate at 12 months and the rate of patients undergoing the full therapeutic sequence.

DISCUSSION

The "ideal" cancer treatment for resectable PDAC would have the following characteristics: administration to the highest possible proportion of patients, ability to identify fast-progressing patients (i.e. poor candidates for surgery), a low rate of R1 resections (through optimisation of local disease control), and an acceptable toxicity profile. The neoadjuvant approach may meet all these criteria. With respect to published data on the efficacy of FOLFOX and mFOLFIRINOX, these two regimens are potential candidates for neoadjuvant use in the aim to optimising oncological outcomes in resectable PDAC.

TRIAL REGISTRATION

ClinicalTrials.gov , NCT02959879 . Trial registration date: November 9, 2016.

Chronologic changes in clinical and survival features of pancreatic ductal adenocarcinoma since 2000: A single-center experience with 2,029 patients

BACKGROUND

To identify chronologic changes in clinical and survival features of pancreatic ductal adenocarcinoma based on diagnosis and treatment strategy development since 2000.

METHODS

Among 2,029 patients enrolled in this study, 746 and 1,283 were treated between 2000 and 2009 (group 1) and between 2010 and 2016 (group 2), respectively. We used patient clinicopathologic, biologic, and molecular factors to assess the prognostic factors.

RESULTS

Group 2 had a better survival outcome than group 1 (median survival time: 24.9 versus 18.4 months; 5-year survival rate: 27.6% versus 22.3%). The tendency for early diagnosis (lower CA19-9 levels, smaller size, and earlier T stage), use of neoadjuvant chemotherapy, decreased morbidity, early recovery (lesser hospital stay and more minimally invasive surgery), and standardization of surgical techniques appeared to improve patient survival. Multivariable analysis for prognosis revealed that tumor biologic factors (increased preoperative serum CA19-9 level, tumor size, tumor differentiation, N stage, and presence of lymphovascular invasion), operational factors (status of the resection margin, type of operation, and year of operation), and genetic factors (K-ras mutations) correlated with patient survival.

CONCLUSION

Early diagnosis and combined efforts, such as neoadjuvant chemotherapy and an established system of patient care, have gradually enhanced patient survival after operative resection for pancreatic ductal adenocarcinoma. Hence, multiplex prognostic parameters could provide additional information for improved prognostic estimation of pancreatic cancer exhibiting heterogeneous results.

Using immunotherapy to boost the abscopal effect

More than 60 years ago, the effect whereby radiotherapy at one site may lead to regression of metastatic cancer at distant sites that are not irradiated was described and called the abscopal effect (from 'ab scopus', that is, away from the target). The abscopal effect has been connected to mechanisms involving the immune system. However, the effect is rare because at the time of treatment, established immune-tolerance mechanisms may hamper the development of sufficiently robust abscopal responses. Today, the growing consensus is that combining radiotherapy with immunotherapy provides an opportunity to boost abscopal response rates, extending the use of radiotherapy to treatment of both local and metastatic disease. In this Opinion article, we review evidence for this growing consensus and highlight emerging limitations to boosting the abscopal effect using immunotherapy. This is followed by a perspective on current and potential cross-disciplinary approaches, including the use of smart materials to address these limitations.

Combination of interferon-expressing oncolytic adenovirus with chemotherapy and radiation is highly synergistic in hamster model of pancreatic cancer

Recent clinical trials utilizing Interferon-alpha (IFN) in combination with chemoradiation have demonstrated significant improvements in the survival of patients with pancreatic cancer. However, efficacy was limited by the systemic toxicity of IFN and low intratumoral levels of the cytokine. We sought to address these drawbacks by using an Oncolytic Adenovirus expressing IFN (OAd-hamIFN) in combination with chemotherapy and/or radiation in regimens mimicking the IFN-based therapies used in clinical trials. IFN expressed from OAd-hamIFN potentiated the cytotoxicity of radiation and chemotherapy (5-FU, Gemcitabine, and Cisplatin), and enhanced pancreatic cancer cell death in both in vitro and in vivo experimental settings. Notably, synergism was demonstrated in therapeutic groups that combined the interferon-expressing oncolytic virus with chemotherapy and radiation. In an in vivo immunocompetent hamster model, treatment regimens combining oncolytic virus therapy with 5-FU and radiation demonstrated significant tumor growth inhibition and enhanced survival. This is the first study to report synergism between an IFN-expressing oncolytic adenovirus and chemoradiation-based therapies. When combined with an IFN-expressing OAd, there is a significant enhancement of radiation and especially chemoradiation, which may broaden the application of this new therapeutic approach to the pancreatic cancer patients who cannot tolerate existing chemotherapy regimens.

Multimodality Therapy in Patients With Borderline Resectable or Locally Advanced Pancreatic Cancer: Importance of Locoregional Therapies for a Systemic Disease

Historically, the clinical staging of pancreatic cancer has centered on the surgical management of the primary tumor, because few effective chemotherapeutic agents were available and long-term survival was only achieved in the context of surgical resection. Such a strategy of complete oncologic surgical care is reasonable when surgery is both the principal therapy and highly effective. However, complex surgery for pancreatic cancer-often performed in older patients after a lengthy period of induction therapy-can be associated with significant morbidity and mortality. The majority of patients with pancreatic cancer present either locally advanced or metastatic disease at the time of diagnosis. In this article, we will discuss the role of multimodality management of patients with borderline resectable and locally advanced pancreatic cancer. Considering that surgery has a modest impact on the natural history of pancreatic cancer in most patients, a neoadjuvant approach to treatment sequencing is favored for patients with borderline resectable pancreatic cancer, and this same rationale has been extended to select patients with locally advanced disease who demonstrate an exceptional response to induction therapy.

Stimulating Innate Immunity to Enhance Radiation Therapy-Induced Tumor Control

Novel ligands that target Toll-like receptors and other innate recognition pathways represent a potent strategy for modulating innate immunity to generate antitumor immunity. Although many of the current clinically successful immunotherapies target adaptive T-cell responses, both preclinical and clinical studies suggest that adjuvants have the potential to enhance the scope and efficacy of cancer immunotherapy. Radiation may be a particularly good partner to combine with innate immune therapies, because it is a highly efficient means to kill cancer cells but may fail to send the appropriate inflammatory signals needed to act as an efficient endogenous vaccine. This may explain why although radiation therapy is a highly used cancer treatment, true abscopal effects-regression of disease outside the field without additional systemic therapy-are extremely rare. This review focuses on efforts to combine innate immune stimuli as adjuvants with radiation, creating a distinct and complementary approach from T cell-targeted therapies to enhance antitumor immunity.

Inflammation and Epithelial-Mesenchymal Transition in Pancreatic Ductal Adenocarcinoma: Fighting Against Multiple Opponents

Pancreatic ductal adenocarcinoma (PDAC) is the most common type of pancreatic cancer and one of the most lethal human cancers. Inflammation is a critical component in PDAC initiation and progression. Inflammation also contributes to the aggressiveness of PDAC indirectly via induction of epithelial-mesenchymal transition (EMT), altogether leading to enhanced resistance to chemotherapy and poor survival rates. This review gives an overview of the key pro-inflammatory signaling pathways involved in PDAC pathogenesis and discusses the role of inflammation in induction of EMT and development of chemoresistance in patients with PDAC.

The Role of Radiation Therapy for Pancreatic Cancer in the Adjuvant and Neoadjuvant Settings

Pancreatic cancer is the third leading cause of cancer-related death in the United States. Although surgery remains the only curative treatment, chemotherapy and radiation therapy are frequently used. In the adjuvant setting, radiation is usually delivered with chemotherapy to eradicate residual microscopic or macroscopic disease in the resection bed. Neoadjuvant radiation therapy has become more frequently utilized. This article reviews the historical and modern literature regarding radiation therapy in the neoadjuvant and adjuvant settings, focusing on the evolution of radiation therapy techniques and clinical trials in an attempt to identify patients best suited to receiving radiation therapy.

Interferon-based chemoradiation followed by gemcitabine for resected pancreatic adenocarcinoma: long-term follow-up

To report long-term follow up of a phase II, single-arm trial of resectable pancreatic ductal adenocarcinoma (PDAC) treated with adjuvant interferon-based chemoradiation followed by gemcitabine to determine survival, recurrence, and complications.

METHODS

From 2002 to 2005, 53 patients with PDAC underwent pancreaticoduodenectomy and received adjuvant interferon-based chemoradiation consisting of external-beam irradiation and simultaneous 3-drug chemotherapy of continuous daily 5-fluorouracil infusion, weekly intravenous bolus cisplatin, and subcutaneous interferon-α, followed by two months of weekly intravenous gemcitabine.

RESULTS

Actual overall survival for the 5- and 10-year periods were 26% and 10%, respectively, with a median overall survival of 25 months (95% CI: 16.4-38.5). Adverse prognostic factors on multivariate analysis were positive tumor margin (p < 0.035), lymphovascular invasion (p < 0.015), and perineural invasion (p < 0.026). Median time to recurrence was 11 months. Positive tumor margin was associated with lymph node involvement (p < 0.005), portal vein resection (p < 0.038), and metastases (p < 0.018). Late complications were frequent and predominated by gastrointestinal and infectious complications.

CONCLUSIONS

Adjuvant interferon-based chemoradiation for PDAC improves long-term survival compared to standard therapy. However, recurrence rates and long-term complications remain high, thus further studies are indicated to assess patient characteristics that indicate a favorable treatment profile.

Clinical Outcomes of Specific Immunotherapy in Advanced Pancreatic Cancer: A Systematic Review and Meta-Analysis

Specific immunotherapies, including vaccines with autologous tumor cells and tumor antigen-specific monoclonal antibodies, are important treatments for PC patients. To evaluate the clinical outcomes of PC-specific immunotherapy, we performed a systematic review and meta-analysis of the relevant published clinical trials. The effects of specific immunotherapy were compared with those of nonspecific immunotherapy and the meta-analysis was executed with results regarding the overall survival (OS), immune responses data, and serum cancer markers data. The pooled analysis was performed by using the random-effects model. We found that significantly improved OS was noted for PC patients utilizing specific immunotherapy and an improved immune response was also observed. In conclusion, specific immunotherapy was superior in prolonging the survival time and enhancing immunological responses in PC patients.

Five-Year Actual Overall Survival in Resected Pancreatic Cancer: A Contemporary Single-Institution Experience from a Multidisciplinary Perspective

BACKGROUND

Successful surgical resection combined with effective perioperative therapy is essential for maximizing long-term survival for pancreatic adenocarcinoma.

PATIENTS AND METHODS

All patients with pancreatic adenocarcinoma who underwent curative resection at our institution from January 2003 to May 2010 were reviewed. Demographic and clinical details were retrospectively collected from medical records and cancer registry data.

RESULTS

Overall, 176 patients were included in the analysis (148 with de novo resectable disease and 28 with borderline resectable disease at presentation). Among 106 patients who received all perioperative therapy at our institution, 94% received neoadjuvant and/or adjuvant treatment in addition to resection. Actual all-cause 5-year overall survival (OS) for all 176 patients was 30.7%, with a median OS of 33.9 months [95% confidence interval (CI) 28.1-39.6 months]. For patients who received all perioperative therapy at our institution, actual all-cause 5-year disease-free survival (DFS) was 32.1%, with a median DFS of 28.8 months (95% CI 20.1-43.6 months). Of these patients, 67/106 (63%) recurred: 8 (8%) locoregional only; 52 (49%) systemic only; and 7 (7%) combined recurrence. No difference in survival rates or recurrence patterns was seen between resectable and borderline resectable patients. In multivariate analysis, tumor differentiation (poor vs. non-poor) and lymph node ratio >20% produced a useful clinical model.

CONCLUSION

The actual OS rates for resected pancreatic cancer shown in this study are reflective of those currently achievable at a tertiary medical center dedicated to this patient population. In considering these results, both frequency and type of adjuvant/neoadjuvant therapy administered in the context of the clinical experience/management techniques of providers administering these treatments will be discussed.

Successes and Failures of Combined Modalities in Upper Gastrointestinal Malignancies: New Directions

Upper gastrointestinal malignancies generally have moderate to poor cure rates, even in the earliest stages, thereby implying that both local and systemic treatments have room for improvement. Therapeutic options are broadening, however, with the development of new immunotherapies and targeted agents, which can have synergistic effects with radiotherapy. Here we discuss the current state of combined modality therapy for upper gastrointestinal malignancies, specifically recent successes and setbacks in trials of radiation therapy with targeted therapies, vaccines, immunotherapies, and chemotherapies.

Current clinical trials testing the combination of immunotherapy with radiotherapy

Increasing evidence demonstrates that radiation acts as an immune stimulus, recruiting immune mediators that enable anti-tumor responses within and outside the radiation field. There has been a rapid expansion in the number of clinical trials harnessing radiation to enhance antitumor immunity. If positive, results of these trials will lead to a paradigm shift in the use of radiotherapy. In this review, we discuss the rationale for trials combining radiation with various immunotherapies, provide an update of recent clinical trial results and highlight trials currently in progress. We also address issues pertaining to the optimal incorporation of immunotherapy with radiation, including sequencing of treatment, radiation dosing and evaluation of clinical trial endpoints.

The Prognostic and Predictive Role of Epidermal Growth Factor Receptor in Surgical Resected Pancreatic Cancer

The data regarding the prognostic significance of EGFR (epidermal growth factor receptor) expression and adjuvant therapy in patients with resected pancreatic cancer are insufficient. We retrospectively investigated EGFR status in 357 resected PDAC (pancreatic duct adenocarcinoma) patients using tissue immunohistochemistry and validated the possible role of EGFR expression in predicting prognosis. The analysis was based on excluding the multiple confounding parameters. A negative association was found between overall EGFR status and postoperative survival (p = 0.986). Remarkably, adjuvant chemotherapy and radiotherapy were significantly associated with favorable postoperative survival, which prolonged median overall survival (OS) for 5.8 and 10.2 months (p = 0.009 and p = 0.006, respectively). Kaplan-Meier analysis showed that adjuvant chemotherapy correlated with an obvious survival benefit in the EGFR-positive subgroup rather than in the EGFR-negative subgroup. In the subgroup analyses, chemotherapy was highly associated with increased postoperative survival in the EGFR-negative subgroup (p = 0.002), and radiotherapy had a significant survival benefit in the EGFR-positive subgroup (p = 0.029). This study demonstrated that EGFR expression is not correlated with outcome in resected pancreatic cancer patients. Adjuvant chemotherapy and radiotherapy were significantly associated with improved survival in contrary EGFR expressing subgroup. Further studies of EGFR as a potential target for pancreatic cancer treatment are warranted.

Interferon-based Adjuvant Chemoradiation for Resected Pancreatic Head Cancer: Long-term Follow-up of the Virginia Mason Protocol

OBJECTIVE

To report the long-term impact of adjuvant interferon-based chemoradiation therapy (IFN-CRT) after pancreaticoduodenectomy (PD) for pancreatic adenocarcinoma (PDAC).

BACKGROUND

In 2003, we reported an actuarial 5-year overall survival (OS) of 55% (22 months median follow-up) using adjuvant IFN-CRT after PD. As the original cohort is now 10 years distant from PD, we sought to examine their actual survival, describe patterns of recurrence, and determine prognostic factors.

METHODS

From 1995 to 2002, 43 patients underwent PD for PDAC and received adjuvant IFN-CRT consisting of external-beam irradiation, continuous 5-fluorouracil infusion, weekly intravenous bolus cisplatin, and subcutaneous interferon-α. Survival was calculated by the method of Kaplan and Meier, and prognostic factors were compared using a log-rank test and a Cox proportional hazards model.

RESULTS

With all patients at least 10 years from PD, the 5-year actual survival was 42% and 10-year actual survival was 28% with median OS of 42 months (95% confidence interval: 22-110 months). Nine patients survived beyond 10 years with 7 currently alive without evidence of disease. Initial recurrence included 4 local, 17 distant, and 4 combined sites at a median of 25 months. IFN-CRT was interrupted in 70% of patients because of grade 3 or 4 toxicity, whereas 42% of patients required hospitalization. Adverse prognostic factors included lymph node ratio of 50% or more, Eastern Cooperative Oncology Group performance status of 1 or higher, and IFN-CRT treatment interruption.

CONCLUSIONS

Adjuvant IFN-CRT after PD can provide long-term survival in resected PDAC. Further studies should focus on patient and tumor factors to maximize benefit and minimize toxicity.

Rare long-term survivors of pancreatic adenocarcinoma without curative resection

Long-term outcome data in pancreatic adenocarcinoma are predominantly based on surgical series, as resection is currently considered essential for long-term survival. In contrast, five-year survival in non-resected patients has rarely been reported. In this report, we examined the incidence and natural history of ≥ 5-year survivors with non-resected pancreatic adenocarcinoma. All patients with pancreatic adenocarcinoma who received oncologic therapy alone without surgery at our institution between 1995 and 2009 were identified. Non-resected ≥ 5-year survivors represented 2% (11/544) of all non-resected patients undergoing treatment for pancreatic adenocarcinoma, and 11% (11/98) of ≥ 5-year survivors. Nine patients had localized tumor and 2 metastatic disease at initial diagnosis. Disease progression occurred in 6 patients, and the local tumor bed was the most common site of progression. Six patients suffered from significant morbidities including recurrent cholangitis, second malignancy, malnutrition and bowel perforation. A rare subset of patients with pancreatic cancer achieve long-term survival without resection. Despite prolonged survival, morbidities unrelated to the primary cancer were frequently encountered and a close follow-up is warranted in these patients. Factors such as tumor biology and host immunity may play a key role in disease progression and survival.

Clinical trials exploring the benefit of immunotherapy and radiation in cancer treatment: A review of the past and a look into the future

Cancer immunotherapy is rapidly redefining the standard of cancer care. The role of radiation therapy in eliciting antitumoral immune response is also being actively investigated in combination with various immunotherapeutic agents to exploit potential synergy between the 2 modalities. In this review, we summarize the rationale and results of past and ongoing clinical trials that combined the use of radiation therapy and immunogenic agents such as vaccines, cytokines, immune checkpoint inhibitors, costimulatory agonists, and myeloid activators.

Pancreatic cancer: optimizing treatment options, new, and emerging targeted therapies

Pancreatic cancer is the fourth leading cause of cancer death in the US and is expected to become the second leading cause of cancer-related deaths in the next decade. Despite 5-fluorouracil/leucovorin with irinotecan and oxaliplatin (FOLFIRINOX) and gemcitabine/nab-paclitaxel significantly improving outcomes for metastatic cancer, refractory disease still poses significant challenges. Difficulties with early detection and the inherent chemo- and radio-resistant nature of this malignancy led to attempts to define the sequential biology of pancreatic cancer in order to improve survival outcomes. Pancreatic adenocarcinoma is characterized by several germline or acquired genetic mutations, the most common being KRAS (90%), CDK2NA (90%), TP53 (75%-90%), DPC4/SMAD4 (50%). In addition, the tumor microenvironment, chemoresistant cancer stem cells, and the desmoplastic stroma have been the target of some promising clinical investigations. Among the core pathways reproducibly shown to lead the development and progression of this disease, DNA repair, apoptosis, G1/S cell cycle transition, KRAS, Wnt, Notch, Hedgehog, TGF-beta, and other cell invasion pathways, have been the target of "precision therapeutics". No single molecularly targeted therapeutic though has been uniformly successful, probably due to the tumor heterogeneity, but biomarker research is evolving and it hopes to select more patients likely to benefit. Recent reports note activity with immunotherapies such as CD40 agonists, CCR2 inhibitors, cancer vaccines, and novel combinations against the immunosuppressive tumor milieu are ongoing. While many obstacles still exist, clearly we are making progress in deciphering the heterogeneity within pancreatic cancers. Integrating conventional and immunological targeting will be the key to effective treatment of this deadly disease.

A mutated anti-CA19-9 scFv-Fc for positron emission tomography of human pancreatic cancer xenografts

PURPOSE

Intact antibodies have a long serum persistence resulting in high background signal that inhibits their direct translation as imaging agents. Engineering of antibody fragments through the introduction of mutations in the fragment crystallizable (Fc) region can dramatically reduce serum persistence. We sought to develop a Fc-mutated, anti-CA19-9 antibody fragment (anti-CA 19-9 scFv-Fc H310A) to provide micro-positron emission tomography (microPET) imaging of pancreatic cancer xenografts.

PROCEDURES

The anti-CA19-9 scFv-Fc H310A was successfully expressed and purified. Biochemical characterization included size exclusion chromatography, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), Western blot, and flow cytometry. The antibody fragment was labeled with iodine-124 ((124)I) and injected into mice containing human pancreatic cancer xenografts. MicroPET/CT images were then obtained. Blood, organ, and tumor radioactivity was measured and expressed as the percent of injected dose per gram of tissue (%ID/g).

RESULTS

Biochemical characterization was consistent with the creation of a 105 kD dimer containing a human Fc region. Flow cytometry demonstrated antigen-specific binding, and cell-based ELISA further established a dissociation constant (K D) of 10.7 nM. (124)I-labeled scFv-Fc H310A localized to the antigen-positive tumor xenografts as detected by microPET. Objective confirmation of targeting was demonstrated by higher %ID/g in the antigen-positive tumor compared to the blood, antigen-negative tumor, and liver.

CONCLUSIONS

We successfully engineered and produced an anti-CA19-9 scFv-Fc H310A antibody fragment that retains similar affinity when compared to the parental intact murine antibody. Additionally, our engineered and mutated fragment exhibited antigen-specific microPET imaging of both subcutaneous and orthotopic pancreatic cancer xenografts at early time points secondary to decreased serum half-life.

Targeting the tumor microenvironment to enhance antitumor immune responses

The identification of tumor-specific antigens and the immune responses directed against them has instigated the development of therapies to enhance antitumor immune responses. Most of these cancer immunotherapies are administered systemically rather than directly to tumors. Nonetheless, numerous studies have demonstrated that intratumoral therapy is an attractive approach, both for immunization and immunomodulation purposes. Injection, recruitment and/or activation of antigen-presenting cells in the tumor nest have been extensively studied as strategies to cross-prime immune responses. Moreover, delivery of stimulatory cytokines, blockade of inhibitory cytokines and immune checkpoint blockade have been explored to restore immunological fitness at the tumor site. These tumor-targeted therapies have the potential to induce systemic immunity without the toxicity that is often associated with systemic treatments. We review the most promising intratumoral immunotherapies, how these affect systemic antitumor immunity such that disseminated tumor cells are eliminated, and which approaches have been proven successful in animal models and patients.

Type I Interferon Receptor Expression in Human Pancreatic and Periampullary Cancer Tissue

OBJECTIVES

Interferons (IFNs) have several anticancer mechanisms. A number of clinical trials have been conducted regarding adjuvant IFN-α therapy in pancreatic cancer. Type I IFNs exert their effect via the type I IFN receptor (IFNAR-1, IFNAR-2c). The aims of the present study were to determine the type I IFN receptor expression in pancreatic and periampullary cancer tissues and to study its relation with clinicopathological factors.

METHODS

Receptor expression was determined by immunohistochemistry in paraffin-embedded cancer tissue of 47 pancreatic and 54 periampullary cancer patients.

RESULTS

The results demonstrated that 91.5% of the pancreatic tumors and 88.9% of the periampullary tumors showed expression of IFNAR-1, of which 23.4% and 13.0% were strongly positive, respectively. Regarding IFNAR-2c expression, 68.1% of the pancreatic tumors and 68.5% of the periampullary tumors were positive, of which 4.3% of the pancreatic tumors and none of the periampullary tumors had a strong expression. No statistically significant associations were found between type I IFN receptor expression and clinicopathological factors or survival.

CONCLUSIONS

Type I IFN receptors are expressed in pancreatic and periampullary cancer tissues although with great intertumoral and intratumoral variability. A small proportion of both tumors showed a strong expression of the IFNAR-1; only a very small percentage of the pancreatic tumors showed strong expression of the IFNAR-2c.

Potentials of interferon therapy in the treatment of pancreatic cancer

Pancreatic cancer is a highly aggressive malignancy with limited treatment options. To improve survival for patients with pancreatic cancer, research has focused on other treatment modalities like adding biological modulators such as type-I interferons (IFNs). Type I IFNs (ie, IFN-α/IFN-β) have antiproliferative, antiviral, and immunoregulatory activities. Furthermore, they are able to induce apoptosis, exert cell cycle blocking, and sensitize tumor cells for chemo- and radiotherapy. A few years ago in vitro, in vivo, and several clinical trials have been described regarding adjuvant IFN-α therapy in the treatment of pancreatic cancer. Some studies reported a remarkable increase in the 2- and 5-year survival. Unfortunately, the only randomized clinical trial did not show a significant increase in overall survival, although the increased median survival implicated that some patients in the experimental group benefited from the adjuvant IFN-α therapy. Furthermore, encouraging in vitro and in vivo data points to a possible role for adjuvant IFN therapy. However, up till now, the use of IFNs in the treatment of pancreatic cancer remains controversial. This review, therefore, aims to describe, based on the available data, whether there is a distinct role for IFN therapy in the treatment of pancreatic cancer.

Combinations of immunotherapy and radiation in cancer therapy

The immune system has the ability to recognize and specifically reject tumors, and tumors only become clinically apparent once they have evaded immune destruction by creating an immunosuppressive tumor microenvironment. Radiotherapy (RT) can cause immunogenic tumor cell death resulting in cross-priming of tumor-specific T-cells, acting as an in situ tumor vaccine; however, RT alone rarely induces effective anti-tumor immunity resulting in systemic tumor rejection. Immunotherapy can complement RT to help overcome tumor-induced immune suppression, as demonstrated in pre-clinical tumor models. Here, we provide the rationale for combinations of different immunotherapies and RT, and review the pre-clinical and emerging clinical evidence for these combinations in the treatment of cancer.

Adjuvant therapy in pancreatic cancer

Pancreatic cancer remains one of the leading causes of cancer related death worldwide with an overall five-year survival of less than 5%. Potentially curative surgery, which alone can improve 5-year survival to 10%, is an option for only 10%-20% of patients at presentation owing to local invasion of the tumour or metastatic disease. Adjuvant chemotherapy has been shown to improve 5-year survival to 20%-25% but conflicting evidence remains with regards to chemoradiation. In this article we review the current evidence available from published randomised trials and discuss ongoing phase III trials in relation to adjuvant therapy in pancreatic cancer.

Neoadjuvant interferon-based chemoradiation for borderline resectable and locally advanced pancreas cancer: a Phase II pilot study

OBJECTIVES

Neoadjuvant chemoradiotherapy (CRT) is a viable treatment strategy for patients with pancreatic cancer. This study was conducted to evaluate the Virginia Mason Protocol (5-fluorouracil, cisplatin, interferon-α and radiation) given in the neoadjuvant setting for the treatment of locally advanced pancreatic cancer.

METHODS

A Phase II pilot study evaluating interferon-based neoadjuvant CRT in patients with locally advanced pancreatic cancer was performed.

RESULTS

A total of 23 patients were enrolled. The mean age of the patients was 58.6 years. Of the 23 patients, seven (30.4%) completed all treatments. In the remaining 16 (69.6%) patients, treatment was interrupted as a result of toxicity. The most commonly reported effects of toxicity were leucopoenia/cytopoenia (n = 19, 82.6%) and gastrointestinal effects (n = 19, 82.6%). Surgical resection was successful in seven (30.4%) patients. Margins were negative in six (85.7%) of these seven patients. Positive lymph nodes were identified in three (42.9%) of seven patients. Overall survival was 11.5 months. Surgery provided improved survival (22.6 months) compared with CRT alone (8.8 months). Disease-free survival in resected patients was 17.2 months.

CONCLUSIONS

Interferon-based neoadjuvant CRT may allow for resection of locally advanced pancreatic cancer, but with significant toxicity. In the absence of surgical resection, survival remains dismal.

Influence of type-I Interferon receptor expression level on the response to type-I Interferons in human pancreatic cancer cells

Pancreatic cancer is a highly aggressive malignancy with limited treatment options. Type-I interferons (e.g. IFN-α/-β) have several anti-tumour activities. Over the past few years, clinical studies evaluating the effect of adjuvant IFN-α therapy in pancreatic cancer yielded equivocal results. Although IFN-α and-β act via the type-I IFN receptor, the role of the number of receptors present on tumour cells is still unknown. Therefore, this study associated, for the first time, in a large panel of pancreatic cancer cell lines the effects of IFN-α/-β with the expression of type-I IFN receptors. The anti-tumour effects of IFN-α or IFN-β on cell proliferation and apoptosis were evaluated in 11 human pancreatic cell lines. Type-I IFN receptor expression was determined on both the mRNA and protein level. After 7 days of incubation, IFN-α significantly reduced cell growth in eight cell lines by 5–67%. IFN-β inhibited cell growth statistically significant in all cell lines by 43–100%. After 3 days of treatment, IFN-β induced significantly more apoptosis than IFN-α. The cell lines variably expressed the type-I IFN receptor. The maximal inhibitory effect of IFN-α was positively correlated with the IFNAR-1 mRNA (P < 0.05, r = 0.63), IFNAR-2c mRNA (P < 0.05, r = 0.69) and protein expression (P < 0.05, r = 0.65). Human pancreatic cancer cell lines variably respond to IFN-α and-β. The expression level of the type-I IFN receptor is of predictive value for the direct anti-tumour effects of IFN-α treatment. More importantly, IFN-β induces anti-tumour effects already at much lower concentrations, is less dependent on interferon receptor expression and seems, therefore, more promising than IFN-α.