Ablative Therapies for Locally Advanced Pancreatic Cancer

Advancements in the application of ablative therapy and its combination with immunotherapy in anti-cancer therapy

Cancer is a significant health issue impacting humans. Currently, systemic therapies such as chemotherapy have significantly increased the life expectancy of cancer patients. However, some patients are unable to endure systemic treatment due to its significant adverse effects, leading to an increased focus on local therapies including radiation and ablation therapy. Ablation therapy is a precise, low-toxicity, and minimally invasive localized therapy that is increasingly acknowledged by clinicians and cancer patients. Many cancer patients have benefited from it, with some achieving full recovery. Currently, numerous studies have shown that ablation therapy is effective due to its ability to kill cancer cells efficiently and activate the body's anti-cancer immunity. It can also convert "cold cancers" into "hot cancers" and enhance the effectiveness of immunotherapy when used in combination. In this article, we categorize ablation therapy into thermal ablation, cryoablation, photodynamic therapy (PDT), irreversible electroporation (IRE), etc. Thermal ablation is further divided into Radiofrequency ablation (RFA), microwave ablation (WMA), high-frequency focused ultrasound (HIFU), photothermal therapy (PTT), magnetic heat therapy (MHT), etc. We systematically review the most recent advancements in these ablation therapies that are either currently used in clinic or are anticipated to be used in clinic. Then, we also review the latest development of various ablative therapies combined with immunotherapy, and its future development. CLINICAL RELEVANCE STATEMENT: Ablation therapy, an invasive localized treatment, offers an alternative to systemic therapies for cancer patients who cannot tolerate their adverse effects. Its ability to kill cancer cells efficiently and activate anti-cancer immunity. This article reviews recent advancements in ablation therapies, including thermal, cryoablation, PDT, and IRE, and their potential clinical applications, both standalone and in combination with immunotherapy.

The miR-1305/KLF5 negative regulatory loop affects pancreatic cancer cell proliferation and apoptosis

Pancreatic cancer (PC) is characterized by a high relapse rate and unfavorable prognosis. Currently, the optimal treatment for PC is complete resection followed by adjuvant systemic chemotherapy. Nevertheless, tumor cell repopulation and subsequent tumor relapse and metastasis after chemotherapy result in a poor prognosis. Therefore, it is of great value to explore the potential molecular mechanisms underlying PC for developing novel treatment strategies. Herein, we aimed to investigate the potential regulatory mechanism of miR-1305 upon aerobic proliferation, metastasis, and apoptosis in PC. miR-1305 was downregulated in PC tissues and cell lines. miR-1305 overexpression prominently inhibited PC cell proliferation and metastasis promoted cell apoptosis in vitro, and alleviated PC formation in vivo. As predicted, KLF5 could directly bind to miR-1305. Silencing of KLF5 or KLF5 inhibitor (ML264) suppressed PC cell viability and cell invasion, and enhanced cell apoptosis. KLF5 restrained miR-1305 transcription and expression by binding to its promoter region. miR-1305 exerted a suppressive effect on PC cell proliferation and apoptosis via regulation of the KLF5-ERBB2 axis; KLF5 gene is a transcriptional regulator of miR-1305, promising to be a new target for the diagnosis and treatment of PC.

Focused Ultrasound in Cancer Immunotherapy: A Review of Mechanisms and Applications

Ultrasound is well-perceived for its diagnostic application. Meanwhile, ultrasound, especially focused ultrasound (FUS), has also demonstrated therapeutic capabilities, such as thermal tissue ablation, hyperthermia, and mechanical tissue ablation, making it a viable therapeutic approach for cancer treatment. Cancer immunotherapy is an emerging cancer treatment approach that boosts the immune system to fight cancer, and it has also exhibited enhanced effectiveness in treating previously considered untreatable conditions. Currently, cancer immunotherapy is regarded as one of the four pillars of cancer treatment because it has fewer adverse effects than radiation and chemotherapy. In recent years, the unique capabilities of FUS in ablating tumors, regulating the immune system, and enhancing anti-tumor responses have resulted in a new field of research known as FUS-induced/assisted cancer immunotherapy. In this work, we provide a comprehensive overview of this new research field by introducing the basics of focused ultrasound and cancer immunotherapy and providing the state-of-the-art applications of FUS in cancer immunotherapy: the mechanisms and preclinical and clinical studies. This review aims to offer the scientific community a reliable reference to the exciting field of FUS-induced/assisted cancer immunotherapy, hoping to foster the further development of related technology and expand its medical applications.

miR-4299 inhibits tumor progression in pancreatic cancer through targeting ADAM17

Pancreatic cancer (PC) is one of the most aggressive malignant tumors in human beings. Tumor capacity of evading immune-mediated lysis is a critical step in PC malignant progression. We aimed to evaluate the underlying regulatory mechanism of miR-4299 in the proliferation, metastasis, apoptosis, and immune escape in PC. miR-4299 and ADAM17 expressions in PC tissues and cell lines were detected using qRT-PCR. MTT assay and flow cytometry were used to detect cell viability and apoptosis, respectively. A luciferase reporter gene assay was conducted to confirm the targeted relationship between miR-4299 and ADAM17. Xenograft tumors in nude mice were used to detect tumorigenesis in vivo. PC cells were co-cultured with NK cells for determining the immune escape ability. NKG2D-positive rate of NK cells was detected using flow cytometry; NK cell-killing ability was detected using MTT assay. miR-4299 was downregulated in PC tissues and cell lines. miR-4299 inhibited PC cell proliferation and invasion, promoted cell apoptosis, and reduced PC tumor growth in vivo. ADAM17 3'UTR directly bound to miR-4299. ADAM17 overexpression could reverse miR-4299 effects on PC cell viability, invasion, apoptosis, and immune escape. miR-4299 exerted suppressive effects on PC cell proliferation, invasion, and immune escape via targeting ADAM17 expression. This study revealed a novel miR-4299/ADAM17 axis-modulating PC progression and proposed to concern the immune regulatory mechanism of miRNAs in PC development.

Immunomodulatory Effects of Endoscopic Ultrasound-Guided Thermal Ablation in Patients with Pancreatic Ductal Adenocarcinoma

Immunological consequences of endoscopic ultrasound (EUS)-local thermal ablation (LTA) for pancreatic ductal adenocarcinoma (PDAC) have not been extensively assessed. We aimed to explore EUS-LTA effects on the systemic immune response in PDAC. Peripheral blood was collected from 10 treatment-naïve patients with borderline resectable and locally advanced PDAC, randomly allocated to Nab-paclitaxel plus Gemcitabine chemotherapy (CT-arm, n = 5) or EUS-LTA with HybridTherm Probe plus CT (HTP + CT-arm, n = 5). Twenty healthy donors were included as controls. Flow-cytometry and multiplex assays were used to profile immune cell subsets and measure serum cytokines/chemokines, respectively. At baseline, PDAC patients showed increased circulating monocytes and lower circulating lymphocytes and CD19+ B cells counts compared to healthy controls. After 4 months, CT induced decrease of B regulatory cells, CD4+ cytotoxic T cells and IL-1β. The addition of EUS-HTP to CT selectively decreased the serum levels of APRIL/TNFSF13 as well as T regulatory cells, total, classic and inflammatory monocytes. Serum levels of APRIL/TNFSF13 and total, classic and inflammatory monocytes counts at baseline were associated with worse overall survival. EUS-HTP has the potential to selectively impact on immune cells and cytokines associated with poor outcomes in PDAC.

US-Guided Percutaneous Radiofrequency Ablation of Locally Advanced Pancreatic Adenocarcinoma: A 5-Year High-Volume Center Experience

PURPOSE

 The aim of this study was to investigate the safety and effectiveness of percutaneous radiofrequency ablation (RFA) in locally advanced pancreatic cancer (LAPC) of the pancreatic body by assessing the overall survival of patients and evaluating the effects of the procedure in the clinical and radiological follow-up.

MATERIALS AND METHODS

 Patients with unresectable LAPC after failed chemoradiotherapy for at least six months were retrospectively included. Percutaneous RFA was performed after a preliminary ultrasound (US) feasibility evaluation. Contrast-enhanced computed tomography (CT) and CA 19.9 sampling were performed before and 24 hours and 30 days after the procedure to evaluate the effects of the ablation. Patients were followed-up after discharge considering the two main endpoints: procedure-related complications and death.

RESULTS

 35 patients were included, 5 were excluded. All patients underwent RFA with no procedure-related complications reported. The mean size of tumors was 49 mm before treatment. The mean dimension of the ablated necrotic zone was 32 mm, with a mean extension of 65 % compared to the whole tumor size. Tumor density was statistically reduced one day after the procedure (p < 0.001). The mean CA 19.9 levels before and 24 hours and 30 days after the procedure were 285.8 U/mL, 635.2 U/mL, and 336.0 U/mL, respectively, with a decrease or stability at the 30-day evaluation in 80 % of cases. The mean survival was 310 (65-718) days.

CONCLUSION

 Percutaneous RFA of LAPC is a feasible technique in patients who cannot undergo surgery, with great debulking effects and a very low complication rate.

Tissue-reactive drugs enable materials-free local depots

Local, sustained drug delivery of potent therapeutics holds promise for the treatment of a myriad of localized diseases while eliminating systemic side effects. However, introduction of drug delivery depots such as viscous hydrogels or polymer-based implants is highly limited in stiff tissues such as desmoplastic tumors. Here, we present a method to create materials-free intratumoral drug depots through Tissue-Reactive Anchoring Pharmaceuticals (TRAPs). TRAPs diffuse into tissue and attach locally for sustained drug release. In TRAPs, potent drugs are modified with ECM-reactive groups and then locally injected to quickly react with accessible amines within the ECM, creating local drug depots. We demonstrate that locally injected TRAPs create dispersed, stable intratumoral depots deep within mouse and human pancreatic tumor tissues. TRAPs depots based on ECM-reactive paclitaxel (TRAP paclitaxel) had better solubility than free paclitaxel and enabled sustained in vitro and in vivo drug release. TRAP paclitaxel induced higher tumoral apoptosis and sustained better antitumor efficacy than the free drug. By providing continuous drug access to tumor cells, this material-free approach to sustained drug delivery of potent therapeutics has the potential in a wide variety of diseases where current injectable depots fall short.

A novel event-free survival endpoint in locally advanced pancreatic cancer

The treatment paradigm for locally advanced pancreatic cancer (LAPC) is evolving rapidly. The development of neoadjuvant therapies composed of combination therapies and the evaluation of their impact on conversion to borderline resectable (BR) status, resection, and ultimately overall survival (OS) are presently being pursued. These efforts justify re-visiting study endpoints in order to better predict therapeutic effects on OS, by capturing not only the achievement of R0 resection at the end of induction therapy but also the long-term reductions in the rate of local and distal recurrence. The proposed herein event-free survival (EFS) endpoint, with its novel definition specific to LAPC, is formulated to achieve these objectives. It is an analog to disease-free survival (DFS) endpoint in the adjuvant setting applied to the neoadjuvant setting and may be a valuable surrogate endpoint for this patient population.

Laparoscopic ultrasonography-guided cryoablation of locally advanced pancreatic cancer: a preliminary report

OBJECTIVE

To evaluate safety and feasibility of laparoscopic ultrasonography (LUS)-guided cryoablation of locally advanced pancreatic cancer (LAPC).

PATIENTS AND METHODS

From April 2018 to December 2018, ten patients (five women, five men; mean age 58.2 ± 9.4 years) with LAPC underwent the operation. LUS was used to guide the cryoablation. Computed tomography (CT) imaging, biochemical analysis and pain score analysis by numeric rating scale (NRS) were used to assess treatment outcomes at 1 week and 3 months after the operation.

RESULTS

Cryoablation was performed by the operation in all cases. Seven patients received complete ablation and the success rate of operation was 70%. Two cryoablation cycles and an average of 1.4 ± 0.5 cryoprobes were used. The average freezing time and operation time were 23.8 ± 1.0 and 110.5 ± 24.7 min, respectively. The mean blood loss was 52.0 ± 16.6 ml. No major complications were observed after the operation. The mean maximum tumor diameter determined by CT decreased from 4.9 ± 0.7 cm before the operation to 4.7 ± 1.0 cm at 1 week and 4.6 ± 1.3 cm at 3 months, with P values of 0.53 and 0.51 (relative to the preoperative values), respectively. Postoperative CT imaging results suggested tumor necrosis in cryoablation-treated areas. The mean CA19-9 levels decreased from 347.5 ± 345.7 U/mL before operation to 190.4 ± 153.8 U/mL at 1 week and 182.7 ± 165.6 U/mL at 3 months, with P values of 0.15 and 0.14 (relative to the preoperative values), respectively. The average pain scores declined from 6.9 ± 1.1 before operation to 1.3 ± 1.2 at 1 week and 2.0 ± 0.8 at 3 months, with both P values of < 0.01 (relative to the preoperative values).

CONCLUSION

This preliminary study suggested that LUS-assisted cryoablation was a safe and feasible treatment for LAPC.

SHCBP1 interacting with EOGT enhances O-GlcNAcylation of NOTCH1 and promotes the development of pancreatic cancer

O-GlcNAcylation is important in the development and progression of pancreatic ductal adenocarcinoma (PDAC). The glycosyltransferase EGF domain-specific O-linked GlcNAc transferase (EOGT) acts as a key participant in glycosylating NOTCH1. High-throughput sequencing of specimens from 30 advanced PDAC patients identified SHCBP1 and EOGT as factors of poor prognosis. We hypothesized that they could mediate PDAC progression by influencing NOTCH1 O-GlcNAcylation. Thus, 186 PDAC tissue specimens were immunostained for EOGT and SHCBP1. Pancreatic cancer cell lines and nude mouse models were used for in vitro and in vivo experiments. Respectively, The protein expression of EOGT and SHCBP1 was significantly elevated and correlated with worse prognosis in PDAC patients. In vitro, SHCBP1 overexpression promoted pancreatic cancer cell proliferation, migration and invasion, while knocking down SHCBP1 and EOGT inhibited these malignant processes. In vivo data showed that SHCBP1 overexpression promoted xenograft growth and lung metastasis and shortened survival in mice, whereas knocking down either EOGT or SHCBP1 expression suppressed xenograft growth and metastasis and prolonged survival. We further clarified the molecular mechanisms by which EOGT and SHCBP1 enhance the O-GlcNAcylation of NOTCH1, Subsequently promoting the nuclear localization of the Notch intracellular domain (NICD) and inhibiting the transcription of E-cadherin and P21 in pancreatic cancer cells.

Safety and Feasibility of Electrochemotherapy of the Pancreas in a Porcine Model

OBJECTIVES

The use of thermal ablative therapies in the pancreatic tumors is limited because of the risk of the vessel injury and potential pancreatitis or fistula formation. Electrochemotherapy (ECT) is an ablative therapy with an established role in the treatment of cutaneous and liver tumors. This study was designed to evaluate the safety and feasibility of ECT of the pancreas in a porcine survival model.

METHODS

In the first group, 4 animals underwent computed tomography (CT)-guided percutaneous ECT with bleomycin of the pancreatic tail. In the second group (4 animals), the intraoperative ECT with bleomycin of pancreatic tail and head was performed. Animals were followed for 7 days and then killed. Clinical parameters, CT imaging, laboratory, and histologic analysis were performed.

RESULTS

All pigs survived the ECT procedure and none of them developed clinical signs of acute pancreatitis or related complications. There were no signs of acute pancreatitis or damage to the large vessels present in the follow-up CT scans. No significant change in laboratory parameters was obtained after procedure.

CONCLUSIONS

This study shows that ECT with bleomycin is feasible and safe in the pancreatic parenchyma. Clinical studies are needed to evaluate the efficacy of ECT in pancreatic cancer.

Von der Deutschen Gesellschaft für Allgemein- und Viszeralchirurgie konsentierte Operationsindikationen beim duktalen Pankreasadenokarzinom

Hintergrund Die Zahl der Operationen für Pankreaskarzinome in Deutschland nimmt kontinuierlich zu. Das entspricht der steigenden Inzidenz dieser Erkrankung in der Bevölkerung. Diese Übersichtsarbeit fasst die evidenzbasierten aktuellen Operationsindikationen bei Patienten mit Pankreaskarzinom zusammen.

Methode Als DGAV-Initiative wurde eine Arbeitsgruppe von Pankreasexperten eingerichtet. Diese formulierte konkrete Schlüsselfragen nach dem PICO-Schema, führte eine systematische Literatursuche in Medline und Cochrane Library (1989 – 2019) zu Studien und Leitlinien mit Aussagen zu Operationsindikationen bei Pankreaskarzinom durch und erstellte daraus resultierende evidenzbasierte Empfehlungen. Diese wurden innerhalb der CALGP im Rahmen eines Delphi-Verfahrens abgestimmt.

Ergebnisse Die Operationsindikation bei Pankreaskarzinom soll im Tumorboard von erfahrenen Pankreaschirurgen leitliniengerecht und unter Berücksichtigung der individuellen Besonderheiten der Patienten gestellt werden. Fortgeschrittene Infiltration der großen Viszeralgefäße, multiple Fernmetastasen und schwere Komorbiditäten, die einen Eingriff in Vollnarkose verbieten, stellen die häufigsten Kontraindikationen zur Operation dar. Die Therapie von Borderline-resektablen und primär resektablen oligometastatischen Patienten sowie solchen mit sekundärer Resektabilität nach neoadjuvanter Behandlung soll bevorzugt an Zentren und im Rahmen von Studien erfolgen. Die Behandlung an Pankreaszentren reduziert die Mortalität und verbessert das Überleben. Die palliative Bypasschirurgie kann bei endoskopisch nicht therapierbaren Gallenwegs- und Duodenalobstruktionen indiziert sein. Bei diagnostischen Schwierigkeiten kann die Staging-Laparoskopie mit histologischer Sicherung eingesetzt werden.

Schlussfolgerung Unabhängig von der Entwicklung erfolgversprechender multimodaler Behandlungskonzepte bleibt die chirurgische Resektion weiterhin der einzig kurative Therapieeinsatz. Wegen des hohen Anteils von primär fortgeschrittenen und metastasierten Pankreaskarzinomen spielt auch die palliative Chirurgie weiterhin eine wichtige Rolle in der komplexen Versorgung dieses Patientenkollektivs.

Endoscopic Ultrasound-Guided Treatment of Pancreatic Cancer

PURPOSE OF REVIEW

The aim of this review is to evaluate the emerging role of endoscopic ultrasound (EUS) in the guidance of tumor-targeted therapies for patients with pancreatic cancer (PC).

RECENT FINDINGS

EUS-guided ablation, brachytherapy, fiducial marker placement, and antitumor agent injection have been described to date. EUS-guided fiducial placement for SBRT in pancreatic cancer has entered the clinical practice and is performed at many centers clinically without a research protocol. EUS-guided brachytherapy and RFA have been shown to be feasible and safe procedures, and potentially offer local disease control. Other potential techniques of EUS-guided treatment of pancreatic cancer are still considered experimental, with many of them appearing to be safe and reasonably well tolerated. However, their effectiveness and exact role in oncological treatment have yet to be established. Clinical trials with many of the techniques/agents described are underway and multicentric randomized trials with prospective design are eagerly awaited.

Systematic Review of Irreversible Electroporation Role in Management of Locally Advanced Pancreatic Cancer

BACKGROUND

Ablative techniques provide in patients with locally advanced pancreatic cancer (LAPC) symptomatic relief, survival benefit and potential downsizing. Irreversible Electroporation (IRE) represents potentially an ideal solution as no thermal tissue damage occurs. The purpose of this review is to present an overview on safety, feasibility, oncological results, survival and quality of life improvement obtained by IRE.

METHODS

A systematic search was performed in PubMed, regarding the use of IRE on PC in humans for studies published in English up to March 2019.

RESULTS

15 original studies embodying 691 patients with unresectable LAPC who underwent IRE were included. As emerged, IRE works better on tumour sizes between 3-4 cm. Oncological results are promising: median OS from diagnosis or treatment up to 27 months. Two groups investigated borderline resectable tumours treated with IRE before resection with margin attenuation, whereas IRE has proved to be effective in pain control.

CONCLUSIONS

Electroporation is bringing new hopes in LAPC management. The first aim of IRE is to offer a palliative treatment. Further efforts are needed for patient selection, as well as the use of IRE for 'margin accentuation' during surgical resection. Even if promising, IRE needs to be validated in large, randomized, prospective series.

Downregulation of long noncoding RNA SNHG1 inhibits cell proliferation, metastasis, and invasion by suppressing the Notch-1 signaling pathway in pancreatic cancer

BACKGROUND

Pancreatic cancer (PC) has become the fourth most lethal among human cancers. Long noncoding RNAs (lncRNAs) have been reported to play a role in the progression of a variety of cancers. However, the role of lncRNA SNHG1 in PC is not clear.

METHODS

Real-time Quantitative PCR Detection System (qPCR) was used to detect the expression of SNHG1 in PC cells. Then, the SNHG1 knockdown cell was constructed with si-SNHG1. AsPC-1 and PANC1 cells were used to analyze the ability of cell proliferation, invasion, and migration. MTT assay was used to analyze the proliferation ability. Transwell experiments and wound healing experiments were used to detect the capacity of invasion and migration. Finally, Western blot analysis was used to explore the mechanism of SNHG1 in PC.

RESULTS

SNHG1 was significantly upregulated in PC cells. Knockdown of SNHG1 could obviously suppress cell proliferation, invasion, and migration. Furthermore, SNHG1 knockdown inhibited the activation of the Notch-1 signaling pathway and inhibited the expression of N-cadherin, Hes1, Vimentin, Notch-1. The inhabitation was reversed when Notch-1 was overexpressed in si-SNHG1 cells.

CONCLUSION

The lncRNA SNHG1 promotes cell growth and metastasis in PC through activation of the Notch-1 signaling pathway in PC.