Irreversible electroporation of pancreatic adenocarcinoma: a primer for the radiologist

Combination therapy of irreversible electroporation and cytokine-induced killer cells for treating mice bearing panc02 pancreatic-cancer xenografts

The current study aimed to investigate the antitumor effects and potent mechanism of cytokine-induced killer (CIK) cells combined with irreversible electroporation (IRE) via Panc02 cell-bearing mouse model in vivo. CIK cells were isolated from the spleens of Panc02 pancreatic-cancer (PC) subcutaneous-xenograft model and the proportion of different lymphocytes was also determined. The antitumor effect of the combination of IRE and CIK cells in a PC subcutaneous-xenograft model was also investigated. The proportion of cells that were positive for CD3+CD8+ and the proportion of CD3+CD56+ cells were both significantly increased after 21 days of in vitro culture. Combined treatment of IRE and CIK cell significantly inhibited tumor growth and increased the survival rate of Panc02 cell-bearing mice. Furthermore, infiltration of lymphocytes into tumor tissue was significantly increased by this combination therapy compared with the untreated group or monotherapy group. In addition, IRE significantly enhanced the expression of chemokine receptors elicited by CIK cells. In conclusion, IRE combined with CIK cells showed superior antitumor efficacy in a PC xenograft model, which we attributed to the promotion of lymphocytic infiltration, as well as to upregulation of chemokine receptor expression and the regulators of CIK cell proliferation.

Interventional Radiology in the Treatment of Pancreatic Adenocarcinoma: Present and Future Perspectives

Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease; patients' long-term survival is strictly linked to the surgical resection of the tumor but only a minority of patients (2-3%) have a resectable disease at diagnosis. In patients with surgically unresectable disease, interventional radiology is taking on an increasing role in treatment with the application of loco-regional percutaneous therapies. The primary purposes of this narrative review are to analyze the safety and efficacy of ablative techniques in the management of borderline resectable and locally advanced diseases and to underline the role of the interventional radiologist in the management of patients with distant metastases. The secondary purpose is to focus on the synergy between immunotherapy and ablative therapies.

Advances in the Surgical Treatment of Pancreatic Cancer

Three recent advances in the surgical approach to pancreatic cancer over the past decade have improved both short- and long-term outcomes for patients with nonmetastatic, operable pancreatic cancer. These include (1) minimally invasive pancreatectomy to reduce operative morbidity while adhering to principles of open oncologic resections, (2) neoadjuvant chemotherapy to treat radiographically occult metastatic disease and improve locoregional control, and (3) applying irreversible electroporation as an adjunct to surgery, allowing a fraction of locally advanced pancreatic cancer to be resected.

Irreversible Electroporation (IRE) in Locally Advanced Pancreatic Cancer: A Review of Current Clinical Outcomes, Mechanism of Action and Opportunities for Synergistic Therapy

Locally advanced pancreatic cancer (LAPC) accounts for 30% of patients with pancreatic cancer. Irreversible electroporation (IRE) is a novel cancer treatment that may improve survival and quality of life in LAPC. This narrative review will provide a perspective on the clinical experience of pancreas IRE therapy, explore the evidence for the mode of action, assess treatment complications, and propose strategies for augmenting IRE response. A systematic search was performed using PubMed regarding the clinical use and safety profile of IRE on pancreatic cancer, post-IRE sequential histological changes, associated immune response, and synergistic therapies. Animal data demonstrate that IRE induces both apoptosis and necrosis followed by fibrosis. Major complications may result from IRE; procedure related mortality is up to 2%, with an average morbidity as high as 36%. Nevertheless, prospective and retrospective studies suggest that IRE treatment may increase median overall survival of LAPC to as much as 30 months and provide preliminary data justifying the well-designed trials currently underway, comparing IRE to the standard of care treatment. The mechanism of action of IRE remains unknown, and there is a lack of data on treatment variables and efficiency in humans. There is emerging data suggesting that IRE can be augmented with synergistic therapies such as immunotherapy.

Irreversible electroporation of locally advanced pancreatic cancer

Locally advanced pancreatic cancer (LAPC) constitutes approximately one-third of all pancreatic cancer, with standard of care inconsistently defined and achieving modest outcomes at best. While resection after downstaging offers the chance for cure, only a fraction of patients with LAPC become candidates for resection. Chemotherapy remains the mainstay of treatment for the remainder. In these patients, ablative therapy may be given for local control of the tumor. Irreversible electroporation (IRE) is an attractive ablative technique. IRE changes the permeability of tumor cell membranes to induce apoptosis. Unlike other ablative therapies, IRE causes little thermal injury to the target area, making it ideal for LAPC involving major vessels. Compared to systemic chemotherapy alone, IRE seems to offer some survival benefit. Although early studies reported notable morbidity and mortality rates, IRE presents opportunities for those who cannot undergo resection and who otherwise have limited options. Another role of IRE is to extend the margins of resected tumors when there is a concern for R1 resection. Perhaps most exciting, IRE is thought to have effects beyond local ablation. IRE has immunomodulatory effects, which may induce in vivo vaccination and may potentially synergize with immunotherapy. Through electrochemotherapy, IRE may enhance drug delivery to residual tumor cells. Ultimately the role of IRE in the treatment of LAPC still needs to be validated through well designed randomized trials. Investigations of its future possibilities are in the early stages. IRE offers the potential to provide more options to LAPC patients.

The role of interventional radiology in the treatment of patients with pancreatic cancer

Interventional radiology (IR) provides minimally invasive therapeutic and palliative options for the treatment of pancreatic cancer depending on the stage of the disease. IR plays a critical, and also a very effective role, in both pre- and post-operative care of the patients with early stage resectable disease and also in palliative treatment of the patients with locally advanced or metastatic disease. In this article, we aimed to present the capability and the limitations of IR procedures including: local treatment options of primary and metastatic pancreatic cancer, palliation of biliary and intestinal obstructions, minimally invasive treatment of post-operative complications, and pain management.

Ablative, Endovascular, and Biliary Interventions for Patients with Pancreatic Cancer

Interventional radiologists have multiple points of involvement in the treatment and management of patients with pancreatic adenocarcinoma. There is increasing interest in cytoreductive treatment of the primary tumor as well as metastatic disease via arterial and ablative techniques. The focus of this article is on the current evidence for pancreatic irreversible electroporation. For patients undergoing curative surgery or terminal palliation, interventional radiology can manage complications and symptoms. In this article, therapeutic and palliative options in this group of patients including postoperative embolization, biliary drainage, and stent placement are reviewed.

[Ablative therapy of small renal masses]

Renal cell cancer is nowadays predominantly diagnosed in early stages due to the widespread use of sectional imaging for unrelated symptoms. Small renal masses (<4 cm) feature a largely indolent biology with a very low risk for metastasis or even a benign biology in up to 30% of the cases. Consequently, there is a need for less invasive therapeutic alternatives to nephron-sparing surgery. Meanwhile, there is a broad portfolio of local ablation techniques to treat small renal tumors. These include the extensively studied radiofrequency ablation and cryoablation techniques as well as newer modalities like microwave ablation and irreversible electroporation as more experimental techniques. Tumor ablation can be performed percutaneously under image guidance or laparoscopically. In particular, the percutaneous approach is a less invasive alternative to nephron-sparing surgery with lower risk for complications. Comparative studies and meta-analyses report a higher risk for local recurrence after renal tumor ablation compared to surgery. However, long-term oncological results after treatment of small renal masses are promising and do not seem to differ from partial nephrectomy. The possibility for salvage therapy in case of recurrence also accounts for this finding. Especially old patients with an increased risk of surgical and anesthesiological complications as well as patients with recurrent and multiple hereditary renal cell carcinomas may benefit from tumor ablation. Tumor biopsy prior to intervention is associated with very low morbidity rates and is oncologically safe. It can help to assess the biology of the renal mass and prevent therapy of benign lesions.