RESUMO
BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease generally refractory to standard chemotherapeutic agents; therefore improvements in anticancer therapies are mandatory. A major determinant of therapeutic resistance in PDAC is the poor drug delivery to neoplastic cells, mainly due to an extensive fibrotic reaction. Electroporation can be used in vivo to increase cancer cells' local uptake of chemotherapeutics (electrochemotherapy, ECT), thus leading to an enhanced tumour response rate. In the present study, we evaluated the in vivo effects of reversible electroporation in normal pancreas in a rabbit experimental model. We also tested the effect of electroporation on pancreatic cancer cell lines in order to evaluate their increased sensitivity to chemotherapeutic agents. MATERIALS AND METHODS: The application in vivo of the European Standard Operating Procedure of Electrochemotherapy (ESOPE) pulse protocol (1000 V/cm, 8 pulses, 100 µs, 5 KHz) was tested on the pancreas of normal New Zealand White Rabbits and short and long-term toxicity were assessed. PANC1 and MiaPaCa2 cell lines were tested for in vitro electrochemotherapy experiments with and without electroporation. Levels of cell permeabilization were determined by flow cytometry, whereas cell viability and drug (cisplatin and bleomycin) sensitivity of pulsed cells were measured by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay. RESULTS: In healthy rabbits, neither systemic nor local toxic effects due to the electroporation procedure were observed, demonstrating the safety of the optimized electric parameters in the treatment of the pancreas in vivo. In parallel, we established an optimized protocol for ECT in vitro that determined an enhanced anti-cancer effect of bleomycin and cisplatin with respect to treatment without electroporation. CONCLUSIONS: Our data suggest that electroporation is a safe procedure in the treatment of PDAC because it does not affect normal pancreatic parenchyma, but has a potentiating effect on cytotoxicity of bleomycin in pancreatic tumour cell lines. Therefore, ECT could be considered as a valid alternative for the local control of non-resectable pancreatic cancer.
RESUMO
BACKGROUND: Solid pseudopapillary tumors (SPTs) are rare pancreatic neoplasms of low malignant potential that occur mainly in young women. Only 17 cases of SPT treated laparoscopically have been published in the literature and long-term follow-up data are still lacking. METHODS: Retrospective analysis of ten patients (8 women, 2 men; mean age, 25.4 years) (DS: 12.1; minimum 11, maximum 51) who underwent laparoscopic distal pancreatectomy with a definitive histological diagnosis of SPT. Long-term follow-up data were collected. RESULTS: The average tumor size was 43.8 mm (minimum 20, maximum 65 mm). The mean operative time was 177.5 minutes (DS: 53.7; minimum 120, maximum 255). In all, five patients underwent distal splenopancreatectomy; five patients underwent spleen-preserving distal pancreatectomy of whom three with splenic vessel preservation and two with the Warshaw technique. The conversion rate was nil and no case of perioperative mortality was recorded. The mean hospital stay was 7 days (DS: 2.7; minimum 4, maximum 12). Six patients had an uneventful postoperative course and four had postoperative complications. Two of them underwent reoperation, and the other two had nonsurgical complications. After a median follow-up of 47 (range, 5-98) months, all patients were alive and disease-free. CONCLUSIONS: Laparoscopic pancreatic resection is a safe and feasible procedure that could become the treatment of choice for patients affected by pancreatic SPT. Distal pancreatectomy should be performed, if possible, with spleen-preserving technique, especially in young patients. To avoid metastatic spread, laparoscopic or laparotomic biopsy should not be performed in patients affected by SPT.