Pancreatic surgery outcomes: multicentre prospective snapshot study in 67 countries

BACKGROUND

Pancreatic surgery remains associated with high morbidity rates. Although postoperative mortality appears to have improved with specialization, the outcomes reported in the literature reflect the activity of highly specialized centres. The aim of this study was to evaluate the outcomes following pancreatic surgery worldwide.

METHODS

This was an international, prospective, multicentre, cross-sectional snapshot study of consecutive patients undergoing pancreatic operations worldwide in a 3-month interval in 2021. The primary outcome was postoperative mortality within 90 days of surgery. Multivariable logistic regression was used to explore relationships with Human Development Index (HDI) and other parameters.

RESULTS

A total of 4223 patients from 67 countries were analysed. A complication of any severity was detected in 68.7 per cent of patients (2901 of 4223). Major complication rates (Clavien-Dindo grade at least IIIa) were 24, 18, and 27 per cent, and mortality rates were 10, 5, and 5 per cent in low-to-middle-, high-, and very high-HDI countries respectively. The 90-day postoperative mortality rate was 5.4 per cent (229 of 4223) overall, but was significantly higher in the low-to-middle-HDI group (adjusted OR 2.88, 95 per cent c.i. 1.80 to 4.48). The overall failure-to-rescue rate was 21 per cent; however, it was 41 per cent in low-to-middle- compared with 19 per cent in very high-HDI countries.

CONCLUSION

Excess mortality in low-to-middle-HDI countries could be attributable to failure to rescue of patients from severe complications. The authors call for a collaborative response from international and regional associations of pancreatic surgeons to address management related to death from postoperative complications to tackle the global disparities in the outcomes of pancreatic surgery (NCT04652271; ISRCTN95140761).

Rintatolimod: a potential treatment in patients with pancreatic cancer expressing Toll-like receptor 3

Pancreatic cancer has a dismal prognosis, and treatment options for patients with locally advanced or metastatic disease are limited. Early tumor progression after standard chemo- and or radiotherapy remains a major concern in managing these patients. Treating pancreatic cancer patients with the Toll-like receptor 3 (TLR-3) agonist rintatolimod (Ampligen^®) was effective in boosting the immune response. Rintatolimod acts via the TLR-3 receptor on several immune cells. However, the TLR-3 expression pattern in pancreatic cancer cells and how rintatolimod affects pancreatic cancer cells have not yet been investigated. The TLR-3 protein and mRNA expression were evaluated in thirteen PDAC tissue samples as well as in the human PDAC (hPDAC) cell lines CFPAC-1, MIAPaCa-2, and PANC-1 using immunohistochemistry and multiplexed gene expression analysis, respectively. The direct anti-tumor effects of rintatolimod were investigated using a proliferation and migration assay after different incubation time points with increasing concentrations of rintatolimod (ranging from 0.05 to 0.4 mg/ml). The TLR-3 protein and mRNA expression were heterogeneous between the PDAC tissue samples and the three hPDAC cell lines. TLR-3 protein and mRNA expression were high in CFPAC-1, moderate in MIAPaCa-2, and undetectable in PANC-1. Rintatolimod three-day treatment resulted in significantly reduced proliferation of CFPAC-1 cells compared to vehicle-treated control cells. In addition, after 24 hours, rintatolimod-treated CFPAC-1 cells showed less cell migration compared to vehicle-treated control cells, although this difference was not statistically significant. Lastly, we identified fifteen genes, altered with a Log₂ FOC > |1.0| in rintatolimod-treated CFPAC-1 cells, which were significantly related to three transcription factors (NFKB1, RELA, and SP1) regulating the TLR-3 signaling pathway. In conclusion, we propose that rintatolimod treatment might have a direct TLR-3-dependent anti-tumoral effect on pancreatic cancer cells expressing TLR-3.

Abstract A29: Involvement of JAK-STAT signaling in human pancreatic adenocarcinoma cell lines and suitability for targeted therapy

Background: Pancreatic ductal adenocarcinoma is a highly lethal disease and for the past few decades no new advances in treatment have been made. A new potential target for therapy may be the STAT-JAK signaling pathway. This pathway plays a critical role in the regulation of cell survival, proliferation and migration. Recently, high levels of pSTAT3 expression have been associated with a poor outcome in pancreatic cancer. Therefore our main goal was to study the role of the JAK-STAT pathway in various human pancreatic cancer cell lines and its suitability for targeted therapy.

Methods: Protein levels of phosphorylated STAT1 and STAT3 were determined in eight human pancreatic adenocarcinoma cell lines. A JAK1/3-inhibitor (Tofacitinib) was used to inhibit pSTAT1 and pSTAT3 at clinically relevant doses. Its effect on proliferation and migration was evaluated by means of an MTT assay, total DNA levels and a scratch assay. Photomicrographs were taken and compared at starting time point and after eight hours. To study the effect of STAT3 levels on drug-resistance for Gemcitabine, MTT assays were performed in the presence of Tofacitinib.

Results: Levels of phosphorylated STAT1 and STAT3 varied widely amongst the eight cell lines. In five cell lines both STATs were activated. Inhibition with Tofacitinib (200ng/mL) was shown for both, ranging from 26.5% to 77.8% for pSTAT1 and 8.1% to 67.3% for pSTAT3 respectively. No significant effect on proliferation was observed after treatment with 100ng/mL, 200ng/mL and 400ng/mL Tofacitinib for 24, 48 and 72 hours by MTT assay or 200ng/mL Tofacitinib for 24 and 72 hours by DNA measurements. Migration was significantly reduced by Tofacitinib treatment (200ng/mL) in three cell lines: BxPC3 (44.0%, p = 0.0443 ), MIA PaCa2 (62.5%, p = 0.0224 ) and PANC1 (52.4 %, p = 0.0336) when treated with Tofacitinib (200ng/mL), but levels of inhibition did not correspond to STAT1/3 phosphorylation levels in these cell lines. No effect on drug-resistance for Gemcitabine was observed after combined treatment with Tofacitinib.

Conclusion: Contrary to recent publications, suggesting that the JAK-STAT pathway may be involved in the tumor biology of pancreatic cancer, we show no effect of divergent STAT activity levels on cellular behavior in pancreatic cell lines and susceptibility of cells to Tofacitinib. Thus, while STAT1 and STAT3 activity levels vary considerably between tumors, our data suggest that these STATs do not provide a target for precision medicine.

Citation Format: Jesse Fest, Gwenny M. Fuhler, Peter M. van Koetsveld, Maikel P. Peppelenbosch, Casper HJ van Eijck.{Authors}. Involvement of JAK-STAT signaling in human pancreatic adenocarcinoma cell lines and suitability for targeted therapy. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2016 May 12-15; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(24 Suppl):Abstract nr A29.

Circulating DNA and Micro-RNA in Patients with Pancreatic Cancer

Collecting repeat samples of blood ("liquid biopsies") is a broadly used clinical approach for serial monitoring of disease or response to treatments. In patients with cancer the most distinct molecular feature are somatic mutations acquired by cancer cells present in the diseased tissue. Indeed, mutant DNA derived from dying or lysed cancer cells can be isolated from patient serum samples, subjected to DNA sequencing and to analysis of abundance as a measure of tumor burden. Also, changes in the DNA mutation patterns in serum samples collected over time can indicate altered pathways or clonal evolution of the disease and altered abundance of mutant DNA suggests an altered disease burden. In addition, during the course of treatment, changes in circulating DNA mutation patterns can indicate the emergence of resistant clones and prompt changes in treatment. In contrast to mutant DNA, microRNAs (miR) are transcribed, processed, packaged and released from cells in normal and in diseased tissues as part of the extracellular crosstalk between cells. Interestingly, released miR can function in cell-to-cell communication and as hormone-like signals that operate at a distance through their release into the circulation and subsequent uptake into cells in distant tissues. Circulating miR expression patterns can be established from serial serum samples and monitored for alterations over time. Circulating miR provide a readout of the organism's steady state and serial analyses will indicate changes in the response to therapy or an altered physiologic or disease state. Furthermore, changes in circulating miR patterns can indicate treatment efficacy or resistance as well as adverse effects associated with the respective intervention. Thus, the combined serial analysis of mutant DNA and miR in the circulation has the potential to provide a molecular footprint of pancreatic cancer and can be used to monitor treatment responses or resistance to treatment in real time with a minimally invasive procedure.

IFN-β is a potent inhibitor of insulin and insulin like growth factor stimulated proliferation and migration in human pancreatic cancer cells

INTRODUCTION

Pancreatic cancer is a highly aggressive malignancy with few treatment options. The overexpression of several growth factors, including insulin and insulin-like growth factors (IGFs), can underlie the aggressive nature of this disease. Previous research has demonstrated potent effects of interferon (IFN)-β on pancreatic cancer cell growth, however up till now it is unknown whether IFN-β is able to counteract IGF1, IGF2 and insulin-induced pancreatic cancer cell proliferation and migration.

METHODS

Expression of IGF- and insulin receptors was determined and the stimulatory effects of IGF1, IGF2 and insulin on cell proliferation and migration, as well as the inhibitory effects of IFN-β were evaluated in 3 human pancreatic adenocarcinoma cell lines.

RESULTS

Both the insulin- and the IGF1 receptor were variably expressed in the cell lines. IGF1, IGF2 and insulin were capable of stimulating cell proliferation in all three cell lines, however cell migration was significantly enhanced only in the BxPC-3 cell line. IFN-β significantly inhibited IGF1-, IGF2- and insulin-stimulated proliferation in all three cell lines in a dose and time dependent manner. Furthermore, in the BxPC-3 cell line IFN-β significantly inhibited both basal and IGF1-, IGF2- and insulin-stimulated cell migration.

CONCLUSION

Both IGF1, -2 and insulin were capable of stimulating proliferation and migration in human pancreatic cancer cells irrespective of the type of receptor expressed. This study demonstrates that insulin, in addition to IGF1 and IGF2, may play an important role in the progression of pancreatic cancer. Moreover, IFN-β strongly inhibits growth factor stimulated cell proliferation and migration. Our study supports previous findings which have suggested that IFN-β can be a potential promising anti-cancer agent in pancreatic cancer.

Preoperative biliary drainage for periampullary tumors causing obstructive jaundice; DRainage vs. (direct) OPeration (DROP-trial)

Background

Surgery in patients with obstructive jaundice caused by a periampullary (pancreas, papilla, distal bile duct) tumor is associated with a higher risk of postoperative complications than in non-jaundiced patients. Preoperative biliary drainage was introduced in an attempt to improve the general condition and thus reduce postoperative morbidity and mortality. Early studies showed a reduction in morbidity. However, more recently the focus has shifted towards the negative effects of drainage, such as an increase of infectious complications. Whether biliary drainage should always be performed in jaundiced patients remains controversial. The randomized controlled multicenter DROP-trial (DRainage vs. Operation) was conceived to compare the outcome of a 'preoperative biliary drainage strategy' (standard strategy) with that of an 'early-surgery' strategy, with respect to the incidence of severe complications (primary-outcome measure), hospital stay, number of invasive diagnostic tests, costs, and quality of life.

Methods/design

Patients with obstructive jaundice due to a periampullary tumor, eligible for exploration after staging with CT scan, and scheduled to undergo a "curative" resection, will be randomized to either "early surgical treatment" (within one week) or "preoperative biliary drainage" (for 4 weeks) and subsequent surgical treatment (standard treatment). Primary outcome measure is the percentage of severe complications up to 90 days after surgery. The sample size calculation is based on the equivalence design for the primary outcome measure. If equivalence is found, the comparison of the secondary outcomes will be essential in selecting the preferred strategy. Based on a 40% complication rate for early surgical treatment and 48% for preoperative drainage, equivalence is taken to be demonstrated if the percentage of severe complications with early surgical treatment is not more than 10% higher compared to standard treatment: preoperative biliary drainage. Accounting for a 10% dropout, 105 patients are needed in each arm resulting in a study population of 210 (alpha = 0.95, beta = 0.8).

Discussion

The DROP-trial is a randomized controlled multicenter trial that will provide evidence whether or not preoperative biliary drainage is to be performed in patients with obstructive jaundice due to a periampullary tumor.

Minimally invasive 'step-up approach' versus maximal necrosectomy in patients with acute necrotising pancreatitis (PANTER trial): design and rationale of a randomised controlled multicenter trial [ISRCTN13975868]

Background

The initial treatment of acute necrotizing pancreatitis is conservative. Intervention is indicated in patients with (suspected) infected necrotizing pancreatitis. In the Netherlands, the standard intervention is necrosectomy by laparotomy followed by continuous postoperative lavage (CPL). In recent years several minimally invasive strategies have been introduced. So far, these strategies have never been compared in a randomised controlled trial. The PANTER study (PAncreatitis, Necrosectomy versus sTEp up appRoach) was conceived to yield the evidence needed for a considered policy decision.

Methods/design

88 patients with (suspected) infected necrotizing pancreatitis will be randomly allocated to either group A) minimally invasive 'step-up approach' starting with drainage followed, if necessary, by videoscopic assisted retroperitoneal debridement (VARD) or group B) maximal necrosectomy by laparotomy. Both procedures are followed by CPL. Patients will be recruited from 20 hospitals, including all Dutch university medical centres, over a 3-year period. The primary endpoint is the proportion of patients suffering from postoperative major morbidity and mortality. Secondary endpoints are complications, new onset sepsis, length of hospital and intensive care stay, quality of life and total (direct and indirect) costs. To demonstrate that the 'step-up approach' can reduce the major morbidity and mortality rate from 45 to 16%, with 80% power at 5% alpha, a total sample size of 88 patients was calculated.

Discussion

The PANTER-study is a randomised controlled trial that will provide evidence on the merits of a minimally invasive 'step-up approach' in patients with (suspected) infected necrotizing pancreatitis.