State-of-the-art surgery for pancreatic cancer

Loss of GATA6-mediated up-regulation of UTX promotes pancreatic tumorigenesis and progression

Ubiquitously transcribed tetratricopeptide repeat on chromosome X (UTX), also known as lysine (K)-specific demethylase 6A (KDM6A), functions as a tumor suppressor gene or oncogene depending on the tumor type and context. However, its tumor-suppressive mechanisms remain largely unknown. Here, we investigated the clinical significance and biological effects of UTX expression in pancreatic ductal adenocarcinoma (PDA) and determined the potential mechanisms of its dysregulation. UTX expression and its association with clinicopathologic characteristics of PDA patients were analyzed using immunohistochemistry. UTX mRNA and protein expression and their regulation in PDA cell lines were measured using quantitative polymerase chain reaction and Western blot analyses. The biological functions of UTX in PDA cell growth, migration, and invasion were determined using gain- and loss-of-function assays with both in vitro and in vivo animal models. UTX expression was reduced in human PDA cell lines and specimens. Low UTX expression was associated with poor differentiation and prognosis in PDA. Forced UTX expression inhibited PDA proliferation, migration, and invasion in vitro and PDA growth and metastasis in vivo, whereas knockdown of UTX expression did the opposite. Mechanistically, UTX expression was trans-activated by GATA6 activation. GATA6-mediated PDA progression could be blocked, at least partially, by silencing UTX expression. In conclusion, loss of GATA6-mediated UTX expression was evident in human PDA and restored UTX expression suppressed PDA growth and metastasis. Thus, UTX is a tumor suppressor in PDA and may serve as a prognostic biomarker and therapeutic target.

Chain length impact on the retro Diels-Alder mediated release of gemcitabine from hybrid nanoparticles towards pancreatic cancer therapy

Previously reported gold coated iron oxide nanoparticles (Au-IONP's) have demonstrated their effectiveness as drug delivery vehicles for gemcitabine conjugated to a thermally labile Diels-Alder linker containing a chain of 4 carbon atoms (TTLD4) for the treatment of pancreatic cancer. Heat generated via laser irradiation of Au-IONPs facilitated retro Diels-Alder mediated release in a burst release profile where approximately half of all total release over 180 min occurred within the first 5 min. Two analogues of TTLD4, which differ only in linker chain length (TTLD3 & TTLD6) were synthesised and conjugated to Au-IONP's. Heat-mediated release of gemcitabine at 45 °C over 180 min from these formulations was confirmed to be based on linker length, which was 94%, 76% and 45% for TTLD3, TTLD4 and TTLD6, respectively. Drug loading of the Diels-Alder linkers in a 5:1 Drug/Au-IONP w/w ratio appears to favour those containing an even number of carbons TTLD4 (76%) & TTLD6 (57%) over TTLD3 (25%), possibly due to the linker likely being positioned perpendicular to the Au-IONP surface because of the 120 °C-C bond.

Distal pancreatectomy with or without radical approach, vascular resections and splenectomy: Easier does not always mean easy

Because distal pancreatectomy (DP) has no reconstructive steps and less frequent vascular involvement, it is thought to be the easier counterpart of pancreaticoduodenectomy. This procedure has a high surgical risk and the overall incidences of perioperative morbidity (mainly pancreatic fistula), and mortality are still high, in addition to the challenges that accompany delayed access to adjuvant therapies (if any) and prolonged impairment of daily activities. Moreover, surgery to remove malignancy of the body or tail of the pancreas is associated with poor long-term oncological outcomes. From this perspective, new surgical approaches, and aggressive techniques, such as radical antegrade modular pancreato-splenectomy and DP with celiac axis resection, could lead to improved survival in those affected by more locally advanced tumors. Conversely, minimally invasive approaches such as laparoscopic and robotic surgeries and the avoidance of routine concomitant splenectomy have been developed to reduce the burden of surgical stress. The purpose of ongoing surgical research has been to achieve significant reductions in perioperative complications, length of hospital stays and the time between surgery and the beginning of adjuvant chemotherapy. Because a dedicated multidisciplinary team is crucial to pancreatic surgery, hospital and surgeon volumes have been confirmed to be associated with better outcomes in patients affected by benign, borderline, and malignant diseases of the pancreas. The purpose of this review is to examine the state of the art in distal pancreatectomies, with a special focus on minimally invasive approaches and oncological-directed techniques. The widespread reproducibility, cost-effectiveness and long-term results of each oncological procedure are also taken into deep consideration.

Current Approaches for the Curative-Intent Surgical Treatment of Pancreatic Ductal Adenocarcinoma

Radical resection is the only curative treatment for pancreatic cancer. However, only up to 20% of patients are considered eligible for surgical resection at the time of diagnosis. Although upfront surgery followed by adjuvant chemotherapy has become the gold standard of treatment for resectable pancreatic cancer there are numerous ongoing trials aiming to compare the clinical outcomes of various surgical strategies (e.g., upfront surgery or neoadjuvant treatment with subsequent resection). Neoadjuvant treatment followed by surgery is considered the best approach in borderline resectable pancreatic tumors. Individuals with locally advanced disease are now candidates for palliative chemo- or chemoradiotherapy; however, some patients may become eligible for resection during the course of such treatment. When metastases are found, the cancer is qualified as unresectable. It is possible to perform radical pancreatic resection with metastasectomy in selected cases of oligometastatic disease. The role of multi-visceral resection, which involves reconstruction of major mesenteric veins, is well known. Nonetheless, there are some controversies in terms of arterial resection and reconstruction. Researchers are also trying to introduce personalized treatments. The careful, preliminary selection of patients eligible for surgery and other therapies should be based on tumor biology, among other factors. Such selection may play a key role in improving survival rates in patients with pancreatic cancer.

Evolution of pancreatic surgery over time and effects of centralization-a single-center retrospective cohort study

Background

Short-term outcomes of pancreatic surgery have improved globally during the last two decades. Long-term survival of resectable pancreatic ductal adenocarcinoma (PDAC) has also shown slight improvement. We describe a cohort of 566 consecutive pancreatectomies performed at a Northern Finnish tertiary center. We analyze the trends in short-term outcomes of all-cause pancreatic surgery and long-term survival of PDAC patients.

Methods

All pancreatic resections performed at the Oulu University Hospital during years 2000-2020 were included. Patient data was analyzed in four time periods (2000-2005, 2006-2010, 2011-2015 and 2016-2020). Clinicopathological parameters of patients and tumors, complication data and short-term mortality were recorded for all patients and compared between time quartiles. Long-term survival and administration rates of neo-, and/or adjuvant therapy of PDAC patients were analyzed.

Results

A total of 566 pancreatectomies were performed during the study period: 359 (63%) pancreatoduodenectomies (PDs), 130 (23.0%) open left pancreatectomies (LPs), 45 (8.0%) laparoscopic LPs, 26 (5.1%) total pancreatectomies (TPs), and 6 (1.1%) enucleations. Median age of patients was 63 [57-71] years, and 49% [267] of patients were men. Number of pancreatectomies per time period increased from 67 in 2000-2005 to 266 in 2016-2020. American Society of Anesthesiologists (ASA) Physical Classification III patients and T3 tumors were more frequently operated on in later time periods. Complication rates remained at constant low levels throughout the study period, but reoperation rate increased from 9.4% in 2000-2010 to 16.2% in 2011-2020. Short-term (90-day) mortality after pancreatectomy decreased from 3.1% to 0.74%, while 5-year survival improved from 14.3% in 2006-2011 to 21.4% in 2011-2015. Resection rate of diagnosed PDAC cases, as reported by the Finnish Cancer Registry (FCR) for the catchment area, increased from 3.2% to 14.9% over the study period.

Conclusions

The hospital volume of pancreatectomies has increased substantially, while complications and postoperative mortality have remained at acceptable levels. Long-term survival and resection rate of PDAC patients showed notable improvement over two decades.

Impact of endoscopic ultrasound-guided radiofrequency ablation in managing pancreatic malignancy

Pancreatic malignancy is still the most lethal gastrointestinal malignancy. It has a very poor prognosis with low survival rate. Surgery is still the main treatment option for pancreatic malignancy. Most patients already have locally advanced and even late stage disease due to non-specific abdominal symptoms. Even though some cases are still suitable for surgical treatment, due to its aggressiveness adjuvant chemotherapy is becoming the standard treatment for controlling the disease. Radiofrequency ablation (RFA) is a thermal therapy that has been used as one of the standard treatments for liver malignancy. It can also be performed intraoperatively. There are several reports on percutaneous RFA treatment for pancreatic malignancy using transabdominal ultrasound and guided by computed tomography scan. However, due to its anatomical location and the risk of high radiation exposure, these methods seem to be very limited. Endoscopic ultrasound (EUS) has been widely used for pancreatic abnormality evaluation due to its ability to detect more accurately, especially small pancreatic lesions, compared to other imaging modalities. By the EUS approach, it is easier to achieve good visualization of tumor ablation and necrosis as the echoendoscope position is closer to the tumor area. Based on studies and a recent meta-analysis, EUS-guided RFA is a promising treatment approach for most pancreatic malignancy cases, but most studies only collected data from a small sample size. Larger studies are needed before clinical recommendations can be made.

Surgical Treatment of Pancreatic Cancer: Currently Debated Topics on Vascular Resection

Vascular resections involving the superior mesenteric and portal veins (SMV-PV), celiac axis (CA), superior mesenteric artery (SMA) and hepatic artery (HA) have multiplied in recent years, raising the resection rate for pancreatic cancer (PDAC) and the related morbidity and mortality rates. While resection is generally accepted for resectable SMV-PV, the usefulness of associated arterial resection in borderline resectable (BRPC) and locally-advanced PDAC (LAPC) is much debated. Careful selection of splenic vein reconstruction is very important to prevent left-sided portal hypertension (LSPH). During distal pancreatectomy (DP), CA and common HA resection is largely accepted, while there is debate on the value of SMA and proper HA resection and reconstruction. Their resection is useless according to several reviews and meta-analyses, and some international societies, although some high-volume centers have reported good results. Short- and long-term reconstructed vessel patency varies with the type of reconstruction, the material used, and the surgeon's experience. Laparoscopic and robotic pancreaticoduodenectomy and DP are generally accepted if done by surgeons performing at least 10 such procedures annually. The usefulness of associated vascular resection remains highly controversial. Surgeons need to complete numerous minimally-invasive procedures to overcome the learning curve, and prevent an increase in complications and surgical mortality. Higher resectability rates and satisfactory long-term results have been reported after neoadjuvant therapy (NAT) for BRPC and LAPC requiring vascular resection. It is essential to select the most appropriate NAT for a given patient and to assess PDAC resectability preoperatively.

Antibiotic resistance patterns of bacterial bile cultures during pancreatic surgery-a single center analysis and systematic review

BACKGROUND

Septic complications after pancreatic surgery are common. However, it remains unclear if and how a shift of the microbiological spectrum affects morbidity. The aim of the present study was to assess the microbiological spectrum and antibiotic resistance patterns and their impact on outcome.

METHODS

We conducted a retrospective study including patients undergoing pancreatic surgery at our center between 2005 and 2018. A systematic literature review and descriptive meta-analysis of the published and original data was performed according to the PRISMA guidelines.

RESULTS

A total of 318 patients were included in the analysis. Patients with biliary drainage had a significantly higher incidence of bacterobilia (93% vs. 25%) and received preoperative antibiotics (46% vs. 12%). The analyzed bile cultures showed no resistance to piperacillin/tazobactam, fluoroquinolones, or carbapenems. Resistance to cefuroxime was seen in 58% of the samples of patients without biliary drainage (NBD) and 93% of the samples of those with drainage (BD). In general, there was no significant difference in overall postoperative morbidity. However, superficial surgical site infections (SSIs) were significantly more common in the BD group. We included a total of six studies and our own data (1627 patients) in the descriptive meta-analysis. The percentage of positive bile cultures ranged from 53 to 81%. In patients with BD, the most frequent microorganisms were Enterococcus spp. (58%), Klebsiella spp. (29%), and E. coli (27%). Almost all studies demonstrated resistance to first- and second-generation cephalosporins and to third- and fourth-generation cephalosporins for patients with BD.

CONCLUSION

A change in perioperative antibiotic strategy according to local resistance patterns, especially after BD, might be useful for patients undergoing pancreatic surgery. Appropriate perioperative antibiotic coverage may help to prevent abdominal infectious complications and especially superficial SSIs.

[Surgery of pancreatic neuroendocrine neoplasms: state of the art]

Pancreatic neuroendocrine neoplasms (pNEN) have a rising incidence and are increasingly diagnosed at early and thus potentially resectable stages. Due to the rarity of these neoplasms the recommendations of currently available guidelines are mainly based on retrospective data. Surgical and oncological treatment of these rare diseases should only be performed at specialized centers. In cases of resectability without indications of diffuse metastases, complete resection with curative intent should be the treatment of choice. For small nonfunctional pNENs < 2 cm watch and wait strategies are recommended as an alternative to surgical treatment. Recent data, however, also showed an increased survival even of small (1-2 cm) pNENs after resection. For benign insulinomas and small nonfunctional well-differentiated pNENs parenchyma-sparing procedures, such as enucleation and segmental resection are available. The question of the influence of lymph node metastases on long-term disease-free survival and overall survival and consequently the role of systematic lymphadenectomy is still a matter of debate. In pNENs > 2 cm formal resection with lymphadenectomy is considered the gold standard. Minimally invasive and robotic-assisted procedures are of increasing importance also for formal pancreatic resection.