Surgical techniques for improving outcomes in pancreatic ductal adenocarcinoma

Nomogram and a predictive model for postoperative hemorrhage in preoperative patients of laparoscopic pancreaticoduodectomy

To develop a predictive model and a nomogram for predicting postoperative hemorrhage in preoperative patients undergoing laparoscopic pancreaticoduodenectomy (LPD). A total of 409 LPD patients that underwent LPD by the same surgical team between January 2014 and December 2020 were included as the training cohort. The preoperative data of patients were statistically compared and analyzed for exploring factors correlated with postoperative hemorrhage. The predictive model was developed by multivariate logistic regression and stepwise (stepAIC) selection. A nomogram based on the predictive model was developed. The discriminatory ability of the predictive model was validated using the receiver operating characteristic (ROC) curve and leave-one-out method. The statistical analysis was performed using R 3.5.1 (www.r-project.org). The predictive model including the risk-associated factors of postoperative hemorrhage was as follows: 2.695843 − 0.63056 × (Jaundice = 1) − 1.08368 × (DM = 1) − 2.10445 × (Hepatitis = 1) + 1.152354 × (Pancreatic tumor = 1) + 1.071354 × (Bile duct tumor = 1) − 0.01185 × CA125 − 0.04929 × TT − 0.08826 × APTT + 26.03383 × INR − 1.9442 × PT + 1.979563 × WBC − 2.26868 × NEU − 2.0789 × LYM − 0.02038 × CREA + 0.00459 × AST. A practical nomogram based on the model was obtained. The internal validation of ROC curve was statistically significant (AUC = 0.7758). The validation by leave-one-out method showed that the accuracy of the model and the F measure was 0.887 and 0.939, respectively. The predictive model and nomogram based on the preoperative data of patients undergoing LPD can be useful for predicting the risk degree of postoperative hemorrhage.

Can we predict long-term survival in resectable pancreatic ductal adenocarcinoma?

Objective

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive tumour associated with poor 5-year survival. We aimed to determine factors which differentiate short and long-term survivors and identify a prognostic biomarker.

Methods

Over a ten-year period, patients with resected PDAC who developed disease recurrence within 12 months (Group I) and those who had no disease recurrence for 24 months (Group II) were identified. Clinicopathological data was analysed. Ion Torrent high-throughput sequencing on DNA extracted from FFPE tumour samples was used to identify mutations. Additionally, peripheral blood samples were analysed for variants in cell-free DNA, circulating tumour cells (CTCs), and microRNAs.

Results

Multivariable analysis of clinicopathological factors showed that a positive medial resection margin was significantly associated with short disease-free survival (p = 0.007). Group I patients (n = 21) had a higher frequency of the KRAS mutant mean variant allele (16.93% ± 11.04) compared to those in Group II (n = 13; 7.55% ± 5.76, p = 0.0078). Group I patients also trended towards having a KRAS c.35G>A p.Gly12Asp mutation in addition to variants in other genes, such as TP53, CDKN2A, and SMAD4. Mutational status of cell-free DNA, and number of CTCs, was not found to be useful in this study. A circulating miRNA (hsa-miR-548ah-5p) was found to be significantly differentially expressed.

Conclusions

Medial resection margin status and the frequency of KRAS mutation in the tumour tissue are independent prognostic indicators for resectable PDAC. Circulating miRNA hsa-miR-548ah-5p has the potential to be used as a prognostic biomarker.

Pancreatic Cancer Lymph Node Resection Revisited: A Novel Calculation of Number of Lymph Nodes Required

BACKGROUND

Pancreatic cancer is the third leading cause of cancer related deaths in the US. Although lymph node (LN) metastasis is a prognostic indicator, the extent of LN resection is still debated. Our goal was to use the distribution of the ratio of positive to negative LNs to derive a more adequate number of necessary examined LNs based on the target LN threshold (TLNT).

STUDY DESIGN

Using the National Cancer Database, we performed a retrospective study of surgically resected pancreatic adenocarcinoma (2010 to 2015). We evaluated the number of positive LNs and total LNs examined and the log of the ratio of positive LNs to negative LNs (LODDS). The distribution of LODDS was examined to determine a target LNs examined threshold sufficient to detect N1 disease. Using the LODDS distribution of N1 cases, target LNs examined threshold were calculated to encompass 90 of the N1 group distribution.

RESULTS

Of the total 24,038 resected patients included in this study, 26% underwent operation only, 18% received neoadjuvant therapy, and 56% underwent adjuvant therapy. In all, 8,144 (34%) patients had N0 disease and 15,894 (66%) had N1 disease. To capture 90% to 95% of the N1 group, the minimum number of LNs examined would be 18 (LODDS -2.74) to 24 (LODDS -3.04), respectively.

CONCLUSIONS

Although previous studies have suggested 11 to 17 LNs required for adequate LN sampling in pancreatic cancer, our findings suggest that to capture 90% of cases with N1 disease, 18 LNs is more appropriate.

Minimally Invasive Surgical Approaches for Pancreatic Adenocarcinoma: Recent Trends

BACKGROUND

Pancreatic resection for cancer represents a real challenge for every surgeon. Recent improvements in laparoscopic experience, minimally invasive surgical techniques and instruments make now the minimally invasive approach a real "triumph." There is no doubt that minimally invasive surgery has replaced with great success conventional surgery in many fields, including surgical oncology.

METHODS AND RESULTS

However, its progress in pancreatic resection for adenocarcinoma has been dramatically slow. Recent evidence supports the notion that minimally invasive distal pancreatectomy is safe and feasible and that is becoming the procedure of choice mainly for benign or low-grade malignant lesions in the distal pancreas. On the other side, minimally invasive pancreatoduodenectomy has not yet been widely accepted and there is enormous skepticism when applied for pancreatic head adenocarcinoma. In this review, we summarize the current evidence on the potential applications of minimally invasive surgical approaches for this aggressive, heterogeneous, and enigmatic type of cancer.

CONCLUSIONS

Moreover, the potential future applications of these approaches are discussed with the hope to improve the quality of life as well as the survival rates of pancreatic cancer patients.

Electrochemotherapy in pancreatic adenocarcinoma treatment: pre-clinical and clinical studies

Background

Pancreatic adenocarcinoma is currently one of the deadliest cancers with high mortality rate. This disease leads to an aggressive local invasion and early metastases, and is poorly responsive to treatment with chemotherapy or chemo-radiotherapy. Radical resection is still the only curative treatment for pancreatic cancer, but it is generally accepted that a multimodality strategy is necessary for its management. Therefore, new alternative therapies have been considered for local treatment.

Conclusions

Chemotherapeutic resistance in pancreatic cancer is associated to a low penetration of drugs into tumour cells due to the presence of fibrotic stroma surrounding cells. In order to increase the uptake of chemotherapeutic drugs into tumour cells, electrochemotherapy can be used for treatment of pancreatic adenocarcinoma leading to an increased tumour response rate. This review will summarize the published papers reported in literature on the efficacy and safety of electrochemotherapy in pre-clinical and clinical studies on pancreatic cancer.

Pancreatic cancer: current management and treatment strategies

The 5-year survival of patients with pancreatic cancer is poor and, despite oncological advances over the past two decades, has not significantly improved. However, there have been several surgical and oncological advances which have improved morbidity and mortality in surgery and more efficacious chemotherapy regimens, resulting in a better patient experience and an increase in survival by a number of months. Most patients have a tumour at the head of the pancreas and those with resectable disease undergo a pancreaticoduodenectomy, which can be performed laparoscopically. Those who have a pancreatic resection have an increased survival in comparison with those receiving oncological treatment only; however, only a quarter of patients have resectable disease at diagnosis. Some centres are now performing venous resections and/or arterial resections in order to increase the number of patients eligible for curative surgery. Innovative techniques using ablation technologies to downstage tumours for resection are also being investigated. After surgery, all patients should be offered adjuvant gemcitabine-based chemotherapy. Those with locally advanced tumours not suitable for surgery should be offered FOLFIRINOX chemotherapy, after which the tumour may be suitable for surgical resection. The use of radiotherapy in this group of patients is controversial but offered by a few centres. Patients with metastatic disease at diagnosis should also be offered FOLFIRINOX chemotherapy, which can improve survival by a few months. As our knowledge of the tumour biology of pancreatic cancer progresses, a number of new agents targeting specific genes and proteins are under investigation and there is hope that median survival will continue to improve over the next decade.

Pancreatic cancer: current understanding of molecular and genetic aetiologies

Pancreatic ductal adenocarcinoma (PDAC) is one of the few cancers where prognosis has not improved over the past few decades. However, there have been several advances in our understanding of the disease leading to earlier detection and targeted therapeutic treatment. It is now understood that specific somatic and germline mutations lead to the development of the disease, and the risk factors associated with this are clearer. Further, several precursor lesions have been identified which, with early detection and surveillance, allows treatment before the development of carcinoma. PDAC can now be diagnosed with a high sensitivity and specificity following advances in radiology, and treatment can be commenced at an earlier stage of the disease. With continued research we are hopeful that the next decade will see an improved survival rate for all patients with pancreatic cancer.