Surgery for locally advanced pancreatic ductal adenocarcinoma-is it only about the vessels?

Preoperative chemotherapy, radiotherapy and surgical decision-making in patients with borderline resectable and locally advanced pancreatic cancer

Surgical resection combined with systemic chemotherapy is the cornerstone of treatment for patients with localized pancreatic cancer. Upfront surgery is considered suboptimal in cases with extensive vascular involvement, which can be classified as either borderline resectable pancreatic cancer or locally advanced pancreatic cancer. In these patients, FOLFIRINOX or gemcitabine plus nab-paclitaxel chemotherapy is currently used as preoperative chemotherapy and is eventually combined with radiotherapy. Thus, more patients might reach 5-year overall survival. Patient selection for chemotherapy, radiotherapy and subsequent surgery is based on anatomical, biological and conditional parameters. Current guidelines and clinical practices vary considerably regarding preoperative chemotherapy and radiotherapy, response evaluation, and indications for surgery. In this Review, we provide an overview of the clinical evidence regarding disease staging, preoperative therapy, response evaluation and surgery in patients with borderline resectable pancreatic cancer or locally advanced pancreatic cancer. In addition, a clinical work-up is proposed based on the available evidence and guidelines. We identify knowledge gaps and outline a proposed research agenda.

Surgical Planning for "Borderline Resectable" and "Locally Advanced" Pancreatic Cancer During Open Pancreatic Resection

Pancreatic resection for pancreatic ductal adenocarcinoma (PDAC) is one of the most complex procedures in abdominal surgery due to the technical and oncological challenges given by its local aggressive growth. The improvement of new multidrug chemotherapy regimens and surgical techniques has increased the caseload of "borderline resectable" (BR) or even "locally advanced" (LA) PDAC candidates for surgical resection. As a result, the increased heterogeneity of surgical scenarios has made it essential to utilize a tailored surgical strategy for each individual case. Notably, the strategy employed to approach and assess the peripancreatic vessels should be weighted according to tumor's location and the site of suspected vascular infiltration. The aim of this paper is to describe the open surgical approach for "BR" or "LA" PDAC used at our Institution and summarizes a "step-up approach" to manage vascular infiltration.

A more radical perspective on surgical approach and outcomes in pancreatic cancer-a narrative review

Background and Objective

Pancreatic adenocarcinoma remains a dismal disease and is expected to become an even greater burden in the near future. This review focuses on the different surgical aspects for pancreaticoduodenectomy (PD), distal and total pancreatectomy (TP), incorporating lessons from both the western and eastern visions in treating pancreatic cancer.

Methods

We conducted an extensive literature review through PubMed, prioritizing papers published in the last 5 years, but older emblematic papers were also included. We included articles that explored the treatment of pancreatic adenocarcinoma, with focus on the surgical aspect and strategies to improve outcomes. References of selected articles were also reviewed to identify any missed studies. Only papers in English were included.

Key Content and Findings

As evidence continues to build, it is clear that both systemic and surgical therapies have a fundamental and complementary role. State of art surgical treatment encompasses complete mesopancreas excision for radical lymphadenectomy. Preoperative planning of dissection planes, extensive knowledge of vascular anatomic variations, oncological principles and expertise for vascular resections are mandatory to perform a more radical operation, in pursuit of improved outcomes.

Conclusions

Based on current data, patient selection remains key and a more radical surgical approach brings more accomplishing results bringing as to believe that more is better.

Pancreatic cancer, radiomics and artificial intelligence

Patients with pancreatic ductal adenocarcinoma (PDAC) are generally classified into four categories based on contrast-enhanced CT at diagnosis: resectable, borderline resectable, unresectable, and metastatic disease. In the initial grading and staging of PDAC, structured radiological templates are useful but limited, as there is a need to define the aggressiveness and microscopic disease stage of these tumours to ensure adequate treatment allocation. Quantitative imaging analysis allows radiomics and dynamic imaging features to provide information of clinical outcomes, and to construct clinical models based on radiomics signatures or imaging phenotypes. These quantitative features may be used as prognostic and predictive biomarkers in clinical decision-making, enabling personalised management of advanced PDAC. Deep learning and convolutional neural networks also provide high level bioinformatics tools that can help define features associated with a given aspect of PDAC biology and aggressiveness, paving the way to define outcomes based on these features. Thus, the prediction of tumour phenotype, treatment response and patient prognosis may be feasible by using such comprehensive and integrated radiomics models. Despite these promising results, quantitative imaging is not ready for clinical implementation in PDAC. Limitations include the instability of metrics and lack of external validation. Large properly annotated datasets, including relevant semantic features (demographics, blood markers, genomics), image harmonisation, robust radiomics analysis, clinically significant tasks as outputs, comparisons with gold-standards (such as TNM or pretreatment classifications) and fully independent validation cohorts, will be required for the development of trustworthy radiomics and artificial intelligence solutions to predict PDAC aggressiveness in a clinical setting.