Borderline resectable pancreatic cancer: More than an anatomical concept

Limited impact of discretization/interpolation parameters on the predictive power of CT radiomic features in a surgical cohort of pancreatic cancer patients

PURPOSE

To explore the variation of the discriminative power of CT (Computed Tomography) radiomic features (RF) against image discretization/interpolation in predicting early distant relapses (EDR) after upfront surgery.

MATERIALS AND METHODS

Data of 144 patients with pre-surgical high contrast CT were processed consistently with IBSI (Image Biomarker Standardization Initiative) guidelines. Image interpolation/discretization parameters were intentionally changed, including cubic voxel size (0.21-27 mm³) and binning (32-128 grey levels) in a 15 parameter's sets. After excluding RF with poor inter-observer delineation agreement (ICC < 0.80) and not negligible inter-scanner variability, the variation of 80 RF against discretization/interpolation was first quantified. Then, their ability in classifying patients with early distant relapses (EDR, < 10 months, previously assessed at the first quartile value of time-to-relapse) was investigated in terms of AUC (Area Under Curve) variation for those RF significantly associated to EDR.

RESULTS

Despite RF variability against discretization/interpolation parameters was large and only 30/80 RF showed %COV < 20 (%COV = 100*STDEV/MEAN), AUC changes were relatively limited: for 30 RF significantly associated with EDR (AUC values around 0.60-0.70), the mean values of SD of AUC variability and AUC range were 0.02 and 0.05 respectively. AUC ranges were between 0.00 and 0.11, with values ≤ 0.05 in 16/30 RF. These variations were further reduced when excluding the extreme values of 32 and 128 for grey levels (Average AUC range 0.04, with values between 0.00 and 0.08).

CONCLUSIONS

The discriminative power of CT RF in the prediction of EDR after upfront surgery for pancreatic cancer is relatively invariant against image interpolation/discretization within a large range of voxel sizes and binning.

Prediction of Early Distant Recurrence in Upfront Resectable Pancreatic Adenocarcinoma: A Multidisciplinary, Machine Learning-Based Approach

Simple Summary

If pancreatic adenocarcinoma is assessed to be technically resectable, curative surgery is still suggested as the primary treatment option; however, the recurrence rate can be very high even in this selected population. The aim of our retrospective study was to develop a preoperative model to accurately stratify upfront resectable patients according to the risk of early distant disease relapse after surgery (<12 months from index procedure). Through a machine learning-based approach, we identified one biochemical marker (serum level of CA19.9), one radiological finding (necrosis) and one radiomic feature (SurfAreaToVolumeRatio), all significantly associated with the early resurge of distant recurrence. A model composed of these three variables only allowed identification of those patients at high risk for early distant disease relapse (50% chance of developing metastases within 12 months after surgery), who would benefit from neoadjuvant chemotherapy instead of upfront surgery.

Abstract

Despite careful selection, the recurrence rate after upfront surgery for pancreatic adenocarcinoma can be very high. We aimed to construct and validate a model for the prediction of early distant recurrence (<12 months from index surgery) after upfront pancreaticoduodenectomy. After exclusions, 147 patients were retrospectively enrolled. Preoperative clinical and radiological (CT-based) data were systematically evaluated; moreover, 182 radiomics features (RFs) were extracted. Most significant RFs were selected using minimum redundancy, robustness against delineation uncertainty and an original machine learning bootstrap-based method. Patients were split into training (n = 94) and validation cohort (n = 53). Multivariable Cox regression analysis was first applied on the training cohort; the resulting prognostic index was then tested in the validation cohort. Clinical (serum level of CA19.9), radiological (necrosis), and radiomic (SurfAreaToVolumeRatio) features were significantly associated with the early resurge of distant recurrence. The model combining these three variables performed well in the training cohort (p = 0.0015, HR = 3.58, 95%CI = 1.98–6.71) and was then confirmed in the validation cohort (p = 0.0178, HR = 5.06, 95%CI = 1.75–14.58). The comparison of survival curves between low and high-risk patients showed a p-value <0.0001. Our model may help to better define resectability status, thus providing an actual aid for pancreatic adenocarcinoma patients’ management (upfront surgery vs. neoadjuvant chemotherapy). Independent validations are warranted.

Survival equivalence in patients treated for borderline resectable and unresectable locally advanced pancreatic ductal adenocarcinoma: a systematic review and network meta-analysis

BACKGROUND

The clinical relevance of subdivision of non-metastatic pancreatic ductal adenocarcinoma (PDAC) into locally advanced borderline resectable (LA-BR) and locally advanced unresectable (LA-UR) has been questioned. We assessed equivalence of overall survival (OS) in patients with LA-BR and LA-UR PDAC.

METHODS

A systematic review was performed of studies published January 1, 2009 to August 21, 2019, reporting OS for LA-BR and LA-UR patients treated with or without neoadjuvant therapy (NAT), with or without surgical resection. A frequentist network meta-analysis was used to assess the primary outcome (hazard ratio for OS) and secondary outcomes (OS in LA-BR, LA-UR, and upfront resectable (UFR) PDAC).

RESULTS

Thirty-nine studies, comprising 14,065 patients in a network of eight unique treatment subgroups were analysed. Overall survival was better for LA-BR than LA-UR patients following surgery both with and without NAT. Neoadjuvant therapy prior to surgery was associated with longer OS for UFR, LA-BR, and LA-UR tumours, compared to upfront surgery.

CONCLUSION

Survival between the LA-BR and LA-UR subgroups was not equivalent. This subdivision is useful for prognostication, but likely unhelpful in treatment decision making. Our data supports NAT regardless of initial disease extent. Individual patient data assessment is needed to accurately estimate the benefit of NAT.

Basics and Frontiers on Pancreatic Cancer for Radiation Oncology: Target Delineation, SBRT, SIB technique, MRgRT, Particle Therapy, Immunotherapy and Clinical Guidelines

Pancreatic cancer represents a modern oncological urgency. Its management is aimed to both distal and local disease control. Resectability is the cornerstone of treatment aim. It influences the clinical presentation’s definitions as up-front resectable, borderline resectable and locally advanced (unresectable). The main treatment categories are neoadjuvant (preoperative), definitive and adjuvant (postoperative). This review will focus on (i) the current indications by the available national and international guidelines; (ii) the current standard indications for target volume delineation in radiotherapy (RT); (iii) the emerging modern technologies (including particle therapy and Magnetic Resonance [MR]-guided-RT); (iv) stereotactic body radiotherapy (SBRT), as the most promising technical delivery application of RT in this framework; (v) a particularly promising dose delivery technique called simultaneous integrated boost (SIB); and (vi) a multimodal integration opportunity: the combination of RT with immunotherapy.

Clinical Practice Guidelines for Diagnosis, Treatment and Follow-Up of Exocrine Pancreatic Ductal Adenocarcinoma: Evidence Evaluation and Recommendations by the Italian Association of Medical Oncology (AIOM)

Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer-related death in women (7%) and the sixth in men (5%) in Italy, with a life expectancy of around 5% at 5 years. From 2010, the Italian Association of Medical Oncology (AIOM) developed national guidelines for several cancers. In this report, we report a summary of clinical recommendations of diagnosis, treatment and follow-up of PDAC, which may guide physicians in their current practice. A panel of AIOM experts in upper gastrointestinal cancer malignancies discussed the available scientific evidence supporting the clinical recommendations.

Vascular Resection for Pancreatic Cancer: 2019 French Recommendations Based on a Literature Review From 2008 to 6-2019

Introduction: Vascular resection remains a subject of debate in the management of Pancreatic Ductal Adenocarcinoma (PDAC). These French recommendations were drafted on behalf of the French National Institute of Cancer (INCA-2019).

Material and Methods: A systematic literature search, with PubMed, Medline® (OvidSP), EMBASE, the Cochrane Library, was performed for abstracts published in English from January 2008 to June 2019, and identified systematic reviews/metaanalyses, retrospective analyses and case series dedicated to vascular resections in the setting of PDAC. All selected articles were graded for level of evidence and strength of recommendation was given according to the GRADE system.

Results: Neoadjuvant treatment should be performed rather than direct surgery in borderline and locally advanced non-metastatic PDAC with venous and/or arterial infiltration (T4 stage). Patients who respond or those with stable disease and good performance status should undergo surgical exploration to assess resectability because cross-sectional imaging often fails to identify the extent of the remaining viable tumor. Combining vascular resection with pancreatectomy in these cases increases the feasibility of curative resection which is still the only option to improve long-term survival. Venous resection (VR) is recommended if resection is possible in the presence of limited lateral or circumferential involvement but without venous occlusion and in the absence of arterial contact with the celiac axis (CA; cephalic tumors) or the superior mesenteric artery (SMA; all tumor locations) (Grade B). The patients should be in good general condition because mortality and morbidity are higher than following pancreatectomy without VR (Grade B). In case of planned VR, neoadjuvant treatment is recommended since it improves both rate of R0 resections and survival compared to upfront surgery (Grade B). Due to their complexity and specificities, arterial resection (AR; mainly the hepatic artery (HA) or the CA) must be discussed in selected patients, in multidisciplinary team meetings in tertiary referral centers, according to the tumor location and the type of arterial extension. In case of invasion of a short segment of the common HA, resection with arterial reconstruction may be proposed after neoadjuvant therapy. In case of SMA invasion, neoadjuvant therapy may be followed by laparotomy with dissection and biopsy of peri-arterial tissues. A pancreaticoduodenectomy (PD) with SMA-resection is not recommended if the frozen section examination is positive (Grade C). In case of distal PDAC with invasion of the CA, a distal pancreatectomy with CA-resection without arterial reconstruction may be proposed after neoadjuvant therapy and radiologic embolization of the CA branches (expert opinion).

Conclusion: For PDAC with vascular involvement, neoadjuvant treatment followed by pancreatectomy with venous resection or even arterial resection can be proposed as a curative option in selected patients with selected vascular involvement.

Extrapancreatic Neuropathy Correlates with Early Liver Metastasis in Pancreatic Head Adenocarcinoma

Background

Pancreatic ductal adenocarcinoma has a devastatingly poor prognosis, and most prognostic factors reflected the tumor stage more than the tumors' biology. The peripheral nerve plexus is densely distributed in the tumor micro-environment, and there are interactions between tumor cells and these nerves. Perineural invasion is an important risk factor for tumor recurrence and metastasis in pancreatic head adenocarcinoma, but the concrete types of extrapancreatic neuropathy and its role in predicting prognosis are still not clear.

Objective

To clarify the role of extrapancreatic neuropathy in the early postoperative liver metastasis and tumor-related mortality in pancreatic head adenocarcinoma and to study the mechanism of tumor recurrence and liver metastasis in pancreatic head adenocarcinoma.

Methods

We reported a retrospective study of 60 patients with resectable pancreatic head adenocarcinoma, all of whom accepted radical pancreaticoduodenectomy. Plexus pancreaticus capitalis II (PLX-II) was the representation of extrapancreatic plexus in our study, and all of these plexus had immunohistochemical staining. We defined the postoperative tumor recurrence and tumor-related mortality within 6 months as the early prognostic indicators and analyzed the pathological alterations in PLX-II among different prognosis groups.

Results

There were 18 patients suffering early postoperative liver metastasis; these two groups differed significantly in the average number of nerve trunks (P<0.001), the proportion of neuritis (P=0.003), the content of sympathetic nerve fibers (P=0.004) and parasympathetic nerve fibers (P<0.001) per unit area of PLX-II. There were 15 patients suffering early postoperative mortality, and there were significant differences between these two groups in the average number of nerve trunks (P<0.001), the proportion of neuritis (P=0.009), the content of sympathetic nerve fibers (P=0.023) and parasympathetic nerve fibers (P<0.001) per unit area of PLX-II.

Conclusion

The patterns of extrapancreatic neuropathy could reflect the biological behavior of resectable pancreatic head adenocarcinoma, and the pathological features of PLX-II were closely related to early liver metastasis and mortality.

Surgery or Locoregional Approaches for Hepatic Oligometastatic Pancreatic Cancer: Myth, Hope, or Reality?

Despite extensive research, pancreatic ductal adenocarcinoma (PDAC) remains a difficult-to-treat cancer associated with poor survival. Due to the known aggressive disease biology, palliative chemotherapy is the only routinely recommended treatment in the metastatic setting in patients with adequate performance status. However, in a subset of patients with oligometastatic disease, multimodality treatment with surgery and/or locoregional approaches may provide long-term disease control and prolong survival. In fact, in highly selected cases, median overall survival has been reported to extend to 56 months in patients treated with surgery. In particular, liver and extraregional nodal resections may provide long-term tumor control with acceptable morbidity. Current guidelines do not recommend surgery for patients with metastatic PDAC and, in the case of PDAC with oligometastases, there are no published randomized controlled trials regarding locoregional or surgical approaches. Here we review the literature on surgical and locoregional approaches including radiofrequency ablation, irreversible electroporation, and stereotactic body radiation, and focus on patients with hepatic oligometastatic pancreatic cancer. We provide a summary regarding survival outcomes, morbidity and mortality and discuss selection criteria that may be useful to predict the best outcomes for such strategies.

Pancreatic cancer: French clinical practice guidelines for diagnosis, treatment and follow-up (SNFGE, FFCD, GERCOR, UNICANCER, SFCD, SFED, SFRO, ACHBT, AFC)

BACKGROUND

This document is a summary of the French intergroup guidelines regarding the management of pancreatic adenocarcinoma (PA), updated in July 2018.

DESIGN

This collaborative work was produced under the auspices of all French medical and surgical societies involved in the management of PA. It is based on the previous guidelines, recent literature review and expert opinions. Recommendations were graded in three categories, according to the level of evidence.

RESULTS

Over the last seven years, significant changes in PA management have been implemented in clinical practice. Imaging/staging: diffusion magnetic resonance imaging is useful before surgery to rule out small liver metastases.

SURGERY

centralization of pancreatic surgery in expert centers is associated with a decreased postoperative mortality. Adjuvant chemotherapy: modified FOLFIRINOX in fit patients, or gemcitabine, or 5-FU, or gemcitabine plus capecitabine, to be discussed on a case-by-case basis. Locally advanced PA: no survival benefit of chemoradiotherapy. Metastatic PA: FOLFIRINOX and gemcitabine plus nab-paclitaxel combination are first-line standards in fit patients; second-line with 5FU/nal-IRI or 5FU/oxaliplatin combination after first-line gemcitabine.

CONCLUSION

Guidelines for management of PA are continuously evolving and need to be regularly updated. This constant progress is made possible through clinical and translational research. However, as each individual case is particular, they cannot substitute to multidisciplinary tumor board discussion.

Pain Palliation Using Hypofractionated Radiotherapy for Unresectable Pancreatic Cancer

BACKGROUND

Pain is a common symptom for patients with pancreatic cancer and is often treated using palliative radiation therapy. Standard palliative dose regimes typically consist of 2000 cGy to 3000 cGy in 5 to 10 fractions (fx). With the recent advancements in radiation dosimetric planning and delivery, the Juravinski Cancer Centre in Hamilton, Ontario, offers a hypofractionated dose of 2500 cGy in 5 fx for the improvement of pain and tumour control in selected pancreatic cancer patients. This project reviews the safety and efficacy of this prescription.

METHODS

A retrospective analysis of 24 patients diagnosed with unresectable pancreatic cancer was conducted. Patient data were collected using in-house medical record systems including MOSAIQ, Meditech, and Centricity. Nonparametric data analysis tests were conducted using Minitab17.

RESULTS

Nineteen of 24 patients (79%) reported a decrease in pain levels following radiation and 13 of 18 (72%) showed good local control of the tumour on a follow-up CT scan. Around 30% of patients reported nausea and vomiting and fatigue. Only 13% reported diarrhea and 8% reported constipation. Twenty-one percent reported pain flares. All patients were able to finish the entire treatment without pauses or delays.

CONCLUSION

A palliative radiotherapy dose regime of 2500 cGy/5 fx demonstrates a potential for the effective control of pain with limited acute toxicities in patients with unresectable pancreatic cancer. This study aims to indicate the need for further prospective research comparing this regime to other standard treatments in order to determine which is most beneficial for the patient.