Novel implications of combined arterial resection for locally advanced pancreatic cancer in the era of newer chemo-regimens

Re-evaluation of risk and oncological outcomes of resection of veins and arteries in the resection of pancreatic cancer

BACKGROUND

Advances in chemotherapy have led to increasing major vascular resection during pancreatectomy which has been contraindicated due to high morbidity. This study aimed to verify the safety and oncological outcomes of vascular resection during pancreatectomy in the era of neoadjuvant therapy.

METHODS

Data from patients who underwent surgery for pancreatic cancer at Seoul National University Hospital between 2001 and 2021 were reviewed. Clinicopathological outcomes were analyzed according vessel resection. A propensity-score-matched (PSM) analysis was performed to evaluate survival outcomes.

RESULTS

Of 1596 patients, the proportion of those who underwent vascular resection increased from 9.2% to 23.4% over time divided into 5-year intervals. There were no differences in major complications (15.6% vs. 13.0%; p = .266) and 30-day mortality rate (0.3% vs. 0.6%; p = .837) between the vascular and nonvascular resection groups. After PSM, the vascular resection group demonstrated comparable survival outcome with the nonvascular resection group (5 year-survival-rate 20.4 vs. 23.7%; p = .194). Arterial resection yielded comparable survival outcome with nonvascular resection (5 year-survival-rate 38.1% vs. 23.7%; p = .138).

CONCLUSIONS

Appropriate vascular resection-even arterial-is safe and effective in patients carefully selected for radical surgery in the era of neoadjuvant therapy. Further studies are needed to determine the optimal indication and method for vascular resection in patients with pancreatic cancer.

Multimodal Approaches to Patient Selection for Pancreas Cancer Surgery

With an overall 5-year survival rate of 12%, pancreas ductal adenocarcinoma (PDAC) is an aggressive cancer that claims more than 50,000 patient lives each year in the United States alone. Even those few patients who undergo curative-intent resection with favorable pathology reports are likely to experience recurrence within the first two years after surgery and ultimately die from their cancer. We hypothesize that risk factors for these early recurrences can be identified with thorough preoperative staging, thus enabling proper patient selection for surgical resection and avoiding unnecessary harm. Herein, we review evidence supporting multidisciplinary and multimodality staging, comprehensive neoadjuvant treatment strategies, and optimal patient selection for curative-intent surgical resections. We further review data generated from our standardized approach at the Mayo Clinic and extrapolate to inform potential future investigations.

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.

Arterial Resection for Pancreatic Cancer: Feasibility and Current Standing in a High-Volume Center

Background

Arterial resection (AR) during pancreatectomy for curative R0 resection of pancreatic ductal adenocarcinoma (PDAC) remains a controversial procedure with high morbidity.

Objective

To investigate the feasibility and oncological outcomes of pancreatectomy combined with AR at a high-volume center for pancreatic surgery.

Methods

We retrospectively analyzed our experience in PDAC patients, who underwent pancreatic resection with AR and/or venous resection (VR) between 2007 and 2021.

Results

In total 259 PDAC patients with borderline resectable (n = 138) or locally advanced (n = 121) PDAC underwent vascular resection during tumor resection. From these, 23 patients had AR (n = 4 due to intraoperative injury, n = 19 due to suspected arterial infiltration). However, 12 out of 23 patients (52.2%) underwent simultaneous VR including 1 case with intraoperative arterial injury. In comparison, 11 patients (47.8%) underwent AR only including 3 intraoperative arterial injury patients. Although the operation time and bleeding rate of patients with AR were respectively longer and higher than in VR, no significant difference was detected in postoperative complications between VR and AR (P = 0.11). The final histopathological findings of PDAC patients were similar, including M stage, regional lymph node metastases, and R0 margin resection. The mortality of the entire cohort was 6.2% (16/259), with a tendency to increase mortality in the AR cohort, yet without statistical significance (VR: 5% vs AR: 21.1%; P = 0.05). Although 19 (82.6%) patients had PDAC in the final histopathology, only 6 were confirmed to have infiltrated arteria. The microscopic distribution of PDAC in these infiltrated arterial walls on hematoxylin-eosin staining was classified into 3 patterns. Strikingly, the perivascular nerves frequently exhibited perineural invasion.

Conclusions

AR can be performed in high-volume centers for pancreatic surgery with an acceptable morbidity, which is comparable to that of VR. However, the likelihood of arterial infiltration seems to be rather overestimated, and as such, AR might be avoidable or replaced by less invasive techniques such as divestment during PDAC surgery.

"Conversion surgery" for locally advanced pancreatic cancer: A position paper by the study group at the joint meeting of the International Association of Pancreatology (IAP) & Japan Pancreas Society (JPS) 2022

Locally advanced pancreatic cancer (LAPC), which progresses locally and surrounds major vessels, has historically been deemed unresectable. Surgery alone failed to provide curative resection and improve overall survival. With the advancements in treatment, reports have shown favorable results in LAPC after undergoing successful chemotherapy therapy or chemoradiation therapy followed by surgical resection, so-called "conversion surgery", at experienced high-volume centers. However, recognizing significant regional and institutional disparities in the management of LAPC, an international consensus meeting on conversion surgery for LAPC was held during the Joint Congress of the 26th Meeting of the International Association of Pancreatology (IAP) and the 53rd Annual Meeting of Japan Pancreas Society (JPS) in Kyoto in July 2022. During the meeting, presenters reported the current best multidisciplinary practices for LAPC, including preoperative modalities, best systemic treatment regimens and durations, procedures of conversion surgery with or without vascular resections, biomarkers, and genetic studies. It was unanimously agreed among the experts in this meeting that "cancer biology is surpassing locoregional anatomical resectability" in the era of effective multiagent treatment. The biology of pancreatic cancer has yet to be further elucidated, and we believe it is essential to improve the treatment outcomes of LAPC patients through continued efforts from each institution and more international collaboration. This article summarizes the agreement during the discussion amongst the experts in the meeting. We hope that this will serve as a foundation for future international collaboration and recommendations for future guidelines.

Surgical Treatment of Pancreatic Ductal Adenocarcinoma

Simple Summary

Surgery is the only potential cure for pancreatic ductal adenocarcinoma and should always be combined with adjuvant chemotherapy or other multimodal treatment. Besides the advances in such multimodal approaches, there has been substantial progress in surgical techniques to especially address advanced resections. These techniques include specific operative steps, such as ‘artery first’ or ‘uncinate first’ approaches as well as techniques that allow safe vascular resection and reconstruction to achieve radical tumor removal. Most recently, also minimally-invasive and robotic approaches have been adopted for pancreatic cancer surgery; however, there is no high-level evidence on these evolving techniques especially with regards to long-term results compared to conventional surgical techniques.

Abstract

Pancreatic ductal adenocarcinoma (PDAC) represents an aggressive tumor of the digestive system with still low five-year survival of less than 10%. Although there are improvements for multimodal therapy of PDAC, surgery still remains the effective way to treat the disease. Combined with adjuvant and/or neoadjuvant treatment, pancreatic surgery is able to enhance the five-year survival up to around 20%. However, pancreatic resection is always associated with a high risk of complications and regarded as one of the most complex fields in abdominal surgery. This review gives a summary on the surgical treatment for PDAC based on the current literature with a special focus on resection techniques.

Surgical Treatment of Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) represents an aggressive tumor of the digestive system with still low five-year survival of less than 10%. Although there are improvements for multimodal therapy of PDAC, surgery still remains the effective way to treat the disease. Combined with adjuvant and/or neoadjuvant treatment, pancreatic surgery is able to enhance the five-year survival up to around 20%. However, pancreatic resection is always associated with a high risk of complications and regarded as one of the most complex fields in abdominal surgery. This review gives a summary on the surgical treatment for PDAC based on the current literature with a special focus on resection techniques.

Essential updates 2019/2020: Multimodal treatment of localized pancreatic adenocarcinoma: Current topics and updates in survival outcomes and prognostic factors

Overall survival of patients with localized pancreatic ductal adenocarcinoma (PDAC) is extremely poor. Therefore, the establishment of multimodal treatment strategies is indispensable for PDAC patients because surgical treatment alone could not contribute to the improvement of survival. In this review article, we focus on the current topics and advancement of the treatments for localized PDAC including resectable, borderline resectable, and locally advanced PDAC in accordance with the articles mainly published from 2019 to 2020. Reviewing the articles, the recent progress of multimodal treatments notably improves the prognosis of patients with localized PDAC. For resectable PDAC, neoadjuvant chemo or chemoradiation therapy, rather than upfront surgery, plays a key role, especially in patients with a large tumor, poor performance status, high tumor marker levels, peripancreatic lymph nodes metastasis, or neural invasion suspected on preoperative imaging. For borderline resectable PDAC, neoadjuvant treatments followed by surgery is a desirable approach, and maintenance of immunonutritional status during the treatments are also important. For locally advanced disease, conversion surgery has a central role in improving a survival outcome; however, its indication should be standardized.

Sub-adventitial divestment technique for resecting artery-involved pancreatic cancer: a retrospective cohort study

PURPOSE

To introduce sub-adventitial divestment technique (SDT), a procedure to remove the tumor while preserving the artery during curative pancreatectomy. Peri-operative safety profile was also evaluated.

METHODS

In a single center consecutive series of pancreatectomy for pancreatic cancer, the outcome of patients who had pancreatectomy with SDT was compared to standard pancreatic surgery.

RESULTS

From June 2014 to June 2016, 72 patients had pancreatectomy with SDT and 235 had standard surgery. Tumor stage was T4 in all 72 (100%) tumors removed using SDT compared to four (2%) with standard pancreatectomy (p < 0.001). All 72 (100%) tumors in the SDT group were stage III compared to 24 (10%) in the standard surgery group (p < 0.001). Both groups had a high proportion of poorly differentiated tumors (52 (72%) and 163 (69%) respectively) and perineural tumor invasion (62 (86%) and 186 (79%) respectively). R1 (< 1 mm) was found in 24 (86%) of 28 tumors in the SDT group, and in 72 (60%) out of 120 standard pancreatectomy tumors (p = 0.01). Complications occurred in 29 (40%) of the SDT group and in 88 (37%) of the standard group. The in-hospital mortality was four (6%) in the SDT group and one (0.4%) in the standard group (p = 0.01), with a 90-day mortality of 5 (8%)/60 and 6 (3%)/209 (p = 0.07) respectively.

CONCLUSIONS

The sub-adventitial divestment technique appeared to be an effective surgical technique to remove the tumor while preserving the artery. This approach warrants further validation in prospective studies.

Neoadjuvant therapy in pancreatic cancer: what is the true oncological benefit?

BACKGROUND

Neoadjuvant therapies (neoTx) have revolutionized the treatment of borderline resectable (BR) and locally advanced (LA) pancreatic cancer (PCa) by significantly increasing the rate of R0 resections, which remains the only curative strategy for these patients. However, there is still room for improvement of neoTx in PCa.

PURPOSE

Here, we aimed to critically analyze the benefits of neoTx in LA and BR PCa and its potential use on patients with resectable PCa. We also explored the feasibility of arterial resection (AR) to increase surgical radicality and the incorporation of immunotherapy to optimize neoadjuvant approaches in PCa.

CONCLUSION

For early stage, i.e., resectable, PCa, there is not enough scientific evidence for routinely recommending neoTx. For LA and BR PCa, optimization of neoadjuvant therapy necessitates more sophisticated complex surgical resections, machine learning and radiomic approaches, integration of immunotherapy due to the high antigen load, standardized histopathological assessment, and improved multidisciplinary communication.

Vascular Resections for Pancreatic Ductal Adenocarcinoma: Vascular Resections for PDAC

BACKGROUND AND AIMS

It has become clear that vein resection and reconstruction for pancreatic ductal adenocarcinoma (PDAC) is the standard of care as supported by multiple guidelines. However, resection of large peri-pancreatic arteries remains debatable.

MATERIALS AND METHODS

This review examines the current state of vascular resection with curative intent for PDAC in the last 5 years. Herein, we consider venous (superior mesenteric vein, portal vein), as well as arterial (superior mesenteric artery, celiac trunk, hepatic artery) resection or both with or without reconstruction.

RESULTS

Improvement of multidrug chemotherapy has revolutionized care for PDAC that should shift traditional surgical thinking from an anatomical classification of resectability to a prognostic and biological classification.

CONCLUSION

The present review gives an overview on the results of pancreatectomy associated with vascular resection, with consideration of new perspectives offered by the availability of better systemic therapies.