Neoadjuvant Stereotactic Body Radiotherapy After Upfront Chemotherapy Improves Pathologic Outcomes Compared With Chemotherapy Alone for Patients With Borderline Resectable or Locally Advanced Pancreatic Adenocarcinoma Without Increasing Perioperative Toxicity

Phase 1 Study of Adjuvant Allogeneic Granulocyte-Macrophage Colony-Stimulating Factor-Transduced Pancreatic Tumor Cell Vaccine, Low-Dose Cyclophosphamide, and Stereotactic Body Radiation Therapy Followed by FOLFIRINOX in High-Risk Resected Pancreatic Ductal Adenocarcinoma

PURPOSE

Local and distant progression remains common following resection of resectable pancreatic ductal adenocarcinoma (PDAC) despite adjuvant multiagent chemotherapy. We report a prospective institutional phase 1 trial incorporating adjuvant GVAX vaccine, low-dose cyclophosphamide (Cy), and stereotactic body radiation therapy (SBRT) followed by FOLFIRINOX (FFX) among patients who underwent resection of high-risk PDAC.

PATIENTS AND METHODS

The study design was a modified 3+3. Cohort 1 received 5-fraction SBRT to 33 Gy to the tumor bed and 25 Gy to elective nodes followed by 6 cycles of full-dose FFX. After toxicity review, cohort 2 had SBRT and was switched to modified FFX (mFFX). Cohort 3 had 1 cycle of Cy/GVAX followed by SBRT, mFFX, and 4 cycles of maintenance Cy/GVAX with 6-month Cy/GVAX boosts until progression.

RESULTS

Nineteen patients were enrolled with a median follow-up of 36.2 months. To be eligible, patients were required to have close/positive margins (within ≤1 mm) (71%) and/or lymph node metastasis (79%). Overall, 63% of patients had both. In cohort 1, 67% of patients received 6 cycles of FFX; in cohort 2, 75% received 6 cycles of modified FFX. In cohort 3, 12 patients received the first dose of Cy/GVAX and SBRT with 10 individuals (83%) receiving 6 cycles of mFFX. Cohort 3 had acceptable levels of grade ≥3 thrombocytopenia, neutropenia, and diarrhea after 2 cycles of mFFX. Median overall survival (OS)/disease-free survival (DFS) for the overall cohort and cohort 3 was 36.2/18.2 months and 61.3/24.1 months, respectively. One- and 2-year OS for cohort 3 was 83%/75%, respectively. At the last follow-up (median = x), 5 patients were alive (42%) in cohort 3.

CONCLUSIONS

This is the first prospective trial to evaluate adjuvant GVAX, Cy, SBRT, and mFFX in resected PDAC patients with high-risk features. This combination regimen was well tolerated with limited toxicity and promising survival outcomes, warranting future studies to validate this regimen in the adjuvant setting.

Effect of Radiotherapy in Neoadjuvant Treatment of Borderline Resectable and Locally Advanced Pancreatic Cancer: A Systematic Review and Meta-analysis

BACKGROUND

Pancreatic cancer is a malignant tumor with poor prognosis and bad curative effect. Previous studies did not confirm the role of radiotherapy in neoadjuvant treatment of borderline resectable pancreatic cancer (BRPC) and locally advanced pancreatic cancer (LAPC). By reviewing new findings reported in recent years, we conducted this study to evaluate the survival impact by comparing chemoradiotherapy (CRT) with chemotherapy alone.

MATERIALS AND METHODS

PubMed, Embase, MEDLINE, Web of Science, Scopus, and Cochrane Library were searched for studies reporting median overall survival (OS) in patients with BRPC or LAPC treated with neoadjuvant treatment. Secondary outcomes included progression-free survival (PFS) or disease-free survival (DFS) or recurrence-free survival (RFS) and R0 resection rate.

RESULTS

A total of 18 studies were included in the meta-analysis. OS (hazard ratio [HR] = 0.76, 95% confidence interval [CI]: 0.64-0.91, I2 = 61.7%) and PFS/DFS/RFS (HR = 0.72, 95% CI: 0.58-0.91, I2 = 52.3%) are both favored CRT. Although R0 resection rate was increased in CRT group, significant survival benefit of radiotherapy was found in LAPC and low resection rate subgroup in stratification analysis. Regression analysis showed that only tumor resectability was associated with OS.

CONCLUSIONS

For patients with LAPC and who are unlikely to receive resection, neoadjuvant radiotherapy seems to improve OS and PFS/DFS/RFS.

Dose-Escalated SBRT for Borderline and Locally Advanced Pancreatic Cancer: Resectability Rate and Pathological Results of a Multicenter Prospective Study

OBJECTIVE

We demonstrated for the first time the safety and feasibility of escalating up to 55 Gy/11 Gy/fr/5fr in borderline (BRPC)/unresectable locally advanced pancreatic cancer (LAPC), using the standard LINAC platform. The aim of the present study is to assess for the first time the impact of this high-dose neoadjuvant stereotactic ablative radiotherapy (SABRT) protocol on tumor resectability and pathological responses.

MATERIALS/METHODS

From June 2017 to December 2022, patients with BRPC/LAPC were treated with neoadjuvant chemotherapy (ChT) and SABRT-escalated doses of SIB at 45 Gy, 50 Gy, and up to 55 Gy (BED ≥ 100). Radiological evaluation was conducted with a CT scan 6-8 weeks post-treatment to determine resectability status based on established criteria (SAR/APA2014). Surgical decisions were made by the multidisciplinary tumor board of the participating institutions. Pathological assessments post-surgery used criteria from the College of American Pathologists (CAP), categorizing resection status as R0 (negative margins), R1 (microscopic tumor margins), and R2 (macroscopic tumor margins). Tumor response was evaluated with the Tumor Response Scoring (TRS) system, as G0 (no viable cancer cells), G1 (single cells or rare small groups), G2 (residual cancer with evident regression), and G3 (extensive residual cancer).

RESULTS

Thirty-three patients (p) were included: 39.4% (13p) BRPC/60.6% (20p) LAPC. After ChT-SABRT, 45.5% (15p) were considered resectable, with 11/13 (84.6%) BRPC and 4/20 (20%) LAPC (p < 0.0001). One patient refused surgery and other patient died of COVID sepsis. Two more patients had disseminated disease at surgery. Among the 11 patients who underwent full surgery, all patients achieved either clean margins R0: 72.7% (8p) or microscopic affected margins R1: 27.3% (3p). TRS scores were G1: 27.3% (3p), G2: 54.5% (6p), and G3: 18.2% (2p). The present follow-up (FUP) was closed on 1 November 2024 (23.55 months, range: 6-71 months). The mean freedom from local progression as the first cause of disease failure was 43.30 ± 3.09 (37.23-49.38), and the median was not reached. The actuarial 1- and 2-year rates for freedom from local relapse as a first cause of disease failure were 92.3% (87.7-93.3%) and 79.7% (79.7-87.7%), respectively.

CONCLUSIONS

Neoadjuvant ChT-SABRT in LAPC improves resectability rates and induces relevant tumor regression. These promising findings should be validated by larger sample sizes and extended follow-up.

A Review of Stereotactic Body Radiotherapy in the Management of Gastrointestinal Malignancies

ABSTRACT

In this review, we explore the role of stereotactic body radiotherapy (SBRT) and other advanced radiotherapy techniques in the treatment of gastrointestinal malignancies, which primarily involves primary and secondary liver cancers and pancreatic cancers. The review examines radiotherapy in both curative and palliative settings, emphasizing the evolution of SBRT and hypofractionation as alternatives to conventional radiotherapy. We review the recent literature evaluating radiotherapy in the management of unresectable, borderline resectable, and metastatic pancreatic cancer, highlighting recent advances in radiotherapy techniques that aim to improve local control, reduce toxicity, and increase resectability in appropriate patients. For primary liver cancers (hepatocellular carcinoma and cholangiocarcinoma), SBRT has emerged as a potential noninvasive alternative to surgery, particularly in patients with unresectable tumors or those awaiting liver transplantation. The review also provides insights into ongoing clinical trials, comparative studies between SBRT and other local therapies such as radiofrequency ablation, and the use of radiotherapy in managing liver metastases from various primary cancers. Throughout, we emphasize limitations in the available literature and highlight areas of ongoing and future investigation.

Impact of neoadjuvant chemoradiotherapy on pathologic response in pancreatic ductal adenocarcinoma: A systematic review and meta-analysis

BACKGROUND

The impact of chemoradiotherapy on pathologic response, resection margin, and survival benefit is still debated. The aim of this study was to compare the rate of pathologic complete response (pCR) in surgical resection following neoadjuvant chemotherapy vs. chemoradiotherapy, and secondarily, to compare the rate of R0 resection and Overall Survival (OS).

METHODS

A systematic review on MEDLINE/PubMed, Embase, Cochrane, Web of Science and Google Scholar was conducted for studies published between 2012 and 2024 (PROSPERO CRD42022341467). All studies reporting clinical outcomes of patients with Pancreatic ductal adenocarcinoma (PDAC) following neoadjuvant therapy were considered eligible for inclusion. A meta-analysis comparing the rate of pCR, R0 resection rate, and 3-year OS following Chemotherapy vs chemoradiotherapy in patients was performed. The overall quality of evidence was evaluated using a GRADE approach.

RESULTS

Out of 5194 potentially relevant studies, 29 studies were considered eligible for full-text assessment, and 11 studies were included in the systematic review and in the meta-analysis. Of these, five were retrospective single-center, five retrospective multi-center studies, and one was a phase II multi-center RCT. Overall, 1830 Chemotherapy patients and 2299 Chemoradiotherapy patients were included in the meta-analysis. A statistically significant increased rate of pCR and R0 resections were found in chemoradiotherapy patients (OR 3.58, 95 % CI 2.47-5.18, p ≤ 0.00001) (OR 1.49, 95 % CI 1.17-1.90, p = 0.001), whereas 3-year OS (OR 1.07, 95 % CI 0.84-1.36, p = 0.6) did not differ significantly.

CONCLUSIONS

Chemoradiotherapy may have a positive impact on pathologic response and R0 resection rate, whereas a survival benefit was not reported.

Locally Advanced Pancreas Cancer, Is There a Role for Surgery?

Locally advanced pancreatic cancer (LAPC) represents a unique clinical scenario in which the tumor is considered localized but unresectable due to anatomic factors. Despite a consensus against upfront surgery, no standard approach to induction therapy exists for patients with LAPC. Extended systemic therapy has shown promise in establishing tumor response and remains the standard of care. While associated with improved local control, the timing and role of radiation therapy remain in question. Following adequate response to induction chemotherapy, a safe attempt at margin-negative resection can be considered. Special attention should be given to required vascular skeletonization and/or resection with reconstruction.

Executive Summary of the American Radium Society Appropriate Use Criteria for Neoadjuvant Therapy for Nonmetastatic Pancreatic Adenocarcinoma: Systematic Review and Guidelines

For patients with locoregionally confined pancreatic ductal adenocarcinoma (PDAC), margin-negative surgical resection is the only known curative treatment; however, the majority of patients are not operable candidates at initial diagnosis. Among patients with resectable disease who undergo surgery alone, the 5-year survival remains poor. Adjuvant therapies, including systemic therapy or chemoradiation, are utilized as they improve locoregional control and overall survival. There has been increasing interest in the use of neoadjuvant therapy to obtain early control of occult metastatic disease, allow local tumor response to facilitate margin-negative resection, and provide a test of time and biology to assist with the selection of candidates most likely to benefit from radical surgical resection. However, limited guidance exists regarding the relative effectiveness of treatment options. In this systematic review, the American Radium Society multidisciplinary gastrointestinal expert panel convened to develop Appropriate Use Criteria evaluating the evidence regarding neoadjuvant treatment for patients with PDAC, including surgery, systemic therapy, and radiotherapy, in terms of oncologic outcomes and quality of life. The evidence was assessed using the Population, Intervention, Comparator, Outcome, and Study (PICOS) design framework and "Preferred Reporting Items for Systematic Reviews and Meta-analyses" 2020 methodology. Eligible studies included phases 2 to 3 trials, meta-analyses, and retrospective analyses published between January 1, 2012 and December 30, 2022 in the Ovid Medline database. A summary of recommendations based on the available literature is outlined to guide practitioners in the management of patients with PDAC.

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.

Research trends and hotspots of neoadjuvant therapy in pancreatic cancer: a bibliometric analysis based on the Web of Science Core Collection

Neoadjuvant therapy (NAT) for pancreatic cancer (PC) has achieved certain results. This article was aimed to analyze the trends in NAT in PC over the past 20 years using bibliometric analysis and visualization tools to guide researchers in exploring future research hotspots. Articles related to NAT for PC were retrieved from the Web of Science Core Collection for the period 2002-2021. The information was analyzed and visualized using VOSviewer, Citespace, Microsoft Excel and R software. The number of articles per year has continued to increase over the past 20 years. Of the 1,598 eligible articles, the highest number was from the United States (760), and an analysis of institutions indicated that the University of Texas System (150) had the highest number of articles. Matthew H. G. Katz had the highest number of citations and the highest H-index. "Pancreatic cancer" (981), "Resection" (623), "Cancer" (553), "Neoadjuvant therapy" (509) and "Survival" (484) were the top five ranked keywords. Combined with the keywords-cluster analysis and citation burst analysis, current research hotspots were the optimal NAT regimen, NAT response assessment, NAT for resectable PC and management of complications. NAT has received increasing attention in the field of PC over the past 20 years, but greater collaboration between countries and additional multicenter randomized clinical trials are needed. Overall, we have revealed current research hotspots and provided valuable information for the choice of future research directions.

The Timing of Surgery Following Stereotactic Body Radiation Therapy Impacts Local Control for Borderline Resectable or Locally Advanced Pancreatic Cancer

We aimed to evaluate the impact of time from stereotactic body radiation therapy (SBRT) to surgery on treatment outcomes and post-operative complications in patients with borderline resectable or locally advanced pancreatic cancer (BRPC/LAPC). We conducted a single-institutional retrospective analysis of patients with BRPC/LAPC treated from 2016 to 2021 with neoadjuvant chemotherapy followed by SBRT and surgical resection. Covariates were stratified by time from SBRT to surgery. A Cox regression model was used to identify variables associated with survival outcomes. In 171 patients with BRPC/LAPC, the median time from SBRT to surgery was 6.4 (range: 2.7-25.3) weeks. Hence, patients were stratified by the timing of surgery: ≥6 and <6 weeks after SBRT. In univariable Cox regression, surgery ≥6 weeks was associated with improved local control (LC, HR 0.55, 95% CI 0.30-0.98; p = 0.042), pathologic node positivity, elevated baseline CA19-9, and inferior LC if of the male sex. In multivariable analysis, surgery ≥6 weeks (p = 0.013; HR 0.46, 95%CI 0.25-0.85), node positivity (p = 0.019; HR 2.09, 95% CI 1.13-3.88), and baseline elevated CA19-9 (p = 0.002; HR 2.73, 95% CI 1.44-5.18) remained independently associated with LC. Clavien-Dindo Grade ≥3B complications occurred in 4/63 (6.3%) vs. 5/99 (5.5%) patients undergoing surgery <6 weeks and ≥6 weeks after SBRT (p = 0.7). In summary, the timing of surgery ≥6 weeks after SBRT was associated with improved local control and low post-operative complication rates, irrespective of the surgical timing. Further investigation of the influence of surgical timing following radiotherapy is warranted.

Tissue clearing and 3D reconstruction of digitized, serially sectioned slides provide novel insights into pancreatic cancer

Pancreatic cancer is currently the third leading cause of cancer death in the United States. The clinical hallmarks of this disease include abdominal pain that radiates to the back, the presence of a hypoenhancing intrapancreatic lesion on imaging, and widespread liver metastases. Technologies such as tissue clearing and three-dimensional (3D) reconstruction of digitized serially sectioned hematoxylin and eosin-stained slides can be used to visualize large (up to 2- to 3-centimeter cube) tissues at cellular resolution. When applied to human pancreatic cancers, these 3D visualization techniques have provided novel insights into the basis of a number of the clinical characteristics of this disease. Here, we describe the clinical features of pancreatic cancer, review techniques for clearing and the 3D reconstruction of digitized microscope slides, and provide examples that illustrate how 3D visualization of human pancreatic cancer at the microscopic level has revealed features not apparent in 2D microscopy and, in so doing, has closed the gap between bench and bedside. Compared with animal models and 2D microscopy, studies of human tissues in 3D can reveal the difference between what can happen and what does happen in human cancers.

Stereotactic Body Radiotherapy (SBRT) of Pancreatic Cancer-A Critical Review and Practical Consideration

Pancreatic cancer is the third leading cause of cancer death in the developed world and is predicted to become the second by 2030. A cure may be achieved only with surgical resection of an early diagnosed disease. Surgery for more advanced disease is challenging and can be contraindicated for many reasons. Neoadjuvant therapy may improve the probability of achieving R0 resection. It consists of systemic treatment followed by radiation therapy applied concurrently or sequentially with cytostatics. A novel approach to irradiation, stereotactic body radiotherapy (SBRT), has the potential to improve treatment results. SBRT can deliver higher doses of radiation to the tumor in only a few treatment fractions. It has attracted significant interest for pancreatic cancer patients, as it is completed quickly, requires less time away from full-dose chemotherapy, and is well-tolerated than conventional radiotherapy. In this review, we aim to provide the reader with a basic overview of current evidence for SBRT indications in the treatment of pancreatic tumors. In the second part of the review, we focus on practical information with respect to SBRT treatment plan preparation the performance of such therapy. Finally, we discuss future directions related to the use of magnetic resonance linear accelerators.

Pancreatic Cancer: Challenges and Opportunities in Locoregional Therapies

Simple Summary

Pancreatic cancer is a serious ongoing global health burden, with an overall 5-year survival rate of less than 5%. One major hurdle in the treatment of this disease is the predominantly elderly patient population, leading to their ineligibility for curative surgery and a low rate of successful outcomes. Systemic administration introduces chemo-agents throughout the body via the blood, attacking not only tumours but also healthy organs. When localised interventions are employed, chemo-agents are retained specifically at tumour site, minimizing unwanted toxicity. As a result, there is a growing interest in finding novel localised interventions as alternatives to systemic therapy. Here, we present a detailed review of current locoregional therapies used in pancreatic cancer therapy. This work aims to present a thorough guide for researchers and clinicians intended to employ established and novel localised interventions in the treatment of pancreatic cancer. Furthermore, we present our insights and opinions on the potential ideals to improve these tools.

Abstract

Pancreatic cancer (PC) remains the seventh leading cause of cancer-related deaths worldwide and the third in the United States, making it one of the most lethal solid malignancies. Unfortunately, the symptoms of this disease are not very apparent despite an increasing incidence rate. Therefore, at the time of diagnosis, 45% of patients have already developed metastatic tumours. Due to the aggressive nature of the pancreatic tumours, local interventions are required in addition to first-line treatments. Locoregional interventions affect a specific area of the pancreas to minimize local tumour recurrence and reduce the side effects on surrounding healthy tissues. However, compared to the number of new studies on systemic therapy, very little research has been conducted on localised interventions for PC. To address this unbalanced focus and to shed light on the tremendous potentials of locoregional therapies, this work will provide a detailed discussion of various localised treatment strategies. Most importantly, to the best of our knowledge, the aspect of localised drug delivery systems used in PC was unprecedentedly discussed in this work. This review is meant for researchers and clinicians considering utilizing local therapy for the effective treatment of PC, providing a thorough guide on recent advancements in research and clinical trials toward locoregional interventions, together with the authors’ insight into their potential improvements.