Surgical treatment of hepatic oligometastatic pancreatic ductal adenocarcinoma: An analysis of the National Cancer Database

Clinical implications of disappearing pancreatic cancer liver metastases: Lessons from colorectal liver metastases

BACKGROUND

The efficacy of local control for pancreatic cancer liver metastases (PCLM), including surgical treatment, remains controversial, with no consensus on the management and clinical significance of disappearing liver metastases (DLMs). This study aimed to evaluate the clinical implications of DLMs in treating PCLM after multi-agent chemotherapy, utilizing contrast-enhanced imaging modalities.

METHODS

A retrospective analysis was conducted on patients who underwent curative resection for pancreatic cancer with synchronous or metachronous liver metastases between 2014 and 2023. Surgical indications were based on our recently reported ABCD criteria (Anatomical/Biological/Conditional/Duration). Both contrast-enhanced computed tomography (CE-CT) and gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging (EOB-MRI) were used to monitor metastatic lesions in the liver. DLMs were defined as tumors undetected on CE-CT post-chemotherapy.

RESULTS

A total of 58 lesions in 29 patients with PCLM who underwent surgical resection were evaluated. Of the 13 lesions evident on CE-CT, 76.9 % (10/13) contained clinically/pathologically residual tumors. Of the 45 DLMs, 16 (35.6 %) had residual tumors. Twenty-six DLMs (57.8 %) were detected on EOB-MRI or intraoperative screening (contrast-enhanced ultrasonography and palpation), with 42.3 % (11/26) being residual tumors. Nineteen DLMs were undetectable by any modality, of which 26.3 % (5/19) were confirmed to be residual tumors with a median follow-up of 32 months. The median overall survival from initiating treatment for PCLM was 48.5 months.

CONCLUSION

Integrating EOB-MRI into preoperative evaluations for PCLM enhances the detection of clinically relevant DLMs. Our findings highlight the potential benefits of considering an image-guided surgical approach in selected patients.

OligoM-Cancer: A multidimensional information platform for deep phenotyping of heterogenous oligometastatic cancer

Patients with oligometastatic cancer (OMC) exhibit better response to local therapeutic interventions and a more treatable tendency than those with polymetastatic cancers. However, studies on OMC are limited and lack effective integration for systematic comparison and personalized application, and the diagnosis and precise treatment of OMC remain controversial. The application of large language models in medicine remains challenging because of the requirement of high-quality medical data. Moreover, these models must be enhanced using precise domain-specific knowledge. Therefore, we developed the OligoM-Cancer platform (http://oligo.sysbio.org.cn), pioneering knowledge curation that depicts various aspects of oligometastases spectrum, including markers, diagnosis, prognosis, and therapy choices. A user-friendly website was developed using HTML, FLASK, MySQL, Bootstrap, Echarts, and JavaScript. This platform encompasses comprehensive knowledge and evidence of phenotypes and their associated factors. With 4059 items of literature retrieved, OligoM-Cancer includes 1345 valid publications and 393 OMC-associated factors. Additionally, the included clinical assistance tools enhance the interpretability and credibility of clinical translational practice. OligoM-Cancer facilitates knowledge-guided modeling for deep phenotyping of OMC and potentially assists large language models in supporting specialised oligometastasis applications, thereby enhancing their generalization and reliability.

Treatment of oligo-metastatic pancreatic ductal adenocarcinoma to the liver: is there a role for surgery? A narrative review

Pancreatic ductal adenocarcinoma (PDAC) is a prognostically unfavorable malignancy that presents with distant metastases at the time of diagnosis in half of patients. Even if patients with metastatic PDAC have not been traditionally considered candidates for surgery, an increasing number of researchers have been investigating the efficacy of surgical treatment for patients with liver-only oligometastases from PDAC, showing promising results in extremely selected patients, mainly with metachronous metastases after perioperative chemotherapy. Nevertheless, a standardized definition of oligometastatic disease should be adopted and additional investigations focusing on the role of perioperative chemotherapy and tumor biology are warranted to reliably assess the role of resection for PDAC metastatic to the liver.

Radiation therapy of the primary tumour and/or metastases of digestive metastatic cancers

Metastatic gastrointestinal cancer is not an uncommon situation, especially for pancreatic, gastric, and colorectal cancers. In this setting, few data are available on the impact of the treatment of the primary tumour. Oligometastatic disease is associated with longer survival in comparison with more advanced disease. Metastasis-directed therapy, such as stereotactic body radiotherapy, seems related to better outcomes, but the level of evidence is low. In most tumour locations, prospective data are very scarce and inclusion in ongoing trials is strongly recommended.

Treatment of Oligometastatic GI Cancers

Oligometastatic state is believed to potentially represent a transitional stage between early, locoregional state disease and widely metastatic disease. Historically, locoregional approaches, particularly in advanced colorectal cancers, have demonstrated efficacy in select patients with limited burden of metastatic disease. Recent strides in systemic therapies, including biomarker-based treatments and immunotherapy, alongside innovations in surgical techniques and novel locoregional approaches such as stereotactic radiotherapy and ablation, have ushered in a new era of therapeutic possibilities across all oligometastatic GI cancers. Despite these advancements, there remains a significant gap in high-quality prospective evidence guiding patient selection and treatment decisions across various disease types. Ongoing clinical trials are anticipated to provide crucial insights into oligometastatic states, fostering the refinement of disease-specific oligometastatic state definitions and treatment algorithms. This article reviews existing data on the management of oligometastatic GI cancer, summarizes current state of knowledge for each disease state, and provides updates on ongoing studies in this space.

Defining oligometastatic pancreatic cancer: a systematic review and critical synthesis of consensus

BACKGROUND

Small retrospective series suggest that local consolidative treatment (LCT) may improve survival in oligometastatic pancreatic ductal adenocarcinoma (PDAC). However, no uniform definition of oligometastatic disease (OMD) in PDAC exists; this impedes meaningful conclusions.

PATIENTS AND METHODS

A systematic literature search using PubMed, Web of Science, and Cochrane CENTRAL registries for studies and protocols reporting on definitions and/or LCT of OMD in PDAC was performed. The primary endpoint was the definition of OMD. Levels of agreement were categorized as consensus (≥75% agreement between studies), fair agreement (50%-74%), and absent/poor agreement (<50%).

RESULTS

After screening of 5374 abstracts, the full text of 218 studies was assessed, of which 76 were included in the qualitative synthesis. The majority of studies were retrospective (n = 66, 87%), two were prospective studies and eight were study protocols. Studies investigated mostly liver (n = 38, 51%) and lung metastases (n = 15, 20%). Across studies, less than one-half (n = 32, 42%) reported a definition of OMD, while 44 (58%) did not. Involvement was limited to a single organ (consensus). Additional criteria for defining OMD were the number of lesions (consensus), metastatic site (poor agreement), metastatic size (poor agreement), treatment possibilities (poor agreement), and biomarker response (poor agreement). Liver OMD could involve three or fewer lesions (consensus) and synchronous disease (fair agreement), while lung metastases could involve two or fewer lesions and metachronous disease (consensus). The large majority of studies were at a high risk of bias or did not include any control groups.

CONCLUSION

Definitions of OMD were not used or varied widely between studies hampering across-study comparability and highlighting an unmet need for a consensus. The present study is part of a multistep process that aims to develop an interdisciplinary consensus on OMD in pancreatic cancer.

Resection of isolated liver oligometastatic disease in pancreatic ductal adenocarcinoma: Is there a survival benefit? A systematic review

BACKGROUND

Presence of liver metastatic disease in pancreatic ductal adenocarcinoma (PDAC), either synchronous or metachronous after pancreatic resection, is a terminal diagnosis that warrants management with palliative intent as per all international practice guidelines. However, there is an increasing interest on any potential value of surgical treatment of isolated oligometastatic disease in selected cases.

AIM

To present the published evidence on surgical management of PDAC liver metastases, synchronous and metachronous, and compare the outcomes of these treatments to the current standard of care.

METHODS

A systematic review was performed in line with the Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines to compare the outcomes of both synchronous and metachronous liver metastases resection to standard care.

RESULTS

356 studies were identified, 31 studies underwent full-text review and of these 10 were suitable for inclusion. When synchronous resection of liver metastases was compared to standard care, most studies did not demonstrate a survival benefit with the exception of one study that utilised neoadjuvant treatment. However, resection of metachronous disease appeared to confer a survival advantage when compared to treatment with chemotherapy alone.

CONCLUSION

A survival benefit may exist in resection of selected cases of metachronous liver oligometastatic PDAC disease, after disease biology has been tested with time and systemic treatment. Any survival benefit is less clear in synchronous cases; however an approach with neoadjuvant treatment and consideration of resection in some selected cases may confer some benefit. Future studies should focus on pathways for selection of cases that may benefit from an aggressive approach.

Essential updates 2021/2022: Surgical outcomes of oligometastasis in pancreatic ductal adenocarcinoma

Oligometastatic disease has been proposed as an intermediate state between localized and polymetastatic disease that can benefit from multimodal treatment, including surgery. There is a growing concern about performing surgery for oligometastatic pancreatic ductal adenocarcinoma, although there is still little evidence. We reviewed articles published between 2021 and 2022, focusing mainly on surgical outcomes. Furthermore, we summarized the current status of surgery in the multidisciplinary treatment of oligometastatic pancreatic cancer and discuss future perspectives. In liver oligometastasis, multimodal treatment including surgery achieved favorable long-term survival, especially in patients with good responses to preoperative chemotherapy, with a median survival time from 25.5 to 54.6 months. In addition, the data from the National Cancer Database in the United States showed that patients who underwent surgery for oligometastatic liver metastases had a significantly longer overall survival than those who received chemotherapy alone. Prognostic biomarkers were identified, including carbohydrate antigen 19-9 (CA19-9) levels at diagnosis and preoperative chemotherapy with normalization of CA19-9 levels or favorable radiological response. Patients with lung oligometastasis had a more favorable long-term prognosis than those with other recurrence sites, and the updated literature further confirmed the previous studies. Overall survival was favorable, with 84 months after initial surgery and 29.2 months after metastasectomy, and a 5-year survival rate of 60.6% was also reported. In peritoneal oligometastasis, the results of conversion surgery after good responses to preoperative treatment with intraperitoneal therapy or systematic chemotherapy were reported, and the conversion rate and long-term prognosis were favorable. There is a growing concern about performing surgery for oligometastatic pancreatic ductal adenocarcinoma. We reviewed articles published between 2021 and 2022, focusing mainly on surgical outcomes. Furthermore, we summarize the current status of surgery in multidisciplinary treatment of oligometastatic pancreatic cancer and discuss future perspectives.

Pancreatic cancer

The need for a common education and training track in surgical oncology across Europe has been emphasized. ESSO provides several hands-on courses for skills training and face-to-face discussions. The core curriculum provides a framework for the overall theoretical requirements in surgical oncology. The UEMS/EBSQ fellowship exam is designed to test core competencies in the candidate's core knowledge in their prespecified area of expertise. A core set of points for each cancer type is lacking. Hence, a condensed outline of themed expected to be covered in the curriculum and relevant to an optimal practice in surgical oncology is provided. This article outlines pancreatic cancer.

Primary Tumor Resection for Metastatic Colorectal, Gastric and Pancreatic Cancer Patients: In Search of Scientific Evidence to Inform Clinical Practice

The management of the primary tumor in metastatic colorectal, gastric and pancreatic cancer patients may be challenging. Indeed, primary tumor progression could be associated with severe symptoms, compromising the quality of life and the feasibility of effective systemic therapy, and might result in life-threatening complications. While retrospective series have suggested that surgery on the primary tumor may confer a survival advantage even in asymptomatic patients, randomized trials seem not to definitively support this hypothesis. We discuss the evidence for and against primary tumor resection for patients with metastatic gastrointestinal (colorectal, gastric and pancreatic) cancers treated with systemic therapies and put in context the pros and cons of the onco-surgical approach in the time of precision oncology. We also evaluate current ongoing trials on this topic, anticipating how these will influence both research and everyday practice.

Does Surgical Resection Significantly Prolong the Long-Term Survival of Patients with Oligometastatic Pancreatic Ductal Adenocarcinoma? A Cross-Sectional Study Based on 18 Registries

Background: Pancreatic ductal adenocarcinoma (PDAC) is a type of lethal gastrointestinal malignancy. It is mainly discovered at, and diagnosed with, an advanced stage of metastasis. As the only potentially curative treatment for PDAC, surgical resection has an uncertain impact on the survival of these patients. As such, we aimed to investigate if patients with metastatic PDAC (mPDAC) benefit from surgery. Methods: Patients with pancreatic cancer in 18 registries of the Surveillance, Epidemiology, and End Results database between 2000 and 2018 were reviewed retrospectively. According to the American Joint Committee on Cancer (AJCC), the eighth edition staging system was utilized. Propensity score matching was applied to strengthen the comparability of the study. The impact of surgery on survival was evaluated by restricted mean survival time (RMST) and Kaplan−Meier analysis. Results: A total of 210 well-matched mPDAC patients were included in the study. The 1 year, 3 year, and 5 year overall survival (OS) of patients undergoing surgery was 34.3%, 15.2%, and 11.0%, respectively. The 1 year, 3 year, and 5 year cancer-specific survival (CSS) of these patients was 36.1%, 19.7%, and 14.2%, respectively. RMST analysis revealed that mPDAC patients with surgery had better OS and CSS than those without (OS: 9.49 months vs. 6.45 months, p < 0.01; CSS: 9.76 months vs. 6.54 months, p < 0.01). Nevertheless, subgroup analysis demonstrated that such statistical significance especially existed in oligometastatic PDAC patients, which refers to those metastases that were limited in number and concentrated to a single organ in this study. Additionally, surgery was identified as a significant predictor for the long-term prognosis of patients (OS: [HR, hazard ratio] = 0.48, 95% CI: 0.36−0.65, p < 0.001; CSS: HR = 0.45, 95% CI: 0.33−0.63, p < 0.001). Lastly, a nomogram was established to predict whether an individual was suitable for surgical treatment in this study. Conclusions: Surgical resection significantly prolonged the long-term prognosis of oligometastatic PDAC patients. Such insights might broaden the management of patients with mPDAC to a large extent. However, a prospective clinical trial should be conducted before a recommendation of surgery in these patients.