Surgical margin clearance and extended chemotherapy defines survival for synchronous oligometastatic liver lesions of the ductal adenocarcinoma of the pancreas

Surgical treatment of synchronous liver-only oligometastatic pancreatic adenocarcinoma: a systematic review and meta-analysis of long-term outcomes

BACKGROUND

The potential long-term survival benefits of surgical resection for synchronous liver-only metastases of pancreatic ductal adenocarcinoma (liver oligo-PDAC) remain controversial. This systematic review and meta-analysis aim to compare the current evidence on long-term survival outcomes between surgical treatment of liver oligo-PDAC and conventional systemic chemotherapy.

MATERIALS AND METHODS

A systematic review and meta-analysis were conducted using the PubMed and Scopus databases to identify studies comparing surgery and systemic chemotherapy in terms of long-term survival in oligo-PDAC patients. The search included studies published up to October 2024. The meta-analysis was performed using the Jamovi software.

RESULTS

Eleven retrospective studies were selected for a total of 897 patients: 565(63%) underwent synchronous resection of liver metastases and the primary tumor, while 332(37%) received conventional chemotherapy. The majority of patients presented a pancreatic head tumor, and the median number of liver metastases ranged between 1 and 3 in the surgical cohort and 1 and 2 in the nonsurgical cohort. The rate of major surgical complications was 14.4% while the cumulative incidence of postoperative mortality was 2.8%. The median overall survival(OS) in the surgical group ranged from 7.6 to 18.4 months, while a lower value comprised between 6 and 9.9 months was evidenced in the nonsurgical cohort. Six studies were included in the meta-analysis for the OS evaluation, showing significantly better survival outcomes in the surgical group (OR: 0.286, 95% CI: 0.100-0.409; P < 0.0001). According to the Q-test, there was no significant heterogeneity in the true outcomes ( Q = 4.063, P = 0.541, I2  = 0 %). A sensitivity analysis, conducted by excluding one study at a time, confirmed the robustness of the meta-analysis findings.

CONCLUSIONS

Surgical resection of oligo-PDAC may represent a valuable treatment option with potential long-term survival benefits. However, prospective randomized trials are required to further validate these findings.

Surgical Outcomes in Stage IV Pancreatic Cancer with Liver Metastasis Current Evidence and Future Directions: A Systematic Review and Meta-Analysis of Surgical Resection

BACKGROUND/OBJECTIVES

There is increasing evidence that a subset of patients with stage IV pancreatic ductal adenocarcinoma (PDAC) and liver-only metastasis may benefit from surgical resection of both the primary tumor and metastatic lesions.

METHODS

A meta-analysis and systematic review were conducted in patients with stage IV PDAC and hepatic-only metastasis. A comprehensive literature search (January 2015-June 2023) was performed using PubMed with keywords including "pancreatic cancer", "oligometastatic", and "surgery".

RESULTS

Sixteen articles were included in the final review and characterized based on patient selection factors and prognostic indicators. Seven studies reported hazard ratios (HRs) or Kaplan-Meier curves for survival in synchronous resected cohorts versus chemotherapy/palliation alone, which indicated a statistically significant survival benefit in the resection cohorts (pooled HR: 0.41, 95% CI: 0.31-0.53, p < 0.01). Prognostic indicators for synchronous and metachronous resection included lower pre-operative CA19-9, negative margin status of the primary tumor, moderate-to-well-differentiated tumors (grades I-II), and receiving pre-operative chemotherapy.

CONCLUSIONS

Surgical/ablation selection factors are evolving, with priorities on (1) response to induction chemotherapy, (2) ability to achieve R0 resection, and (3) minimally invasive approaches remaining critical to optimal patient selection. Standardized radiologic and tumor marker evaluation and response to neoadjuvant therapy and optimizing performance status are critical to improved outcomes.

Surgery for Oligometastatic Pancreatic Cancer: Defining Biologic Resectability

Pancreatic ductal adenocarcinoma (PDAC) is most often metastatic at diagnosis. As systemic therapy continues to improve alongside advanced surgical techniques, the focus has shifted toward defining biologic, rather than technical, resectability. Several centers have reported metastasectomy for oligometastatic PDAC, yet the indications and potential benefits remain unclear. In this review, we attempt to define oligometastatic disease in PDAC and to explore the rationale for metastasectomy. We evaluate the existing evidence for metastasectomy in liver, peritoneum, and lung individually, assessing the safety and oncologic outcomes for each. Furthermore, we explore contemporary biomarkers of biological resectability in oligometastatic PDAC, including radiographic findings, biochemical markers (such as CA 19-9 and CEA), inflammatory markers (including neutrophil-to-lymphocyte ratio, C-reactive protein, and scoring indices), and liquid biopsy techniques. With careful consideration of existing data, we explore the concept of biologic resectability in guiding patient selection for metastasectomy in PDAC.

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.

Currently Debated Topics on Surgical Treatment of Pancreatic Ductal Adenocarcinoma: A Narrative Review on Surgical Treatment of Borderline Resectable, Locally Advanced, and Synchronous or Metachronous Oligometastatic Tumor

BACKGROUND

Previously considered inoperable patients (borderline resectable, locally advanced, synchronous oligometastatic or metachronous pancreatic adenocarcinoma (PDAC)) are starting to become resectable thanks to advances in chemo/radiotherapy and the reduction in operative mortality.

METHODS

This narrative review presents a chosen literature selection, giving a picture of the current state of treatment of these patients.

RESULTS

Neoadjuvant therapy (NAT) is generally recognized as the treatment of choice before surgery. However, despite the increased efficacy, the best pathological response is still limited to 10.9-27.9% of patients. There are still limited data on the selection of possible NAT responders and how to diagnose non-responders early. Multidetector computed tomography has high sensitivity and low specificity in evaluating resectability after NAT, limiting the resection rate of resectable patients. Ca 19-9 and Positron emission tomography are giving promising results. The prediction of early recurrence after a radical resection of synchronous or metachronous metastatic PDAC, thus identifying patients with poor prognosis and saving them from a resection of little benefit, is still ongoing, although some promising data are available.

CONCLUSION

In conclusion, high-level evidence demonstrating the benefit of the surgical treatment of such patients is still lacking and should not be performed outside of high-volume centers with interdisciplinary teams of surgeons and oncologists.

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.