Locoregional Treatment of Metastatic Pancreatic Cancer Utilizing Resection, Ablation and Embolization: A Systematic Review

Abstract

The prognosis of metastatic pancreatic ductal adenocarcinoma (mPDAC) remains universally poor, requiring new and innovative treatment approaches. In a subset of oligometastatic PDAC patients, locoregional therapy, in addition to systemic chemotherapy, may improve survival. The aim of this systematic review was to explore and evaluate the current evidence on locoregional treatments for mPDAC. A systematic literature search was conducted on locoregional techniques, including resection, ablation and embolization, for mPDAC with a focus on hepatic and pulmonary metastases. A total of 59 studies were identified, including 63,453 patients. Although subject to significant bias, radical-intent local therapy for both the primary and metastatic sites was associated with a superior median overall survival from metastatic diagnosis or treatment (hepatic mPDAC 7.8–19 months; pulmonary mPDAC 22.8–47 months) compared to control groups receiving chemotherapy or best supportive care (hepatic mPDAC 4.3–7.6 months; pulmonary mPDAC 11.8 months). To recruit patients that may benefit from these local treatments, selection appears essential. Most significant is the upfront possibility of local radical pancreatic and metastatic treatment. In addition, a patient’s response to neoadjuvant systemic chemotherapy, performance status, metastatic disease load and, to a lesser degree, histological differentiation grade and tumor marker CA19-9 serum levels, are powerful prognostic factors that help identify eligible subjects. Although the exact additive value of locoregional treatments for mPDAC patients cannot be distillated from the results, locoregional primary pancreatic and metastatic treatment seems beneficial for a highly selected group of oligometastatic PDAC patients. For definite recommendations, well-designed prospective randomized controlled trials with strict in- and exclusion criteria are needed to validate these results.

A population-based study of synchronous distant metastases and prognosis in patients with PDAC at initial diagnosis

“…An analysis of the SEER database suggests that CDC (cancer–directed surgery) is capable of prolonging survival of oligometastatic PDAC patients ( 50 ). In addition, locally-ablative treatments like microwave ablation (MWA) and radiofrequency ablation (RFA) are considered complementary to radical surgery ( 51 ). As for pancreatic cancer with lung metastases, a retrospective analysis of patients with pulmonary metachronous metastasis after PDAC collected from a database of two high-volume pancreatic cancer centers demonstrates that patients might benefit from surgical approaches of metachronous pulmonary metastasis ( 52 ).…”

Survival Benefit of Resection Surgery for Pancreatic Ductal Adenocarcinoma with Liver Metastases: A Propensity Score-Matched SEER Database Analysis

“…Other developments include locally-ablative treatments like microwave ablation (MWA) and radiofrequency ablation (RFA), which have been established for the treatment of liver metastasis in a variety of tumors. But these treatments remain to be sufficiently proven in a metastatic PDAC setting and are thus considered complementary to surgery and systemic therapy [ 65 ]. The caveat to an extended treatment approach is increased physical stress to the patient.…”

Worth it or not? Primary tumor resection for stage IV pancreatic cancer patients: A SEER‐based analysis of 15,836 cases

“…However, some researchers have recommended nonsurgical treatment options. [24][25][26] In our study, PTR improved the OS and CSS more than distant/regional site resection. In multivariate Cox analyses, combined distant/regional site resection could not contribute to OS/CSS increase on the basis of PTR.…”