Oligometastatic pulmonary metastasis in pancreatic cancer patients: Safety and outcome of resection

Abstract

Objective: To assess the perioperative and long-term outcome following pulmonary resection in patients with metachronous metastasis of pancreatic ductal adenocarcinoma (PDAC).

Background: Most patients with PDAC relapse or develop tumor spread to secondary organs. Currently, it remains unclear how to proceed with pulmonary metastasis in the metachronous setting. In particular, the role of surgery remains controversial.

Methods: Data of patients with pulmonary metachronous metastasis after PDAC collected from 2003 to 2015 in databases of two high-volume pancreatic cancer centers were retrospectively analyzed. Clinical and pathological aspects of primary PDAC as well as the perioperative and long-term outcome following pulmonary metastasectomy (PM) was evaluated, respectively. Patients with synchronous liver metastasis or metastasis to other secondary organs were excluded. Univariate survival analysis was performed.

Results: We identified 15 patients undergoing pulmonary resection for suspected metastasis after primary pancreatic resection. Operative and histopathologic evaluation revealed resectable pancreatic pulmonary metastasis in 11 patients (73.3%). The median disease-free survival (DFS) and overall survival (OS) after PM diagnosis was 18 months and 26 months, respectively. The median time to metachronous metastasis (TMM) was 17 months [3-64 months]. Perioperative morbidity was low with only one readmission (8.3%). There was no perioperative mortality. Patients who developed pulmonary metastasis later than 17 months after primary surgery showed better OS compared to those who did earlier (32.2 vs. 14.75 months, p = 0.025). In addition, patients with high-grade tumors had worse survival (12.4 vs. 31 months, p = 0.02). Elevated serum CEA levels or CA 19-9 levels were also not associated with shortened OS.

Conclusions: This study suggests that pulmonary metastasectomy after PDAC is safe and effective. Patients with extended DFS after primary pancreatic surgery as well as favorable tumor grading seem to particularly benefit from pulmonary surgery.

Keywords: Lung metastasis; Pancreatic ductal adenocarcinoma; Pulmonary metastasis; Recurrence; Survival.