The Impact of Different Metastatic Patterns on Survival in Patients with Pancreatic Cancer.

Background: The aims of this study were to compare the metastatic patterns of pancreatic ductal adenocarcinoma (PDAC) of head and body/tail and to determine the prognostic factors. Methods: Data of metastatic PDAC (MPC) between 2004 and 2015 from the Surveillance, Epidemiology and End Results (SEER) database was extracted and analyzed. The correlation analyses of metastatic patterns were also conducted. Multivariate Cox regression analyses were used to analyze prognosis. Results: A total of 27470 eligible MPC patients were collected from SEER database. Patients in the head group had a higher proportion of single-metastasis while those in the body/tail group had a higher proportion of two-site metastases. Similar distributions of metastatic sites were observed in cases with single-metastasis between two groups. Patients with liver and peritoneum metastases in the head group had significantly higher overall survival (OS) rates than those in the body/tail group. Also, the OS rates stratified by varied tumor sites did not differ significantly in patients with bone, brain, and lung metastases. Chemotherapy could prolong survival in almost all MPC patients while radiotherapy or surgery could only benefit certain types of metastases. Tumor site, therapy and vascular invasion were independent prognostic factors of OS in MPC patients. Conclusions: MPC of the head and body/tail presented with different metastatic patterns. Chemotherapy benefited patients with metastases while surgery and radiotherapy could only prolong survival in patients with liver and peritoneum metastases. Our findings may provide more details for the precise management of patients with MPC in clinical practice. (C) 2021 IAP and EPC. Published by Elsevier B.V. All rights reserved.