Association between primary origin (head, body and tail) of metastasised pancreatic ductal adenocarcinoma and oncologic outcome: A population-based analysis

Abstract

Introduction: The relation between the primary origin of metastasised pancreatic ductal adenocarcinoma (PDAC)-head, body or tail-metastatic patterns and outcomes has not yet been investigated in large population-based studies.

Methods: Patients with metastasised PDAC at diagnosis from the Netherlands Cancer Registry were included (2005-2015). We compared number of metastatic organ sites (1, 2, ≥3) and specific metastatic organ sites (peritoneum, liver, lung and extra-regional lymph nodes) for the different primary tumour locations. Cox regression analyses were used to determine the association of tumour location and metastatic organ site(s) with overall survival.

Results: Overall, we included 9952 patients with metastasised PDAC. The primary origin was head in 5644 (57%), body in 1671 (17%) and tail in 2637 (26%) patients. Differences between primary origins were the number of metastatic organ sites (proportions ≥3 sites for head: 4%, for body: 8% and for tail: 13%, p < 0.0001) and peritoneal metastases (present in 13% for head, 24% for body and 30% for tail; p < 0.0001). Median overall survival was 2.6 months for head PDAC (reference), 2.4 months for body PDAC (HR 1.02 [0.97-1.08]) and 1.9 months for tail PDAC (HR 1.20 [1.15-1.26]). Of patients with one metastatic organ site, the worst survival compared with other sites was seen with liver only metastases (2.5 months vs. 2.7-5.1 months), and the best survival for patients, with extra-regional lymph node only metastases (5.1 months).

Conclusion: Metastatic patterns differ among the primary origins for PDAC with metastasised tail tumours having more metastatic sites, more often peritoneal metastases and worse survival.

Keywords: Body; Chemotherapy; Head; Metastases; Pancreatic ductal adenocarcinoma; Survival; Tail.