Meta-analyses of factors associated with long-term survival after resection of pancreatic ductal adenocarcinoma.

Abstract

4165 Background: Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies. Long-term survival (>5 years, LTS) is rarely seen even after ‘curative-intent’ resection. With improved systemic control via effective systemic therapies, LTS is now being reported more frequently. However, our understanding of LTS in PDAC remains limited. The aim of the current study was to perform a systematic review and meta-analysis to quantify the associations between various clinicopathological factors and LTS following resection of PDAC. Methods: The PubMed, Embase, Scopus, and Cochrane CENTRAL databases were systematically searched for articles reporting actual patient survival data. Two reviewers independently screened and reviewed articles, extracted relevant data, and assessed the risk of bias in included studies using the Newcastle-Ottawa scale (NOS). Data that compared patients who achieved LTS after resection with those who did not were extracted from the included studies. Meta-analyses using a random effects model were conducted to identify associations between LTS and various patient, tumor, and treatment related factors. Results: Overall, 33 studies with 46,981 patients after resection of PDAC were included. Most articles received a ‘good’ NOS assessment, indicating acceptable risk of bias. The median rate of LTS was 15.27% (IQR: 9.47-20.72). Multiple clinicopathological factors were found to be associated with LTS, including tumor grade (OR: 0.40, 95%CI: 0.31-0.52), tumor stage (OR: 0.36, 95%CI: 0.31-0.41), and margin status (OR: 0.43, 95%CI: 0.36-0.50). Factors that were not associated with LTS included patient age, tumor size, tumor location, or genetic mutations. Notably, adjuvant therapy (OR: 1.68, 95%CI: 1.24-2.28) but not neoadjuvant therapy (OR: 1.08, 95%CI: 0.62-1.87) were associated with LTS. Conclusions: This meta-analysis revealed that 15% of patients achieved LTS after resection of PDAC. Multiple clinicopathological factors are associated with LTS whereas presence of ‘traditional’ negative prognostic factors does not rule out LTS. Further studies are required to identify robust predictors of LTS in resected PDAC. [Table: see text]