Neoadjuvant therapy decreases rates of local recurrence but not of distant metastasis in pancreatic cancer – a systematic review and meta-analysis

Abstract

Background: Neoadjuvant therapy/NTx is currently solely indicated for downstaging borderline or unresectable pancreatic cancer/PCa. In this context, several studies reported that NTx is able to increase resectability rates exceeding 60%. Nevertheless, the true impact of NTx on patterns of recurrence in PCa has not been sufficiently investigated, yet. Therefore, a systematic review with meta-analysis was conducted. Methods: For this purpose, systematic review with meta-analysis were performed according the PRISMA-guidelines. After screening databases of Pubmed, Embase, Ovid, Scopus and Google Scholar for predefined terms, comparative data between NTx and upfront surgery were pooled in meta-analyses. Results: A total of 4,257 studies could be identified. After exclusion, 11 studies could be included in our meta-analysis. Importantly, NTx reduced the risk for overall recurrence (RR 0.82; 95%-CI:0.74-0.90,p<0.0001) and for local recurrence (RR 0.42; 95%-CI:0.32-0.55,p<0.00001). In contrast, no effect of NTx could be observed on the risk for developing distant metastasis (RR 1.02 ;95%-CI:0.91-1.43,p=0.78), hepatic metastasis (RR 0.86; 95%-CI:0.68-1.10,p=0.23), pulmonary metastasis (RR 0.99; 95%-CI:0.37-2.66,p=0.98) and peritoneal metastasis (RR 0.88; 95%-CI:0.57-1.38,p=0.58). Conclusion: This is the first systematic review with meta-analysis showing the favourable effect of NTx on local recurrence in PCa. To underline these findings, prospective, randomised controlled trials are urgently needed.