Neoadjuvant chemotherapy with or without radiotherapy versus upfront surgery for resectable pancreatic adenocarcinoma: a meta-analysis of randomized clinical trials

BACKGROUND: The role of neoadjuvant chemotherapy (NC) in resectable pancreatic cancer (RPC) has yet to be defined. This review aims to analyze the benefit of NC in RPC compared with upfront surgery (US) in terms of overall survival (OS) and disease-free survival (DFS). PATIENTS AND METHODS: PubMed, CENTRAL (The Cochrane Library), and Embase were systematically reviewed until 3 November 2021. Abstract proceedings and virtual meeting presentations from the American Society of Clinical Oncology and the European Society of Medical Oncology conferences, reference articles of published clinical trials, and review articles were considered. Only randomized clinical trials (RCTs) comparing NC administration with or without radiotherapy previous with surgery (experimental arm) versus US followed by adjuvant chemotherapy with or without radiotherapy (control arm) for RPC were included. RESULTS: A total of 1135 studies were screened. Of these, 1117 studies were primarily excluded. Of the remaining 18 studies, 5 were excluded because of no adequate trial design for this work and 7 others had no available results. Finally, 6 trials with 469 patients with pancreatic cancer randomized to NC (n = 212) or US (n = 257) were selected. Compared with US, NC significantly improved OS [hazard ratio (HR) 0.75; 95% confidence interval (CI) 0.58-0.98; P = 0.033] and DFS (HR 0.73; 95% CI 0.59-0.89; P = 0.002). While the NC approach was not significantly associated with lower resection rate [relative risk (RR) 0.92; 95% CI 0.84-1.01; P = 0.069], the R0 resection rate was significantly higher for NC than for US (RR 1.31; 95% CI 1.13-1.52; P = 0.0004). CONCLUSION: This is the first meta-analysis of RCTs showing that NC improves OS for RPC compared with US followed by adjuvant therapy. Ongoing RCTs should confirm these findings with FOLFIRINOX to generalize the indication of NC.