Does neoadjuvant treatment in resectable pancreatic cancer improve overall survival? A systematic review and meta-analysis of randomized controlled trials

Background: Neoadjuvant chemotherapy may improve overall survival (OS) in 'borderline' resectable pancreatic cancer (RPC). Whether the results are the same in upfront RPC is unknown. Materials and methods: To evaluate the association of neoadjuvant treatment and survival outcomes in RPC, a systematic literature review was carried out including prospective randomized trials of neoadjuvant treatment versus upfront surgery. Articles indexed in PubMed, Embase and Scopus were evaluated. Data regarding systemic treatment regimens, R0 resection rates, disease-free survival (DFS) and OS were extracted. The outcomes were compared using a random-effects model. The index I2 and the graphs of funnel plot were used for the interpretation of the data.Results: Of 3229 abstracts, 6 randomized controlled trials were considered eligible with a combined sample size of 805 RPC patients. Among the trials, PACT-15, PREP-02/JSAP-05 and updated long-term results from PREOPANC and NEONAX trials were included. Combining the studies with meta-analysis, we could see that neoadjuvant treatment in RPC does not improve DFS [hazard ratio (HR) 0.71 (0.46-1.09)] or OS [HR 0.76 (0.52-1.11)], without significant heterogeneity. Interestingly, R0 rates improved similar to 20% with the neoadjuvant approach [HR 1.2 (1.04-1.37)]. It is importantd to note that most studies evaluated gemcitabine-based regimens in the neoadjuvant setting.Conclusions: Neoadjuvant chemotherapy or chemoradiation does not improve DFS or OS in RPC compared to upfront surgery followed by adjuvant treatment. Neoadjuvant treatment improves R0 rates by similar to 20%. Randomized ongoing trials are eagerly awaited with more active combined regimens including modified FOLFIRINOX.