Surgical resection offers the only chance of cure for non-metastatic pancreatic cancer Only 15 to 20% of patients have potentially resectable disease at diagnosis 30 to 40% have locally advanced unresectable tumours•Optimal management of this group of patient remains controversial We aim to determine the benefit of adding radiotherapy (RT) to chemotherapy in locally advanced unresectable pancreatic cancer

We searched MEDLINE for comparative studies comparing chemoradiotherapy with chemotherapy for patients with unresectable pancreatic cancer Methodological quality of the included studies was assessed using the MERGE criteria Meta-analysis was performed with random effects model using Revman 5.3 to estimate the pooled hazard ratios (HR), confidence intervals (CI), P values (P) and I squared statistic (I2) Primary outcome was overall survival (OS) Secondary outcomes include progression-free survival (PFS) and adverse events (AE) We used the GRADE approach to appraise the quality of evidence from randomized...

We found five randomised and three retrospective comparative studies including 830 patients Only two randomized trials were judged to have low to moderate risk of bias (B1) Other included studies had moderate to high risk of bias in their methodology (B2) Randomised trials showed addition of RT did not improve OS (HR 0.87, 95% CI 0.63 to 1.21, P = 0.41, I2 = 67%) with very low quality evidence No improvement in PFS (HR 0.90, 95% CI 0.74 to 1.10, P= 0.30, I2 = 11%)...

Most of the published studies have methodological limitations No clear evidence of an effect on OS and PFS for adding RT to chemotherapy for patients with unresectable pancreatic cancer Future research with high quality randomized trials is warranted to determine the role of RT for this group of patients Biomarkers should be concurrently studied for the best patient selection

1. Hammel P, Huguet F, van Laethem J, Goldstein D, Glimelius B, Artru P et al. Effect of Chemoradiotherapy vs Chemotherapy on Survival in Patients With Locally Advanced Pancreatic Cancer Controlled After 4 Months of Gemcitabine With or Without Erlotinib. JAMA. 2016;315(17):1844. 2. Loehrer P, Feng Y, Cardenes H, Wagner L, Brell J, Cella D et al. Gemcitabine Alone Versus Gemcitabine Plus Radiotherapy in Patients With Locally Advanced Pancreatic Cancer: An Eastern Cooperative Oncology Group Trial. Journal of Clinical Oncology. 2011;29(31):4105-4112. 3. Chauffert B, Mornex...