Concurrent radiotherapy with oral fluoropyrimidine versus gemcitabine in locally advanced pancreatic cancer: a systematic review and meta-analysis

BACKGROUND Gemcitabine (GEM) is the most widely utilized systemic agent in combination with radiation therapy (RT) for treating locally advanced pancreatic cancer (LAPC) in the concurrent setting. Despite recent interest in using two novel oral fluoropyrimidines (FUs), capecitabine and S-1, in this setting, there is a lack of randomized controlled trials (RCTs) to support this approach. METHODS Trials published between 1994 and 2014 were identified by an electronic search of public databases (Medline, Embase, and the Cochrane Library). All prospective studies were independently identified by two authors for inclusion. Demographic data, treatment response, objective response rate (ORR), progression-free and overall survival (PFS and OS, respectively), and toxicities were extracted and analyzed using comprehensive meta-analysis software (version 2.0). RESULTS Twenty-three cohorts with 843 patients were included: 497 patients were treated with GEM and 346 patients were treated with oral FU. Pooled OS was significantly higher at 1 and 2 years for S-1 plus RT than for GEM plus RT (relative risk [RR] 1.27; 95% confidence interval [CI], 1.00-1.65; P=0.03; and RR 1.75; 95% CI, 1.18-2.60, P=0.002, respectively), while 1-year PFS and ORR were not significantly different between S-1 and GEM-based chemoradiotherapy (P=0.37 and P=0.06, respectively). Additionally, comparable efficacy was found between capecitabine and GEM-based chemoradiotherapy in terms of OS, PFS, and ORR. As for grade 3 and 4 acute toxicity, oral FU plus RT significantly reduced the risk of developing hematologic toxicities, nausea, and vomiting when compared to GEM plus RT (P<0.001). CONCLUSIONS Oral FU plus RT may be a safe and feasible regimen for patients with LAPC, with similar efficacy and low rate of toxicities compared with GEM plus RT. Our findings support the need to compare S-1 with GEM in the concurrent setting in large prospective RCTs due to its potential survival benefits.