Effect of neoadjuvant chemotherapy in patients with gastric cancer: a PRISMA-compliant systematic review and meta-analysis

BACKGROUND: Neoadjuvant chemotherapy (NAC) is extensively used in the treatment of patients with gastric cancer (GC), particularly in high risk, advanced gastric cancer. Previous trials testing the efficacy of NAC have reported inconsistent results. METHODS: This study compares the combined use of NAC and surgery with surgery alone for GC by using a meta-analytic approach. We performed an electronic search of PubMed, EmBase, and the Cochrane Library to identify randomized controlled trials (RCTs) on NAC published before Oct 2015. The primary outcome of the studies was data on survival rates for patients with GC. The summary results were pooled using the random-effects model. We included 12 prospective RCTs reporting data on 1538 GC patients. RESULTS: Patients who received NAC were associated with significant improvement of OS (P = 0.001) and PFS (P < 0.001). Furthermore, NAC therapy significantly increased the incidence of 1-year survival rate (SR) (P = 0.020), 3-year SR (P = 0.011), and 4-year SR (P = 0.001). Similarly, NAC therapy was associated with a lower incidence of 1-year (P < 0.001), 2-year (P < 0.001), 3-year (P < 0.001), 4-year (P = 0.001), and 5-year recurrence rate (P = 0.002). Conversely, patients who received NAC also experienced a significantly increased risk of lymphocytopenia (P = 0.003), and hemoglobinopathy (P = 0.021). CONCLUSIONS: The findings of this study suggested that NAC is associated with significant improvement in the outcomes of survival and disease progression for GC patients while also increasing some toxicity.