Although the very high locoregional recurrence rates reported with limited D0/D1 surgery can be reduced with extended D2 gastrectomy for operable gastric cancer, overall relapse and survival rates remain poor and can only be improved with adequate perioperative adjuvant treatment. However, despite intensive research, no regimen has been established as standard. Meta-analyses have demonstrated a marginal survival benefit with adjuvant chemotherapy. Two recent large randomized trials for operable gastric cancer, the MAGIC trial and the INT-0116 trial, provide evidence that some patients may benefit from perioperative chemotherapy and chemoradiation, respectively. However, while both trials suggest an overall survival benefit with adjuvant treatment, they don’t provide the harm–benefit ratio for specific subsets of patients wih different extent of surgery (D1 or D2) and tumor stage (early [T1,2]/advanced [T3,4]). This lack of evidence complicates current therapeutic adjuvant decisions. Estimating the risk of local and distant recurrence (high, moderate or low) after D1 or D2 surgery in various tumor stages and the expected harm–benefit ratio, the authors provide useful information for decisions on adjuvant chemotherapy with or withour radiotherapy in individual patients. Research on newer cytotoxic and targeted agents may improve treatment efficacy. Simultaneously, advances with microarray-based gene-expression profiling signatures may improve individualized treatment decisions. However, the validation and translation of these genomic classifiers as biomarkers into a completed ‘bench-to-bedside’ cycle for tailoring treatment to individuals is a major challenge and limits inflated expectations.