Prognostic significance of the controlling nutritional status (CONUT) score in patients undergoing gastrectomy for gastric cancer: a systematic review and meta-analysis

BACKGROUND: In recent years, the clinical evidence of the controlling nutritional status (CONUT) score has increased in patients with gastrointestinal cancers. The purpose of this systematic review and meta-analysis was to investigate the association between the preoperative CONUT score and outcomes in patients undergoing gastrectomy for gastric cancer (GC). METHODS: A systematic literature search for studies reporting the prognostic impact of the CONUT score in patients with GC was conducted. Meta-analyses of survival, postoperative outcomes, and postoperative clinico-pathological parameters were conducted. RESULTS: Five studies with 2482 patients were found to be eligible and subsequently reviewed and analyzed. The CONUT score was significantly associated with overall survival (HR 1.85, 95%CI 1.38–2.48, P < 0.001), cancer-specific survival (HR 2.56, 95%CI 1.24–5.28, P = 0.01) and recurrence/relapse-free survival (HR 1.43, 95%CI 1.12–1.82, P = 0.004). Moreover, the CONUT score was associated with the incidence of postoperative complications (OR 1.39, P = 0.003) and mortality (OR 6.97, P = 0.04), and clinico-pathological parameters (T factor [OR 1.75, P < 0.001], N factor [OR 1.51, P < 0.001], TNM stage [OR 1.73, P < 0.001], and microvascular invasion [OR 1.50, P = 0.006]), but not with tumor differentiation (OR 0.85, P = 0.13). CONCLUSIONS: The preoperative CONUT score is an independent prognostic indicator of survival and postoperative complications, and is associated with clinico-pathological parameters in patients with GC. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s12893-019-0593-6) contains supplementary material, which is available to authorized users.