Controlling Nutritional Status (CONUT) as a prognostic immunonutritional biomarker for gastric cancer after curative gastrectomy: a propensity score-matched analysis

Background In clinical practice, it is not unusual to treat oncologic patients whose tumor markers are within normal range, even with advanced cancer. The Controlling Nutritional Status (CONUT) score could provide a useful nutritional and immunological prognostic biomarker for cancer patients. In this study, we assessed the prognostic value of the CONUT score for patients with gastric cancer, including a subgroup analysis with stratification based on serum carcinoembryonic antigen (CEA) level. Methods We retrospectively reviewed the medical records of 368 consecutive patients who underwent curative laparoscopy-assisted gastrectomy. The prognostic value of the CONUT score was compared between patients with a low (<= 2) and high (>= 3) score, with propensity score matching (PSM) used to control for biasing covariates (Depth of tumor, Lymph node metastasis, pathological TNM (pTNM) stage). Results Overall survival (OS) among all patients was independently predicted by the tumor stage (hazard ratio (HR): 2.231, p = 0.001), the CONUT score (HR: 2.254, p = 0.001), and serum CEA level (HR: 1.821, p = 0.025). Among patients with a normal preoperative serum CEA level, tumor stage (HR: 2.350, p = 0.007), and the CONUT score (HR: 1.990, p = 0.028) were independent prognostic factors of OS. In the high serum CEA level group, tumor size (HR: 2.930, p = 0.015) and the CONUT score (HR: 3.707, p = 0.004) were independent prognostic factors of OS. Conclusions It is advantageous to use both CEA level and the CONUT score to assess the prognosis of patients with gastric cancer, which reflect both tumor-related factors and host-related factors, respectively.