Combined use of tumor markers in gastric cancer: A novel method with promising prognostic accuracy and practicality

Background: The effect of a single tumor marker on the prognosis of gastric cancer patients is not ideal. This study explored a novel prognostic assessment method for gastric cancer (GC) patients using a combination of three important tumor markers (CEA, CA72-4 and CA19-9). Method The data of 1966 GC patients who underwent curative gastrectomy at Sun Yat-Sen University Cancer Center (Guangzhou, China) were included. Hazard ratios (HR) for all factors for overall survival (OS) were analyzed by Cox regression. Nomogram and calibration curve was used to establish the survival prediction model. The prediction accuracy was evaluated with the concordance index (C-index). Results All patients were divided into four groups (C0-C3) according to the number of elevated tumor markers. The 5-year OS rates of the patients in preoperative groups C0-C3 were 83.8% (81.3%-86.4%), 72.8% (68.5%-77.4%), 58.9% (50.4%-68.9%), and 18.5% (4.0%-33.0%), respectively, and those in postoperative groups C0-C3 were 82.1% (79.4%-84.8%),76.1% (72.2%-80.3%) ,57.6% (48.4%-68.5%), and 16.8% (5.1%-28.5%), respectively, with significant differences between each C0-C3 subgroup both in pre- and post-cohort. Multivariate analysis showed that preoperative (HR: 6.001, 95%CI: 3.523–10.221) and postoperative (HR: 8.149, 95%CI: 4.962–13.528) elevated tumor markers were independent risk factors for GC patients. The C-index for the combined use of tumor markers was 0.65–0.66, which was higher than that for using a single tumor marker (0.53–0.56). Conclusion The combined use of tumor markers significantly improved the prognostic value compared to using a single tumor marker. The survival prediction model including the combined tumor markers was accurate and effective.