The Number of Positive Tumor Markers (NPTM) Achieves Higher Value in the Prognosis Prediction of Gastric Cancer

Abstract

Purpose. The clinical application of combined tumor markers is still limited. We aim to explore the value of the combination of multiple tumor markers in gastric cancer (GC) prognosis. Methods. The prognostic significance was evaluated using Kaplan–Meier log-rank survival analysis and multivariable Cox regression analysis. The estimated area under the curve (AUC) was compared to evaluate the discriminatory ability of different indicators. A nomogram was constructed based on the results of multivariable cox regression, and its performance was evaluated by Harrell’s concordance index and calibration curve. Results. NPTM (number of positive tumor markers) displayed independent prognostic significance whether in the whole cohort or in patients with different stages. Patients with the all-negative tumor markers had a worse prognosis after postoperative chemotherapy in all cohort ( $P=0.023$ ) or in age ≤60 subgroup ( $P=0.012$ ), while patients with positive tumor markers had a better prognosis after postoperative chemotherapy in stage III ( $P=0.012$ ). The AUC value of NPTM is higher than any individual tumor marker. The 1-, 3-, and 5-year AUC values of the CTNM (combination of NPTM and pTNM) increased by 5%, 4.8%, and 3.6%, respectively, compared with TNM staging system. The nomogram constructed including NPTM showed its high accuracy ( $\text{C}-\text{index}=0.706$ ) versus TNM staging system ( $\text{C}-\text{index}=0.646$ ) and CTNM ( $\text{C}-\text{index}=0.681$ ). Conclusions. NPTM was an independent predictor of gastric cancer prognosis, showing more accurate prognostic performance than individual tumor markers. Especially its significance in guiding postoperative adjuvant chemotherapy regimens and predicting prognosis by combination with TNM staging system may have a better clinical application value.