Abstract
OBJECTIVE: Elevated plasma D-dimer has been reported to be associated with advanced tumor stage and poor survival in several types of malignancies. The purpose of this study was to assess the potential impact of preoperative plasma D-dimer level (PDL) on overall survival (OS) of gastric cancer (GC) patients undergoing curative surgery by applying propensity score analysis. METHODS: A total of 1,025 curatively resected GC patients in Tianjin Medical University Cancer Institute & Hospital were enrolled. Patients were categorized into two groups based on preoperative PDL: the elevated group (EG) and the normal group (NG). To overcome bias due to the different distribution of covariates for the two groups, a one-to-one match was applied using propensity score analysis, after matching, prognostic factors were analyzed. RESULTS: In analysis for the whole study series, patients in the EG were more likely to have a larger proportion of tumor size ≥5 cm (67.5% vs. 55.8%, P=0.006), elder mean age (64.0±10.8 years vs. 60.5±11.6 years, P<0.001) and advanced tumor (T), node (N), and TNM stage. Patients with elevated PDL demonstrated a significantly lower 5-year OS than those with normal PDL (27.0%vs. 42.6%, P<0.001), however, the PDL was not an independent prognostic factor for OS in multivariate analysis [hazard ratio: 1.13, 95% confidence interval (95% CI): 0.92-1.39, P=0.236]. After matching, 163 patients in the EG and 163 patients in the NG had the same characteristics. The 5-year OS rate for patients in the EG was 27.0% compared with 25.8% for those in the NG (P=0.809, log-rank). CONCLUSIONS: The poor prognosis of GC patients with elevated preoperative PDL was due to the advanced tumor stage and elder age rather than the elevated D-dimer itself.