Objective: To analyze relationships between the tumor deposits (TD) and clinicopathologic features of gastric cancer and investigate the value of TD in staging and prognosis in gastric cancer patients.
Methods: Retrospective cohort study was conducted to evaluate the clinicopathologic data of 388 gastric cancer patients who underwent surgical procedures in Chinese PLA General Hospital between November 2011 and December 2012. Relationships between TD and clinicopathologic features were analyzed by χ2 or Fisher exact tests. Survival curves were also generated by Kaplan-Meier method. The univariate and multivariate analysis were performed with Log-rank and COX proportional hazard model to examine the association between prognosis and TD.
Results: TD were observed in 67 (17.3%) of 388 gastric cancer patients, including 48 male patients (48/289, 16.6%) and 19 female patients (19/99, 19.2%). There were 40 patients (40/198, 20.2%) whose age was above 64 years old. TNM staging of positive TD patients was as follows: for pathology, there were 5 patients (5/64, 7.8%) in stage II(b, 6 patients (6/58, 10.3%) in stage III(a, 14 patients (14/75, 18.7%) in stage III(b, 30 patients (30/135, 22.2%) in stage III(c, 12 patients (12/39, 30.8%) in stage IIII( and no one in stage I(b or II(a; for T-staging, there were 2 patients (2/18, 11.1%) in stage T2, 2 patients (2/27, 7.4%) in stage T3, 36 patients (36/259, 13.9%) in stage T4a and 27 patients (27/84, 32.1%) in stage T4b; for N-stage, there were 5 patients (5/72, 6.9%) in stage N0, 6 patients (6/72, 8.3%) in stage N1, 19 patients (19/82, 23.2%) in stage N2, 27 patients (27/100, 27.0%) in stage N3a and 10 patients(10/62, 16.1%) in stage N3b; for M-stage, there were 12 patients (12/40, 30.0%) in distal metastases; for vascular invasion, there were 29 patients (29/129, 22.5%). Among positive TD patients, the number of TD >3 was found in 38 of 67 cases(56.7%). TD was associated with pTNM-stage (χ2=16.898, P=0.010), T-stage (χ2=17.382, P=0.001), N-stage (χ2=18.080, P=0.001), M-stage (χ2=5.060, P=0.036) and vascular invasion(χ2=3.675, P=0.039). The median survival time of positive TD patients was significantly shorter as compared to negative TD patients (22 months vs. 32 months, χ2=23.391, P=0.012). Among positive TD patients, the median survival time of patients with TD number >3 was significantly shorter as compared to those with TD number <3 (17 months vs. 25 months, χ2=5.157, P=0.023). Multivariate survival analysis showed that TD number >3 was the independent risk factor of prognosis (RR=2.350, 95%CI:1.345 to 4.106, P=0.003).
Conclusions: TD state is closely associated with the staging of gastric cancer and TD number >3 indicates a poor prognosis.