AIM: To determine the relationship between CD11 c expression level and prognosis in patients with gastric cancer(GC).METHODS: This retrospective survival study was performed from July 31,2008 to June 30,2014. Our study inclusion criteria included all the patients with GC who underwent surgical resection between January 1998 and December 2009 in the Third Affiliated Hospital of Soochow University. CD11 c expression levels in 140 patients with GC at different UICC stages were evaluated using immunohistochemistry,and GC tissues from 16 cases were further verified by q RTPCR. The χ2 test was used to compare the patientand disease-related factors between the low CD11 c expression group and the high expression group. Univariate probabilities of overall survival(OS) and disease-free survival(DFS) were assessed using the Kaplan-Meier method. The log rank test was used to compare survival curves. Different multivariate COX models were used to estimate the association between CD11 c expression and both death and recurrence riskin GC patients.RESULTS: The average CD11 c expression level was 5.1 ± 1.8/high power field(HPF) in 10 gastritis samples,4.5 ± 2.3/HPF in 10 gastric polyp samples and 9.7 ± 6.3/HPF in 140 gastric cancer samples,respectively. The CD11 c expression level was significantly decreased from UICC stage Ⅰ to stage Ⅳ(stage Ⅰ: 16.0 ± 7.4,stage Ⅱ: 10.4 ± 5.5,stage Ⅲ: 9.4 ± 6.1,stage Ⅳ: 5.3 ± 3.2,P < 0.001). Patients in the high CD11 c expression group had a greater 3- and 5-year OS probability and longer median survival time compared with the low CD11 c expression group,(67.7% vs 39.2%; 51.4% vs 29.0%; 67.0 mo vs 28.0 mo; χ2 = 6.80,P = 0.009),and had a greater 3- and 5-year DFS probability and longer median DFS time(63.7% vs 24.0%; 49.1% vs 11.9%; 64.0 mo vs 18.0 mo; χ2 = 15.39,P < 0.001). Patients with high CD11 c high expression had a reduced risk of death(HR = 0.56,95%CI: 0.33-0.98,P < 0.05) and relapse(HR = 0.39,95%CI: 0.23-0.67,P < 0.01) compared with patients with low CD11 c expression after adjustment of potential confounders,with the exception of tumor size. However,the protective effect related to death(HR = 0.90,95%CI: 0.49-1.67,P = 0.749) and relapse(HR = 0.65,95%CI: 0.36-1.19,P = 0.160) disappeared when tumor size was incorporated into the model.CONCLUSION: High expression of CD11 c decreased the risk of death and relapse,and may be regarded as an alternative indicator of favorable prognosis in patients with GC. AIM: To determine the relationship between CD11c expression level and prognosis in patients with gastric cancer (GC). METHODS: This retrospective survival study was performed from July 31, 2008 to June 30, 2014. Our study inclusions included all the patients with GC who underwent surgical resection between January 1998 and December 2009 in the Third Affiliated Hospital of Soochow University. CD11 c expression levels in 140 patients with GC at different UICC stages were evaluated using immunohistochemistry, and GC tissues from 16 cases were further verified by q RTPCR The χ2 test was used to compare the patient and disease-related factors between the low CD11 c expression group and the high expression group. Univariate probabilities of overall survival (OS) and disease-free survival (DFS) were assessed using the Kaplan-Meier method. The log rank test was used to compare survival curves. Different multivariate COX models were used to estimate the association between CD11 c expression and both death and recurrence risk in GC patients .RESULTS: The average CD11 c expression level was 5.1 ± 1.8 / high power field (HPF) in 10 gastritis samples, 4.5 ± 2.3 / HPF in 10 gastric polyp samples and 9.7 ± 6.3 / HPF in The CD11 c expression level was significantly decreased from UICC stage I to stage IV (stage I: 16.0 ± 7.4, stage II: 10.4 ± 5.5, stage III: 9.4 ± 6.1, stage IV: 5.3 ± 3.2 , P <0.001). Patients in the high CD11 c expression group had a greater 3- and 5-year OS probability and longer median survival time compared with the low CD11 c expression group, (67.7% vs 39.2%; 51.4% vs 29.0 %; 67.0 mo vs 28.0 mo; χ2 = 6.80, P = 0.009), and had a greater 3- and 5-year DFS probability and longer median DFS time (63.7% vs 24.0%; 49.1% vs 11.9%; 64.0 mo vs Patients with high CD11 c high expression had a reduced risk of death (HR = 0.56, 95% CI: 0.33-0.98, P <0.05) and relapse (HR = 0.39, 95 % CI: 0.23-0.67, P <0.01) compared with patientswith low CD11c expression after adjustment of potential confounders, with the exception of tumor size. However, the protective effect related to death (HR = 0.90,95% CI: 0.49-1.67, P = 0.749) 95% CI: 0.36-1.19, P = 0.160) disappeared when tumor size was incorporated into the model. CONCLUSION: High expression of CD11 c decreased the risk of death and relapse, and may be viewed as an alternative indicator of favorable prognosis in patients with GC.