A risk signature with inflammatory and immune cells infiltration predicts survival and efficiency of chemotherapy in gastric cancer

OBJECTIVE Tumor immune microenvironment biomarkers might add predictive value for outcomes. This study aimed to construct a risk signature with tumor infiltration immune and inflammatory cells to improve the prediction of survival. METHODS A risk signature model in combination with CD66b + neutrophils, CD3+ T, CD8+ T lymphocytes, and FOXP3 + regulatory T cells was developed in a training cohort of 327 GC patients undergoing surgical resection between 2011 and 2012, and validated in a validation cohort of 285 patients from 2012 to 2013. RESULTS The high CD66b expression predicted the poor disease special survival (DSS) and inversely correlated with the CD8 (P < 0.05) and FOXP3 expression (P < 0.05) in the training cohort. This was comparable to the disease-free survival (DFS) findings observed in the validation cohort. Furthermore, a risk stratification was developed from the integration of CD66b + neutrophils and T immune cells. For DFS and DSS, both demonstrated the worse prognosis in the high-risk group, when compared to the low-risk group in both the training cohort and validation cohort (all P < 0.05). In addition, the high-risk group was associated with post-operative relapses, and this risk signature model increased the predictive accuracy and efficiency for post-operative relapses. Moreover, the high-risk group identified a subgroup of GC patients who tended not to benefit from the adjuvant chemotherapy. CONCLUSIONS The incorporation of neutrophils into T lymphocytes could provide more accurate prognostic information in GC and this risk stratification has potential for identifying the subgroup of GC patients who could benefit from adjuvant chemotherapy.