ObjectiveTo systematically evaluate the expression and clinical features of phospho-p70 ribosomal protein S6 kinase (p-p70S6K) in lung cancer. MethodsWe systematically searched the published researches about p-p70S6K expression and clinical features of lung cancer in Medline, EMbase, Chinese BioMedical Literature, China National Knowledge Infrastructure and WeiPu databases from their establishment to February 4th, 2014. According to the inclusion and exclusion criteria, the data were extracted and the Cochrane Review Manager 5 and Stata 12.0 were used for data analysis. ResultsEight studies including 953 patients were included in this systematic review. Analysis with random effects model showed that the positive expression rate of p-p70S6K in non-small cell lung cancer (NSCLC) tissues spread from 41% to 70%. In small cell lung cancer tissues, the positive expression rate of p-p70S6K ranged from 17% to 91%. The positive expression rate of p-p70S6K in NSCLC was significantly higher than adjacent normal tissues[OR=5.08, 95%CI (2.96, 8.71), P<0.00001]. Divided by status of cell differentiation, the positive expression rate of p-p70S6K between low differentiation and moderate-high differentiation groups had no statistically significant difference[OR=1.40, 95%CI (0.50, 3.92), P=0.53]. In addition, the positive expression rate of p-p70S6K was not related to lymph node metastasis[OR=1.11, 95%CI (0.56, 2.23), P=0.76]. ConclusionCompared with adjacent normal tissues, positive expression rate of p-p70S6K in NSCLC is significantly higher, indicating that p-p70S6K may be associated with the development of lung cancer. The positive expression rate of p-p70S6K in different kinds of lung cancer is still unclear, which needs further studies to explore.