2.4. Statistical analysis

The data were analyzed with SPSS software 18.0 (SPSS Inc.). Values of P < .05 were deemed statistically significant. The paired‐sample t test was used to assess differences between two experimental groups. The relationships between clinicopathological characteristics (age, primary location, differentiation type, clinical stage, smoking history, etc) and RP11‐169D4.1‐001 were analyzed by the chi‐square test or Fisher's exact test, and the data in the study are expressed as the means ± standard deviations to determine high and low expression levels based on the mean of the HSCC tissue expression. The Kaplan‐Meier method was used to create survival curves for patients with high or low RP11‐169D4.1‐001 expression and used multivariate regression analysis to define the determinating factors for prognosis. Diagnostic value was determined by an evaluation of receiver operating characteristic (ROC) curves.