Statistical analysis
Patient sex, age-related risk, tumor stage, Shimada status, recurrence, death, and clinical follow-up data were distributed in relative frequencies. Correlation analyses among the clinical data, COX-2 protein expression, and CNAs were performed using the nonparametric Spearman multivariate test with IBM SPSS Statistics (IBM Corp., Version 23.0, Armonk, NY). For this analysis, CNAs were categorized as no alteration (0), loss or deletion (-1), and gain or amplification (+1). Correlations with p-values ​​<0.05 were considered significant. Pre/Post-paired comparisons were performed with the Wilcoxon signed-rank test (p < 0.05).