The results of multivariate analysis using the Cox proportional hazards regression model with stepwise selection also demonstrated that the independent prognostic factors for decreased RFS in patients with node-negative disease were a tumor located in the upper chest (P = 0.007, odds ratio [OR] = 4.767), CEA ≥5 μg/ml (P = 0.007, OR = 5.466) and the presence of VI (P = 0.037, OR = 3.534). This evidence concerns the gene CEACAM5 and neoplasm.