SLC6A3 and metastasis: Univariate Cox regression analysis indicated that an increased SLC6A3 immunostaining was correlated with poor progression-free survival (all p = 0.012; hazard ratio 6.7, 95 % confidence interval 3.4-18322.9); however, the predictive value was lost in a multivariate model which included pT-stage, lymph node/distant metastasis and grading (p = 0.365).