CD24 expression in urothelial carcinoma of the upper urinary tract correlates with tumour progression

Expression of the mucin-like adhesion molecule CD24 has been implicated in the progression of several types of cancer and has been identified as new prognostic factor. We evaluated CD24 expression in 268 consecutive cases of upper urinary tract urothelial carcinoma with respect to associations with tumour stage, grade, angioinvasion and infiltrative growth pattern using a tissue microarray technique and correlated data with patient outcome. CD24 expression was demonstrated in 161/259 (62%) evaluable tumours and was associated with high tumour stage [77/139 (55%) pTa/pT1 vs 84/120 (70%) pT2-pT4; P=0.02] and high tumour grade [68/139 (49%) low vs 93/120 (78%) high grade; P<0.001] as well as presence of angioinvasion (P=0.002) and infiltrative pattern of invasion (P=0.007). Patients with CD24-positive tumours tended to have a higher risk of disease progression (P=0.065). Multivariate analysis, however, proved pT stage >1 [P<0.001, risk ratio (RR)=5.87, 95% confidence interval (CI)=2.88-11.95] and high tumour grade (P<0.001, RR=3.30, 95% CI 1.75-6.22) as only independent predictors of metastatic disease. In conclusion, CD24 expression in upper urinary tract urothelial cancer is associated with advanced tumour stage and high tumour grade as well as histopathological features indicative of aggressive tumour behaviour, but it lacks independent impact on patient outcome.