P21 and p27 Immunoexpression in Upper Urinary Tract Urothelial Carcinomas

p21 and p27 are members of cyclin-dependent kinase family, which function as tumor suppressors and they are involved in development and progression of several malignancies. We investigated their expression in upper urinary tract urothelial carcinoma (UUTUC). Radical nephroureterectomy materials of 34 patients were assessed by immunohistochemistry to evaluate expression of p21 and p27 in UUTUC. Results were correlated with various clinicopathological variables as age, gender, tumor grade and stage, tumor architecture, multifocality, subsequent bladder carcinoma development and clinical outcome.

p21 and p27 expression was observed in 52.9 % (n = 18) and 88.2 % (n = 30), respectively. A total of 21 tumors (61.7 %) showed either total loss of p21 expression (n = 16, 47 %) or lower expression (n = 5, 14.7 %). No correlation was found between p21 expression and clinicopathologic variables. Cases showing total loss or lower p27 expression (11.7 % and <25.6 %, respectively) (n = 19, 55.8 %) constituted 67.6 % (n = 23) of the cases totally. This loss or lower p27 expression correlated with a shorter overall survival in both univariate and multivariate analysis (p = 0.039 and p = 0.037, respectively). None of the noninvasive tumors (papillary and nodular tumors) showed loss of p27 (p = 0.016) while 33.3 % of invasive ones showed p27 loss. Noninvasive tumor architecture also correlated with subsequent bladder carcinoma development (p = 0.032) while invasive tumor architecture correlated with advanced stage (T3 and T4) (p = 0.003). p27 is widely expressed in UUTUC, while p21 expression is observed in half of the cases. Loss of p27 expression correlated with tumor architecture and overall survival in UUTUC. However, further research is needed to assess their role in UUTUC.