Urachal carcinoma of the bladder - impact of clinical and immunohistochemical parameters on prognosis

Abstract

PURPOSE: Urachal carcinoma of the bladder (UrC) is a rare malignancy. Its histological phenotype is similar to that of primary bladder adenocarcinomas and colorectal adenocarcinomas. The aim of this study was to explore the expression and prognostic relevance of six selected protein markers in UrC (p53, Ki67, RHAMM, BGN, IMP3 and MMP-7), which were formerly shown to be prognostic in urothelial carcinoma and colorectal adenocarcinoma. PATIENTS AND METHODS: Clinical and follow-up data were obtained from 26 patients with UrC treated at two university hospitals. Immunohistochemical (IHC) analyses of p53, Ki67, RHAMM, BGN, IMP3 and MMP-7 expression were performed in samples of 15 patients. Clinicopathological parameters and IHC-results were tested for their prognostic values in uni- and multivariable analyses. RESULTS: Follow-up was 50 months. Five year overall (OS) and progression-free survival were 46% and 32%. Positive resection margin was an independent predictor of poor OS (p=0.025) in multivariable analysis. RHAMM (p=0.0431), IMP3 (p=0.0052), Ki67 (p=0.0006) and p53 (p=0.0024) expression-rates were significantly elevated in UrC cells compared to normal urothelium. IMP3 was elevated in tumor stage Sheldon IIIA compared to >/=IIIB (p=0.0048). None of the analyzed protein markers was associated with survival. CONCLUSION: The independent prognostic value of positive resection margin underlines the importance of the complete surgical removal of UrC combined with en-bloc resection of the median umbilical ligament and umbilicus. Our results on a limited number of samples show that Ki67, p53, RHAMM and IMP3 expressions are enhanced but have no prognostic significance in UrC.