Prostate stem cell antigen predicts tumour recurrence in superficial transitional cell carcinoma of the urinary bladder.
OBJECTIVE
To evaluate the relationship between prostate stem cell antigen (PSCA) expression level in transitional cell carcinoma (TCC) of the urinary bladder and various clinicopathological features, including stage and grade; and to determine whether PSCA mRNA expression predicts disease recurrence in superficial (not muscle-invasive) TCC of the bladder.


METHODS
Real-time reverse transcriptase-polymerase chain reaction (RT-PCR) was performed on 97 TCC tissue samples and in 36 samples of normal bladder urothelium; the findings were analysed in relation to clinicopathological factors. Immunohistochemical expression was examined using light and confocal immunofluorescence microscopy to validate the RT-PCR data.


RESULTS
Twenty-seven patients developed disease recurrence, while the remaining 22 had no evidence of recurrence of superficial TCC of the bladder. There was significantly higher PSCA mRNA expression in TCC than in normal urothelium samples (P = 0.008). Superficial (TaT1) tumours had significantly higher PSCA expression than muscle-invasive (> or = pT2) tumours (P < 0.001). There was no significant difference between patients with G1-2 tumours and those with G3 tumours (P = 0.109). Immunohistochemical analysis showed markedly greater PSCA expression in superficial than invasive TCC. Notably, from a multivariate analysis, the expression level of PSCA was an independent predictor of disease recurrence in superficial TCC (P = 0.012).


CONCLUSIONS
These findings suggest that the PSCA expression level measured by real-time RT-PCR could be a valuable prognostic marker for tumour recurrence in superficial TCC of the bladder.
Elsamman
Essam
E
Department of Urology, The University of Tokushima Graudate School Institute of Health Biosciences, Tokushima, Japan.
Fukumori
Tomoharu
T
Kasai
Toshinori
T
Nakatsuji
Hiroyoshi
H
Nishitani
Masa-Aki
MA
Toida
Kazunori
K
Ali
Nermin
N
Kanayama
Hiro-Omi
HO