Decreased expression of transforming growth factor β receptor type I is associated with poor prognosis in bladder transitional cell carcinoma patients

Transforming growth factor (TGF) β, a potent growth inhibitor of proliferation in most cells, usually exerts its effects through an interaction with membrane receptors, type I (TβR-I) and type II (TβR-II). In the present study, the expression of TGF-β receptors was correlated with tumor grade, pathological stage, and probability of progression and survival in patients with bladder transitional cell carcinoma (TCC). To this end, immunohistochemistry was carried out in specimens obtained from 59 patients who underwent either radical cystectomy or transurethral resection of bladder tumor. Among these patients, 18 (30.5%) had loss of TβR-I expression, whereas 27 (44.0%) had loss of TβR-II expression. There was a correlation between the loss of expression of TβR-I and TβR-II and the tumor grade (P = 0.041 and P = 0.026, respectively). In addition, both pathological and lymph node status also were associated with the loss of TβR-I and TβR-II expression (P = 0.025 and P = 0.004, respectively). Interestingly though, only the loss of expression of TβR-I was associated with an increased probability of tumor progression and a decreased probability of survival (P = 0.0046 and P = 0.0022, respectively). These results suggest that the status of TβR-I expression may be a potential prognostic marker in patients with bladder TCC.