Background: Elevated expression of transforming growth factor-beta 1 (TGF-beta 1) has been reported in several types of human cancer. However, the significance of TGF-beta 1 expression in clinical bladder cancer is not well known.
Methods: The levels of TGF-beta 1 expression were quantitated using a polymerase chain reaction-based method in tissue specimens obtained from 51 patients with bladder cancer.
Results: Transforming growth factor-beta 1 expression in bladder cancer was higher than that found in normal bladder epithelium (P < 0.01). Significantly higher levels of TGF-beta 1 transcripts were observed in low and intermediate grade (Grade 1 and 2) tumors than in high grade (Grade 3) tumors (P < 0.02). Superficial (pTa and pT1) tumors had higher levels of TGF-beta 1 than invasive (pT2 or higher) tumors (P < 0.05).
Conclusions: These results suggest that enhanced expression of TGF-beta 1 is specific to low grade and stage bladder cancer. Transforming growth factor-beta 1 may play an important role in the early stages of human bladder cancer development, and TGF-beta 1 expression could provide a new relevant tumor marker for determining tumor progression in patients with bladder cancer.