Relation between basement membrane degradation and serum levels of laminin P1 in patients with transitional cell carcinoma of the bladder.

In 47 patients with transitional cell carcinoma (TCC) of the bladder, we investigated the relationship between tissue laminin distribution and serum laminin levels. The results were compared with those obtained from 6 patients with pathologically proven normal bladder mucosa as well as those obtained previously from 50 controls and 16 patients with benign bladder disorders. Interruption of the basement membrane (BM) laminin staining pattern was correlated with high serum laminin levels (r = 0.34; p < 0.01). The majority of patients with discontinuous BM laminin staining (82%) showed elevated serum laminin levels above the upper limit of normal range. In addition, the mean value of serum laminin P1 was significantly higher in patients with discontinuous BM than that in patients with intact BM (t = 3.18; p < 0.005). These data suggest that the high serum laminin levels in TCC patients are largely caused by the process of BM breakdown and loss.