Can bladder cancer cause proteinuria?

Bladder cancer generally does not directly cause proteinuria, but under certain circumstances, it may indirectly lead to its occurrence. Bladder cancer itself does not produce proteins, so early-stage bladder cancer typically does not cause proteinuria. When bladder cancer progresses to an advanced stage, the tumor may spread to deeper tissues or directly invade the kidneys, causing kidney function impairment and subsequently leading to proteinuria. In addition, complications of bladder cancer or its treatments, such as chemotherapy and radiotherapy, may also damage the kidneys and increase the risk of proteinuria. Therefore, if patients develop proteinuria during the later stages of bladder cancer or after related treatments, they should seek timely medical evaluation and further treatment.