How serious is bladder cancer compared to other cancers?

As with any cancer, bladder cancer, if left untreated, is deadly.

I am not well versed in bladder cancer treatments. However, tuberculosis is the disease caused by mycobacterium tuberculi, which is a bacteria and is treated with antibiotics.

yes, any cancer left untreated is invariably fatal in the end! so any cancer if detected should be treated ASAP! yes, one of the modalities of treatment for bladder cancer is instillation of BCG (bacillus Calmette Guerin) in the urinary bladder. this is a live attenuated bacteria, used in immunization against TB. so you might become montoux positive but surely you will not end up with TB.