Bladder Cancer
A urothelial field-change cancer, usually driven by carcinogen exposure across the whole urinary tract lining, that classically bleeds painlessly because early tumours are superficial and have not yet invaded pain-sensitive tissue.
First principles
Bladder cancer is a field-change disease of the whole urothelium, not a single-spot problem
Over 90% of bladder cancers are urothelial (transitional cell) carcinomas, arising from the specialised epithelium that lines the entire urinary tract from the renal pelvis to the proximal urethra. Because this epithelium is chronically exposed to whatever is concentrated in urine, carcinogens excreted by the kidney, chiefly from tobacco smoke and certain occupational aromatic amines, bathe the whole urothelial surface, not just one location. This is why bladder cancer behaves as a field-change disease: multiple areas of the urothelium can harbour genetic damage simultaneously, explaining the tendency for multifocal tumours and for recurrence at new sites even after apparently complete resection.
Educational content pending clinical review. Not medical advice.