Bladder cancer

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What is bladder cancer?

Bladder cancer starts in the cells of the bladder. A cancerous (malignant) tumour is a group of cancer cells that can grow into nearby tissue and destroy it. The tumour can also spread (metastasize) to other parts of the body.

The bladder is part of the urinary system. It is a hollow organ in the pelvis that stores urine (pee) (a liquid waste product) before it passes out of the body.

Diagram of the location of the bladder

Cells in the bladder sometimes change and no longer grow or behave normally. These changes may lead to non-cancerous (benign) tumours such as papillomas. They can also lead to non-cancerous conditions such as urinary tract infections (UTIs).

But in some cases, changes to bladder cells can cause bladder cancer. Most often, bladder cancer starts in urothelial cells that line the inside of the bladder. This type of cancer is called urothelial carcinoma of the bladder (also called transitional cell carcinoma). Urothelial carcinomas make up more than 90% of all bladder cancers. They are often diagnosed at an early stage and have not grown into the deeper muscle layer of the bladder wall.

Rare types of bladder cancer can also develop. These include squamous cell carcinoma and adenocarcinoma of the bladder.

urinary system

The group of organs that make, collect, store and pass urine out of the body.

The urinary system includes the kidneys, ureters, bladder and urethra.


The lower part of the abdomen between the hip bones that contains the urinary system and reproductive system.

Pelvic means referring to or having to do with the pelvis, as in pelvic exam.

urinary tract

The pathway that urine takes from the kidneys to the urethra.

The urinary tract includes the renal pelvis in the kidneys, as well as the ureters, bladder and urethra.