About bladder cancer

The bladder

The bladder is a hollow, muscular sac that stores urine (wee or pee). It sits behind the pubic bone in the pelvis, and is part of the urinary system.

The urinary system also includes 2 kidneys, 2 tubes called ureters that lead from the kidneys into the bladder, and another tube called the urethra that leads out of the bladder. In males, the urethra is a long tube that passes through the prostate and down the penis. In females, the urethra is shorter and opens in front of the vagina (birth canal).

The kidneys produce urine, which travels to the bladder through the ureters. The bladder is like a balloon and expands as it fills with urine. A layer of muscle wraps around the urethra and works like a valve to keep the bladder closed and stop leaking of urine. When you are ready to empty your bladder, the bladder muscle tightens and the valves open, and urine passes through the urethra and out of the body.

Layers of the bladder wall
There are 4 main layers of tissue in the bladder:

Urothelium
The inner layer. It is lined with cells called urothelial cells that stop urine being absorbed into the body.

Lamina propria
The layer of tissue and blood vessels that surrounds the urothelium.

Muscularis propria
The thickest layer. It consists of muscle that tightens to empty the bladder.

Perivesical tissue
The outer layer. Mostly made up of fatty tissue, it separates the bladder from nearby organs.

The urinary system

How common is bladder cancer?

Each year, about 3350 Australians are diagnosed with bladder cancer. Most people diagnosed with bladder cancer are aged 60 or older, but it can occur at any age. About 1 in every 67 males will be diagnosed with bladder cancer before age 85, making it 1 of the 10 most common cancers in males. For females, the risk is about 1 in 234 before age 85, although it is often diagnosed at an advanced stage.