Bladder cancer begins when cells in the lining of the bladder (urothelium) become abnormal. This causes the cells to grow and divide out of control. As the cancer grows, it may start to spread into the deeper layers of the bladder wall. Some cancer cells can also break off and travel outside the bladder to other parts of the body.
Learn more about:
Types of bladder cancer
There are three main types of bladder cancer, which are named after the cells they start in.
| urothelial carcinoma |
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| squamous cell carcinoma |
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| adenocarcinoma |
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There are also rarer types of bladder cancer. These include sarcomas, which start in the muscle, and aggressive forms called small cell carcinoma, plasmacytoid carcinoma and micropapillary carcinoma.
The bladder
The bladder is a hollow, muscular sac that stores urine (wee or pee). It is located in the pelvis and is part of the urinary system.
The urinary system also includes two kidneys, two 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. When you are ready to empty your bladder, the bladder muscle contracts, and urine passes through the urethra and out of the body.
Layers of the bladder wall
There are four 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 | A layer of tissue and blood vessels surrounding the urothelium. |
| muscularis propria | The thickest layer. It consists of muscle that contracts 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
Who gets bladder cancer?
Each year, almost 3100 Australians are diagnosed with bladder cancer. Most people diagnosed with bladder cancer are 60 or older, but it can occur at any age.
About 1 in every 110 men will be diagnosed with bladder cancer before age 75, making it one of the 10 most common cancers in men. For women, the chance is about 1 in 500.
What causes bladder cancer?
Research shows that people with certain risk factors are more likely to develop bladder cancer.
Risk factors include:
| Smoking | Cigarette smokers are up to three times more likely than non-smokers to develop bladder cancer. |
| Older age | About 90% of people diagnosed with bladder cancer in Australia are over 60. |
| Being male | Men are around three times more likely than women to develop bladder cancer. |
| Chemical exposure at work | Chemicals called aromatic amines, benzene products and aniline dyes are linked to bladder cancer. These chemicals are used in rubber and plastics manufacturing, in the dye industry, and sometimes in the work of painters, machinists, printers, hairdressers, firefighters and truck drivers. |
| Frequent infections | Squamous cell carcinoma of the bladder has been linked to urinary tract infections (including parasite infections, although these are very rare in Australia) and untreated bladder stones. |
| Long-term catheter use | Using urinary catheters over a long period may be linked with squamous cell carcinoma. |
| Previous cancer treatments | These include the chemotherapy drug cyclophosphamide and radiation therapy to the pelvic area. |
| Diabetes treatment | The diabetes drug pioglitazone can increase the risk of bladder cancer. |
| Personal or family history | Having one or more close blood relatives diagnosed with bladder cancer, or having inherited a gene linked to bladder cancer, increases the risk of bladder cancer. |
→ READ MORE: Bladder cancer symptoms
Key resource
Download a PDF booklet on this topic.
More resources
Prof Dickon Hayne, Professor of Urology, UWA Medical School, The University of Western Australia, Chair of the Bladder, Urothelial and Penile Cancer Subcommittee, ANZUP Cancer Trials Group, and Head of Urology, South Metropolitan Health Service, WA; A/Prof Tom Shakespeare, Director, Radiation Oncology, Coffs Harbour, Port Macquarie and Lismore Public Hospitals, NSW; Helen Anderson, Genitourinary Cancer Nurse Navigator (CNS), Gold Coast University Hospital, QLD; BEAT Bladder Cancer Australia; Mark Jenkin, Consumer; Dr Ganessan Kichenadasse, Lead, SA Cancer Clinical Network, Commission of Excellence and Innovation in Health, and Medical Oncologist, Flinders Centre for Innovation in Cancer, SA; A/Prof James Lynam, Medical Oncology Staff Specialist, Calvary Mater Newcastle, NSW; Jack McDonald, Consumer; Caitriona Nienaber, 13 11 20 Consultant, Cancer Council WA; Tara Redemski, Senior Physiotherapist – Cancer and Blood Disorders, Gold Coast University Hospital, QLD; Prof Shomik Sengupta, Consultant Urologist, Eastern Health and Professor of Surgery, Eastern Health Clinical School, Monash University, VIC.
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