What is the function of the bladder?
The urinary bladder (referred to as ‘the bladder’) is the organ that collects and stores urine produced by the kidneys. It is a hollow stretchy bag made of muscle tissue that sits on the pelvic floor muscles. The bladder expands as urine from the kidneys collects before being passed out of the body through the urethra.
Fig 1: The lower urinary tract in men (a) and in women (b).
What is bladder cancer?
Bladder cancer is the growth of abnormal tissue (tumour) in the urinary bladder (referred to as ‘the bladder’). There are several stages of bladder cancer. Your treatment and experience depend on the specific characteristics of the tumour and the expertise of your medical team.
The sections in this series provide general information about bladder cancer, diagnosis, and various treatment options. Discuss with your doctor what is best in your individual situation.
Several biological factors and harmful substances can increase the risk of developing bladder cancer. A higher risk does not necessarily mean that someone gets cancer. Sometimes bladder cancer develops without any known cause.
Stages of the disease
A tumour that grows towards the centre of the bladder without growing into the muscle tissue of the bladder is called non–muscle invasive. These tumours are superficial and represent an early stage. This is the most common type of bladder cancer. In most cases, these tumours are benign and rarely spread to other organs, so they are not usually lethal.
As the cancer grows into the muscle of the bladder and spreads into the surrounding muscles, it becomes muscle- invasive bladder cancer. This type of cancer has a higher chance of spreading to other parts of the body (metastatic) and is harder to treat. In some cases, it may be fatal.
If bladder cancer spreads to other parts of the body such as the lymph nodes or other organs, it is called locally advanced or metastatic bladder cancer. At this stage, cure is unlikely, and treatment is limited to controlling the spread of the disease and reducing the symptoms.
Fig. 2: A healthy bladder.
Risk factors for bladder cancer
Bladder cancer develops slowly and is more common in older people (age 60 and older). According to the European Association of Urology’s bladder cancer guidelines, tobacco smoking contains many harmful substances and is responsible for almost half of the bladder cancer cases.
Another well-known source of risk is occupational exposure to chemicals used in the production of paint, dye, metal and petroleum, although workplace safety guidelines have helped reduce this risk.
Infections from certain viruses, bacteria or parasites and chronic urinary tract infections increase risk of developing bladder cancer.