About bladder cancer

The bladder

The bladd er is a hollow, muscular, ballo on-like organ that collects an d stores urine. It is in the lower part of the abdomen (the pelvis).

The position of the bladder

The inside of the bladder is covered with a urine-proof lining (called the urothelium ) which stops urine being absorbed back into the body. The cells of this lining are called transitional cells or urothelial cells.

Our kidneys (most peopl e have two) pr oduce urine, which is carried to the bladder by thin tubes c alled ureters. The bladder sto res the urine which is made up of water and waste products that the bo dy does not need. When the bladder is full enough, nerve signals are sent to the brain. To get rid of the urine, the muscle of the bladder contracts, forcing the urine out of the body throug h another fine tube called the urethra.

In women the urethra is a short tube wh ich lies in front of the vagina. In men the urethra is longer as it passes th rough the prostate gland and to the tip of the p enis.

What is cancer?

The organ s and tissues o f the body are made up of tin y building bloc ks called cells. Cancer is a disease of these cells.

Cells in different parts of the body may look and work differently but most reproduce themselves in the same wa y. Cells are constantly becoming old and dying, and new cells are produced to replace them. Norma lly, cells divide in an orderly an d controlled ma nner. If for so me reason the process gets o ut of control, the cells carry on dividing, developing into a lump which is called a tumour.

Tumours can be either benign or malignant. Cancer is the name given to a malignant tumour. Doctors can tell if a tumour is benign or malignant by examining a small sample of cells under a microscope. This is called a biopsy.

In a benign tumour the cells do not spread to other parts of the body and so are not cancerous. However, if they continue to grow at the original site, they may cause a problem by pressing on the surrounding organs.

A malignant tumour consists of cancer cells that have the ability to spread beyond the original area. If the tumour is left untreated, it may spread into and destroy surrounding tissue. Sometimes cells break away from the original (primary) cancer. They may spread to other organs in the body through the bloodstream or lymphatic system.

The lymphatic system is part of the immune system - the body's natural defence against infection and disease. It is a complex system made up of organs, such as bone marrow, the thymus, the spleen, and lymph nodes. The lymph nodes (or glands) throughout the body are connected by a network of tiny lymphatic ducts.

When the cancer cells reach a new area they may go on dividing and form a new tumour. This is known as a secondary cancer or metastasis.

It is important to realise that cancer is not a single disease with a single type of treatment. There are more than 200 different kinds of cancer, each with its own name and treatment.

Types of cancer

Carcinomas

The majority of cancers, about 85% (85 in a 100), are carcinomas. They start in the epithelium, which is the covering (or lining) of organs and of the body (the skin). The common forms of breast, lung, prostate and bowel cancer are all carcinomas.

Carcinomas are named after the type of epithelial cell that they started in and the part of the body that is affected. There are four different types of epithelial cells:

• squamous cells - that line different parts of the body, such as the mouth, gullet (oesophagus), and the airways
• adeno cells - form the lining of all the glands in the body and can be found in organs such as the stomach, ovaries, kidneys and prostate
• transitional cells - are only found in the lining of the bladder and parts of the urinary system
• basal cells - that are found in one of the layers of the skin.

A cancer that starts in squamous cells is called a squamous cell carcinoma. A cancer that starts in glandular cells is called an adenocarcinoma. Cancers that start in transitional cells are transitional cell carcinomas, and those that start in basal cells are basal cell carcinomas.

Leukaemias and lymphomas

These occur in the tissues where white blood cells (which fight infection in the body) are formed, i.e. the bone marrow and lymphatic system. Leukaemia and lymphoma are quite rare and make up about 6.5% (6.5 in 100) of all cancers.

Sarcomas

Sarcomas are very rare. They are a group of cancers that form in the connective or supportive tissues of the body such as muscle, bone and fatty tissue. They account for less than 1% (1 in 100) of cancers.

Sarcomas are split into two main types:

• bone sarcomas - that are found in the bones
• soft tissue sarcomas - that develop in the other supportive tissues of the body.

Others forms of cancer

Brain tumours and other very rare forms of cancer make up the remainder of cancers.