Download Communication Workers Union - Fact Sheet

Communication Workers Union - Fact Sheet
About Mesothelioma
What is Cancer?
Firstly it is important to understand that cancer is not a single illness, there are very many different types and mesothelioma is
just one type.
Our bodies are made of tiny building blocks called cells, cancer is a disease of these cells. Cells from different parts of the body
look and work differently and millions of new cells are made everyday to replace those lost through old age or wear and tear.
Throughout the body new cells are produced when existing cells divide into two and there is normally a perfect balance
between those that are dying and those that are dividing. This vital balance is controlled by a very complicated process, if
control of this process is lost it can lead to too many cells being produced which results in a tumour. Most tumours are not
cancerous (sometimes described as benign) and they remain in the area where they first developed. A wart is a common
example.
The development of cancer involves a change in the quality of the cells as well an increase in the quantity. They become more
aggressive, destructive and independent of normal cells. They are able to invade surrounding tissues, glands and blood vessels
and thus spread away from where they started to divide and grow. When the cancer cells reach a new site they may go on
dividing and form a new tumour, this is often referred to as a secondary or metastasis (secondary).
What is Mesothelioma?
Illustrated image of Lungs and Pleura
In the UK about 2500 people a year are diagnosed with mesothelioma. It is also known as ‘diffuse’ or ‘malignant’ mesothelioma.
Mesothelioma is a form of cancer that affects the Mesothelium, which is a thin membrane that lines the inner surface of the
chest wall, known as the pleura, and abdomen, known as the peritoneum. It also surrounds the organs found within these
cavities for example the heart, lung and intestines. It is far more common to have mesothelioma in the chest than in the
abdomen, there is approximately 12 cases of pleural mesothelioma to every 1 case of peritoneal mesothelioma.
Pleural Mesothelioma
Illustrated image of healthy and diseased lung
The pleural lining has two layers: the visceral (inner) layer is next to the lung and the parietal (outer) layer lines the chest wall.
The pleura produces fluid that lubricates the space between the two layers, this allows the two layers to slide comfortably over
each other as we breathe in and out.
Pleural mesothelioma causes the pleura to thicken. This thickening of the pleura might begin to press onto the lungs or attach
itself to the inside of the chest wall. In either case the expansion of the lung becomes progressively restricted by the tumour.
Fluid, sometimes several litres, can collect between the two layers of the pleura; this affects the lungs ability to expand and
causes the person to feel breathless. This is known as a pleural effusion.
Peritoneal Mesothelioma
Illustrated image of Abdominal Cavity and peritoneum
The peritoneum also has two layers the inner (visceral) layer which is next to the abdominal organs and the outer (parietal) layer
which lines the abdominal wall.
Peritoneal mesothelioma causes the peritoneum to thicken and fluid to collect in the abdomen. This collection of fluid is called
ascites and causes the abdomen to swell. Because pleural mesothelioma is more common and often spreads to the peritoneal
cavity, it is sometimes necessary to determine if pleural mesothelioma is the primary cancer.
Communication Workers Union - Fact Sheet
(Acknowledgement: Mesothelioma UK)