Exposure to all types of asbestos is known to cause lung cancer and malignant mesothelioma.
Abnormal cells, i.e., cancer, destroy healthy cells and spread to other parts of the body. Cancer cells multiply faster than healthy cells and form too much tissue, resulting in a tumor.
In a benign tumor the cells do not spread to other parts of the body and are not cancerous. They could cause a problem if they continue to grow and press on surrounding organs.
A malignant tumor consists of cancer cells that have the ability to spread beyond the original site. If a tumor is left untreated, it can spread into and destroy surrounding tissue. Cells can break away from the original (primary) cancer site and spread to other organs in the body through the bloodstream or lymphatic system. The lymphatic system is part of the immune system. It involves the bone marrow, the thymus and the spleen, and lymph nodes throughout the body that are connected by a network of tiny lymphatic vessels. Cancer cells can spread this way and go on dividing and form a new tumor. This is secondary or a metastasis.
If you have a cancer which started elsewhere in the body but has spread to the lung, it is called secondary lung cancer. Treatment for secondary lung cancer will depend on where the cancer first started.
Primary lung cancer is grouped as small cell or non-small cell. Small cell lung cancer is sometimes called oat cell carcinoma because its cells are a distinctive oat shape. There are three different types of non-small cell lung cancer:
- Squamous cell carcinoma: It comes from the cells which line the airways.
- Adenocarcinoma: Develops from the cells which produce mucus. These cells are also found in the lining of the airways.
- Large cell carcinoma: Gets its name from the large, rounded cells that are seen when they are examined under the microscope.
Lung cancer occurs inside the lungs, and is different from mesothelioma in that malignant pleural mesothelioma affects the covering of the lungs. Malignant mesothelioma is cancer of the pleura, the membrane which covers the surface of the lungs and lines the inside of the chest.
Mesothelioma is a rare form of cancer in which cancerous cells are found in the mesothelium, a protective sac that covers most of the body’s internal organs. The mesothelium is composed of two layers of cells: One layer surrounding the organ; the other forms a sac around it. The mesothelium produces a lubricating fluid that is released between these layers, allowing moving organs move easily.
The mesothelium has different names, depending on its location in the body. The peritoneum is the mesothelial tissue that covers most of the organs in the abdominal cavity. The pericardium covers and protects the heart. The pleura is the membrane that surrounds the lungs and lines the wall of the chest cavity.