The human body is made up of millions of tiny cells, and when these cells become abnormal, divide uncontrollably and invade tissue the disease is known as Cancer. Cancer cells can spread around the body though the blood and lymphatic systems.
There are over 100 different forms of cancer, and they can be broadly grouped into the following categories:
- Carcinoma –cancer that originates in the skin or tissues that line or cover the internal organs. This category is broken down further into subcategories including, adenocarcinoma, basal cell carcinoma, squamous cell carcinoma and transitional cell carcinoma
- Sarcoma –cancer that begins in the bone, cartilage, fat, muscle, blood vessels, connective tissue and supportive tissue
- Leukemia –cancer starting in blood-forming tissue, e.g. bone marrow, causing large numbers of abnormal blood cells to produced and enter the blood
- Lymphoma and myeloma –types of cancer that begin in the immune system
Central nervous systems – beginning in the brain and spinal cord
WHAT IS LUNG CANCER?
Lung cancer is one of the most common forms of cancer in the UK, with over 40,000 new cases diagnosed each year in the UK alone.
Cancer that originates in the lungs is known as primary lung cancer, cancer that begins in another part of the body and subsequently spreads to the lungs is known as secondary lung cancer.
There are two main types of primary lung cancer, classified by the type of cells in which the cancer starts;
- Non-small-cell lung cancer (NSCLC) –the most common form, responsible for more than 80% of cases. This type of lung cancer can either be squamous cell carcinoma, adenocarcinoma or large-cell carcinoma
- Small-cell lung cancer (SCLC) –a less common form, usually spreading faster than non-small-cell lung cancer
Non-small-cell lung cancer usually spreads more slowly than small-cell lung cancer and reacts and responds differently to treatment.