What is lung cancer?
Lung cancer is a cancer that starts in the lungs. Cancer is a disease in which abnormal or cancerous cells grow out of control, taking over normal cells and organs in the body. The abnormal cells no longer do the work of normal cells. Instead, the cancer cells replace and destroy the healthy tissues around them. Lung cancer is one of the most common types of cancer in men and women.
There are different types of lung cancer. Each type grows and spreads in different ways. Each type of lung cancer will be treated differently. The two major types of lung cancer are:
Non-small cell lung cancer
This is the most common type of lung cancer. Approximately 85% of lung cancers are non-small cell types. It usually spreads more slowly than other lung cancers. There are three major types of non-small cell lung cancer:
- Squamous cell carcinoma
- Large cell carcinoma
Small cell lung cancer
This type of lung cancer is less common (10-15%) and tends to spread more quickly than non-small cell lung cancer. There are three major types of small cell lung cancer:
- Small cell carcinoma
- Mixed small cell/large cell
- Combined small cell carcinoma
Another type of lung cancer is called lung carcinoid tumor. It is rare (5% of lung cancers) and is sometimes called lung neuroendocrine tumor. Most grow slowly and rarely spread.
Cancer found in the lungs can be a type of cancer that has spread from another part of the body and metastasized to the lungs. These tumors are called lung metastases and are not the same as lung cancer. They are usually the same as the original or primary cancer from which they spread.