What is lung cancer?
Lung cancer may spread to the lymph nodes or other organs in the body that commonly include the liver, bones, brain and adrenal glands. When cancer cells spread from one organ to another, it is called metastases.
How long does lung cancer take to develop?
The time taken for lung cancer to develop is variable. It takes several years for cancer to develop in the lungs. Early lung cancer does not alert obvious physical changes. Moreover, patients can live with lung cancer for many years before they show any signs or symptoms.
What are the signs and symptoms of lung cancer?
Most often, lung cancer does not show any signs and symptoms until it has advanced to higher stages when it becomes difficult to treat. The signs and symptoms vary among patients but may include the following:
What are the different stages of lung cancer?
The four stages of lung cancer (based on a grading system) are known as TNM classification. The TNM grades have been derived from diagnostic tests such as
- blood tests,
- computed tomography (CT) scans,
- positron emission tomography (PET) scans, etc.
In the increasing order of severity, the stages of cancer are as follows:
- Stage 0: This stage describes cancer in situ, which means “in place”. Stage 0 cancers are still located in the place they started and do not spread to the nearby tissues. This stage of cancer is often highly curable, usually by removing the entire tumor with surgery.
- Stage I: This stage is usually a small tumor that has not grown deeply into the nearby tissues. It is often called early-stage cancer.
- Stages II and III: At these two stages, lung cancer has grown more deeply into its adjacent tissues. Lung cancer may have spread to the lymph nodes.
- Stage IV: This stage means that lung cancer has spread or metastasized in other organs. This is usually known as the advanced stage of lung cancer.