An uncontrolled growth of abnormal cells that originates in one or both lungs is termed as lung cancer. It is important to note that the abnormal cells of cancer do not perform any function of normal lung cells and do not grow into healthy lung tissue. Lungs are organs of respiration that are situated in the chest. The lungs are of a sponge-like consistency and function by taking in oxygen during inhalation and releasing carbon dioxide during exhalation. The oxygen is delivered to the various organs via the bloodstream.
Lung cancer is classified into distinct types based on the appearance of the cancer cells under the microscope. Typing of lung cancer is important because the treatment is based on the type of cancer. The structure of the lungs is like a tree with branches known as bronchioles. The bronchioles end in the alveoli which are tiny balloon-like sacs in which the exchange of gases between the bloodstream and lung takes place. The alveoli are also glandular since they secrete mucus. Most cancers of the lung are adenocarcinomas, as they occur in the glandular structures in epithelial tissue. The types of lung cancer are:
Small cell lung cancer requires immediate treatment due to their aggressive nature.
Staging of lung cancer is done to express the extent or progression of the disease. It is done based on the medical history and the results of the diagnostic tests to develop an appropriate treatment plan by the oncologist.
Staging of small cell lung cancer: Small cell lung cancer stages is done as follows:
Staging non-small cell lung cancer: Non-small cell lung cancer (NSCLC) staging is done in two ways namely the TNM system and the numbering stages:
In addition to the TNM grading, a number between 0 to 4 or the letter X is assigned to each stage. An increase in the number is indicative of the increasing severity of the disease. The letter X denotes inability to assess the exact severity. For example, a tumor with a T3 score will be considered as more severe as compared to a tumor with a T2 score. The number staging is as follows:
Occult-stage: Presence of cancer cells in sputum, but the imaging tests or bronchoscopy do not reveal the presence of the tumor or it may be too small to be determined.