Lung Cancer


What is Lung Cancer?

The lungs are a pair of organs in the chest that help the body inhale the oxygen it needs and exhale carbon dioxide. Lung cancer forms when cells in the lungs begin to grow rapidly and uncontrollably. These cells can invade and destroy healthy lung tissue, and other surrounding structures, and eventually interfering with normal breathing function. Lung cancer cells can also spread to the lymph nodes or bloodstream and metastasize (spread) to other parts of your body, where they can grow additional tumors. Lymph nodes are part of your immune system that are everywhere in your body. This is often the first place lung cancer cells will spread if it moves outside of the lung.

Types of Lung Cancer

There are two main types of lung cancer (non-small cell and small cell), classified by the type of cells in the tumor:

Non-small Cell

Most lung cancers are non-small cell tumors, which make up over 80% of all diagnoses. There are a few different types of non-small cell lung cancer, which look and behave differently, but have similar staging and treatments:

adenocarcinoma

  • Adenocarcinoma

    Adenocarcinomas form from the cells lining the alveoli, the tiny air sacs in your lungs. Adenocarcinomas are the type of lung cancer found most often in non-smokers.

Squamous cell carcinoma

  • Squamous cell carcinoma

    Squamous cell carcinomas form in the flat cells lining the bronchus tubes and are strongly linked with smoking. Squamous cell carcinomas may cause symptoms in early stages because they often form in the upper part of the airways before they form more deeply in the lungs.

Large cell carcinoma

  • Large cell carcinoma

    Large cell carcinomas look and behave differently from adenocarcinomas and squamous cell carcinomas. These tumors tend to spread early and be more aggressive than other non-small cell lung cancers, making it more difficult to remove surgically.

Small Cell

Small-cell lung cancer makes up about 15% of all lung cancer diagnoses and is usually directly related to smoking. These tumors are very aggressive as they tend to spread early. They usually form in the center of the lungs and can spread throughout the body quickly, before causing any symptoms. Because this form of lung cancer is more widespread at diagnosis, doctors stage and treat it differently than non-small cell lung cancer.