The Bonnie J. Addario Lung Cancer Foundation

Types of Lung Cancer

There are two main forms of lung cancer: small cell and non-small cell. It is important to distinguish non-small cell from small cell because the two types of cancer are treated in different ways. The two types of lung cancer are distinguished by the way cells look and the way the cancer spreads through the body.

Non-small cell lung cancer (NSCLC) is the most common form of lung cancer, accounting for approximately 80% of all cases. Within NSCLC, there are three major sub-types based on the histopathologic nature of the cancer:

Epidermoid or squamous carcinoma: generally arises in one of the large breathing tubes know as the bronchi and tends to grow relatively slowly.

Adenocarcinoma: generally arises near the outside surface of the lung and can vary in size and how fast it groes. Bronchioloalveolar carcinoma, or BAC, is a type of adenocarcioma that is generally considered to be resistant to chemotherapy. It presents two to six percent of all lung cancers and typically forms a line of smaller, consecutive masses.

Large cell carcinoma: may appear in any part of the lung and tends to grow and spread more quickly.
The average age-adjusted 5-year relative survival rate for Americans with non-small cell lung cancer is 15 percent. The more advanced the non-small cell lung cancer is at time of diagnosis, the poorer the prognosis. The expected median survival rate for advanced NSCLC patients for whom one or more chemotherapy regimens has failed is approximately four months when they receive supportive care but no active therapy. Best supportive care for NSCLC patients typically aims to treat symptoms through pain medication and oxygen.