Lung cancer is not a single disease. In fact, there are many different types of lung cancer.
Lung cancers are broadly classified into two types — small cell lung cancers (SCLC) and non-small cell lung cancers (NSCLC) — which are then broken down into a specific subtype. Both small cell lung cancer and non-small cell lung cancer are named for the kinds of cells found in the cancer and how the cells appear when viewed under a microscope. The cancer cells of each type grow and spread in different ways.
Small Cell Lung Cancer
The two general types of small cell lung cancer include:
- Small cell carcinoma (also known as oat cell cancer because of how it looks)
- Combined small cell carcinoma
Smoking tobacco is the major risk factor for developing small cell lung cancer.
Non-Small Cell Lung Cancer
NSCLC is the most common type of lung cancer in the United States, accounting for about 80% to 85% of lung cancers. There are three main types of non-small cell lung cancer, which include:
- Squamous cell carcinoma (epidermoid carcinoma). This cancer begins in the squamous cells, which are thin, flat cells that resemble fish scales when seen under a microscope. These cells line the inside of the airways in the lungs. Squamous cell lung tumors usually occur in the central part of the lung or in one of the main airways (left or right bronchus).
- Large cell carcinoma. These cells are distinguished from small cell lung cancer cells by their larger size. Large cell lung cancers do not necessarily occur near the chest wall, though they often occur near the edge of the lung rather than near a bronchus (in the center).
- Adenocarcinoma. Lung adenocarcinoma starts in glandular cells, which secrete substances such as mucus, and tends to develop in smaller airways, such as alveoli. It is usually located more along the outer edges of the lungs and tends to grow more slowly than other lung cancers.
Other less common types of non-small cell lung cancer include pleomorphic, carcinoid tumor, salivary gland carcinoma, and unclassified carcinoma.
Smoking can increase the risk of developing non-small cell lung cancer.
Visit the National Cancer Institute where this information and more can be found about Small Cell and Non-Small Cell Lung Cancer or ask your Minnesota Oncology cancer care team questions about your individual situation.