Lung cancer is not a single disease. In fact, there are many different types of lung cancer. It is important to understand each as they affect both your treatment options and your prognosis. At Affiliated Oncologists our goal is to provide you with the information you need in order to feel more confident and knowledgable regarding your diagnosis.
Lung cancers are broadly classified into two types — small cell lung cancers (SCLC) and non-small cell lung cancers (NSCLC). These two types are broken down into subtypes. Both small cell lung cancer and non-small cell lung cancer are named for the types 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 differently.
Small Cell Lung Cancer
SCLC is a fast-growing cancer that accounts for about 10% to 15% of all lung cancers. The two general types include:
- Small cell carcinoma (also known as oat cell cancer)
- Combined small cell carcinoma
Smoking tobacco is a major risk factor for developing small cell lung cancer.
Non-Small Cell Lung Cancer
NSCLC accounts for about 80% to 85% of lung cancers, making it the most common type of lung cancer in the United States. There are three main types of non-small cell lung cancer:
- Squamous cell carcinoma (epidermoid carcinoma). A cancer that begins in the squamous cells—the thin, flat cells resembling 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. The larger size of these cells set them apart from small cell lung cancer cells. Large cell lung cancers do not always occur near the chest wall. They do 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 increases the risk of developing non-small cell lung cancer.
Other Types of Lung Tumors
Other types of tumors can occur in the lungs, including:
- Rare tumors like adenoid cystic carcinomas, sarcomas, lymphomas, and hamartomas (benign lung tumors).
- Lung carcinoids tumors. These tumors start in neuroendocrine cells, which are a special kind of cell found in the lungs. This type of cancer can be found in younger than average lung cancer patients.
- Mesothelioma. A rare type of cancer that occurs in thin tissue called mesothelium, which lines the lungs and abdomen. This type of lung cancer is linked to asbestos exposure.
- Cancers that spread to the lungs. Sometimes, cancer that starts in another organ can metastasize to the lungs. Cancers such as these are not considered lung cancer but rather a cancer of the organ in which it originated and would be treated as such.
Ask your Affiliated Oncologists cancer care team questions about your individual situation.