Types of Lung Cancer | UC Davis Health

We treat commonly as well as rarely occurring forms of lung cancer. Lung cancer isn’t a single disease, but rather is a term for any of several diseases in two main types: small cell lung cancers and non-small cell lung cancers. Those terms describe the way the tumor cells appear under a microscope, which is the way that oncologists diagnose the type of lung cancer that a patient has. About 85% of lung cancers are of the non-small cell type. Although small cell lung cancer occurs less frequently, it is the most aggressive form of the disease. We’re here to help you navigate your way through diagnosis and treatment.

Non-small cell lung cancer, which usually is less aggressive than small cell lung cancer, has three subtypes:

• Adenocarcinoma is the most common subtype of non-small cell lung cancer as well as the most common type of lung cancer in patients who do not smoke. It occurs more frequently in women than in men. Adenocarcinoma usually develops in the outer areas of the lungs, and often responds better to treatment than other types of lung cancer do.
• Squamous cell carcinoma, which is also called epidermoid carcinoma, is most frequently diagnosed in men, and is linked to smoking. This slow-growing cancer commonly develops in the middle of the lungs in the flat cells that line the small airway tubes, called bronchi.
• Large cell undifferentiated carcinoma is the least common but fastest-growing subtype of non-small cell lung cancer. It can develop in any part of the lung and tends to spread quickly, which makes treatment more urgent and more difficult.

Non-small cell lung cancer also can take other forms, including adenosquamous carcinoma and sarcomatoid carcinoma.

Small cell lung tumors usually develop in the bronchi deep within the lungs and are aggressive. You may also hear small cell lung cancer called “oat cell lung cancer” because under a microscope the cells resemble oats. They often metastasize — spread to lymph nodes or other organs, including bones, the liver and the brain.

• Small cell carcinoma accounts for most small cell lung cancer cases.
• Combined small cell carcinoma is a less commonly occurring type of lung cancer that consists of small cell carcinoma cells as well as non-small cell lung cancer cells.

Accurate diagnosis and treatment of thoracic malignancies — cancer occurring in the lungs and other organs of the chest — requires a multidisciplinary team of health care professionals. That’s why the UC Davis thoracic oncology program has assembled a team of oncologists, thoracic surgeons, radiation oncologists and pulmonologists. These specialists work together in developing a treatment plan that is tailored to each patient’s specific type and stage of cancer, overall health and preferences.

Our multidisciplinary lung cancer team at UC Davis offers world-class expertise in treating complex cases of lung cancer, mesothelioma and rare conditions such as cancer of the thymus gland, an organ that is vital to the human immune system. UC Davis lung cancer physicians have a worldwide reputation for helping to advance medical knowledge through research and clinical trials in which they investigate rare thoracic malignancies such as thymic cancers.