What Is the Difference Between Small Cell Lung Cancer & Non-Small Cell Lung Cancer?

Non-small cell lung cancer is the most common form of lung cancer, accounting for approximately 85 percent of all cases. It can be further classified into subtypes:

  • Adenocarcinoma – The most common subtype, which is slow growing and usually forms in the outer parts of the lungs
  • Squamous cell carcinoma – A very slow growing form of non-small cell lung cancer that often develops in one of the lungs’ airways (bronchi)
  • Large cell carcinoma – The most uncommon subtype of non-small cell lung cancer, which is fast growing and more likely to spread


Small cell lung cancer is more uncommon, accounting for the other 15 percent of lung cancer cases. This malignancy typically originates in the bronchi in the middle of the chest. Small cell lung cancer tends to grow more quickly and often spreads to the lymph nodes or other organs, though it is also typically more responsive to chemotherapy. Small cell lung cancers can be further classified as:

  • Small cell carcinoma – The most common type of small cell lung cancer where the cells look flat underneath a microscope
  • Combined small cell carcinoma – A less common type of cancer where the tumor is made up of small cell carcinoma cells and a small number of non-small cell lung cancer cells

How do I know which type of lung cancer I have?

When your physician first suspects you have lung cancer, you will likely need a medical imaging scan, such as an MRI or X-ray, to identify any abnormal growths. If a tumor is present, an oncologist will obtain a small sample of the lesion through a biopsy, which will then be examined through a microscope to determine the kind of lung cancer you have. Each type of lung cancer has different characteristics that helps with identification. For example, as its name suggests, the cells of small cell lung cancer are typically smaller than the cells of non-small cell lung cancer. The most effective course of treatment for you will depend on the type and subtype of your malignancy, in addition to many other factors.

If you have been recently diagnosed with lung cancer, Moffitt Cancer Center can provide you with the comprehensive treatment you need to achieve the best possible outcome and an improved quality of life. The specialists in our Thoracic Oncology Program create individualized treatment plans for our patients to address the challenges of each unique cancer. Schedule a consultation at Moffitt by calling 1-888-663-3488 or by submitting a new patient registration form online. Referrals are not required.