Types of lung cancer

Lung cancer is a group of diseases defined by what type of lung tissue the abnormal cells originated in. This is known as the “histology” of the cells. There are 2 main types of lung cancer. Understanding the differences between each type is critical to treatment decisions and outcomes.

In order to determine a treatment plan, you need to know what type of lung cancer you have. This is usually determined by having a biopsy.

graphic illustration of lung cancer

How many types of lung cancer are there, and what are they?

There are 2 main classifications of lung cancer, and 4 types of lung cancer in total:

  • Non-small cell lung cancer (NSCLC)
    • adenocarcinomas
    • squamous cell carcinomas (aka epidermoid carcinomas)
    • large cell carcinomas
  • Small cell lung cancer (SCLC) (aka oat cell lung cancer)

These broad classifications, based on histology, can greatly affect an individual’s approach and response to treatment.

Pie chart showing the four most common types of lung cancer by histologyTypes of Non-small cell lung cancer (NSCLC)

Non-small cell lung cancer is the most common type of lung cancer.  More than 8 out of every 10 lung cancer cases are NSCLC.

Within the non-small cell lung cancer category, there are 3 subtypes:

  • adenocarcinomas
  • squamous cell carcinomas (aka epidermoid carcinomas)
  • large cell carcinomas

Adenocarcinoma

Adenocarcinoma is the most common histologic type of lung cancer, and begins in the cells in the glands located on the outer part of the lungs. It is most frequently found in women, non-smokers, and people under the age of 45.

Squamous cell carcinoma

Squamous cell carcinomas make up 25 – 30% of all lung cancers, and are the most common lung cancers found in smokers. Squamous cell carcinomas are more common in men than in women. The majority of cases of squamous cell carcinoma start in the center of the lung. Often, and at an earlier stage than other tumors, squamous cell carcinomas cause symptoms such as coughing up blood.

Large cell carcinomas

Large cell carcinomas tend to grow quickly and are usually undetected until they have metastasized. The rarest of the lung cancers, large cell carcinomas only appear in roughly 1 in every 10 cases. As more precise diagnostics have become available, many lung cancers previously diagnosed as large cell carcinomas are being re-classified as adenocarcinoma or squamous cell lung cancer.

A lot of research is being done surrounding treatments for all forms of NSCLC and there are many clinical trials in the pipeline for patients navigating a NSCLC diagnosis.

Stages of non-small cell lung cancer

  • Stage 0: the cancer is found only in the top lining of the lung and has not spread outside the lung
  • Stage I (IA and IB): the cancer has not spread to the lymph nodes or other parts of the body. The difference between each sub-stage is based on the size of the tumor and whether it has spread to the lung lining
  • Stage II (IIA and IIB): the cancer is larger than Stage I and has begun to spread to nearby lymph nodes or tissues, but not to distant organs. The difference between each sub-stage is based on the size of the tumor, its location, and whether it has spread to the lymph nodes or not
  • Stage III (IIIA, IIIB, and IIIC): the cancer may be difficult to remove via surgery. The difference between each sub-stage is based on the size of the tumor, its location, and how much it has spread
  • Stage IV: the cancer has spread (metastasized) to other areas of the body outside the lungs

Small cell lung cancer (SCLC) (aka oat cell lung cancer)

Small cell lung cancer is a much less common form of lung cancer, affecting roughly 1 in every 10 people diagnosed with lung cancer. Small cell lung cancer is particularly aggressive. It often returns after initial rounds of chemotherapy.

Because of the Recalcitrant Cancer Research Act, the National Cancer Institute (NCI), in partnership with the lung cancer research community, is making SCLC a major focus of research, resulting in a greater number of clinical trials in the pipeline.

Stages of small cell lung cancer

  • Limited stage: the cancer is only in one lung or in nearby tissue
  • Extensive stage: the cancer has spread to tissue and organs outside the original lung, such as the opposite lung or distant organs

 


Receiving a lung cancer diagnosis is daunting at best, but it is important to educate yourself regarding your particular type of lung cancer.

If you or a loved one are experiencing symptoms consistent with those of lung cancer, see your doctor. LCFA is here to provide hope, information, and resources for you and your family.

Make an appointment with your doctor whenever you have symptoms that concern you.

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In fact, you can play a vital role in working with your doctor to determine the best treatment options.

Get answers to your questions about personalized medicine – download our FREE Personalized Therapies for Lung Cancer Q&A brochure today.