Several types of non-small cell lung cancer may occur. Three of the subtypes make up most of the cases of lung cancer. A few additional rare subtypes also exist. While each subtype differs, many of the treatment options are the same.

The two main types of lung cancer include small cell and non-small cell. Non-small cell lung cancer is a form of cancer that starts in the epithelial cells of the lungs.

According to the American Cancer Society, up to 85% of lung cancer cases are non-small cell.

Non-small cell lung cancer (NSCLC) is further divided into subtypes. The specific type of lung cells that the cancer develops from determines the subtype. Treatment and prognosis for each subtype may vary, also depending on the stage of the disease at diagnosis.

The article below takes a look at the different subtypes, including their treatment options and prognosis.

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Adenocarcinoma is the most common form of lung cancer. According to 2016 research, about 40% of all lung cancers are adenocarcinomas.

This subtype of NSCLC typically starts in the outer part of the lung in type 2 alveolar cells. Although it mostly occurs in people who smoke, it is also the most common form of lung cancer in nonsmokers.

According to the American Cancer Society (ACS), adenocarcinoma usually starts in the outer part of the lung. Diagnosis is more likely to occur before this subtype spreads, which improves prognosis.

Treatment for adenocarcinoma varies depending on the stage. Treatment may include:

The prognosis for adenocarcinoma depends on the stage. However, various factors play a role in prognosis, including:

  • the stage of disease
  • age
  • other health issues

Learn more about lung adenocarcinoma here.

Squamous cell carcinoma occurs in about 25–30% of all people with lung cancer. Squamous cell lung cancer develops in the epithelial cells of the bronchial tubes in the middle of the lungs. Smoking is a big risk factor for developing this subtype.

About 60–70% of people with squamous cell carcinoma have advanced disease at diagnosis, which limits treatment options. Because of advanced disease, the prognosis remains poor. Treatment options may include chemotherapy and radiation therapy.

Learn more about squamous cell carcinoma here.

Large cell undifferentiated carcinoma usually starts in the central portion of the lung. It is the third most common form of NSCLC and accounts for about 5­–10% of all lung cancer cases. This form of lung cancer is also strongly linked to smoking.

Large cell undifferentiated carcinoma often involves fast-growing cells and may quickly spread to:

  • nearby lymph nodes
  • the chest wall
  • distant organs

Treatment typically involves chemotherapy and radiation therapy. Surgery is also an option in some cases.

Learn more about large cell carcinoma here.

Adenosquamous carcinoma is a rare subtype of NSCLC. This form of lung cancer has features of both squamous cell carcinoma and adenocarcinoma. Adenosquamous carcinoma only accounts for about 0.4­ to 4% of cases of lung cancer.

Although it can affect females, it typically occurs in males. Most people diagnosed have a smoking history. Surgery is the most common treatment, but adenosquamous carcinoma is aggressive, and the prognosis is poor.

Lung sarcomatoid is also a rare subtype of lung cancer. It accounts for only about 0.1 to 0.4% of lung cancers. Sarcomatoid usually develops in the upper lobes. It is more common in older males who have a heavy smoking history.

Treatment may include surgery in the early stages and chemotherapy in advanced disease. Sarcomatoid has a poor prognosis when compared with other subtypes of NSCLC, even in the early stage of the disease.

Salivary gland-type tumors in the lung generally start in the submucosal glands in the central airways. Salivary gland carcinoma is a rare form of lung cancer.

Compared with other subtypes of NSCLC, salivary gland carcinoma usually occurs in people who are younger. It is a slow-growing tumor, which improves prognosis.

Typically, surgery is the main treatment without the need for additional chemotherapy or adjunct therapy. Prognosis depends on several factors, including the stage of the cancer, the person’s age, and whether they have any other health issues.

Carcinoid tumors start in neuroendocrine cells, which are a type of cell in the lungs. Neuroendocrine cells help control the growth of other lung cells, as well as control the flow of blood and air into the lungs.

There are two types of carcinoid tumor: typical and atypical. Typical carcinoid tumors grow slowly and are unlikely to grow beyond the lungs. The ACS states that they account for 90% of carcinoid tumors. Atypical carcinoid tumors grow more quickly and are more likely to spread beyond the lungs.

Carcinoid tumors only account for about 1–2% of lung cancer cases. Usually, carcinoid tumors occur in people who are a little younger than those usually diagnosed with lung cancer. For example, the average age of diagnosis for typical carcinoid tumors is about 45 years old.

The prognosis is good for people with this form of lung cancer. The 5-year survival rate is about 90%. Treatment may include surgery, radiation, and chemotherapy.

In some cases, doctors cannot determine the specific subtype of NSCLC.

For example, in about 20% of the pathology reports from a tissue sample, the subtype remains unclassified. Unclassified carcinoma may occur due to an inadequate sample or for other unclear reasons.

The two main types of lung cancer include small cell and non-small cell lung cancer. NSCLC is further broken down into subtypes. The subtypes have similar treatment options. However, the specifics, such as what part of the lung cancer develops, may vary.

The prognosis for most subtypes of NSCLC depends on what stage the disease is in at diagnosis. The earlier the stage, the better the prognosis.

For example, people with localized NSCLC have about a 60% 5-year survival rate, according to the ACS. The overall 5-year relative survival rate for people with NSCLC in general is 25%.