graphic of lungs

Lung cancers develop in cells that line the bronchi and in a part of the lung tissue called the alveoli, which are air sacs where gases exchange. Changes to DNA cause cells to grow more rapidly.

There are two main types of lung cancer: non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). 

Keep reading to find out more about the similarities and differences between these two types.

What Is Non-Small Cell Lung Cancer?

Approximately 85 to 90 percent of lung cancer cases are NSCLC. There are three types of NSCLC:

  • Adenocarcinoma is a slow-growing lung cancer usually discovered in an outer area of the lung, often before it has a chance to spread. It occurs more often in smokers, but it’s the most common form of lung cancer in nonsmokers as well.
  • Squamous cell carcinoma generally occurs in the center of the lung. It tends to develop in smokers.
  • Large cell carcinoma occurs anywhere in the lung, and it usually grows and spreads at a rapid rate.

What Is Small Cell Lung Cancer?

SCLC usually starts near the center of the chest in the bronchi. It’s a fast-growing form of cancer that tends to spread in its early stages. It tends to grow and spread much faster than NSCLC. SCLC is rare in nonsmokers.

What Are the Symptoms of Lung Cancer?

Early stage lung cancer doesn’t usually produce obvious symptoms. As the cancer progresses, there may be:

  • shortness of breath
  • coughing
  • coughing up blood
  • chest pain 

Other symptoms may include:

  • fatigue and weakness
  • loss of appetite and weight loss
  • hoarseness
  • difficulty swallowing
  • pain in the bones and joints
  • swelling of the face or neck

How Does Lung Cancer Spread?

Cancer may spread from the original tumor to other parts of the body. This is called metastasis. There are three ways this can happen:

  • Cancer can invade nearby tissue.
  • Cancer cells can travel from the primary tumor to nearby lymph nodes. They can then travel through the lymphatic system to reach other parts of the body.
  • Once cancer cells enter the bloodstream, they can travel anywhere in the body (hematogenous spread). 

A metastatic tumor that forms somewhere else in the body is the same type of cancer as the original tumor.

What Are the Stages of Lung Cancer?

Stages describe how far the cancer has progressed and are used to determine treatment. Earlier stage cancers have a better outlook than later stage cancers.

The stages of lung cancer range from 0 to 4, with stage 4 being the most severe. It means that the cancer has spread to other organs or tissues.

How Is Lung Cancer Treated?

Treatment depends on many factors, including stage at diagnosis. If the cancer hasn’t spread, removing a part of the lungs may be a first step. 

Surgery, chemotherapy, and radiation may be used alone or in some combination. Other treatment options include laser therapy and photodynamic therapy. Other medications may be used to alleviate individual symptoms and side effects of treatment. Treatment is tailored to individual circumstances and may change accordingly.

What Is the Outlook for Lung Cancer?

The outlook varies according to the cancer type, stage at diagnosis, and treatment. Survival rates are higher for stage 1 and stage 2 lung cancers. 

The five-year survival rate ranges from 45 to 49 percent for those with stage 1 NSCLC.

About 10 percent of those with SCLC will remain free of disease during the first two years of therapy. The five-year survival rate is around 5 to 10 percent.

While SCLC is much more aggressive than NSCLC, finding and treating lung cancer early is one of the best ways to ensure a longer, healthier life.