Non-small cell lung cancer (NSCLC) is the most common type of lung cancer in the United States. The American Cancer Society (ACS) estimates that more than 200,000 people in the United States will be diagnosed with lung cancer in 2022 and notes that about 84% of lung cancer cases are NSCLC.

Like all other cancers, NSCLC is most treatable when doctors can diagnose it before it spreads. Multiple factors influence the speed and progression of NSCLC, including the stage at diagnosis, the type of NSCLC, the ethnicity of the person with NSCLC, and the person’s response to treatment.

The spread of NSCLC is measured using a system called staging. The stage of cancer indicates how much it has spread. Cancer in earlier stages is contained to a small area, while cancer in later stages has spread to other areas of the body.

Doctors represent the stages of NSCLC on a scale from 0 to 4. In stages 0 and 1, cancer has not spread beyond the lungs or airways. In stages 2 and higher, cancer has spread to chest walls, lymph nodes, or other parts of the body.

Knowing the stage of your cancer helps doctors plan your treatment. Staging occurs when you receive a diagnosis based on your initial tumor size and spread. Your healthcare team will re-stage your cancer throughout treatment.

There is no set timeline for moving through NSCLC stages. However, getting a diagnosis at an earlier stage can allow you to receive treatment before your cancer progresses any further. This can prevent your cancer from spreading and improve your outlook.

Scientists often measure the growth rate of a tumor in doubling time. That’s how much time it takes for a group of cancer cells to double in size.

A 2019 study found that the median doubling time of NSCLC was 230 days. Some tumors studied doubled in size in as few as 19 days, but others never grew that much.

The researchers divided the study participants into two groups: those whose tumors had doubling times of 400 days or more, and those whose tumors had doubling times of fewer than 400 days. Participants in the group with shorter doubling times were more likely to be male and older.

In contrast, a 2020 review lists the doubling time for small cell lung cancer (SCLC) as 86 days.

There are three primary types of NSCLC:

  • Adenocarcinoma: This is the most common type of NSCLC and the most common type of lung cancer overall in the United States.
  • Squamous cell carcinoma: This type of NSCLC begins in flat squamous cells in the airways. More than 90% of these cases occur in smokers.
  • Large cell carcinomas: This type of NSCLC can grow anywhere in the lungs and is typically fast-growing.

A 2018 study found that the median doubling time varies by type of NSCLC:

  • Adenocarcinomas had a median doubling time of 261 days.
  • Squamous cell carcinomas had a median doubling time of 70 days.
  • Other lung cancers, which included large cell carcinomas and SCLC, also had a median doubling time of 70 days.

This means that adenocarcinomas typically progress much more slowly than other types of lung cancer.

Remember that these numbers represent the median, or the middle of all results. How NSCLC progresses depends on many factors unique to each person’s cancer. A 2020 study found that different subtypes of lung adenocarcinomas had median doubling times ranging from 229 days to 647 days.

Research has looked into racial and ethnic variations in NSCLC progression. A 2016 study found that NSCLC progresses more quickly in white Americans than in African Americans or Asian Americans. The study notes that the data is consistent with earlier population studies in Europe, Africa, and Asia that looked at survival times and mortality rates.

The study suggests that, in white Americans, it takes less than 1 year for a tumor to progress from a limited stage to an advanced stage. It takes 1 to 1.5 years for this to occur in African Americans or Asian Americans. This could influence how often people at high risk of NSCLC should be screened.

Some theories have looked into factors that might influence this difference, but more research is needed to determine the exact cause.

Treatments can help slow and even stop the spread of NSCLC. The exact treatment you need will depend on your stage at diagnosis, the location of the tumor, and your overall health.

Treatment options include:

  • Surgery: You might have surgery to remove all or part of the affected lung.
  • Ablation: Ablation destroys tumors by heating them or freezing them. It can be an option for people who cannot have surgery.
  • Chemotherapy: Chemotherapy can kill cancer cells and prevent tumors from growing back.
  • Radiation therapy: Radiation therapy can help shrink tumors and kill cancer cells.
  • Targeted therapy: Targeted therapy is specialized medication that finds and attacks cancer cells.
  • Immunotherapy: Immunotherapy enhances your immune system and helps it destroy cancer cells.

Where does NSCLC spread?

It’s common for NSCLC to spread, or metastasize, to nearby tissues, lymph nodes, and bones and then throughout the body. NSCLC can spread to regions such as the previously unaffected lung, the brain, the liver, and the adrenal glands.

Where NSCLC spreads can influence your outlook. A 2015 study found that cancer that had spread to the brain or extremities had the most unfavorable outlook.

The outlook for NSCLC is best when doctors can find and treat it early. According to the ACS, the 5-year survival rate for NSCLC found before it spreads beyond the lung is 64%.

In about 30% to 40% of people diagnosed with NSCLC, the cancer has already spread by the time of diagnosis. If cancer has spread to distant regions of the body, such as the brain, the 5-year survival rate drops to 8%.

These numbers are the survival rates with treatment. Without treatment, the mortality rates for NSCLC are high. The average survival time without treatment is around 7 months.

These figures stress the importance of early diagnosis and treatment for the best possible outlook.

NSCLC can progress quickly, although not as quickly as SCLC. The speed of its spread can depend on several factors, including the type and stage of the cancer. Your ethnicity and how you respond to treatment can also affect its progression.

It’s important to keep in mind that, as a result of new research, lung cancer treatments are consistently improving. Newer understandings of NSCLC and new treatment options mean that current survival rates are likely higher than those published.

Early diagnosis and treatment are key. Regular screening is important if you are at high risk of developing NSCLC. Talk with a healthcare professional about how often you should be screened.