Small cell lung cancer in the brain can occur when cells from a cancerous lung tumor break off and enter the lymph system or bloodstream. When the cells reach the brain, they can multiply and form a tumor, causing symptoms such as headache, vomiting, and seizures.

At this stage, treatment may involve chemotherapy, along with an immunotherapy drug. Because this is an aggressive cancer, the average survival time is 6 months.

The American Cancer Society estimates that in 2021 around 235,760 people in the United States will receive a diagnosis of lung cancer. Of these, about 13% will have the type called small cell. Small cell lung cancer has a high rate of progression to the brain.

In this article, we discuss small cell lung cancer in the brain and how fast it develops. We also look at potential symptoms and treatments.

SCLC is a type of cancer that can spread to the brain.Share on Pinterest
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Metastasis is the spread of cancer to another body part. If small cell lung cancer spreads to the brain, it is called brain metastasis. When this happens, it means that cancer cells have broken off from the primary tumor in the lungs and reached the brain via the lymph system or bloodstream.

In such cases, the cancer cells in the brain are lung cancer rather than brain cancer. For this reason, the illness is described as metastatic small cell lung cancer rather than brain cancer.

According to a 2019 study, 10–20% of people with small cell lung cancer have brain metastasis when doctors diagnose their primary tumor.

A 2016 study found that the average incidence of brain metastasis in 4,235 small cell lung cancer patients who did not have brain metastasis at initial diagnosis was 18%. The average was slightly higher for African American patients, but the amount was not statistically significant.

After small cell lung cancer metastasizes to the brain, it reduces a person’s survival time. Brain metastasis also leads to debilitating and life threatening symptoms and significant reductions in quality of life.

Small cell lung cancer that metastasizes to the brain is highly aggressive, as it multiplies quickly.

Evidence indicates that once metastasis occurs, the median survival time is 6 months.

Once lung cancer spreads to the brain, it can cause the following symptoms:

  • Increased intracranial pressure: This is the cause of most symptoms and refers to higher pressure within the skull.
  • Headaches: This is the first symptom in about 50% of people.
  • Vomiting: Vomiting occurs more frequently in children who have small cell lung cancer than adults. It can be so forceful that doctors call it projectile vomiting.
  • Epileptic seizures: Approximately 35% of individuals with brain tumors experience epileptic seizures. The risk of seizures with a brain tumor increases with age, especially in people older than 45 years.
  • Changes in consciousness: Changes may occur to the level and quality of consciousness. These range from subtle personality changes to a coma.

The American Cancer Society lists the following potential treatment options for small cell lung cancer that has spread:

Combination chemotherapy

Initial treatment can consist of combination chemotherapy, which frequently shrinks tumors.

Combination chemotherapy involves the use of more than one chemotherapy drug. The most common combination is etoposide (Vepesid) plus either cisplatin (Platinol) or carboplatin (Paraplatin). Side effects of combination chemotherapy may include tiredness, nausea, and hair loss.

Radiation therapy

If a person responds well to combination chemotherapy, a doctor may order radiation therapy, which delivers high energy rays from a machine to kill cancer cells. Radiation therapy may help people with small cell lung cancer in the brain live for longer.

Side effects may include tiredness and sunburn-like changes to the skin at the site of radiation.

Clinical trials

Clinical trials are experimental studies that test the effectiveness and safety of new treatments. They compare standard treatments with those that might prove more effective and offer a means to get the latest therapies.

People can speak with a doctor to find out if any relevant clinical trials are taking place at an accessible clinic or hospital. If someone does take part in a clinical trial, they will have the option to stop at any point.

More information on clinical trials for lung cancer is available on the American Cancer Society’s website.

Researchers evaluated data from 489 people who received treatment for small cell lung cancer with brain metastasis at the Medical University of Vienna between 1990 and 2018.

Data analysis demonstrated that individuals who received a diagnosis of limited small cell lung cancer did not have brain metastasis until around 11 months later. On average, those with extensive small cell lung cancer did not have brain metastasis until 9 months later.

Once brain metastasis occurred, the average survival time of people with neurological symptoms was 5 months. Those with no neurological symptoms had an average survival time of 8 months.

The American Cancer Society suggests the following questions a person could ask a doctor if they have small cell lung cancer:

  • Could my symptoms have another cause?
  • What is the stage of my cancer, and what does this stage mean?
  • What treatment do you recommend for me, and what is its goal?
  • What side effects does the treatment have?
  • Can I do anything to help the treatment work better?
  • Is there a clinical trial in which I could participate?
  • Can a certain kind of diet or nutritional supplement help?
  • What happens after treatment?
  • How long do you think I will live?

Small cell lung cancer in the brain is a fast-growing cancer. It can cause increased intracranial pressure, headaches, and changes in consciousness.

Typically, doctors first treat it with chemotherapy and immunotherapy medication. If a person responds well to these, radiation therapy may follow. An additional treatment option involves participation in a clinical trial.

The outlook for people with small cell lung cancer in the brain is poor. Evidence indicates that after someone receives this diagnosis, their survival time ranges from 5–8 months.

People with small cell lung cancer that has spread to the brain should work with a healthcare team on a treatment plan that addresses their health and quality of life needs.