Small-cell lung cancer (SCLC) is a form of lung cancer that is challenging to treat. Recent advances in immunotherapies can improve outcomes for people with SCLC.

SCLC is either limited, where the tumor is confined to the lung, or extensive, where the tumor has spread to other areas. Treating either type is challenging.

Keep reading to learn about recent advances and current research that aims at improving treatment for SCLC.

A person receiving treatment for SCLC.Share on Pinterest
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Doctors use a variety of methods to treat SCLC, depending on whether it is limited or extensive.

According to the American Cancer Society, in most cases, SCLC has already spread and requires chemotherapy. This involves taking chemotherapy drugs that travel through the bloodstream and kill cancerous cells around the body.

Doctors may recommend that people with SCLC also receive radiation therapy, which uses high doses of radiation to kill cancer cells.

In rare cases, doctors may recommend surgery to remove a tumor. However, for this to be a possibility, a person needs to be healthy enough to handle the removal of part or all of their lung, and the tumor needs to be small and confined to the lung.

SCLC treatment can slow or stop the spread of cancer cells and extend a person’s life. In some cases, people can recover from SCLC and live for years without the cancer returning.

However, SCLC remains a challenging condition to treat, as current treatment options can cause debilitating side effects.

For example, in addition to attacking and killing cancerous cells, radiation therapy and chemotherapy attack healthy cells, potentially leading to side effects and complications, such as:

Advances in treatment are necessary to address these problems.

A 2020 study found that SCLC death rates are declining in the United States. However, this is likely due to fewer people developing SCLC rather than advances in treatment, as survival rates for this type of cancer have not improved.

One factor responsible for the decline in people developing SCLC is a fall in smoking rates in the U.S. since the 1960s. Tobacco use is a leading cause of SCLC.

Learn more about SCLC prognosis here.

A promising area for advancing SCLC treatment could be the development of new immunotherapies. Immunotherapies are a class of treatment that supports the body’s immune system in its fight against cancer.

For example, immune checkpoint inhibitors block checkpoints that typically prevent the body’s immune response from becoming too intense. Blocking these checkpoints allows these drugs to strengthen the body’s immune response to fight cancer.

In 2015, the Cancer Research Institute (CRI) described the approval of checkpoint inhibitors by the Food and Drug Administration (FDA) as a landmark event in lung cancer treatment.

A 2019 review highlights promising immune checkpoint inhibitor drugs for SCLC. These include:

  • nivolumab
  • pembrolizumab
  • atezolizumab
  • durvalumab

Doctors may recommend combining chemotherapy with immunotherapy for people with extensive SCLC.

Targeted therapies attack specific parts of cancer cells, such as genes, to slow or prevent their growth. These drugs have been an important advance in treating many forms of lung cancer.

However, identifying suitable targets for SCLC has been challenging.

Immunotherapies are a major focus of current research into lung cancer treatment, including SCLC.

According to the CRI, there are several clinical trials underway that are testing the effectiveness of immunotherapies for lung cancer, including:

  • Targeted antibodies: These are proteins that the immune system produces. Scientists can engineer these proteins to slow or stop the growth of cancerous cells. For example, lung cancers can increase the production of mesothelin, a protein that experts associate with the spread of cancer.
  • Immunomodulators: These are drugs that influence how the immune system responds to cancer cells. Checkpoint inhibitors are an example of immunomodulators. Other examples include adjuvants, which increase the protection from or number of antibodies by the immune system to fight cancerous cells.
  • Adoptive cell therapy: This involves removing and adapting immune cells to improve their ability to fight cancer cells, before reinserting them into the body. For example, activating MAGE antigens can help the immune system identify cancer cells.
  • Cancer vaccines: These drugs aim to trigger the immune system to identify and attack cancerous cells with specific properties. For example, vaccines could target survivin, a protein whose production lung cancers commonly increase.
  • Oncolytic virus therapy: This therapy uses modified viruses to infect cancer cells and destroy them. For instance, scientists can modify the measles virus to infect cancerous cells in the lungs.

Chemotherapy remains the first-line treatment for most cases of SCLC.

The majority of advances in this area focus on combining chemotherapy or radiation therapy with more sophisticated methods.

For instance, immunotherapies and targeted therapies can attack cancer cells without the excessive damage to healthy cells that occurs as a result of chemotherapy or radiation therapy.

The development of more effective targeted therapies and immunotherapies may eventually replace the need for chemotherapy and radiation therapy.

A 2020 study observes that the death rate from SCLC is declining due to a lower prevalence of the condition. However, study authors also note that survival rates have not improved.

According to the National Cancer Institute (NCI), chemotherapy and radiation therapy do improve survival for people with SCLC. However, tumors in people with SCLC typically spread to other areas of the body, and long-term survival is still low.

The NCI suggests that most of the improvements in survival that occur result from people joining clinical trials of new therapies.

SCLC is a type of lung cancer that is challenging to treat, and advances in this area are still limited compared with the development of treatments for other forms of lung cancer.

Immunotherapies are a promising area for improving treatment outcomes for people with SCLC. Research to develop new immunotherapies and targeted therapies for SCLC is still ongoing.