Small Cell Lung Cancer

Small cell lung cancer is a rare fast-growing lung cancer. It can affect anyone but it typically affects people who have a long history of smoking tobacco. Healthcare providers can cure some people if the disease is found early; for others, they can help them live longer. The only way to prevent small cell lung cancer is to stop smoking.

Overview

(Left) Exterior view of lung. (Right) Lung cut in half to show small cell lung cancer tumors.
Lung (left) and small cell lung cancer tumors in lung cut in half (right). This cancer can affect anyone but it typically affects people who have a long history of tobaccos use, specifically smoking cigarettes.

What is small cell lung cancer?

Small cell lung cancer is a rare fast-growing lung cancer. Small cell lung cancer can affect anyone, but it typically affects people who have a long history of tobacco use, specifically smoking cigarettes. Healthcare providers can cure some people if the disease is found early; for others, they can help them live longer. The only way to prevent small cell lung cancer is to stop smoking.

How common is this condition?

Overall, about 57 in 100,000 people in the U.S. develop lung cancer. Small cell lung cancer represents about 15% of those cancer diagnoses. It’s less common than non-small cell lung cancer.

How does small cell lung cancer affect my body?

Small cell lung cancer starts when healthy cells in your lungs mutate or change into cancerous cells. These cells then divide and multiply uncontrollably. Eventually, the cancerous cells clump together in masses (tumors) in your lungs.

These tumors may shed cancer cells that your blood or lymph pick up and carry throughout your body. (Lymph is fluid that travels through your body to your lymph nodes.)

Small cell lung cancer typically spreads to:

  • Lymph nodes.
  • Bones.
  • Brain.
  • Liver.
  • Adrenal glands. These glands are located near your kidneys.

Once the cells have spread, they may create new cancerous tumors in your lymph nodes and organs. Small cell lung cancer may also cause fluid to build up in your lungs or in the space around your lungs. It can make your lung collapse by pushing air out of your lung. This is called a pleural effusion.

There are two types of small cell lung cancer:
  • Small cell carcinoma: This is the most common form of small cell lung cancer.
  • Combined small cell carcinoma: Combined small cell carcinoma represents about 2% to 5% of all small cell carcinomas. This small cell type is a combination of non-small cell and small cell lung cancer cells.
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Symptoms and Causes

What are the symptoms of small cell lung cancer?

Small cell lung cancer that hasn’t spread rarely causes symptoms. When symptoms happen, they may include:

Many of these symptoms are similar to other less serious conditions. Having one or more of these symptoms isn’t a sign you have small cell lung cancer. That said, if you smoke or you used to smoke and you notice these types of symptoms, talk to a healthcare provider. They’ll evaluate your situation and recommend any next steps.

What causes small cell lung cancer?

While anyone can get lung cancer, people who smoke, used to smoke or who are exposed to tobacco smoke (second-hand smoke) have an increased risk of developing small cell lung cancer. Other risk factors include:

  • Exposure to radiation from cancer treatments or imaging scans.
  • Exposure to radon gas. Radon is a colorless radioactive gas that may seep into homes and other buildings.
  • Exposure to workplace hazards like asbestos, arsenic, nickel, tar or toxic chemicals.
  • Having a family history of lung cancer.
  • Having human immunodeficiency virus (HIV).
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Diagnosis and Tests

How do healthcare providers diagnose small cell lung cancer?

Chest X-rays are typically the first step to evaluate someone for any type of lung cancer. If images show suspicious spots on your lung, a healthcare provider may order one or more of these diagnostic tests:

  • Imaging scans: Computed tomography (CT) and positron emission tomography (PET) scans detect lung tumors. CT scans are the primary way to diagnose lung cancer. These tests also can help gauge cancer spread.
  • Biopsy: A needle biopsy removes tissue samples from your lungs. Lab pathologists check the biopsy for cancer cells.
  • Bronchoscopy: Using a bronchoscope, your provider looks inside of your lung’s airways for tumors. At the same time, they may remove tissue samples to biopsy.

What are the stages of small cell lung cancer?

Healthcare providers use a two-stage system to diagnose the spread of small cell lung cancer. This information also helps guide treatment. The two stages of small cell lung cancer are:

  • Limited stage: This means there’s cancer in one of your lungs that may have spread to an area between your lungs or to lymph nodes just above your collarbone. About 1 out of 3 people with small cell lung cancer have limited stage cancer at diagnosis.
  • Extensive stage: In extensive stage, the cancer has spread to your other lung or beyond your lungs to lymph nodes. It also may have spread to your bones, brain and other organs.

Management and Treatment

What are treatments for small cell lung cancer?

Treatment depends on many factors including your age, overall health and cancer stage. Treatment options include:

  • Surgery: About 1 in 20 people with small cell lung cancer have tumors that haven’t spread beyond their lung. In this circumstance, a surgeon may remove part of your lung or your entire lung. People who can’t have surgery may receive radiation therapy or chemotherapy.
  • Radiation therapy: External radiation therapy uses a machine to deliver strong X-ray beams directly to the tumor. In addition to killing cancer cells, this therapy can relieve symptoms. Healthcare providers typically use radiation therapy to treat limited stage small cell lung cancer.
  • Chemotherapy: If you had surgery, your healthcare provider may combine chemotherapy drugs with other treatments to kill lingering cancer cells. People with extensive stage cancer often receive chemotherapy. Chemotherapy can’t cure small cell lung cancer, but it can shrink cancer tumors, ease symptoms and help people to live longer.
  • Immunotherapy: This treatment engages your body’s immune system to fight and destroy cancer cells. Immune checkpoint inhibitors are a type of immunotherapy that treats extensive small cell lung cancer. Healthcare providers may use this treatment along with chemotherapy to shrink cancer tumors and ease symptoms.

What happens if I can’t have surgery and other treatments aren’t making a difference?

There are options your healthcare provider may recommend and you may want to consider, such as:

  • Shifting treatment from trying to cure small cell lung cancer to treatment that eases symptoms. For example, if your lung passages are blocked, your healthcare provider may use a bronchoscope to open those passages.
  • Considering participating in a clinical trial. For example, recent clinical trials that combined chemotherapy and immunotherapy helped people with advanced small cell lung cancer to live longer. About 15% of people who received the combined treatment were alive three years after completing treatment.
  • Considering palliative care: This care focuses on helping you manage symptoms, including pain, and cancer treatment side effects.
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Prevention

How do I reduce my risk of developing this condition?

Avoiding tobacco is the best way to prevent small cell lung cancer. If you currently smoke tobacco, try to quit as soon as possible. Regardless of how old you are or how long you’ve been smoking, your lungs begin to heal as soon as you stop. Giving your lungs a chance to heal reduces your risk of developing small cell lung cancer. If you smoke tobacco and want to quit, ask a healthcare provider about smoking cessation treatment and programs.

What about lung cancer screening tests?

Unlike other types of lung cancer, there isn’t a screening test for small cell lung cancer.

What else can I do to reduce my risk?

These steps may also help:

  • Maintain a weight that’s healthy for you.
  • Eat a nutritious diet.
  • Exercise regularly.
  • Test your home for radon.
  • Install a mitigation system to remove radon from your home, if needed.
  • Protect yourself from cancer-causing chemicals (arsenic, asbestos, nickel) at work.

Outlook / Prognosis

What is the prognosis for small cell lung cancer?

Small cell lung cancer is a very aggressive illness. Without treatment, most people with small cell lung cancer die a few months after they’re diagnosed. Healthcare providers can treat small cell lung cancer, but the disease often comes back. A 2020 study showed more than 50% of people treated for small cell lung cancer had a recurrence, meaning the cancer came back. According to 2020 data, about 7% of all people with small cell lung cancer were alive five years after diagnosis.

Many factors affect small cell lung cancer prognoses:

  • The cancer stage: Healthcare providers have more success treating small cell lung cancer that hasn’t spread from where it started.
  • Treatment options: Surgery to remove tumor is an option for 1 in 20 people with limited stage small cell lung cancer. People who can’t have surgery may receive chemotherapy and radiation therapy.
  • Recurrence: Healthcare providers have fewer options for treating small cell lung cancer that comes back.

There’s no question that the prognoses for small cell lung cancer are grim. It’s important to remember a prognosis is what may happen, not what will happen. If you have small cell lung cancer and want to know your prognosis, ask your healthcare provider to explain what you may expect.

What is the survival rate?

Survival rates are estimates based on the experiences of groups of people. About 70% of people with small cell lung cancer aren’t diagnosed until after the cancer has spread (extensive-stage small cell lung cancer.) These people have fewer treatment options. According to 2020 data:

  • Overall, 7% of all people with small cell lung cancer were alive five years after their diagnosis.
  • About 27% of people with limited stage small cell lung cancer were alive five years after diagnosis. Someone with limited stage small cell lung cancer has cancer in one lung and nearby lymph nodes.
  • About 16% of people with cancer that’s spread outside their lungs to nearby tissues and organs were alive five years after diagnosis.

Remember — just like prognoses, survival rates are estimates based on the experiences of groups of people. What’s happened to other people may not apply in your situation.

Living With

I have small cell lung cancer. How do I take care of myself?

Surgery and other cancer treatment can be physically challenging. You may feel exhausted after completing treatment. Here are some things you can do to stay strong through treatment:

  • Eat a nutritious diet: The combination of cancer symptoms and cancer treatment can affect your appetite. If you’re having trouble eating, ask if you can work with a nutritionist. They’ll have suggestions for ways to make sure you’re getting the nutrition you need.
  • Get some exercise: Cancer is stressful. Gentle exercise may help relieve stress.
  • Seek support: Small cell lung cancer is a rare, incurable illness. It can be lonely to be one of the few people with a medical issue. Talk to a healthcare provider about support groups where you can connect with people who understand what you’re going through.
  • Consider mental health support: You may feel you have to keep your cancer worries to yourself to avoid upsetting your loved ones. If that’s your situation, consider working with a mental health specialist.

What questions should I ask my healthcare provider?

If you have small cell lung cancer, you may want to ask your healthcare provider:

  • Why did I get small cell lung cancer?
  • What stage is the lung cancer?
  • What does this mean for my prognosis?
  • What’s the best treatment for someone in my situation?
  • What are the treatment risks and side effects?
  • Should I consider a clinical trial?
  • What type of follow-up care do I need after treatment?
  • Will the cancer come back?
  • What are the symptoms of recurring small cell lung cancer?
  • How can I stop smoking?

Additional Common Questions

What is the difference between non-small cell lung cancer and small cell lung cancer?

There are several differences:

  • Small cell lung cancer typically starts in one kind of cell based in one area of your lung. Non-small cell cancer may start in three different kinds of cells and different areas of your body. For example, adenocarcinoma affects glands that line your organs. In non-small cell lung cancer, adenocarcinoma starts in the outer portions of your lungs.
  • Small cell lung cancer spreads more quickly than non-small cell lung cancer.
  • Viewed under a microscope, small cell lung cancer cells are much smaller than non-small cell lung cancer cells.

A note from Cleveland Clinic

More people with small cell lung cancer are living longer thanks to early cancer screenings and newer treatments. Healthcare providers have treatments to help people to live longer and with a good quality of life and that may cure some people

Tobacco use causes small cell lung cancer. If you smoke, try to stop. It’s never too late to stop smoking, even if you already have lung cancer. Ask your healthcare provider for help finding smoking cessation programs.

Medically Reviewed

Last reviewed by a Cleveland Clinic medical professional on 09/28/2022.

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