What is small cell lung cancer?

Lung cancer is common, accounting for about 14% of new cancer diagnoses each year. In fact, lung cancer is the third most common cancer affecting American adults. Only skin cancer, prostate cancer in men, and breast cancer in women occur more frequently. There are two main types of lung cancer—non-small cell lung cancer and small cell lung cancer. Non-small cell is by far the most common form. Small cell lung cancer makes up about 10 to 15% of lung cancer cases. Doctors call it small cell because of the way the cells look under the microscope. You may also hear people refer to it as small cell carcinoma.

There are two subtypes of small cell lung cancer:

• Oat cell is the most common form of small cell lung cancer. These cancer cells look like oat grains under a microscope.
• Combined small cell carcinoma is less common. Under a microscope, there are also larger tumor cells within this type of cancer.

In general, lung cancer often has very few symptoms early in the disease. People can also mistake the symptoms for another problem. Because it is usually advanced at diagnosis, lung cancer is the leading cause of cancer-related deaths.

Small cell lung cancer is an aggressive form of lung cancer that grows and spreads quickly. It usually starts in the center airways (bronchi) and affects both lungs. It can rapidly spread or metastasize to the brain, liver, bones, and other organs and body parts. However, it is also highly preventable. Nearly all cases of small cell lung cancer are due to smoking. It rarely occurs in people who have never smoked. This means quitting smoking, or better yet, never starting is the most effective way to prevent small cell lung cancer.

Successfully treating any cancer, including lung cancer, is more likely when doctors find it as early as possible. This is difficult with lung cancer. You might increase the chances of finding it early by seeking prompt medical care if you have a cough that persists for more than a few days or worsens with time. Seek immediate medical care (call 911) if you cough up blood or bloody or rust-colored mucus.

What are the symptoms of small cell lung cancer?

Lung cancer tumors can grow in the lungs without causing pain or discomfort. Because of this, symptoms are not common early in the disease. Small cell lung cancer is usually too advanced to be cured by the time most people notice symptoms.

Common symptoms of small cell lung cancer

When they develop, the most common small cell lung cancer symptoms are:

• A new cough that persists or gets worse with time
• Chronic cough or ’smoker’s cough’ that changes or worsens
• Fatigue or weakness
• Hoarseness
• Loss of appetite or unintended weight loss
• Wheezing

Serious symptoms that might indicate a life-threatening condition

Lung cancer can cause serious symptoms that are similar to other life-threatening conditions. Seek immediate medical care (call 911) if you, or someone you are with, have any of these symptoms including:

• Chest pain that may worsen with deep breathing, coughing or laughing
• Coughing up blood or bloody or discolored mucus
• Shortness of breath or wheezing that makes it difficult to breathe

Lung cancer symptoms can mimic other conditions, such as a cold or other infection. This can lead people to put off seeing their doctor. Don’t take the chance, especially if you smoke. See your doctor to find out for sure. Seeking an early diagnosis offers the best chance for a successful outcome, regardless of the underlying cause.

What causes small cell lung cancer?

All cancers start when normal cells start to grow out of control. Normal cells have several so-called ‘checkpoints’ that keep growth and division under control. However, different types of genetic changes (gene mutations) can accumulate in cells over time that cause them to multiply abnormally and form a tumor. Scientists do not fully understand what triggers the specific changes in cells to make them multiply so abnormally.

For lung cancer, tobacco and other chemical exposures can damage the cells, increasing the risk of cancer-causing mutations. It’s also possible to inherit gene mutations that further increase the risk of developing cancer, including both types of lung cancer. This explains, in part, why lung cancer can run in families.

What are the risk factors for small cell lung cancer?

Risk factors are things scientists have identified that increase the likelihood of developing a disease. For small cell lung cancer, the primary risk factor is smoking. Almost all cases of small cell lung cancer occur in people who smoke cigarettes, cigars or pipes. While it is possible for nonsmokers to get SCLC, this is very rare. People who have never smoked have the lowest risk of lung cancer. Your risk increases the longer you smoke and the more cigarettes per day you smoke. You can decrease, but not eliminate your risk by stopping smoking.

Other less common risk factors include:

• Exposure to asbestos

• Exposure to hazardous chemicals and materials, especially in the workplace

• Exposure to radon

• Family history of lung cancer

• Previous radiation therapy to the chest

Is small cell lung cancer genetic?

Genetic factors include both inherited and non-inherited, or acquired gene mutations. Acquired gene mutations are those that occur at any time after conception. Some of these mutations can eventually cause cancer. It’s not clear if a family history of lung cancer relates to inherited gene mutations or to common household exposures, such as secondhand smoke or radon. It’s likely a combination of environmental factors and gene mutations.

The vast majority of small cell lung cancers are not hereditary, but genetics does play a role. That’s because exposure to the substances listed above increase the risk of acquiring gene mutations during your lifetime that may eventually cause lung cancer, and other cancers.

Reducing your risk of small cell lung cancer

For most cancers, prevention and risk reduction is about changing controllable risk factors. Since small cell lung cancer almost always affects a smoker, this means it is almost always preventable—don’t start smoking. If you are currently a smoker, you can reduce your risk by quitting. Ten years after quitting, the risk of developing lung cancer is half that of current smokers.

Making it 10 years can sound impossible, especially if you are a heavy smoker. It’s more helpful to think about the process one day at a time. Start by talking with your doctor about strategies and treatments for quitting. Choose one that fits your needs and give it a try. If you have a setback, do not get discouraged. Never quit trying to quit. Work with your doctor to see if a different approach would be better.

You may be able to lower your risk of small cell lung cancer by:

• Avoiding secondhand smoke by supporting smokers in your life to stop or working out arrangements to keep smoke away from you and loved ones

• Eating a healthy diet with plenty of whole grains and fresh fruits and vegetables as part of an overall healthy living strategy

• Following all safety precautions if you work with potentially hazardous substances to limit exposure to cancer-causing materials and chemicals

• Testing your home and installing a mitigation system if necessary to avoid radon exposure

How is small cell lung cancer treated?

Treatment starts with small cell lung cancer staging.

What are the stages of small cell lung cancer?

Staging gives doctors an idea of how widespread and serious a cancer is. They use the results of imaging exams, biopsies, and other tests to determine the cancer’s stage. For small cell lung cancer, there are two stages:

• Limited: The cancer only affects a limited area of one lung. Tumors are not widely dispersed in the lung. Cancer may have spread to lymph nodes near the collarbone on the same side of the chest. About 1 in 3 people have limited disease at diagnosis.

• Extensive: The cancer has spread throughout one lung, to both lungs, to lymph nodes on the other side of the chest, or to other organs or areas.

The stage plays a role in small cell lung cancer prognosis, meaning small cell lung cancer life expectancy. People with limited disease have a slightly better outlook. However, small cell lung cancer in general is very difficult to treat. Your doctor is the best resource for information about your prognosis.

Small cell lung cancer treatment

In most cases, treatment cannot cure or eliminate small cell lung cancer. Instead, treatment aims to reduce symptoms and prolong life.

Chemotherapy and radiation therapy are the two main treatments for small cell lung cancer. Chemotherapy uses powerful drugs to kill cancer cells. For small cell lung cancer, you typically get intravenous (IV) chemo so it can reach all areas of the body. This is important because small cell lung cancer is usually widespread at diagnosis. Doctors often add radiation therapy to chemotherapy for small cell lung cancer. Doctors rarely use lung resection for small cell lung cancer. The disease is usually too widespread and advanced for it to help.

What are the potential complications of small cell lung cancer?

Lung cancer is the leading cause of cancer-related deaths. Small cell lung cancer is the most aggressive and deadly form of the disease. For most people, the outlook is poor. However, there are other factors that affect survival. This includes your age, your overall health, and how well the cancer responds to treatment. Rely on your doctor for guidance on treatment and prognosis.