Does Smoking Cause Small Cell Lung Cancer?

Small cell lung cancer (SCLC) is an aggressive form of lung cancer predominantly caused by cigarette smoking, making up 13% of all U.S. cancer cases.

SCLC tends to grow and spread faster than non-small cell lung cancer (NSCLC).

SCLC is lethal if not caught early, so you never want to take any upper respiratory symptom lightly if you are a smoker. Even more, traditional cancer treatments like chemotherapy and radiation usually target rapidly dividing cells, which means that SCLC is more responsive to chemotherapy and radiation treatment, underscoring the importance of early diagnosis and treatment. 

This article discusses smoking and SCLS risk level, and how to reduce your risk.

Small Cell Lung Cancer and Smoking

Small cell carcinoma (SCLC) makes up between 10% to 15% of all lung cancers.

Two types of this aggressive form of lung cancer exist:

• Small cell carcinoma
• Combined small cell carcinoma

These fast-growing cancers are extremely lethal.

In fact, at the time of diagnosis, about 70% of people with SCLC have a metastatic spread of their cancer. Radiation and chemotherapy provide little relief.

Other Small Cell Lung Cancer Risk Factors

Smoking is not the only SCLC risk factor. Other risk factors are outlined below.

Secondhand Smoke

The association between secondhand smoke and lung cancer is well known—nearly 7,300 people die every year from secondhand smoke-related forms of lung cancer—but there is growing evidence that points to exposure to passive smoke as a growing cause of aggressive SCLC.

Even more, secondhand smoke leads to many illnesses, from asthma, emphysema, and COPD, that can lead to hospitalizations and a substantial decrease in your quality of life.

Radon

Radon is a radioactive chemical found in ground soil. It is the second leading cause of lung cancer in the U.S. and the first leading cause of cancer in those with no smoking history.

High radon levels can accumulate in the lungs when this inert, odorless, colorless gas becomes trapped indoors through cracks or holes in a building’s foundation. Radon exposure for a short period may be harmless. Still, if exposed for an extended period, these harmful particles can lodge into the lung lining and give off radiation, damaging your cell's DNA and forming cancerous tumors. 

While the radon effect on SCLC is not entirely understood, low-dose residential radon exposure of more than 1.0 picocuries per liter of air (pCi/l) to radon has been associated with an increased risk of SCLC, underscoring the importance of radon testing in houses.

Asbestos

Asbestos is one of the most common causes of cancer, accounting for 18% of all cases and nearly 3,000 deaths per year. It causes three types of lung cancer: non-small cell, small cell, and mesothelioma. These cancers usually develop 15 or more years after exposure.

Inhaling asbestos fibers is less common today due to regulations on its use in construction materials like cement, floor tiles, and pipes. However, it is still a problem in older houses (built before the 1980s). These houses that have not been inspected or are being redone may result in you unknowingly inhaling toxic levels of this cancer-causing substance.

Air Pollution

Lung cancer from residential air pollution is a growing cause of concern in urban U.S. cities and around the world. In California, a study looking at over 350,000 people found that people who lived in highly polluted areas were much more likely to develop SCLC, NSCLC, and adenocarcinomas. However, the associations were for people with early-stage non-small cell cancers, particularly adenocarcinomas.

Similar results were found in a South Korean study, which found that air pollution accounts for nearly one-quarter of all lung cancer cases, with the highest rates clustered around densely populated urban centers.

Arsenic in Drinking Water

Chronic exposure to arsenic—usually via inadvertent ingestion of contaminated water or occupational exposure—has been associated with the development of SCLC in lifetime nonsmokers.

Of note, case reports have identified cases of SCLC arising over 30 years after chronic exposure to arsenic, an ingredient that is found in traditional Chinese medicines used in the treatment of asthma.

Radiation Therapy to the Lungs

Radiation therapy is a commonly used lung cancer treatment initiated during or after treatment to kill hard-to-see lung cancer cells, lessening recurrence or the likelihood that your cancer will return.

Radiation therapy uses high doses of X-rays to damage the DNA of rapidly dividing cancer cells, destroying them in the process. Radiation therapy rarely causes lung cancer, especially the small cell subtype, but if it does, it’s usually different from the one that is being treated.

Family History

Sometimes your genetics may predispose you to lung cancer. This is more likely the case in individuals with an immediate non-smoking family member who has or had lung cancer. Certain inherited mutations can be passed down from parents to their children, although the link between these genes and the exact development of lung cancer has not been established

International data from the Nationwide Swedish Family-Cancer Database found a 1.77% increased risk of lung cancer for the offspring of parents who were affected by lung cancer and an even higher risk—2.15% among siblings.

Familial forms of lung cancer may be influenced by several non-genetic factors, including similar lifestyles, such as diet and exercise, and similar environments, like living in areas with high levels of indoor and outdoor air pollution.

Can You Get Lung Cancer If You Don’t Smoke?

Exposure to toxic substances like asbestos, radon, secondhand smoke, and air pollution are common causes of lung cancer in people who have no smoking history.

People who are frequently exposed to the following, often radioactive, substances in the workplace also have a higher risk of lung cancer: 

• Uranium
• Arsenic
• Cadmium
• Chromium
• Nickel
• Some petroleum products

Non-small cell carcinoma (NSCLC) is the most common type of malignant lung neoplasm, making up 80% to 85% of all lung cancers. While current and former smokers may develop this type of cancer while smoking or years after quitting, most non-smoking-related lung cancers also fall in this category. The three main types of NSCLC are:

• Adenocarcinoma: The most common type of lung cancer in the United States
• Large cell carcinomas: Can appear anywhere in the lungs
• Squamous cell carcinomas: Often associated with smoking
  

Of note, chronic exposure to asbestos—a mineral fiber used in rocks and soil—can put you at risk of mesothelioma, a rare cancer of the chest lining. It accounts for about 5% of all lung cancer cases.

Other lung tumors that may affect the lungs include lymphomas, adenoid cystic carcinomas, and sarcomas. The causes of these tumors may be linked to genetic conditions or idiopathic causes. 

How to Reduce Your Risk of Lung Cancer

Below are two ways you can reduce your risk of lung cancer.

Quit Smoking

The harmful chemicals of tobacco products are the single biggest culprit of SCLC. While never smoking and quitting early are the two best ways to prevent lung cancer, new research shows that quitting at any point—even after a diagnosis of lung cancer—may significantly improve your overall health outlook, prolonging life and lowering the risk of disease progression.

Recognize the Signs of Lung Cancer

Early signs of lung cancer may be subtle and nonspecific. It’s common to attribute your symptoms to something else—even if you are a longtime smoker—like asthma or pneumonia, but there are several telltale signs of lung cancer that you may want to be aware of and don’t want to ignore, including:

• A persistent cough
• Shortness of breath, especially when you exert yourself
• Repeated respiratory infections like bronchitis and pneumonia
• Coughing up blood (hemoptysis)
• Shoulder, arm, chest, or back pain
• Unexplained weight loss

Summary

Small cell lung cancer is an aggressive form of lung cancer that is predominantly caused by cigarette smoking. 

A Word From Verywell 

When you think of lung cancer, you probably think of traditional cigarettes but e-cigarettes, vape pens, and hookah are taking center stage with their rise in popularity in teenage and young adult populations.

These tobacco products are even more unregulated than traditional cigarettes, so the overall harm to the body is unknown. Even more, the fruity flavors and deceptive marketing strategies can sometimes trick young people into thinking that these products are less harmful than they are.