Facts About Lung Cancer
(en Español)

Causes

You can get lung cancer even if you never smoked a day in your life. Scientists estimate that environmental tobacco smoke (secondhand smoke ) causes about 3,000 lung cancer deaths per year among adult nonsmokers in the United States.(3)

While smoking is the #1 cause of lung cancer it's not the ONLY cause of lung cancer. Second hand smoke , Radon gas, asbestos, and exposure to other carcinogens also contribute. For example, radon gas is the second leading cause of lung cancer deaths in the U.S. according to the American Lung Association (ALA). Radon gas comes up through the soil and seeps through the cracks  in foundations and walls in homes and buildings. It can also enter through gaps in insulation, cracks in pipes, and drains. The ALA says that Radon gas causes 12% of all lung cancer deaths each year in the United States. Radon is a gas that you can't see or smell and the only way to detect is to measure radon levels. 1 Where does it come from? Radon is a natural by-product of decaying uranium in the earth's soil.  Outdoors, radon exists in low concentrations that are generally not a health concern. In enclosed spaces, however, such as basements, radon can accumulate and may be cause for concern. For more information on radon detectors, click here .

Smoking does increase your chance of lung cancer by 10 times of that compared to someone who has never smoked. However, for every year you quit smoking you give your lungs a second chance. The cells repair themselves. And after 10 years of not smoking, your risk drops to a range of 1/3 to 1/2 of someone who continues to smoke. In addition, smoking causes other diseases such as emphysema and heart disease.

Tobacco is responsible for 85% of lung cancer cases (this includes secondhand smoke). However, radon is the #1 cause of lung cancer among nonsmokers, according to the Environmental Protection Agency.

Is lung cancer hereditary?

Even though the role of heredity in lung cancer is not as well-known, having a family history of lung cancer does increase our risk to some degree. Hereditary lung cancer is higher in women, nonsmokers and those with early onset lung cancer (lung cancer that occurs before the age of 60). Overall, it has been estimated that 1.7% of lung cancers up to the age of 68 are hereditary. Several factors are associated with hereditary lung cancer, including:

  • How Closely a Family Member is Related - Having a first-degree family member (parent, sibling or child) with lung cancer roughly doubles the risk of developing lung cancer. This risk is more for women and less for men and stronger in nonsmokers than smokers. Having a second-degree relative (an aunt, uncle, niece or nephew) with lung cancer raises your risk to around 30%.
    (source: About.com)

  • Type of Lung Cancer and Heredity - studies vary, but those with Non-small cell lung cancer are more likely to have a family history of lung cancer than small cell lung cancers

  • Smoking Status - smoking amplifies the risk of lung cancer if you have a family history.

  • Race - African Americans with first-degree relatives have a greater risk of early onset lung cancer than whites.

Types

Most lung cancers fall into two types of categories: Non-small Cell Lung Cancer and Small Cell Lung Cancer. Each type grows and spreads at different rates and each is treated differently.

Non-Small Cell Lung Cancer  - is the most common type of Lung Cancer comprising of nearly 80% of all cases. Non-small cell lung cancer is divided into three different subcategories. Squamous cell carcinoma (also called epidermoid carcinoma) originates in the thin, flat cells that line the passages of the respiratory tract. Adenocarcinoma begins in the cells that form the lining of the lungs. Large cell carcinomas make up a group of cancers that look large and abnormal under a microscope. (2)

Small Cell Lung Cancer - makes up nearly 20% of all Lung Cancer cases. It is associated with cancer cells smaller in size than most other cancer cells. These cells may be small, but they can rapidly reproduce to form large tumors. Their size and quick rate of reproduction allows them to spread to the lymph nodes and to other organs of the body. This type of Lung Cancer is almost always caused by smoking or second hand smoke. (2)

Stages

Each type of lung cancer has different stages. It simply depends on how far the cancer has progressed. For non-small cell lung cancer there are 4 stages. For small cell lung cancer there are 2 stages.

Non-small cell lung cancer:

  • Stage 1 means that the cancer is localized to the lung and there is no cancer in the surrounding lymph nodes.
  • Stage 2 means that it has spread to the lymph nodes closest to the affected lung or that it has not spread to the lymph nodes but instead to the chest cavity, chest wall, outer covering of the lung, or the outer covering of the heart.
  • Stage 3 means that the cancer has either spread to the nodes on the other or same side of the chest, that there is more than one tumor in the affected lung, that there is fluid around your lung that contains cancer cells, or that the tumor has grown into another major structure in your chest.
  • Stage 4 usually means that the cancer has spread to another part of the body such as the liver, brain, or bones.

Small cell lung cancer: 

  • Limited stage means that the cancer can only be seen in the lung,  surrounding lymph nodes or in fluid around the lung. 
  • Extensive stage means that the cancer has spread outside of the lungs to another area of the body. Typically, the chest, liver or brain. Because small cell lung cancer is comprised of tiny cells and not a solid tumor, it is usually inoperable, except in rare cases in the early limited stage. (3)

    Regardless of the stage of small cell lung cancer, the prognosis is unsatisfactory even though tremendous strides on treatment and diagnosis over the past 15 years have been made. Because of this, all patients diagnosed with this kind of cancer are eligible to participate in ongoing clinical trials. For more information on clinical trials, you can visit the National Cancer Institute's website .

Treatment Options

Chemotherapy, radiation and surgery are the various common types of treatment for lung cancer patients. There is also alternative medicine approach, such as using herbs, etc.

  • Chemotherapy: This is treatment using drugs. These drugs kill off cancer cells and try to cause less damage to normal cells. (although it can kill off some normal cells too). There are several kinds of chemotherapy drugs.

Common side effects of chemotherapy include nausea and vomiting, hair loss, mouth sores, and fatigue.(3)

  • Radiation (or Radiotherapy): This is treatment using x-rays. It directs painless highly concentrated energy beams to the area being treated. It works by killing the cancerous cells. It can be used on it's own or in combination with surgery or chemotherapy.

Common side effects of radiation therapy are a dry, sore throat; difficulty swallowing; fatigue; skin changes at the site of treatment; and loss of appetite. Patients receiving radiation to the brain may have headaches, skin changes, fatigue, nausea and vomiting, hair loss, or problems with memory and thought processes.(3)

  • Surgery: For non-small cell lung cancer, if the cancer has not spread and is confined to a solid tumor, then surgery is often the most common form of treatment. However, in small-cell lung cancer surgery is not an option. (it's not an option because it's not a solid tumor. Small-cell tumors are comprised of tiny cells making up a mass in the lung or chest area.)

Common side effects of lung cancer surgery are pain or weakness in the chest and the arm and shortness of breath.(3)