Causes, Symptoms, Diagnostic Tests & Treatments For Lung Cancer

Submitted on March 27, 2012

As the name suggests, lung cancer is a type of cancer that originates in the lungs and largely affects the respiratory system. Since the lungs are in the chest, lung cancer may affect other organs of the chest as well. Lung cancer usually begins in the cells lining the bronchi, and from there it could spread to some of the other organs as well.

Types of Lung Cancer

There are two major types of lung cancer.

Small Cell Lung Cancer: Of the two types of lung cancer, this is the faster growing cancer. This small cell cancer is almost always caused due to cigarette smoking. Though the cancer cells are small, they grow very quickly and form large tumors. Since the cells are small, metastasis is also usually very quick, and the cancer may not be detected before it is too late for successful treatment.

Non-small Cell Lung Cancer: This is the most common kind of lung cancer and is slow growing. The cancer cells may occur in any part of the lungs, but are usually found in the bronchus or in the outer parts.


There are several tests for lung cancer. The doctor first performs an elaborate physical examination, after which other tests are performed. There is no specific lung cancer test; instead there are several tests that can indicate the presence of cancer in the lungs. Some of the most common tests include:

  • Chest X-ray: This can help show any abnormal growths in the chest cavity.
  • Bone scan: This can help detect if the bone density has changed. Bone density may change if the cancer has reached the bones.
  • Blood chemistry: A complete blood count (CBC) can help detect any unusual rise in the white blood cells, which is an indication of infection or inflammation in the body.
  • Imaging tests: Apart from X-rays, there are some other imaging tests such as MRI, CT scan and PET scan that can be used to detect the presence of cancer in the lungs or the chest.
  • Thoracentesis: The fluid around the lungs is extracted with the help of a needle and studied for cancer markers.
  • Lung biopsy and bronchoscopy: A sample of tissue from the bronchi or the lungs may be taken and studied to look for presence of cancer cells.
  • Mediastinoscopy: This is a procedure in which a mediastinoscope, or a lighted instrument, is inserted into the chest. This instrument is then used to retrieve a sample of tissue from any cancerous growth or the lymph nodes. This tissue sample is then studied for presence of cancerous elements and cells.

The doctor may prescribe some of these tests during the course of the treatment too. This is done to gauge the efficacy of the treatment being given.

If you feel that you may be suffering from lung cancer or if you feel that you are at a high risk, it is best to speak with a doctor for proper advise, diagnosis, and treatment.


Apart from active smoking, which is considered to be the most common cause of both small and non-small lung cancer, there are several other causes of lung cancer. Some of these include:

  • Passive smoking: Cigarette smoke contains tar and inhaling this smoke can cause as much damage as active smoking. Usually, the more smoke you inhale, the higher are your chances of getting lung cancer.
  • Asbestos: Asbestos fibers can cause extreme damage to lungs and may be the precursor to small cell lung cancer.
  • Radon gas: Radon gas is a by-product of the decay of several metals. It may also be present as the by-product of aerosols and certain other chemicals used in the daily life. This gas is usually very short lived, but its exposure may eventually cause lung cancer.
  • Exposure to chemicals: Other than radon and asbestos, there are certain other chemicals that may also cause lung cancer. Some of these chemicals include nickel chromates, uranium, chloromethyl, beryllium, mustard gas, diesel exhaust, and vinyl chloride, among others.
  • Lung diseases: Certain lung diseases, especially those that are genetic in nature, may also eventually cause lung cancer. A family history of lung cancer may also increase the risk of developing the cancer.
  • Air pollution: Air pollution contains a variety of substances that can trigger cancer in the lungs. Air pollution is a combination of smoke, chemicals, and other carcinogenic materials, all of which damage the lungs in a lot of different ways, eventually causing cancer.
  • Arsenic exposure: Arsenic is naturally found in water dug out from the deeper levels of the earth. Arsenic may also seep into water through industrial waste and chemical pollution. Drinking water with high levels of arsenic may also damage the lungs and cause cancer.
  • Radiation therapy: High levels of radiation exposure to the lungs may cause lung cancer. Such high levels of radiation usually occur when a person gets radiation therapy for cancer or tumors in the vicinity of the chest area.


Some of the most common symptoms of lung cancer include:

  • Chest pain: This may not even be noticeable at first, but when you try to take a deep breath, or sit or stand suddenly, the pain may reappear.
  • Persistent cough: Like the pain, the cough may not be noticeable at first. However, the cough may become persistent and cause an increasing amount of pain in your chest.  
  • Blood in the sputum: As the cancer ravages your lungs, it can cause damage to the tissues. As you keep coughing, you may notice blood or blood droplets in your sputum.
  • Repeated respiratory infections: One of the most telling symptoms of lung cancer is repetitive respiratory infections. If you have been experiencing more infections than usual, it should be a warning signal for lung cancer.
  • Unexplained weight loss or fatigue: A classic symptom of any kind of cancer, unexplained weight loss and persistent fatigue usually indicates a severe underlying problem and warrants a visit to a specialist.
  • Shortness of breath or wheezing: These are some of the other respiratory symptoms that indicate lung cancer.

In the later stages of lung cancer, some other severe symptoms may begin to appear. These often include:

  • Drooping of the eyelids
  • Brittle nails
  • Pain and tenderness in the bones, especially in the joints
  • Facial paralysis
  • Difficulty in swallowing
  • General fatigue and weakness
  • Swelling in the face and other parts of the body

These symptoms are not necessarily linked to lung cancer, so do talk to your healthcare provider and get yourself thoroughly tested.


The treatment for lung cancer depends on the type of cancer: small cell lung cancer and the stage to which the cancer has progressed. Here are some of the commonly used methods.


Surgery is usually performed when the lung cancer has not yet metastasized. There are several types of surgeries for lung cancer, depending on the stage of the disease. If the cancer is in its earlier stages and has only affected one of the lobes, a surgery known as lobectomy is performed. In case the cancer is slightly more widespread, a small part of the lung may have to be removed. This is known as a wedge removal or segment removal surgery. Only when the condition is very severe and the cancer has spread to a large area, is the entire lung removed. This is known as a pneumonectomy.


Some patients reach a stage where chemotherapy is required. Drugs are given to the patient to stop the cancer cells from growing. These drugs also attack the existing cell growths and attempt to shrink them. Chemotherapy is used when the cancer has metastasized and spread outside the lungs. Chemotherapy is often also given before a surgery or radiation therapy. If a surgery has been performed to remove part of the lungs, chemotherapy may be given to target any remaining cancer cells.

Radiation Therapy

In cases where surgery is not possible, chemotherapy is often paired with radiation therapy. This is a treatment method in which X-ray radiations or any other forms of radiation are used to shrink tumors and kill cancer cells. This therapy is not only used to treat the cancer, but may also be used to relieve the symptoms and the pain, especially when the cancer has metastasized. However, radiation therapy is usually used only when the cancer has spread to the bones and is extremely painful, because of its severe side effects.