Lung Cancer

Lung cancer starts when abnormal cells grow out of control in the lung. These cells can invade nearby tissue and form tumors. Lung cancer can start anywhere in the lungs and affect any part of the respiratory system.

The cancer cells can spread, or metastasize, to lymph nodes and other body parts.

Lung cancer, the leading cause of cancer death worldwide, is classified as non-small cell lung cancer (NSCLC) or small cell lung cancer (SCLC). Eighty percent of lung cancer is NSCLC. SCLC tends to grow more quickly and is more likely to spread than NSCLC.  



Although there are a number of potential causes and risk factors for lung cancer, the most common, by far, is smoking. The risk of developing lung cancer from smoking is related to how much and how long you have smoked. 

Other risk factors include:

  • Exposure to asbestos or the odorless, radioactive gas radon
  • Exposure to secondhand smoke
  • Having another lung disease, such as tuberculosis
  • Having a family history of lung cancer
  • Exposure to certain air pollutants
  • Exposure to coal dust


The symptoms of lung cancer are often vague. Symptoms depend on where in the lungs the cancer has developed and how advanced the cancer has become. Early in the disease, there are typically few or no symptoms present. As lung cancer grows, common symptoms may include:

  • A cough that doesn't go away and worsens over time
  • Constant chest pain
  • Coughing up blood (hemoptysis)
  • Shortness of breath, wheezing or hoarseness
  • Recurring pneumonia or bronchitis
  • Swelling of the neck and face
  • Loss of appetite or weight loss
  • Fatigue

If you are experiencing any of these symptoms (especially if you are or have been a smoker), make an appointment to see a doctor. 


Diagnosing Lung Cancer

Various tests and procedures may be used to diagnose lung cancer.

X-rays of the chest (from the back and side) are typically the first test used if lung cancer is suspected. If anything suspicious is found, the next step is usually a CT scan.

CT scans show the anatomy of any masses, or tumors, in the lung and chest. If the tumor is malignant, a CT scan also helps determine if the cancer has metastasized, or spread, to lymph nodes or other organs.

Although imaging technology is one tool in determining if lung cancer is present, the only way to know for certain is to remove and test samples of cells or tissue in a procedure called a biopsy. In rare instances, some people may require surgery to explore the chest area to obtain a biopsy.

Lung cancer screening is available based on your age, overall health and whether you previously or currently smoke cigarettes. Screening is done with low-dose CT scans. 


Specific treatment plans for lung cancer depend on the stage of the cancer, as well as your overall health, physical condition and other factors. The stage indicates the extent of cancer, ranging from I (the most contained) to IV (the most widespread). In general, early stage lung cancers (stage I and II) are most often treated by surgically removing the tumor or by targeting the tumor with radiation.

For more advanced tumors, a combination of treatments is used depending on the cancer stage and your overall health. If the cancer has spread to other organs, chemotherapy or supportive care is generally the preferred treatment method.

Lung resection surgery

Lung resection is the surgical removal of the diseased portion of a lung or the entire diseased lung. It is the preferred treatment for people with early stage NSCLC. Surgery can be performed with minimally invasive techniques, such as thoracoscopy or video-assisted thoracic surgery (VATS), robotic surgery, or open incision (thoracotomy).

At the time of surgery, thoracic surgeons have the ability to remove certain portions of the lung because the lungs are divided into lobes and segments. There are several types of lung resection.

  • Lobectomy: An entire lobe of the lung is removed.
  • Segmentectomy: A segment of the lung lobe is removed.
  • Wedge resection: The surgeon removes only a small part of the lung affected by cancer, including the tumor and some surrounding lung.
  • Pneumonectomy: An entire lung is removed.

The amount of lung removed depends on several factors, including the size and location of the tumor, whether lymph nodes have cancer and how well the lungs are functioning. Not all lung cancers are amenable to surgery, and some are initially treated with chemotherapy and radiation.

Thoracoscopy or video-assisted thoracic surgery (VATS)

Thoracoscopy is a surgical technique that accesses the lung through small incisions, compared with larger incisions and without rib spreading as required by traditional open surgery. A video camera is inserted through one of these smaller incisions, allowing surgeons to view the lung on a high-definition monitor and pinpoint the area that contains the tumor. Then, using surgical staplers and clips, surgeons can remove the diseased portion of the lung.

Radiation therapy

Radiation therapy, or radiation oncology, uses targeted, penetrating rays of energy (radiation) to destroy cancer cells. For lung cancer, radiation therapy can be used before surgery to shrink a tumor or after surgery to kill any remaining cancer cells. If surgery is not possible, radiation alone or in combination with chemotherapy may be used to destroy the tumor. 

External beam radiation therapy is the most common form of radiation therapy used to treat lung cancer. It is produced by a machine called a linear accelerator that fires short, targeted bursts of X-rays at the cancer.


With chemotherapy, medications are used to kill cancer cells via the bloodstream. Different chemotherapy drugs destroy cancer cells by a variety of different mechanisms.