About Lung Cancer

Lung cancer is the uncontrolled growth of abnormal cells in one or both lungs. The two major types of lung cancer are:

  • Non-small cell lung cancer (the most common)
  • Small cell lung cancer

There are also less common types of lung cancer. One example is mesothelioma, which affects the lining of several organs in the body, but most commonly the lungs. Another less common cancer is a carcinoid tumor, which grows slowly and is generally cured by surgery.


Most lung cancers do not cause any symptoms until they have spread too far to be cured, but symptoms do occur in some people with early disease. The most common symptoms of lung cancer are:

  • A cough that gets worse or does not go away
  • Chest pain that is often worse with deep breathing, coughing, or laughing
  • Hoarseness
  • Weight loss and loss of appetite
  • Bloody or rust-colored sputum (spit or phlegm)
  • Shortness of breath
  • Recurring infections such as bronchitis and pneumonia
  • New onset of wheezing

When lung cancer spreads to distant organs, it may cause:

  • Bone pain
  • Neurologic changes (such as headache, weakness or numbness of a limb, dizziness, or recent onset of a seizure)
  • Jaundice (yellowing of the skin and eyes)
  • Lumps near the surface of the body, due to cancer spreading to the skin or to lymph nodes (collections of immune system cells) in the neck or above the collarbone

You may not have any symptoms of lung cancer, or you may have symptoms such as a cough or shortness of breath that you think are related to a respiratory illness. Lung cancer screening is now available for those who have a high risk for lung cancer.

Risk factors

  • Cigarette smoking
  • Exposure to certain industrial substances, such as arsenic
  • Some organic chemicals
  • Radon and asbestos, particularly for persons who smoke
  • Radiation exposure from occupational, medical
  • Environmental sources, such as air pollution and tuberculosis
  • Environmental tobacco smoke in nonsmokers


Smoking causes most cases of lung cancer, and secondhand smoke can be a contributor, as well. However, people who have never smoked can be diagnosed with lung cancer, as well. The American Cancer Society notes that if you stop smoking before a cancer develops, your damaged lung tissue gradually starts to repair itself. No matter what your age or how long you've smoked, quitting may help you live longer. People who stop smoking before age 50 cut their risk of dying in the next 15 years in half compared with those who continue to smoke.


Air pollution may increase the risk of lung cancer, but it is much less a risk factor than smoking. Additional causes of lung cancer may include exposure to radon, a naturally occurring radioactive gas that results from the breakdown of uranium in soil and rocks, and exposure to asbestos fibers in the workplace or home. Treatment with radiation therapy to the breast or chest may be a risk factor. Cancer-causing agents found in the workplace include radioactive ores such as uranium; inhaled chemicals or minerals such as arsenic (or arsenic in the water), beryllium, cadmium, vinyl chloride, nickel compounds, chromium compounds, coal products, mustard gas, and chloromethyl ethers; and diesel exhaust.

History of cancer

Individuals who have had lung cancer in the past have a higher risk of developing another lung cancer. Genetics is another factor, as brothers, sisters, and children of those who have had lung cancer may have a slightly higher risk.

Combined risk factors

When smoking is combined with other risk factors, the risk of developing lung cancer is increased. The American Cancer Society notes that people who are current smokers should realize that the best way to avoid dying from lung cancer is to stop smoking.

Lung cancer screening allows us to identify lung cancer at an earlier stage than previously possible. If you need additional testing after screening, or if you are experiencing symptoms associated with lung cancer, you will likely meet with a doctor called an interventional pulmonologist.

GPS Tracks Down Lung Cancer

Natalie Barnhill was diagnosed with lung cancer. Dr. Samir Makani at UC San Diego used electromagnetic navigation bronchoscopy to biopsy the lesion. Traditional biopsy of lung cancer involves using a needle through the chest and into the lung which can cause bleeding and collapse of the lung. The new GPS-like biopsy method enables doctors to definitively diagnose lung cancer in areas of the lung that are hard to diagnose so that treatment can be started earlier.

They will ask about your personal and family health history, conduct a physical exam, and may order a procedure such as endobronchial ultrasound bronchoscopy (EBUS) or electromagnetic navigation bronchoscopy (ENB). Both are non-surgical alternatives to conventional mediastinoscopy, which requires a small incision in the upper part of the chest, and can be used to diagnose and stage lung cancer. For more about diagnostic methods, see Interventional Pulmonology


    A process called staging is used to determine how much your cancer has spread and what treatment options will be considered.

    Generally, physicians consider the cancer to be:

    • Early stage
    • Locally advanced
    • Advanced

    The mainstay of early stage lung cancer treatment is surgical removal, sometimes augmented by chemotherapy and radiation. Locally advanced cancer may involve a combination of chemotherapy, radiation and surgery, in different treatment sequences. In advanced cases, chemotherapy is the main treatment, with radiation or ablation sometimes used to control symptoms. Clinical trials could be offered for patients in all stages of the disease.


    Our lung surgery team has more than 20 years of experience with thousands of lung cancer patients. Many studies have shown that the best surgical outcomes occur in medical centers with a high volume of cases.

    If your lung tumor has not spread beyond the lung, surgery is frequently the first choice of treatment to remove all the cancer. A variety of techniques may be used, depending on the size of the tumor, its location and your overall health. One option is video-assisted thoracic surgery (VATS), in which the surgeon uses a video camera to help visualize and operate upon the lung, resulting in surgical incisions that are much smaller than those required for other forms of surgery.

    The surgical team also works closely with your medical oncologist and radiation oncologist to ensure that your therapy is ideal for your specific case. For example, in some cases, radiation or chemotherapy will shrink the tumor to assist in its removal by the surgeon. Read more about Lung Surgery at UC San Diego Health.

    Radiation therapy

    While surgery is often the primary treatment for lung cancer, radiation therapy may also be beneficial:

    • After surgery, to destroy any remaining cancer cells
    • Before surgery, to shrink the tumor for a safer, easier surgery
    • As the main treatment for individuals who are not candidates for surgery
    • In cases of cancer recurrence
    • As palliative care to decrease pain and improve quality of life.

    A multi-step process, radiation therapy begins with your consultation, followed by a “simulation” visit, where your radiation oncologist precisely outlines the area in your body that needs to be treated, and, together with the medical physicist and dosimetrist, generates your treatment plan. Once your treatment plan is finalized, you will begin therapy.  UC San Diego Health offers among the most advanced radiation therapies available, including stereotactic radiotherapy, proton therapy and brachytherapy. Your radiation oncology team will advise you on which technique is most suited to your particular cancer. For more information, see Radiation Therapy.


    Chemotherapy is an outpatient treatment using drugs to kill cancer cells. The decision about chemotherapy is made with your input and heavily relies on your acceptance of aggressive vs non-aggressive management of your disease.

    Chemotherapy can be used to increase the chance of cure after the surgery, to increase survival in advanced lung cancer, and to help reduce pain and other problems caused by lung cancer. Side effects depend mainly on the type of drug, how much of it is used, how often it is given and for how long.

    Targeted therapy

    Targeted therapy, also called molecularly guided therapy, involves genetic analyses of tumor specimens to determine if there is a specific cancer mutation or aberration that can be targeted by a specific drug. (Examples of targetable mutations include EGFR, ALK, and ROS1, among others.) Treatments for cancers with "driver mutations" involve targeted therapies, which are often in the form of pills that can be taken at home. UC San Diego is involved in many clinical trials studying more advanced genetic analysis of tumors (tumor sequencing) to look for new mutations that can be targeted with newly developed medications.


    Immunotherapy involves treatments that stimulate and re-educate your body's immune system to kill cancer cells. These therapies are in the form of oral medications, infusions of therapeutic antibodies, or re-infusion of cells modified to target your specific tumor. UC San Diego is developing and studying many of these treatments through our clinical trials. For more information, see Immunotherapy.

    Palliative care

    Palliative care can help improve a patient's quality of life by treating symptoms and side effects such as pain, fatigue, anemia, hair loss, nausea, and depression. For more information, see Palliative Care.