Lung Cancer Diagnosis

By Dr. Ananya Mandal, MDReviewed by Sally Robertson, B.Sc.

Lung cancer does not usually present with symptoms until it has reached an advanced stage, which means patient outcomes are often less positive than with some other forms of cancer. Research has shown that around one in three people diagnosed with lung cancer will live for one year or more, but only one in ten will live for five years or more.

People should seek medical advice if they develop any lung cancer symptoms such as coughing up blood, a persistent cough or shortness of breath. The following diagnostic steps will then be carried out.

• A physician will ask about symptoms, as well as asking for a detailed history of any smoking habits and the presence of other risk factors such as occupational exposure to carcinogens and family history of the condition.
• A physical examination is carried out, including a lung function test using a technique called spirometry.
• A blood test may be carried out to rule out any other possible causes of the symptoms.
• Individuals who have been coughing up blood are usually given a chest X-ray or referred to a specialist in chest disorders. Lung cancer usually shows up as a white or grey mass on X-ray. However, it can be difficult to distinguish between a tumor and a lung abscess, meaning an X-ray is not a definitive test. When a mass is revealed, patients are referred to a lung specialist who carries out more detailed investigations to check whether lung cancer is present and how advanced it is.

If cancer is detected in the central part of the chest, a bronchoscopy is advised. Here an endoscopic tube called a bronchoscope is used to look at the lungs and take a biopsy sample of the tissue.

Staging of the cancer

Once lung cancer is diagnosed, it is staged to help predict the potential outcomes and treatment options.

Non-small-cell lung cancer stages

The most common form of lung cancer is non-small-cell lung cancer, which is staged as follows:

• Stage 1 – The cancer is confined to the lung and has not spread to nearby lymph nodes. The tumor is no larger than 5 cm in size.
• Stage 2 – A stage 2A tumor is either 5-7cm in size or less than 5cm in size, but has spread to nearby lymph nodes. A stage 2B tumor is either larger than 7cm or between 5 and 7cm but has spread to nearby lymph nodes. Stage 2B also describes a tumor that has not spread to lymph nodes, but has spread to other tissues, a main airway, or caused the lung to collapse.
• Stage 3 – The cancer has either spread to the lymph nodes in the middle of the chest, either side of the chest, to surrounding tissues such as the pleura or chest wall or to other important structures such as the heart or esophagus.
• Stage 4 – Here, the cancer is either affecting both lungs or has spread to another body part such as the brain or liver. Stage 4 cancer also describes cancer that has caused an accumulation of fluid-filled cancer cells around the lungs or heart.

Small-cell lung cancer stages

This less common form of lung cancer is either described as limited disease if it has not spread beyond the lung or extensive disease if it has spread beyond the long.

Further Reading

• All Lung Cancer Content
• Lung Cancer
• Lung Cancer Causes
• Lung Cancer Symptoms
• Epidemiology of Lung Cancer