Testing

There are different tests that may be used to diagnose lung cancer, which include examining lung cells in a lab. Cells may be taken from lung secretions, fluid in the area around the lung or suspicious mass using a needle or surgery (biopsy).

• Sputum Cytology: Sputum, or mucus that you cough up from the lungs, is checked in a lab to look for cancer cells. This test is more likely to help discover cancers that start in the major airways of the lung, such as squamous cell lung cancers.
• Needle Biopsy: A sample of the suspicious mass is removed using a needle (different sizes) and tested. There are different tools that may be used to guide the needle (e.g. CT scan, ultrasound, scope). There are different types of needle biopsies, which may include a fine needle aspiration (FNA) biopsy, core biopsy, or transthoracic needle biopsy.
  
  If lung cancer spreads, it tends to spread to lymph nodes inside the lugs or then lymph nodes outside of the lungs. Imaging results can help your healthcare team decide which lymph nodes to biopsy, if needed. The mediastinum is the space between your lungs that has many lymph nodes that may be tested for lung cancer.
• Thoracentesis: Fluid that may have collected around the lungs (pleural effusion) is removed by a hollow needle and checked in a lab to determine if it is caused by cancer spreading to the lining of the lungs or another condition.
• Pericardiocentesis: Fluid that may have collected around the heart is removed with a needle.
• Bone Marrow Biopsy and Aspiration: If cancer has spread to your bone marrow, which is the soft center of the bones, a bone marrow aspiration (removes liquid bone marrow) or bone marrow biopsy (removes core of bone and soft bone marrow) may be conducted in SCLC.

• Chest X-Ray: A beam of radiation is used to take images of your chest from different angles. This is typically the first test that your doctor may use to look for any abnormal issues in the lungs, and additional tests may be ordered if something suspicious is found.
• CT or CAT Scan (Computed tomography scan): Detailed pictures from different angles show any abnormalities where 3-D images of the inside of your body are generated using a computer. This can show the size and location of a lung tumor and/or metastases. A low-dose CT scan may also be recommended.
• PET Scan (Positron Emission Tomography): A test that uses a radioactive sugar substance (injected into body) and special camera to take pictures inside of body that show areas where sugar is collected through the body (since cancer cells absorb high amounts of this sugar). May be combined with a CT scan.
• Magnetic Resonance Imaging (MRI) Scan: Uses radio waves and strong magnets to show detailed images of the body which can show location and size of a tumor, as well as any metastases.
• Bone Scan: Shows if a cancer has spread to the bones by injecting a small amount of radioactive material into the blood and seeing if it collects in abnormal areas of the bone using a special camera. PET scans are often used in lieu of a bone scan in people with NSCLC so may not be recommended. PET scans can usually show this as well, so bone scans are not always needed.

• Bronchoscopy: A thin, flexible tube is guided down the throat and used to see the inside of the lungs. Tools are used to extract fluid or tissue samples and/or biopsy the lymph nodes.
• Mediastinoscopy: A lighted tube is inserted under the breast bone to take lymph node samples. A mediastinotomy (slightly larger incision between 2nd and 3rd rib) may be done if the lymph nodes can’t be reached.
• Thoracoscopy: A special instrument and small camera are used to examine the inside of the chest.

• Lung Function Tests: Lung (or pulmonary) function tests may be used to check how well your lungs are working. In a spirometry, you blow into a tube to measure how much air and how fast you breathe. In a gas diffusion test, you breathe in a harmless gas to measure how much you breathe out and how much oxygen travels from your lungs into the blood. In a body plethysmography, you breathe into a tube to assess how much air your lungs can hold and how much air is left in your lungs after you exhale.

• Biomarker/Molecular Testing: Biomarker tests are used to look for biological clues (markers) that are unique to your cancer, and include testing of either a blood or tumor sample that can help identify your cancer subtype and whether certain treatments are more likely to work for your cancer. Mutations are genes with one or more changes that can contribute to the growth of lung cancer.