When to See a Doctor for Non-Small-Cell Lung Cancer?
Any pain in the chest, side, or back, breathing problem, or cough that persists, worsens, or produces blood warrants an immediate visit to a health-care professional, especially if you are or ever were a smoker.
How Is Non-Small-Cell Lung Cancer Diagnosed?
Medical Evaluation and Tests
The symptoms of lung cancer can be caused by many different medical conditions. Even a chest X-ray film that shows what looks like a tumor is not enough to make the diagnosis of lung cancer. The health-care provider's job is to gather all available information and to make the diagnosis. Correct and prompt diagnosis is essential so that appropriate treatment can be started as soon as possible.
The first step in the evaluation is the medical interview. The health-care provider asks the patient questions about symptoms and when they started, current or past medical problems, medications taken, family medical problems and family cancer history, work and travel history, and habits and lifestyle. This is followed by a thorough physical examination.
The remainder of the evaluation focuses on confirming the presence of lung cancer and staging the tumor. Although primary-care providers are able to conduct this evaluation, they may prefer to refer the patient to a specialist in lung diseases (pulmonologist) or cancer (oncologist).
No blood test can confirm that a patient has lung cancer. Blood tests are performed to check the patient's general health, to rule out other conditions that might cause similar symptoms, and to detect certain paraneoplastic syndromes. The usual blood tests include the following:
- Complete blood cell counts
- Liver and kidney function tests
- Blood chemistry and electrolyte levels
Respiratory (breathing) symptoms are usually evaluated with a chest X-ray film, CT scan of the chest, or both. X-ray films are limited in the amount of detail they provide, but they clearly show some tumors. CT scans shows much greater detail in a 3-D format. A CT scan is needed if the X-ray film findings are not definitive. If imaging studies show evidence of a tumor, further testing is needed.
Sputum analysis: Sputum is mucus in the lungs. Sputum is the body's natural system for removing small particles and contaminants from the airways. Many people, especially those who smoke, produce sputum when they cough. In some cases of lung cancer, tumor cells are sloughed off into the sputum and can be detected by cytologic (cell) testing of the sputum. For this test, the patient is asked to cough, and the sputum is collected and examined.
- This simple test, if the result is positive for tumor cells, confirms the diagnosis of cancer. A result negative for tumor cells, however, does not confirm that no cancer is present.
- In either case, further testing is needed: if positive for tumor cells, to determine the type of cancer; if negative for tumor cells, to seek definitive evidence of whether a tumor is present.
Bronchoscopy: This is the use of a device called an endoscope to view the lungs directly. An endoscope is a thin tube with a light and a tiny camera on the end. The endoscope is inserted through the mouth or nose into the bronchus (airway) and down to the lung. The camera transmits pictures of the inside of the patient's airways that can be viewed on a video screen.
- Bronchoscopy allows the doctor to look directly at the tumor (if one is present). This allows the doctor to determine the tumor's size and the extent to which it is blocking the airway.
- The bronchoscope can also be used to collect a biopsy. A biopsy is a small sample of the tumor or any abnormal-appearing lung tissue that health-care professionals remove for further testing.
- The biopsy is examined under a microscope by a pathologist, a specialist in diagnosing diseases in this way. The pathologist confirms whether the sample taken from the mass is cancer and, if so, the type of cancer.
- This technique is also used to examine the area around the main airway, between the lungs in the middle of the chest (mediastinum). The cancer can infiltrate the lymph nodes in this area. The endoscope is inserted through a small incision just above or to the side of the breastbone. This technique is called mediastinoscopy. Enlarged lymph nodes and other abnormal tissues can be removed during this procedure.
Endobronchial ultrasound (EBUS): This technique that combines bronchoscopy with an ultrasound, allowing good visualization of lymph nodes and biopsy without an incision.
Fine-needle aspiration or core needle biopsy: These techniques allow sampling of abnormal tissue without the need for open surgery, using ultrasound, or CT scanning to localize the abnormal area. It is used for tumors that cannot be reached with a bronchoscope, usually because they are in the outer part of the lung. Again, this material is examined to confirm the presence of a tumor and to determine the type of tumor.
Testing of the Tumor Material
For certain NSCLC, genetic testing to look for mutations in the DNA of the tumor are recommended to determine whether targeted therapy (see below) may be effective. Current treatment practice is to recommend analysis of either the original tumor or of a metastasis in the case of late-stage disease, for epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK) for all patients whose tumor is of a subtype known as adenocarcinoma. Testing for other tumor markers may be performed to help determine which specific drugs will be most effective for a given tumor. This testing is performed in the laboratory using biopsy tissue samples.
Biopsies from other sites: Material can also be obtained from other sites with abnormalities to confirm the diagnosis. These sites include enlarged lymph nodes or liver and collections of fluid around the lung (pleural effusion) or heart (pericardial effusion).