Initially, your doctor will do a physical examination searching for signs indicating lung cancer. He can use a stethoscope to hear the sound of your lungs to determine if they work fine. In addition, you will be asked questions about the conditions of your symptoms and your medical history.
However, to confirm the presence of cancer in your lungs, several tests and exams should be performed. In general, it may recommend a complete blood count (CBC), spectrum test, imaging techniques, liver function tests and biopsy.
Sputum Test – a sputum culture is the easiest way to detect and identify bacteria or fungi that infect the lungs or breathing passages.
Complete blood count (CBC) – this exam is done to analyze quantitatively and qualitatively the elements of the blood: red cells, white cells and platelets. It is a very simple test consists of taking sample of blood with a needle for laboratory analysis. The blood obtained is analyzed by a pathologist who measures the number of red blood cells, hemoglobin and hematocrit (Ht or HCT), the volume of red blood cells circulating in the blood compared to the total volume of blood. In addition, the CBC is used to calculate the MCV (mean corpuscular volume), MCHC (corpuscular hemoglobin concentration) and the MCH (mean corpuscular hemoglobin).
Bone scan – this imaging technique allows your doctor to diagnose or detect very early bone abnormalities, sometimes not even visible on x-rays. During the procedure, the specialist will inject a small amount of radioactive agent in your body which will bind to the diseased bone. The radiation emitted is detected by a gamma camera that allows your physician to create image. The purpose of this test in the diagnosis of lung cancer is to determine if the cancer has spread to any bone in your body.
CT scan – this medical technique consists of using x-rays to form images of internal organs. It can detect abnormalities not visible on standard x-rays and ultrasound. The scanner allows not only to confirm the diagnosis but also to highlight lymph nodes or liver metastases.
Magnetic resonance imaging (MRI) – MRI with injection of contrast helps your doctor to visualize organs of your body. In the case of lung cancer diagnosis, he can analyze the structure of your lungs, to look for abnormalities, inflammation, and highlight the presence of the tumor. MRI not only allows your physician to detect the cancer but also to discover the exact size and extent of the tumor.
Bronchoscopy – this medical procedure can be performed to visualize the interior of the bronchial tree by introducing a bronchoscope, a small camera used to see the inside of the lungs. A bronchoscopy may be used for diagnostic purposes, or as a surgical treatment for some lung conditions.
Chest x-ray – a chest x-ray is a painless procedure which lasts between 5 and 10 minutes. It allows your physician to view and study your lungs, trachea, bronchi and layers surrounding the lungs (pleura). This procedure cannot give specific details on a cancer, but it allows your doctor to detect the presence of the tumor.
Ultrasound – during thisimaging technique, your physician uses painless high-frequency sound waves to visualize different organs of your body including your lungs. During the test, an ultrasound sensor (transducer) is applied on your chest in order to obtain images of your lungs.
Liver function tests – this is a group of tests that are used to evaluate the functions of the liver. Usually, a medical technologist will perform those tests to determine if the cancer has spread to your liver.
Positron emission tomography (PET) scan – a PET scan is a diagnostic method based on the administration of a tracer slightly radioactive which allows your doctor to study the metabolism in the body. Positron emission tomography differs from conventional technologies – x-rays and magnetic resonance – it can detect metabolic damage at an earlier stage and thus help your doctor to stop the progress of the pathology before complications.
Thoracentesis – also known as thoracocentesis or pleural tap, thoracentesis is an invasive procedure involves draining fluid or air from your pleural cavity. Thoracentesis may be performed for diagnostic purposes – the fluid removed is studied under a microscope; or as therapeutic procedure to improve lung function. During the procedure, a cannula or hollow needle is carefully injected into your chest, usually after administering a local anesthesia to remove the liquid. Although useful in the diagnosis of lung cancer, thoracentesis can lead to low blood pressure, pneumothorax (air in the chest cavity), hemothorax (blood in the chest cavity), hypotension (low blood pressure) and reexpansion pulmonary edema (an uncommon lung disease complication).
Biopsy – the preceding tests are necessary to detect the cancer; however, to confirm a lung cancer diagnosis a biopsy is necessary. During the biopsy, your doctor will take small sample of your lungs, especially in the tumor for laboratory analysis. This microscopic study aims at obtaining accurate information on the overall structure of the fragment removed. The biopsy is important to confirm with certainty the presence of cancer cells in your lungs. In general, your physician will perform one of these biopsies:
- CT scan-directed needle biopsy
- Mediastinoscopy with biopsy
- Open lung biopsy
- Pleural biopsy.