Tests To Identify Lung Cancer
Updated: Jan 26
According to the CDC, Lung cancer is the third most common cancer in the U.S. Early detection for different types of lung cancer can be tough however, screening offers a chance to catch cancer early on when it’s easier to treat. Noticeable symptoms of lung cancer don't arise until the later stages when the tumor gets big enough to cause problems. Sometimes there are earlier warning signs of lung cancer, if you experience any of these symptoms seek medical attention and call your doctor right away.
The most common detection for lung cancer is through screening, but the majority of lung cancers are found after they have started causing health problems.
Doctor Examination: Medical History and Physical Exam
It is important to be knowledgeable of your medical and family history. This will help your doctor during the examination to learn more about your symptoms and possible risk factors. Your doctor will also examine you to look for signs of lung cancer or other health problems. If there is any indication that suggests you might have lung cancer further tests will be conducted. These could include imaging tests and/or biopsies of the lung.
Imaging Tests To Identify If You Have Lung Cancer
Imaging tests create pictures of the inside of your body. Imaging tests include x-rays, magnetic fields, sound waves, or radioactive substances. These tests might be conducted before and after being diagnosed with lung cancer for many reasons including; looking at suspicious areas (the origin of cancer), the spread (potential stage of cancer), treatment, and possible reoccurrence of cancer.
The first step or test that your doctor will order is a chest x-ray. This is so they can look for anything abnormalities in the lung. If the results are positive or something is suspicious looking, the doctor will order more tests to see things the x-ray didn't pick up.
Computed Tomography (CT) Scan
A CT scan usually follows an x-ray examination because it makes a more detailed image of your body. The CT scan will take multiple pictures and a computer will combine them to make a detailed image of the particular area the doctor wants to examine.
An x-ray of the chest is less likely to show signs of lung tumors, but it is routine to have an x-ray first in the event something does show up. CT scans are more likely to show any signs of tumors, as well as the size, shape, and position, and any enlarged lymph nodes that might contain cancer indicating that is spreading. This test can also be used to look for masses in the adrenal glands, liver, brain, and other organs that might be due to the spread of lung cancer.
CT-Guided Needle Biopsy
If the doctor suspects the area of cancer is deep within your body, a CT scan might be used to guide a needle into this area to collect a tissue sample. This process is referred to as a biopsy needle to help check for cancer.
Magnetic Resonance Imaging (MRI) Scan
Similar to CT scans, a Magnetic Resonance Imaging scan shows detailed images of the soft tissue in the body using radio waves and strong magnets. If a doctor is concerned about lung cancer spreading to the brain or spinal cord, an MRI scan is the most common test ordered.
Positron Emission Tomography (PET) Scan
A Position Emission Tomography scan injects a form of sugar known as FDG into the body. This slightly radioactive sugar collects mainly in cancer cells.
Sometimes a PET scan can be used side by side with a CT scan. A special machine conducts both scans simultaneously so a doctor can compare the higher radioactivity on the PET scan to the CT scan of a more detailed image.
This test is common in lung cancer patients because it has many useful attributes. These include showing a doctor if the spread of cancer has entered the liver, bones, adrenal glands, or other organs, but not the brain or spinal cord, and in diagnosing lung cancer.
A bone scan injects a small amount of low-level radioactive material into the blood. This collects in abnormal areas of the bones showing if cancer has spread to a particular part of the bones. A doctor is less likely to order a bone scan because a PET scan can usually show if cancer has spread to the bone.
Tests To Identify If Lung Cancer Has Spread To The Chest
It's important to know if lung cancer has spread to the lymph nodes located between the lungs (mediastinum) or other nearby areas because this can affect the patient's options for treatment. Several types of tests can be used to look for this cancer spread and lung function.
If a biopsy needs to be taken, an endobronchial ultrasound can help doctors see lymph nodes and other structures in the area between the lungs.
Endoscopic Esophageal Ultrasound
Endoscopic esophageal ultrasound is another way to show lymph nodes that may contain cancer cells. This ultrasound goes down the esophagus, and biopsies of the abnormal lymph nodes can be taken while doing the procedure.
Mediastinoscopy and Mediastinotomy
The difference between Mediastinoscopy and Mediastinotomy is the location and size of the incision. These procedures look more directly at and collect samples from the structures in the area between the lungs (mediastinum).
A mediastinoscopy is a procedure that uses a lighted tube inserted behind the sternum (breast bone) and in front of the windpipe to look at and take tissue samples from the lymph nodes along the windpipe and the major bronchial tube areas.
A mediastinotomy may be ordered for a surgeon to remove the biopsy sample of the lymph nodes. When lymph nodes can't be reached by a mediastinoscopy, a doctor may order a mediastinotomy to have them removed. This procedure requires a slightly larger incision (usually about 2 inches long) between the left second and third ribs next to the breast bone is needed.
Thoracoscopy helps identify if cancer has spread to spaces between the lungs and the chest wall or the linings of these spaces. Thoracoscopy has many uses, including sampling tumors on the outer parts of the lungs and nearby lymph nodes, fluid, and assessing whether a tumor is growing into nearby tissues or organs.
This procedure is ordered by a doctor when other lung cancer tests such as needle biopsies are not able to collect enough of the sample. Thoracoscopy can also be used as part of the treatment to remove part of a lung in some early-stage lung cancers.
Tests To Identify Specific Proteins On Tumor Cells
Lab tests might to done to identify specific proteins on tumor cells to see if the lung cancer will respond better to one treatment compared to another.
Blood tests provide information on a patient's overall health and can be beneficial in providing information to determine if that person is healthy enough to have surgery.
Complete Blood Count
A complete blood count (CBC) shows you different types of blood cells and if you fall in the normal range. A complete blood count evaluates the red blood cells, white blood cells, and platelets to detect a variety of diseases and conditions, such as infections, anemia, and leukemia. This test could be repeated regularly during treatment because many cancer drugs can affect blood-forming cells of the bone marrow.
Blood Chemistry Tests
Blood chemistry tests take a sample of blood to measure the number of certain substances in the body. These substances include electrolytes (sodium, potassium, and chloride), fats, proteins, glucose (sugar), and enzymes. Blood chemistry tests help find abnormalities in some of your organs, such as the liver or kidneys.