Lung Cancer: Diagnosis

How Is Lung Cancer Diagnosed?

The evaluation and diagnosis of lung cancer often includes:

• A complete history and physical exam

• A chest X-ray

• A chest CT scan (a specialized X-ray, which produces detailed pictures of the lungs)

• Breathing tests, called pulmonary function tests. These detect emphysema and asthma as well as their impact on airflow out of the lungs.

• A lung biopsy. A biopsy is important to obtain a sample to view under a microscope. A pathologist can determine if the cells are normal, abnormal or lung cancer cells.

• A PET scan and brain scan may be needed to examine the entire body and determine the extent of a lung cancer or its stage.

• Brain imaging with either MRI or CT

If the chest X-ray or chest CT scan identifies an abnormality in the lung that is suspicious for lung cancer, the next step is often a biopsy. The abnormality found on the X-rays may be referred to as a spot or nodule. Nodules in the lung are common. They can be seen in one out of every four lung CT scans. Most lung nodules (more than nine out of 10) are not cancerous. Benign or noncancerous nodules can be caused by previous infections or old surgery scars.

A lung nodule may be considered suspicious for lung cancer based on its size, shape and appearance on a chest X-ray or CT scan, as well as any risk factors you may have for lung cancer, such as your age, smoking history, family history of lung cancer, etc. The lung nodule will need to be biopsied to determine if it is a lung cancer. A biopsy is a procedure to get a sample from the lung nodule to view under a microscope.

A biopsy of the lung nodule can be done by bronchoscopy, by placing a needle through the chest wall and into the nodule under radiographic guidance (CT-Guided Fine Needle Aspirate), or through a small operation (Video Assisted Thoracoscopic Surgery or VATS).

• Bronchoscopy: Getting a biopsy using bronchoscopy is an outpatient procedure. It is not an operation and is done without any cutting, sutures or needles. During a bronchoscopy, you will be sedated, and your nose, mouth and throat will be numbed. A small tube (bronchoscope) with an even smaller video camera on the end will be placed through the nose and into the lungs. The bronchoscope will be guided to the lung abnormality based on its location on the chest X-ray or CT and, often, using a computer-assisted guidance system, by the doctor operating the instrument. A biopsy of the lung nodule is taken and examined by a pathologist (a doctor who identifies diseases by studying cells and tissue under a microscope), using special techniques to be certain of the diagnosis.

• CT-Guided Fine Needle Aspirate: Getting a biopsy using a fine needle aspirate is also an outpatient procedure, and not an operation. During a fine needle aspirate you may be sedated. You will be placed in a chest CT machine, and a thin needle will be inserted into the skin, which is numbed. The doctor guides the needle to the lung nodule by observing repeated CT scans during the procedure. The needle is advanced into the lung nodule, and then an aspirate or biopsy is taken. The sample is examined by the pathologist as described above.

• VATS: Occasionally a surgical biopsy of the lung nodule must be performed. This is typically done using Video Assisted Thoracoscopic Surgery (VATS). This is an operation performed in an operating room as an inpatient (staying overnight) in the hospital. A small incision is made between the ribs; the lung is deflated; and a small camera is inserted into the chest cavity. When the area or nodule to be biopsied is identified, small surgical instruments are inserted through two to three other small incisions (less than an inch) between the ribs, and the nodule is biopsied or removed. The instruments are removed; the lung is reinflated; and any incisions are sutured shut.

If you receive a diagnosis of lung cancer, you will be referred to a cancer specialist, called an oncologist. The oncologist will recommend a combination of treatments, based on the type and stage of your lung cancer.