Lung Cancer Risk Factors, Screenings and Diagnosis
Learn more about the signs of lung cancer and how the MedStar Georgetown Cancer Institute can help identify lung cancer risk factors and assist in the diagnosis of the disease.
While we don’t always know what causes lung cancer, a number of factors increase your risk of getting the disease:
- Smoking: 85 to 90 percent of lung cancers are linked to cigarettes, cigars and pipes. The risk depends on how early you started, how much you smoked and how many years you did it. Once you stop, the risk lowers as the years pass.
- Exposure to:
- Secondhand smoke
- Radon, an invisible, odorless and tasteless radioactive gas that occurs naturally in soil and rocks
- Asbestos, chromium, nickel, arsenic, soot or tar
- Air pollution
- Family history of lung cancer
- Previous radiation therapy to the breast or chest
- Human immunodeficiency virus (HIV) infection
- Beta carotene supplement consumption, combined with heavy smoking
The risk of developing lung cancer is even greater if you smoke (or smoked) and have other risk factors, too.
Screening for Smokers
We offer low-dose CT (computed tomography) scans for lung cancer screening and support the recommendations from the U.S. Preventive Services Task Force about who should participate. Please speak with a doctor and consider annual testing if you:
- Are between 55 and 80 years old
- Still smoke or quit within the past 15 years
- AND have a 30 pack-year smoking history. Some examples:
- 20 cigarettes per day for 30 years
- 15 cigarettes per day for 40 years
- 10 cigarettes per day for 60 years
Annual screening can stop once you have not smoked for 15 years or if you have a health problem that limits your life expectancy or your ability or willingness to get curative lung cancer treatment. The Affordable Care Act requires commercial insurers to cover high-risk screening starting in 2015, though some may do so sooner. Medicare has so far declined to provide coverage but might reconsider.
Symptoms and Diagnosis
Lung cancer does always cause symptoms, especially in its earlier stages. But people can experience some of the following signs of lung cancer:
- Coughing that does not get better within a few weeks
- Coughing up blood
- Chest pain
- Unexplained weight loss
- Trouble breathing or swallowing
- Swelling in the face and/or neck veins
Other conditions can cause these symptoms, too, so it’s important to see a doctor.
If lung cancer is suspected, our doctors take several steps to ensure a thorough and accurate diagnosis:
- Physical exam and discussion of medical history and symptoms
- Imaging Tests:
- CT (CAT) Scan: Computed tomography takes a series of X-rays from different angles and stitches them together into 3D images.
- MRI: Magnetic resonance imaging uses a powerful magnetic field and radio waves to create detailed 3D images at higher contrast than CT scans—useful for clarifying other test results.
- PET Scan: After a substance called radionuclide glucose is injected into one of your veins, a positron emission tomography scanner rotates around your body and creates a map of cancer cells, which take in more glucose and show up brighter.
- PET/CT Scan: PET/CT scans combine the two technologies.
- Bone Scan: A small amount of a radioactive substance is injected in a vein and shows up in abnormal bone areas, possibly indicating cancer.
- Biopsies and Endoscopic Procedures: Your doctor may also use thin tubes (endoscopes) to look at your lungs and surrounding tissue for signs of lung cancer. The only way to confirm suspicious findings is to take a tissue or fluid sample (biopsy), usually during a procedure like bronchoscopy or with a needle (fine needle aspiration, or FNA) inserted through the chest. Your doctor may also examine coughed-up mucus (sputum cytology).
Electromagnetic Navigation Bronchoscopy (superDimension)
Bronchoscopy is a minimally invasive diagnostic procedure to help identify sings of lung cancer that involves:
- Maneuvering a thin, flexible tube (bronchoscope) with a light and camera down the mouth or nose and into the trachea (windpipe) and lungs
- Looking for abnormalities
- Possibly taking a biopsy
The conventional way of doing this has limits, though: Doctors can’t look at the deeper and narrower branches of the airways, where 70 percent of lung cancers start. That leaves just needle or surgical biopsy, invasive procedures that sicker patients often can’t tolerate.
Lately we’ve been using electromagnetic navigation bronchoscopy (i.e., superDimension), a system that lets our doctors examine the entire lung and take minimally invasive biopsies. Patients lie on a special electromagnetic panel while our doctors use bronchoscopes equipped with sensors, sending out GPS-type directions that are displayed in 3D on a monitor.
If needed, our doctors can place a stent to open an airway blocked by a tumor or scarring, or place tiny metal tags as guides for later radiation therapy. Even patients with the most challenging lung problems can undergo the procedure, including those who:
- Have COPD (chronic obstructive pulmonary disease)
- Underwent previous cancer surgery
- Underwent chemotherapy or radiation treatments
Endobronchial and Endoscopic Esophageal Ultrasound
Using ultrasound at the end of special probes (endoscopes) is an advanced technology that provides real-time imaging of chest abnormalities to help identify signs of lung cancer. It’s a highly effective tool for diagnosing and staging cancer, though it takes special training and experience to perform it accurately — expertise our doctors have. There are two types of lung ultrasound, and we often combine them with superDimension to avoid a second office visit:
- Endobronchial Ultrasound (EBUS): A special endoscope — a bronchoscope — with an ultrasound probe is passed down the windpipe (trachea) to look at lymph nodes and other structures in the chest. A hallow needle is threaded through to take a biopsy.
- Endoscopic Esophageal Ultrasound: This procedure is similar but looks at the throat and esophagus.
Other Diagnostic Lung Procedures
Other diagnostic lung procedures to help identify signs of lung cancer include:
- Mediastinoscopy: If your doctor suspects that lung cancer may have spread to your lymph nodes, you are given anesthesia and a small incision is made at the base of your neck, so that the doctor can insert a special scope into the area between the lungs (the mediastinum).
- Thoracentesis: A needle is placed between the ribs and removes a sample of the fluid (pleural fluid) that surrounds the lungs.
- Thoracoscopy: Your doctor makes several small incisions in your chest and back andinserts a special scope to look at the lungs and chest cavity and possibly biopsy tissue.
- Thoracotomy: To diagnose lung cancer, a thoracic surgeon may need to open your chest with a long incision (while you’re under anesthesia) and remove any abnormalities or lymph nodes for testing.