For our in-depth article on lung cancer screening, click here.
By Tiffanie L. Hammond, Amrita Ford, MA, and Anna E. Mazzucco, Ph.D.
Lung cancer is the second most commonly diagnosed cancer in both men and women in the U.S., but it is the #1 cancer killer. In 2013, approximately 228,000 men and women were diagnosed with lung cancer and close to 160,000 men and women died from it. One of the reasons lung cancer is so deadly is that symptoms usually appear during the later stages, when treatment is least effective. General symptoms include:
- a persistent cough that may worsen over time, including coughing up blood
- breathing trouble, such as shortness of breath
- chest pain
- raspy or hoarse voice
- frequent lung infections, such as pneumonia
- extreme and constant fatigue
- unintentional weight loss
If you experience any of these symptoms, call your doctor.
The purpose of screening for cancer is to diagnose it before symptoms appear, when it can be treated more effectively. In July 2013, the U.S. Preventative Task Force (USPTF) released a draft recommendation for screening those at highest risk for lung cancer using low-dose computerized tomography scans (low-dose CT), which was finalized in December. CT scans provide very detailed pictures of your lungs, much more detailed than x-rays. Researchers found that using low-dose CT scans could reduce lung cancer deaths by 20%. People who should be screened include:
- Current smokers between 55 and 79 years-old who have a smoking history of “30 pack-years” (20 cigarettes a day for 30 years, 40 cigarettes a day for 15 years, and so on)
- Former smokers (who quit in the last 15 years) who are between 55 and 79 years-old and had a “30 pack-year history of smoking.
To calculate your pack years, visit http://smokingpackyears.com/.
This draft recommendation was finalized at the end of 2013. Already insurance companies are covering the cost of the screening, as long as the person meets the screening criteria.
As with any screening, there are risks as well as benefits. Some of the risks include radiation exposure and a high rate of false positive test results—test results indicating that a person has something worrisome in their lung that turns out to be nothing serious. Some experts call this “over-diagnosis.” In the largest study done so far, about 1 in 4 people had a false positive finding if they had three years of annual screening. A false positive finding can lead to invasive procedures, such as needle biopsies, which can puncture the lung and cause it to collapse. Although very serious complications are rare (less than one in 1,000), they can occur. Even low-dose CT scans of the lungs expose patients to much more radiation than a chest x-ray. There is almost no short-term risk from this radiation, but having many x-rays or several CT scans can increase a person’s risk of cancer. A 2012 law increased funding for lung cancer research to promote better detection and treatments in the future. Research is also being done to find ways to reduce the number of false-positives and unnecessary follow-up procedures.
For more detailed information about lung cancer risk factors, symptoms, detection, and CT screening, including the risks of radiation and over-diagnosis, see this article.