Ask Dr. K: Lung cancer screening recommended for people at high risk

That’s because screening for lung cancer involved using standard chest X-rays, and they produced too many “false positive” results: They identified “spots” in the lungs that were harmless. And they also produced too many “false negative” results: They failed to find small, early and potentially curable cancers. When screening chest X-rays found lung cancer, it was big and old enough that it usually already was incurable.

Computed tomography (CT) scans of the lungs, however, take much clearer pictures than standard chest X-rays. Studies in recent years have shown that when people are at high risk for developing lung cancer, CT scans find many more small, early and potentially curable lung cancers — with an acceptable number of “false positive” results. Most important, the evidence is that current types of CT do not just find cancers early; they also save lives among people who are at high risk for getting lung cancer.

After advising for many years against screening for lung cancer (with standard chest X-rays or other techniques), the U.S. Preventive Services Task Force (USPSTF) reviewed the latest studies. It now recommends yearly tests for people at high risk for lung cancer. The USPSTF is a group of experts in evaluating scientific studies and in preventive medicine.

Specifically, the USPSTF recommends annual, low-dose computed tomography (CT) scans of the lungs for high-risk adults ages 55 to 79. You are considered high-risk if you have smoked for at least 30 “pack-years.” This could be 30 years of smoking one pack a day, 15 years at two packs a day, or other equivalent combinations. Screening is recommended for anyone in this group who is a current smoker or has quit in the last 15 years.

Any kind of X-ray — and CT scans use X-rays — involves radiation. Fortunately, the CT scanners that are used to screen for lung cancer involve relatively little radiation. Most experts agree that the radiation risks from screening with these scanners are very small.

When it comes to lung cancer, however, prevention remains even more important than early detection. And the biggest change you can make to prevent lung cancer is not to smoke. If you smoke now, commit to quit.

Quitting strategies include:

— Behavior programs, such as one-on-one counseling and support groups.

— Nicotine replacement, available in many forms including skin patches, chewing gum, lozenges, nasal spray or inhalers.

— Quit-smoking medications such as varenicline (Chantix) and buproprion (Zyban).

— Hypnosis, acupuncture and other alternative treatments.

If you fall into the USPSTF high-risk categories, talk to your doctor. The sooner you begin to be screened, the earlier these tests might detect a tumor. I’ve certainly changed my practice since the USPSTF published its opinion.

Dr. Komaroff is a physician and professor at Harvard Medical School. To send questions, go to AskDoctorK.com, or write: Ask Doctor K, 10 Shattuck St., Second Floor, Boston, MA 02115.