Maybe you started as a teen, lighting up to be cool—then got hooked. Hopefully, you put cigarettes aside years ago or are working hard to kick the habit now. But if you have a history of smoking (or if someone you love does), you’ll want to know about a painless screening test that significantly reduces the odds of dying from lung cancer. It’s a type of computed tomography (CT) scan called a low-dose helical CT (aka spiral CT) of the chest.
Background: The deadliest malignancy, lung cancer claims more lives than breast, ovarian, colon and prostate cancers combined. Lung cancer causes no symptoms in its earliest and most curable stages, and by the time people develop telltale signs (chest pain, wheezing, coughing up blood), it’s usually too late. The five-year survival rate for all lung cancer patients is less than 16%…and previous attempts to develop an early-detection test failed to reduce the death rate.
Encouraging: The recent National Lung Screening Trial (NLST) involved 53,454 symptom-free former or current heavy smokers ages 55 to 74. Participants underwent three annual screenings using either standard chest X-ray (which produces a single image in which anatomic structures of the chest overlie each other)…or helical CT (in which a CT scanner rotates around the person for seven to 15 seconds, producing multiple detailed images). Participants were followed for an average of 6.5 years from the first screening, during which time 442 people in the X-ray group and 354 in the CT group died of lung cancer. Translation: Low-dose helical CT screening reduced lung cancer death risk by 20%.
Explanation: A screening test does not reduce a person’s odds of getting lung cancer, of course. What a helical CT can do is find lung abnormalities when they are still so small that they can be completely removed surgically, said Christine D. Berg, MD, chief of the Early Detection Research Group in the Division of Cancer Prevention at the National Cancer Institute and NLST project officer. Risks: Though the radiation exposure from a low-dose helical CT is significantly less than from a regular diagnostic chest CT, it is about 30 times higher than from a single-view chest X-ray. Another concern is the high rate of false-positive results (37% with helical CT versus 14% with X-ray), which can lead to unnecessary testing and anxiety.
Who should consider testing? Dr. Berg stated that screening with low-dose helical CT is reasonable for anyone between ages 55 and 74 who meets the NLST entry criterion of at least 30 “pack-years.” (To calculate your pack-years, multiply the average number of packs smoked per day by the number of years you smoked.) Research is being done to determine whether the test’s benefits outweigh its potential harms for younger individuals and/or those with less of a smoking history, such as 20 pack-years. The test is not appropriate for people with a history of light smoking or no smoking, even if they have a family history of lung cancer.
Low-dose helical CT scans of the chest are available at most imaging facilities that provide CTs. Cost ranges from about from $350 to $2,000, depending on location. At present, insurance generally does not cover helical CT lung cancer screening—though Dr. Berg stated that this may change within the next few years as the US Preventive Services Task Force weighs in based on the new evidence of the test’s benefits.