Lung cancer screenings may carry hidden dangers, researchers announced Saturday at the American Society of Clinical Oncology meeting in Orlando.
The National Institutes of Health is running a large study to find out if screening patients with CT scans can save lives. Some doctors are already offering the screenings in the hopes of finding tumors early, when they might be more curable. Lung cancer kills more people than any other tumor, with 215,000 new cases a year and 162,000 deaths, according to the American Cancer Society.
But the scan's results aren't always clear or easy to interpret, leading to false alarms.
People who are screened have a 21% chance of being unnecessarily frightened by findings that initially seem suspicious, but turn out to be benign, says lead author Jennifer Croswell.
Yet the exams, performed with CT scans, can produce more than just anxiety, according to Croswell's report, a pilot study for the ongoing National Lung Screening Trial, which includes 50,000 patients.
Suspicious findings can lead to invasive follow-up exams, such as biopsies or even surgeries in which doctors crack open the chest to access to the lungs, Croswell says.
Out of 1,600 smokers and ex-smokers in the study who had the CT scans, 40 had real cancer, but eight had unnecessary surgery for non-cancerous conditions.
Yet Croswell can't say whether the screenings actually helped anyone. That's because the larger study hasn't gone on long enough to show whether screening saves lives, she says. And because lung surgeries are risky, she says it's possible for the screenings themselves to cause death.
CT scans also expose people to radiation, which increases the risk of cancer, says Peter Bach, a pulmonologist at New York's Memorial Sloan-Kettering Cancer Center.
Other research has suggested that tumors found through screening could be much less lethal than lung cancers that are found because they cause symptoms, so that finding these slow-growing cancers may not help anyone. Also, longtime smokers or ex-smokers could die of other causes, such as heart attacks or strokes, long before their cancer becomes a threat.
In fact, people who get CT scans are 100 times more likely to get a false alarm then they are to die of lung cancer, says Bach, the author of a 2007 study on lung cancer screening.
The American Cancer Society does not recommend lung screenings and they are not covered by insurance, Bach says. Insurers do cover follow-up tests and lung cancer treatments.
Go here to see what other readers think.
