Lung Cancer Study: What Does It Mean for Ex-Smokers?
(CBS/AP) What does it mean for me?
That's what the estimated 80 million smokers and ex-smokers may be wondering about a new study showing that special CT scans can detect lung cancer early enough to modestly lower their risk of death.
"This finding has important implications for public health, with the potential to save many lives among those at greatest risk for lung cancer," said National Cancer Institute Director Dr. Harold Varmus, who released the study results Thursday. But, "we don't know the ideal way yet to do this screening."
Just who should get the scans isn't an easy question to answer, because the tests are costly and carry their own risks - including repeated radiation exposure and anxiety-provoking false alarms that trigger unnecessary repeat testing and even surgery.
Specialists with the American Cancer Society - which hadn't recommended the screening because of lack of evidence - planned to evaluate the findings when the full data are published in a few months.
Until then, "the best advice we can give is to encourage people to have conversations with their doctors about whether lung cancer screening is right for them," said chief medical officer Dr. Otis Brawley.
"For heavy smokers I think it's very reasonable to talk to their doctors about getting screened," says CBS News medical correspondent Dr. John Lapook. "But there are drawbacks."
The massive National Lung Screening Trial enrolled 53,000 current or former heavy smokers with no initial symptoms of cancer. It found 20 percent fewer deaths from lung cancer among those screened with spiral CTs than among those given chest X-rays, the NCI said Thursday, a difference significant enough that it ended the study early.
The actual difference: Of those who got a spiral CT, 354 died over the eight-year study period compared with 442 deaths among those who got chest X-rays.
But with about 200,000 new lung cancers diagnosed in the U.S. each year and 159,000 deaths, even a modest reduction could translate into big benefits. Today, lung cancer usually is diagnosed at advanced stages, and the average five-year survival rate is just 15 percent.
The new trial enrolled people ages 55 to 74 who are or had been very heavy smokers, puffing at least 30 "pack-years," the equivalent of a pack a day for 30 years or two packs a day for 15 years. They had one scan a year - either spiral CT or a standard chest X-ray - for three years, and then had their health tracked.NCI's Varmus stressed that the study provided no data on whether screening helped lighter or younger smokers.
There were risks. The CTs frequently mistake scar tissue from an old infection or some other benign lump for cancer, giving about 25 percent of the spiral CT recipients a false alarm.
Then there are the matters of cost - each scan runs $300 to $400 - and radiation exposure. The new study used low-dose spiral CTs, equivalent to the radiation from a mammogram. That's far lower than the radiation emitted by regular CT scans used to diagnose various medical conditions, but several times more than is emitted by a standard X-ray.
Of course, the scans do nothing to prevent lung cancer. For that, the advice hasn't changed:
Don't smoke.
