STEVE INSKEEP, host:
Ninety million Americans are smokers or former smokers, and they're among the people who may be affected by a debate over how to protect them from lung cancer, the deadliest cancer of all. For years, many have hoped that computerized X-ray machines called CT scanners could spot lung cancers when they are early and curable. Last fall, one large study concluded CT screening for lung cancers saves lives. But today, another study casts doubt on that claim.
NPR's Richard Knox has more.
RICHARD KNOX: Like many health care centers, Stamford Hospital in Connecticut recently decided it's time to offer patients CT screening for lung cancer even though they have to pay $350 out of their own pockets for it.
Ms. LIZ MANFREDO (Administrator, Oncology Services, Stamford Hospital): For people who are at high risk, who have smoked a number of packs of cigarettes a day for years, if we can catch cancers early and treat them, then we'll be doing a huge service to our patient population.
KNOX: That's Liz Manfredo of Stamford Hospital. Doctor Peter Bach is a skeptic. He led the study that appears in this week's Journal of the American Medical Association.
Dr. PETER BACH (Pulmonologist, Memorial Sloan-Kettering Cancer Center): We have done a terrific job in public health of telling people, catch it early, it will save your life. And we did that to promote proven screening tests like mammography and the Pap smear.
KNOX: But when it comes to lung cancer, Bach thinks it unfortunately doesn't work that way. Bach and his colleagues looked at the experience of three lung cancer screening programs - two in this country, one in Italy. Out of 3,200 former smokers, lung CT scans found 144 lung cancers. That's three times the number expected from such a group. That should be a good thing, that's what screening is supposed to do. But Bach says it didn't work out as intended.
Dr. BACH: We saw 10 times as many surgeries being done because of the CAT scanning and no one's life was saved. Not one case of advanced cancer was prevented.
KNOX: There were 39 deaths from lung cancer among the three groups. The same number, Bach calculates, would occur among a similar population that never got CT screening. He says this was a big disappointment.
Dr. BACH: And we have all hoped that the CT would be sensitive enough to pick up very small cancers before they spread, before they cause illness, before they kill people. But it looks like those cancers we don't seem to be able to catch with CT very often.
KNOX: Unfortunately, the deadly cancers tend to arise very quickly, in between scans. On the other hand, many doctors are coming to understand that many people - smokers and non-smokers - harbor small lung tumors that look just like cancer on CT scans and even under the microscope after they're removed, but they don't behave like you'd expect lung cancer to. Dr. William Black is professor of radiology at Dartmouth Medical School.
Dr. WILLIAM BLACK (Radiology, Dartmouth Medical School): We do know from autopsy studies that we can find a lot of small cancers, and many of these small cancers do not appear to have - they're related to the patient's death. Now if you were to find one of these small cancers with CT screening and treated, you might falsely assume that you've prevented the death when in fact that death never would have occurred.
KNOX: The new study is under attack from those who think CT lung screening is already proven to work. Dr. Claudia Henschke is foremost among those. She criticizes the new study's method and stands by her study of last fall claiming that CT screening greatly lengthens lung cancer survival.
Dr. CLAUDIA HENSCHKE (Radiology, Weill-Cornell Medical College): There are more and more people that are convinced that screening works. Certainly, there are more people being screened, I'm sure, in the country.
KNOX: But many in the field say we won't really know if lung cancer screening works until results of a $220 million federal study are in. That won't be until early 2010.
Richard Knox, NPR News.
INSKEEP: Here's what you can do right now, you can calculate your risk of lung cancer at npr.org.
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