天博体育

Lung cancer is usually discovered late when it鈥檚聽difficult to treat and has often spread outside the lung. A聽reliable screening test聽to find it at an earlier, more treatable stage would be a legitimate聽breakthrough鈥攁nd聽could potentially save thousands of lives. About 160,000 Americans die each year from lung cancer, which is more than who die聽from .

Chest x-rays聽do a good job of finding small lung cancers that can be removed surgically.聽Why not use them to screen for lung cancer?聽Because聽at least a half-dozen聽studies have been done and for reasons that aren鈥檛 entirely clear,聽early detection with chest x-rays hasn鈥檛聽translated into prevention of fewer deaths from lung cancer.聽And聽in聽screening, early detection is聽a means to an end. The real goal is preventing deaths from the disease that is being聽screened for (and deaths in general).

So it was big news today when the showed that screening聽current and former heavy smokers with computed tomography (CT)聽scans did, in fact, reduce聽the risk of dying from lung cancer by 20% compared with screening聽them聽with chest x-rays.聽Moreover, those who were screened with CT scans were 7% less likely to die from any cause during the study鈥檚 five-year follow-up period.

Good news, and a long time coming for those who have watched聽disappointing findings from the聽chest x-ray studies pile up.

But if today was first time that most of us heard about the聽, it probably wouldn鈥檛聽be the last. It鈥檚聽almost聽certainly going to stir up聽more than its fair share of聽controversy.

Here are a few of the聽hot buttons:

• The聽NCI says there are more than 94 million current and former smokers in the United States (mind you, not all of them are heavy smokers, so the population to be screened may be smaller).聽It will聽be very expensive to screen them all with CT scans. How much a screening CT of the lung will cost is hard to say, especially if they become routine, but the NCI says the current Medicare reimbursement rate for a diagnostic CT scan of the lung is $300.
• Some may argue that smokers聽shouldn鈥檛 be聽entitled to such an expensive test鈥攐r should have to shoulder a large share of the cost. The counterargument is聽why single out smokers when聽other bad health habits result in expensive tests and treatments.
• The聽NCI itself showed that there鈥檚 concern that some people may see an effective screening test as a reason聽to tune out聽the dire health warnings about tobacco and cigarettes.聽In a聽 posted on聽its Web site today (which is well worth reading if you want more detail about the聽study),聽the third question is, 鈥淚s it OK to keep smoking because there is a screening test that has benefit?鈥� The answer begins with an emphatic, 鈥淣o.鈥澛營t鈥檚聽hard to imagine that people would聽actually ask such聽question, but聽the NCI apparently was worried聽enough to pose it.
• (and CT scans in particular) has become a major issue. Will the radiation from CT screening for lung cancers add to the problem? The NCI position:聽the radiation from a screening CT is far less than the dose聽from a diagnostic one and that benefit of finding and treating early lung cancer will likely outweigh the risk聽from a low dose of radiation from CT scanning.
• In the聽Q&A about the study, the聽NCI says that between 20% and 60% of聽 screening CT scans of current and former smokers show some kind of abnormality and that most are not lung cancer. CT scanning for lung cancer could generate a large number of false聽positives:聽results that indicate the possibility of cancer but聽turn out not to be.聽False positives result in worry and聽additional聽tests, which in the case of lung cancer would include invasive biopsies.

Of course many of our current screening tests for cancer have shortcomings, cost plenty, and are controversial. The debates about the value of mammography never seem to end. Yet we get behind screening tests聽for a whole variety of reasons, not the least of which is that cancer caught late is so lethal and, these days, astronomically expensive to treat.