Case:
I get asked by many who smoke or who have just quit smoking for help making the decision to have/not have a CT scan to screen for lung cancer. The man responsible for the question above had been smoking his entire life, and, at age 62, he raised the question.
Screening is the term used when tests are done for patients without symptoms. The hope of screening is that a test will find lung cancer (or any other clinical situation for which screening tests are considered) early in the course of the condition so treatment may be beneficial. In the study above, 87 fewer people of the nearly 54,000 in the study died of lung cancer in the LDCT arm. In addition, the number of people dying of other conditions beside lung cancer was fewer (1526 died of other conditions in the LDCT group and 1557 in the CXR group). I did not present this data on the figure as the difference is small and it is unclear why LDCT would reduce other reasons for dying.
The harm of screening, as discussed in earlier blog posts, is that some people will have a positive test and not have cancer. This can cause worry, but in this clinical situation, additionally, the abnormalities found by the test are located in the lung. Getting to these lesions to provide assurance that cancer is not present may be dangerous and costly, and in this study, more people did die early in the LDCT arm.
Since I believe only patients can decide for their tests/treatments, a person would have to trade-off the potential 0.4% added chance of not dying of lung cancer in the future against the potential 40 fold greater chance of a false positive finding and a potential 0.24% added chance dying early or having a major complication by following a LDCT strategy.Continue reading…






