CT screening for smokers and ex-smokers shows little benefit
The latest round of number crunching spells trouble for CT lung screening. A research firm estimates a cost of more than $2 million per quality-adjusted life-year (QALY) gained for ex-smokers.
In addition to high costs, CT screening for lung cancer often leads to false-positive results that can result in anxiety-inducing invasive procedures. Direct-to-consumer marketing of CT screening for lung cancer is therefore not advisable, according to the study?s lead author, Dr. Parthiv J. Mahadevia, a research scientist at Medtap International.
The results of the study offered three main points: · Smokers and concerned patients should first speak with their physicians on the pros and cons of CT screening. · Direct-to-consumer marketing should provide adequate details to allow patients to make informed decisions. · Physicians should continue to encourage smoking cessation.
?From a marketing point of view, we need to show some restraint because of the possibility of incurring increased costs and invasive diagnostic tests,? Mahadevia said.
The researchers used a computer-simulated program to study hypothetical cohorts of 100,000 60-year-old heavy smokers who kept smoking, were in the process of quitting, or had already quit. The program compared yearly spiral CT screening with no screening.
To measure the efficacy of CT screening, Mahadevia and colleagues changed the clinical stage distribution of lung cancers so that those in the screened group had fewer advanced-stage cancers and more localized cancers than the group that did not receive screening.
The team used a computer simulation to incorporate study biases such as lead time, length, and overdiagnosis bias. Assuming a 50% stage shift over a 20-year period, they found that the heavy smokers had 553 fewer lung cancer deaths and 1186 false positives, which led to invasive procedures, following screening. The researchers also measured cost-effectiveness and found a cost of $116,300 per QALY gained for current smokers. Smokers who were in the process of quitting and former smokers showed costs of $558,600 and $2,322,700, respectively, per QALY gained. Other screening tests that are now reimbursed by insurers run about $100,000 per QALY gained.
Mahadevia found that none of the most influential parameters on the results of the study provided enough of a benefit to make screening cost-effective for any of the study cohorts. The study was published in the Jan. 15 issue of JAMA.
Patients and physicians should wait until the results of the National Cancer Institute?s eight-year trial comparing CT scans with chest x-rays provides conclusive evidence on the values of CT screening, Mahadevia said.
?In the interim, the best advice to concerned patients is to quit smoking. Smoking cessation is the only proven and cost-effective means to reduce lung cancer risk,? Mahadevia said.
For more information from the Diagnostic Imaging archives:
