Earlier this spring there was much attention given after a study suggested using low-dose CT scans could reduce mortality rates from lung cancer. This followed a 2011 study that found using low-dose CT scans could reduce deaths from lung cancer by 20 percent. Advocates for this method of lung cancer screening pressed their case to expand the use of CT scans for lung cancer screening.
It is hard to argue against preventive screening to detect and prevent lung cancer. After all, more men and women die of lung cancer than any other cancer (American Lung Association). So, when studies suggest that preventive screening using low-dose CT imaging is a good idea, we need a good reason if we are to reject it. But, with cancer screening, health policy experts, insurers and those who run government programs like Medicare must navigate the risk-reward spectrum.
Unfortunately for advocates of this research, a Medicare advisory committee recommended against providing Medicare coverage. They did so because of the uncertainty about the benefits outweighing the risks in the real world, outside of a carefully controlled trial.
The committee’s perspective is based on real-world experience using other forms of screening for cancer. Screening people for lung cancer carries real risks, including radiation exposure and complications that can arise from invasive procedures performed to prove or disprove whether a "suspicious" CT finding is actually cancer.
The committee was likely influenced by Dr. Richard Ablin, the inventor of the PSA test, who calls the use of PSA for prostate cancer screening "a profit-driven public health disaster" (NY Times). CT screening for lung cancer using the criteria proposed by the U.S. Preventive Services Task Force could be even bigger. The fear is that, as a way to boost profits, some hospitals or clinics may offer the CT screening to lower-risk patients (or “worried well”) that don't fit the population demographics of the patients studied in the CT screening trials.
Additionally, the population of patients evaluated in the CT screening studies do not address regional issues that may occur in evaluating possible positive findings on CT imaging. For example, individuals who reside in the Southwestern U.S. (not well represented in the NLST study) may have a higher prevalence of benign lung nodules which would lead to even higher false positive tests, invasive test, complications, cost, etc.
Ultimately, evidence strongly suggests that CT screening strategy will likely lead to over-diagnosis, where some cancers are detected earlier but treatment earlier or later may have no impact on that individual’s survival.
I’d love to hear your opinion on this matter. Would you be willing to get a CT scan, and pay for it, to screen you or your loved ones for lung cancer?
Read more about lung cancer diagnosis and treatments.