The Soft Underbelly of Lung Screening

“Those who cannot remember the past are condemned to repeat it.”

—George Santayana, 20th century philosopher and writer

Screening programs, like the one in the last century to detect lung cancer, sometimes assume an almost mystical sense of destiny. From the 1950s into the ‘70s, physicians performed chest X-rays and sputum cytology in the mistaken belief that with these technologies they could spot lung cancer at an early and curable stage. It was noble but scientifically flawed, a venture whose soft underbelly was revealed finally by clinical studies in the 1970s.

Now American healthcare appears ready to embark on a new kind of lung cancer screening using low-dose computed tomography (LDCT) in place of chest radiography. 

Some estimates put the number of current and reformed smokers at more than one in three Americans — about 100 million. The actual number who would qualify for screening, however, may be substantially lower. The U.S. Preventive Services Task Force (USPSTF) recommended last month LDCT chest scans for adults 55 to 80 who have a “30 pack-year” smoking history within the last 15 years.

The USPSTF concluded that the benefit of screening outweighs the costs only for heavy current or recent smokers, defined as those who smoke (or until 15 years ago had smoked) a pack of cigarettes or more a day for 30 years — jargonized as “30 pack-years.” 

Still the number who might be screened is likely to be significant and remarkably expensive. The Affordable Care Act requires Medicare and private insurers to cover medical exams and procedures receiving a grade of “B” or better from the USPSTF. (Grades “A” and “B” recommend the procedure; “C” recommends it depending on the patient’s situation; “D” is not recommended.) The USPSTF gave LDCT lung screening a “B” as 2013 came to a close. Forty years earlier, it gave chest radiography and sputum cytology a “D”, effectively quashing that effort.

The decision in favor of lung cancer LDCT screening was made on the basis of clinical trials published between 2000 and 2013. Among these, the National Lung Screening Trial stood out, “Reduced lung-cancer mortality with low-dose computed tomographic screening,” http://www.ncbi.nlm.nih.gov/pubmed/21714641%20?iframe=true&width=100%&height=100%), demonstrating a 20 percent reduction in lung cancer mortality.

With an estimated 160,000 Americans dying each year from the disease, finding a preventive measure to combat lung cancer would seem a good idea. Focusing on heavy smokers makes sense, considering that 85 percent of those who die from lung cancer are cigarette smokers.

But a modernized lung cancer screening program may do less than expected. And the costs both financial and medical could be extraordinary.

Otis Brawley, M.D., chief medical officer of the American Cancer Society, notes that screening in the trial cut lung cancer deaths by 20 percent. He underscores, however, that the results also mean that 80 percent of lung cancer deaths still occur ( See “Is lung cancer screening right for you?”  http://www.wtnh.com/news/health/is-lung-cancer-screening-right-for-you).

The estimated 8,000 to 22,000 lung cancer lives that might be saved through screening will come at a hefty price. Assuming a charge of $1,000 per CT scan, if just 10 percent of the more than 100 million Americans who are believed to have smoked or are now doing so were screened, the effort could cost as much as $10 billion for the initial wave. Repeated screenings would amplify the costs.

Then there is the radiation burden. An average low-dose CT at 1.5 mSv is roughly equivalent to 15 chest radiographs. Because dose is cumulative, repetitive screenings will increase dose linearly.

Suspicious findings will trigger follow-on testing (higher dose CT, FDG-PET/CT and biopsy), adding to radiation and financial costs for false and true positives alike. Brawley expects that screening will lead to further testing in at least one out of every four. Yet, only four out of every 100 who undergo further tests, he says, will actually have lung cancer.

Most troubling, from a psychological perspective, is the possibility that a screening program might enable some smokers to continue their risky behavior as they rationalize lung screening as a way to increase the safety of their habit. How ironic would it be that a program designed to reduce the risk of lung cancer increased it?

These possible consequences raise philosophical and operational issues. For example, would the money — conservatively speaking, $10 billion — be better spent on counseling and smoking cessation treatments for at-risk patients? Or, at the very least, should participation in a cessation program be a condition of reimbursement for the screening test? Such a requirement would benefit the patient by promoting preventive care, while curtailing costs over the long-term.

Yet there has been no talk of such a precondition.

Most sobering is that a screening program will do absolutely nothing to benefit the one in six people with lung cancer who, according to Brawley, are nonsmokers.

Before embarking on a new initiative to screen for lung cancer, insurers and regulators would be well advised to look at past efforts aimed at this disease and make sure the program they implement this time will substantially reduce lung cancer mortality and have no significant mitigating consequences; that no other approach would have a greater positive effect; and that the burdens put on the patient and the healthcare system are justified.