SCREENING FOR LUNG CANCER

If all screening-eligible current and former smokers underwent low-dose computed tomography (LDCT) screening, 12,000 deaths from lung cancer could be averted each year in the United States, according to an analysis published onlineFebruary 25 in Cancer.

"Recently, the National Lung Screening Trial [NLST] demonstrated that, compared with chest x-ray, screening with LDCT reduced lung cancer mortality by 20% among current and former smokers, but the annual number of lung cancer deaths that could potentially be averted is unknown," senior author Ahmedin Jemal, DVM, PhD, from the American Cancer Society in Atlanta, Georgia, told Medscape Medical News.

"In this study, we sought to provide the first national estimate of the total number of lung cancer deaths that could be potentially averted with full implementation of lung cancer screening in current and former heavy smokers, aged 55 to 74 years, who smoked at least 1 pack per day for 30 years," Dr. Jemal said.

The investigators, led by colleague Jiemin Ma, PhD, MHS, also from the American Cancer Society, used a specially developed equation to estimate the number of lung cancer deaths that could be averted with screening.

The equation took into account the size of the American population (from 2010 Census data), the prevalence of screening eligibility (estimated from 2010 National Health Interview Survey [NHIS] data), and the lung cancer mortality rates in screening-eligible populations (estimated using 2000 to 2004 NHIS data and the Third National Health and Nutrition Examination Survey–linked mortality files).

In 2010, 8.6 million Americans (5.2 million men and 3.4 million women) were eligible for lung cancer screening.

According to the estimate, if the screening regimen used in the NLST was fully implemented in this population, 12,250 (95% confidence interval, 10,170 - 15,671) lung cancer deaths (8990 in men and 3260 in women) would be averted each year.

Start the Discussion With Your Patient

"Doctors with access to high-volume, high-quality lung cancer screening and treatment centers should initiate discussion with their eligible patients about the benefits, uncertainties, and harms of lung cancer screening," Dr. Jemal said.

"Our findings could provide additional data for setting or updating lung cancer screening guidelines," he explained. "They could also stimulate further studies on avertable lung cancer deaths and the cost effectiveness of LCDT screening under different scenarios of risk, various screening frequencies, and various uptake rates."

In an accompanying editorial, Larry Kessler, ScD, from the University of Washington School of Public Health in Seattle, writes that the most important influence on lung cancer mortality is the reduction in smoking.

He notes that antismoking campaigns in the United States have averted "hundreds and thousands of deaths," but that public health efforts are still needed to further reduce the prevalence of smoking.

Efforts to reduce smoking "should not minimize the potential importance of screening," he writes. "In many ways, these efforts must go hand in hand."

Dr. Kessler questions whether the 20% reduction in lung cancer mortality found in the NLST and the estimated 12,000 lives saved per year found in this study are sufficient justification to implement a national policy for screening.

"It is clear why a decision has not been yet taken in this direction," he writes. The high rate of false-positive tests, the related workup costs, and the cost of treatment that does not benefit patients complicate the issue.

The limits of screening emphasize the continued need for antismoking efforts, Dr. Kessler says. He issues a call to use "all of our technologies, primary prevention methods, screening methods, and treatment" to tackle this issue.