Studies Project Cost Effectiveness of Lung Cancer Screening

NEW YORK—The cost effectiveness of screening high-risk populations for lung cancer with spiral low-dose CT scans appears to be reasonable, according to two researchers who used somewhat different statistical models and data to arrive at this conclusion. Both researchers presented their results at the Second International Conference on Screening for Lung Cancer.

Using a best-case scenario, Deborah Marshall, PhD, manager of medical research and health economics, Bayer Diagnostics, Emeryville, Calif., reported a cost estimate for screening of $6,000 per life-year saved. In a model based on less rosy statistics, the figure was $23,000, and in her least optimistic scenario, $58,000.

Robert Clark, MD, professor of radiology, University of South Florida, Tampa, and chief of radiology, H. Lee Moffitt Cancer Center and Research Institute, arrived at cost estimates ranging from $28,000 to $49,000 per life-year saved.

The cost of screening mammography for women under age 50, Dr. Marshall noted, has been estimated in other studies at $232,000 per life-year saved, and annual screening for cervical cancer has been es-timated at about $50,000. Because of differences in study methodologies, these figures may not be directly comparable, she said, “but at least they give you a reference range.”

Dr. Marshall and Dr. Clark stressed that their own projections were based on available data and some assumptions whose validity has not been proven. Among the unproven assumptions is that screening for early lung cancer will reduce mortality. “We don’t know that yet,” Dr. Clark said.

The Model

Dr. Marshall’s model evaluated a one-time prevalence screen in smokers 60 to 74 years of age. Data to populate the model, she reported, came from published results of the Early Lung Cancer Action Project (ELCAP) and survival estimates from National Cancer Institute Surveillance, Epidemiology, and End Results (SEER) data. Cost estimates were based on Medicare reimbursement rates and payments. In the analysis, she estimated the cost of a baseline low-dose spiral CT screen to be $150.

Using data based on the projected total costs of running a dedicated outpatient screening unit, Dr. Clark came up with a range of $98 to $191 per CT scan, depending on varying circumstances. “The cost is related to screening efficiency,” he said. “Certainly, in high volume, this can be minimized tremendously.”

In his analyses, Dr. Clark assumed screening at four per hour and also six per hour, the number of mammograms his center is doing in a dedicated mammography unit. Since screening CT “is much easier to perform than mammography,” he said the estimate of six per hour is “not at all unrealistic.”

His models for cost minimization and cost effectiveness included estimates for salaries and benefits of personnel (one radiologist, two technicians, and one clerical worker), $800,000 to purchase the CT equipment, a service contract, and space cost, as well as variable expenses such as those for archiving film. Indirect overhead costs were assumed to be 100% of the direct costs.

“I think there is still a lot of work to be done to sufficiently demonstrate the effectiveness of lung cancer screening,” Dr. Marshall said. “But certainly the results from CT studies are very encouraging. Exploratory economic models underscore that if any screening test is going to be done, it has to be targeted to a high-risk group and also detect a high proportion of the cancers early on, as CT scanning does with stage I lung cancer.” Her models, she said, “suggest that early detection of lung cancer may be, in fact, reasonably cost effective.”

Dr. Clark added, “At least at first blush, the cost effectiveness of screening CT looks very promising. There’s certainly no reason at this point that we can see to dismiss it out of hand. It looks like a promising technique.”