NEW YORKThe 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 dont know
that yet, Dr. Clark said.
Dr. Marshalls 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. Theres
certainly no reason at this point that we can see to dismiss it out
of hand. It looks like a promising technique.