The clinical effectiveness and
cost-effectiveness of computed
tomography screening for lung
cancer: systematic reviews
C Black,1*A Bagust,2A Boland,3S Walker,4
C McLeod,3R De Verteuil,1J Ayres,5L Bain,1
S Thomas,1D Godden6and N Waugh1
1Department of Public Health, University of Aberdeen, UK
2University of Liverpool Management School, UK
3Liverpool Reviews and Implementation Group (LRiG),
University of Liverpool, UK
4Department of Radiology, Aberdeen Royal Infirmary, UK
5School of Medicine, Environmental and Occupational Medicine,
University of Aberdeen, UK
6School of Medicine, University of Aberdeen, UK
* Corresponding author
Health Technology Assessment
NHS R&D HTA Programme
Health Technology Assessment 2006; Vol. 10: No. 3
The clinical effectiveness and cost-effectiveness of computed
tomography screening for lung cancer
Screening for lung cancer has been the subject of
debate for the past three decades. This has largely
stemmed from the results of chest X-ray screening
studies where improvements in survival were
obtained but without reductions in disease-specific,
or total, mortality. The debate raises two issues:
the design of studies to evaluate screening for
lung cancer, in particular the choice of
comparator; and the potential role of over-
diagnosis of well-differentiated, slow-growing
tumours that would not have led to symptoms or
death in the lifetime of the affected patient.
Lung cancer is the leading cause of death from
cancer in the UK, killing approximately 34,000
people per year. By the time symptoms develop,
the tumour is often at an advanced stage and the
prognosis is bleak. Treatment at a less advanced
stage of disease with surgical resection has been
shown to substantially reduce mortality.
Screening would be attractive if it could detect
presymptomatic lung cancer at a stage when
surgical intervention is feasible.
The aim of this review is to examine the clinical
and cost-effectiveness of screening for lung cancer
using computed tomography (CT) to assist policy
making and to clarify research needs.
Fifteen electronic databases and Internet
resources were searched from 1994 until
December 2004/January 2005. In addition,
bibliographies of the retrieved articles were
searched and the register of projects held by the
International Network of Agencies for HTA
(INAHTA) was also checked.
Studies were included where screening for lung
cancer was the principal theme of the paper. The
initial search was for randomised trials in which
survival in a group receiving CT screening was
compared with a group not screened, but because
of the lack of such studies, no restriction was
placed on study type. Studies were reviewed by two
Data extraction included details of the screening
protocol, follow-up, diagnosis and participants.
Information was sought about test characteristics,
including sensitivity and specificity. The checklists
and methods described in NHS Centre for
Reviews and Dissemination (CRD) Report 4 were
used for the quality assessment of studies.
Separate narrative summaries were performed for
the clinical effectiveness and cost-effectiveness.
Cost-effectiveness analysis resulting in a cost per
quality-adjusted life-year was not feasible,
therefore the main elements of such an appraisal
were summarised and the key issues relating to the
existing evidence base were discussed.
Summary of clinical effectiveness
In total, 12 studies of CT screening for lung
cancer were identified, including two randomised
controlled trials (RCTs) and ten studies of
screening without comparator groups. The
quality of reporting of these studies was variable,
but the overall quality was adequate. The two
RCTs were of short duration (1 year) and therefore
there was currently no evidence that screening
improves survival or reduces mortality. The
proportion of people with abnormal CT findings
varied widely between studies (5–51%). The
prevalence of lung cancer detected was between
0.4 and 3.2% (number need to screen to detect
one lung cancer = 31–249). Incidence rates of
lung cancer were lower (0.1–1% per year).
Detection of stage I and resectable tumours was
high, 100% in some studies. Adverse events,
as a result of investigation or surgery, or the
screening process per se were poorly reported.
Incidental findings of other abnormalities
requiring medical follow-up were reported to
be as high as 49%.
Executive summary: The clinical effectiveness and cost-effectiveness of computed tomography screening for lung cancer
Summary of cost-effectiveness
Six full economic evaluations of population CT
screening programmes for lung cancer were
included in the review. The magnitude of cost-
effectiveness ratios reported vary widely. None
was set in the UK and generalisation was
complicated by wide variation in the data used
in different countries and a paucity of UK
data for comparison. All six made the
fundamental assumption that screening with CT
for lung cancer reduced mortality. At the current
time, there is no evidence to support that
In the absence of evidence of health gains from
screening for lung cancer, in terms of either
quantity or quality of life, and faced with a range
of uncertainties, from the frequency of abnormal
screening findings within a population to the
natural history of screening detected lung cancers,
it is not feasible at the current time to develop
accurately and meaningfully an economic
argument for CT screening for lung cancer in the
UK. For subgroups, in particular certain
occupational groups, there is evidence of
increased risk of lung cancer, but the role of
screening has not been demonstrated by the
The accepted National Screening Committee
criteria are not currently met, with no RCTs, no
evidence to support clinical effectiveness and no
evidence of cost-effectiveness.
Recommendations for research
In terms of what information is needed to assist
decision-making about CT screening for lung
cancer, the following research priorities were
G RCT evidence is needed about the effect of CT
screening on mortality, either with whole-
population screening or for particular
subgroups. One such trial is underway in the
USA, recruiting 50,000 participants, and is due
to end in 2009, although final follow-up will not
complete until around 2014.
G UK data about the rate of positive screening
with CT and detected lung cancers could be
obtained from an RCT or a cohort study. Even
relatively small-scale studies would provide
valuable information when trying to assess the
generalisability of RCT data currently being
G There is a need to understand better the
natural history and epidemiology of screening-
detected lung cancers, particularly small, well-
differentiated adenocarcinomas. This could be
met, in part, by lung cancer screening RCTs or
cohort studies, but a review of existing
published epidemiological and pathological
data, along with primary analysis of UK lung
cancer epidemiology, would usefully inform
G Information about the quality of life impact of
CT screening, acceptability of screening, and
uptake and retention rates in the UK would be
valuable in any future assessment of the cost-
effectiveness of screening in the UK.
G Increased collection is needed of UK health
service data regarding resource use and safety
data for lung cancer management and services.
G Research is needed into the feasibility and
logistics of tracing people who have in the past
worked in industry where there was exposure to
Black C, Bagust A, Boland A, Walker S, McLeod C,
De Verteuil R, et al. The clinical effectiveness and
cost-effectiveness of computed tomography
screening for lung cancer: systematic reviews.
Health Technol Assess 2006;10(3).
Health Technology Assessment 2006; Vol. 10: No. 3 (Executive summary)
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