Low Dose CT Screening for Lung Cancer (LDCT)
Health Technology Assessment Committee Recommendations
- There is high quality evidence that Low Dose CT screening for lung cancer (LDCT) is clinically and cost-effective for patients aged 55-74 years with 30+ pack-years of smoking, in current or former smokers who quit less than 15 years ago. At the same time, there is uncertainty with regard to the optimal design of a screening program, including the appropriate number and frequency of screening, use of pre and/or post-screening risk stratification tools, and smoking cessation intervention.
- It is recommended that the most cost-effective approach to screening that includes smoking cessation intervention be implemented until there is more evidence in the literature regarding optimal program design and parameters. The Committee recommends a provincially coordinated LDCT lung cancer screening program utilizing a single screen strategy, with post-risk stratification and smoking cessation intervention.
- It is recommended that results of ongoing studies be incorporated into future decision making to refine screening parameters associated with optimal program design.
- It is recommended that smoking cessation programs in use by health authorities be evaluated to determine the most clinically and cost-effective program(s) in order to achieve the desired health benefits.
- It is recommended that a provincially coordinated implementation strategy be developed to mitigate potential risks and patient harms.
Health Technology Assessment Committee Findings
The business case submitted to the Health Technology Assessment Committee (HTAC) reviewed the clinical effectiveness, cost-effectiveness and budget impact of Low Dose CT screening for lung cancer (LDCT). Recommendations were based on the following committee findings:
- The outcomes for lung cancer are generally poor because most patients (~75%) are diagnosed when the cancer is advanced and available treatments have little impact. Early detection in asymptomatic people at high risk for lung cancer is desirable.
- The evidence used to assess LDCT relied mainly on eight Systematic Reviews (SRs) and Health Technology Assessments (HTAs). One very large rigorous US trial, the National Lung Screening Trial (NLST), dominated conclusions across SRs and HTAs. The NLST showed a 20% reduction in mortality from lung cancer and a 6.7% reduction in all-cause mortality through early detection.
- As a result of the NLST, the Canadian Task Force on Preventive Health Care (CTFPHC) issued guidelines recommending screening for lung cancer among adults 55 to 74 years of age with at least a 30 pack-year smoking history, who smoke or quit smoking less than 15 years ago, with LDCT every year up to three consecutive years.
- While the SRs and HTAs reviewed were all generally supportive of LDCT screening based on the NLST, there was variation in the degree to which it was felt that additional research was needed before implementing screening, due to uncertainty with respect to optimal screening parameters i.e. number and frequency of screening, concomitant smoking cessation intervention and provision of risk stratification tools, which have not been evaluated in the NLST.
- In order to assess cost-effectiveness of LDCT, UBC evaluated a number of screening scenarios, including the NLST study criteria and multiple variations in the aforementioned screening parameters. LDCT was determined to be cost-effective compared to no screening; however, relative cost-effectiveness fluctuated based on the screening parameters applied.
- With the inclusion of smoking cessation intervention, which was considered important, a single screen strategy with post-risk stratification and smoking cessation was considered the most cost-effective with an estimated favourable ICER of $20,133/QALY and gain in Quality of Life Years (QALYs) of 6,386 over 20 years.
- Cumulative incremental costs for LDCT screening would be $125 million over 20 years. Most costs would be incurred by MSP ($309 million) and health authorities could expect to see a net savings of -$184 million over the 20 years due to savings in downstream treatment and care costs. Costs to both MSP and HAs are high in the first two years (high demand/volumes of scans in early years) after which MSP costs drop and HAs can expect to start seeing a net savings (see Appendix A).
- In order to maximize cost-effectiveness and minimize risks and patient harms, LDCT screening would need to be well-designed with sufficient planning and coordination. Implementation considerations include:
- Capacity of CT scanners and human resources
- Hospital time for follow-up procedures
- Quality and costs related to scan interpretation, including a potential new fee code for Radiologists
- Management of positive screens, including demand for diagnostic services
- Regional access
- Consideration of a phased introduction with collection of evidence.
- LDCT lung cancer screening could reduce health inequities in socio-economically disadvantaged and marginalized populations, where smoking prevalence is disproportionately higher, provided the program is designed well with access by these populations in mind.
- Results from ongoing studies due in the next 12 months, including a Canadian study led by Dr. Stephen Lam at BCCA on lung cancer screening outcomes and resource use patterns, the Pan-Canadian Early Detection of Lung Cancer Study (PanCan study), are expected to help build the evidence base.
- The committee concluded that implementation of LDCT screening is likely to have fewer risks than implementation of the colorectal cancer screening program; however, emphasized the need to incorporate lessons from that experience into LDCT implementation planning.