Heavy smokers can benefit from lung cancer screening using low-dose CT

Lung cancer screening using low-dose computed tomography (CT) offers more benefits than harms for heavy active and former smokers: The procedure can prevent some people from dying from lung cancer and may also prolong overall survival. This conclusion was already drawn in the benefit assessment published by the German Institute for Quality and Efficiency in Health Care (IQWiG) in November 2020.

The corresponding ordinance of the Federal Ministry for the Environment, Nature Conservation, Nuclear Safety and Consumer Protection (BMUV) came into force on 1 July 2024, meaning that a screening procedure using low-dose CT is permitted under radiation protection law.

Against this background, the Federal Joint Committee (G-BA) initiated the consultation procedure on the introduction of lung cancer screening using low-dose CT for active and former smokers in November 2023 and commissioned IQWiG to update its benefit assessment. The Institute was also asked to assess different lung cancer screening strategies using low-dose CT, with different screening intervals as well as different types of technical equipment and image analysis.

IQWiG’s current final conclusion is that the recent evidence emphasizes the benefits of low-dose CT screening and that the benefits outweigh any potential harms, such as the risk of mis- or overdiagnosis. Compared with 2020, the advantage for mortality increased from a hint (low certainty of conclusions) to an indication of benefit (moderate certainty of conclusions).

Smokers can benefit from low-dose CT screening

For the current report, IQWiG evaluated the results of a further study and thus a total of nine randomized controlled trials (RCTs) involving more than 94,000 people—with a clear finding: Low-dose CT screening can prevent five out of 1,000 (former) heavy smokers from dying of lung cancer within about ten years. Heavy smokers are, for example, people who have smoked at least one pack of cigarettes a day for 20 years or at least two packs a day for 10 years.

Lung cancer is often only detected at a late stage, which means that only one-fifth to one-sixth of people affected are still alive five years after diagnosis. There is currently no systematic screening for lung cancer in Germany.

Following the BMUV’s approval of a screening procedure using low-dose CT according to radiation protection law, lung cancer screening could be offered initially as a self-pay service and later—following the G-BA’s decision on the inclusion of the screening test in the catalogue of services provided by statutory health insurance—as part of a national screening program.

Accordingly, the possible design of a screening program for (former) heavy smokers should be considered in the assessment. However, only one study comparing annual screening with biennial screening was available for the benefit assessment of different lung cancer screening strategies using low-dose CT.

Overall, it was not possible to determine whether biennial low-dose CT screening is more beneficial, more harmful, or at least equivalent to annual screening. Other screening strategies, such as a risk-based adjustment of the screening interval, are currently being studied.

Evidence is lacking for all other aspects, such as the standard of the technical equipment, the conduct of the imaging analysis and the algorithms for clarifying abnormal or unclear findings in people without suspected lung cancer. This also applies to people with findings requiring clarification due to previous imaging as part of a screening program. In addition, usable data on health-related quality of life are still not available (as was the case for the first benefit assessment in 2020).