Targeted screening for lung cancer is here but who do we target and how

In October 2019, an Independent Review of Adult Screening Programmes in England was published, authored by Mike Richards.1 Two key recommendations were that targeted screening programmes should be given equal weight to population screening programmes and that there should be a single advisory body covering both population and targeted screening programmes. The review identified the importance of defining individual risk of cancer to identify a target population at sufficient risk of the condition to be cost-effective. Secretary of State for Health and Social Care, Matt Hancock has asked the chief medical officers of the four UK countries to agree a mechanism for overseeing the new ‘targeted programmes’.2 Screening for lung cancer with low radiation dose CT (LDCT) is the largest of these programmes and is a considerable challenge to implement. In other countries the distinction between population and targeted screening is emphasised less but the criteria used to select eligible people remain crucial in determining cost-effectiveness.3 4 Targeting avoids subjecting people at low risk, who have little chance of developing the disease and benefiting from screening, to similar harms as those who are more likely to develop the disease and potentially benefit. Multivariable models have been shown to have better sensitivity and specificity than selection based on age and tobacco smoking alone, the most common criteria currently used on a global basis.5 6 In the UK, the first trial to use a multivariable model to define eligibility was the UK Lung Screening Trial (UKLS).7 The cancer detection rate was 2.1%, but there was some concern that the threshold risk (5% over 5 years) was too high.8 UK pilots have used both the Liverpool Lung Project version 2 (LLPv2), as was used in UKLS, and the Prostate Lung Colorectal and Ovarian (modified 2012) (PLCO …