gms | German Medical Science

Background: Lung cancer is one of the most common cancers and cancer deaths ranks first among men, second among women. Tobacco smoking is the main risk factor, with 9/10 incidences (men) and 8/10 incidences (women) attributed to long-term heavy smoking. Several large-scale randomized trials have shown effective lung cancer mortality reduction through low-dose CT (LDCT) lung cancer screening. However, the most optimal strategy in risk-based lung-thoracic screening is still unknown regarding the optimal and most cost-effective (e.g., targeted) strategy to determine the (risk-based) screening interval. Personalised regimens based on the baseline CT result can potentially retain 85% of the mortality reduction achievable through screening at 45% less screens, thus potentially saving much unnecessary harm associated with screening.

Methods: The first large-scale multi-centered implementation trial on LDCT lung cancer screening across 5 European countries was set up to develop and implement the most optimal and personalized LDCT lung cancer screening program for high-risk individuals and to assess the relative safety (i.e., comparable detection of favorable lung cancer stages I-II) of a personalized risk-based (often) less intensive screening regimen after a negative baseline scan. To this effect, 24.000 men and women will be recruited, aged 55-97 years with a (1) smoking history of at least 30 pack-years, and being a current smoker or a former smoker who quit less than 15 years prior (USPSTF2013 criteria) or (2) a PLCOm2012 model 6-year risk for lung cancer incidence over 1.83%. Participants will be randomized into Arm A annual screening or Arm B biannual screening, and followed-up for several years for lung cancer incidence and mortality. We will show here the current status of the Heidelberg center, with a projected final recruitment until end of 2024.

Results: Several recruitment methods have resulted in so far 1708 out of 3000 planned baseline-screened participants, with further 759 scheduled participants until summer 2024. Recruitment methods applied were postal letters to all citizens of eligible age in Heidelberg and Mannheim, re-contacting participants of previous studies (LUSI and EPIC), advertisements through general practitioners and pneumologists, and use of social networks. Citizens of further surrounding municipalities will be contacted to reach 3000 baseline screened participants by end of 2024. Participation rate based on the general population was 1.7 so far (i.e. 100,000 contacts). Between 35-45% of interested citizens did not fulfil the eligibility criteria, predominantly because of insufficient smoking history (88%). Out of the 1708 baseline screens, 79% were categorized as negative, 16% as indeterminate with a 3-months repeat scan planned and 4% as suspicious positive. Of those with a repeat scan, 88% resulted in a negative scan whereas 7% were positively screened. Of the 87 screened positive, most are still under clinical work-up, 15 are false-positive and 17 are true-positive (12 men, 5 women). The true-positives presented primarily with stage I/II lung cancers (83%), were adenocarcinoma (44%) and classified as C34.1.

Discussion: Our population-based recruitment approaches in Heidelberg yielded very low participation rates. However, as anticipated, a higher percentage of early stage tumours presented after LDCT baseline screening.

The authors declare that they have no competing interests.

The authors declare that a positive ethics committee vote has been obtained.