Lung Cancer Screening in a Population Exposed to Occupational Lung Carcinogens

The good clinical practice guidelines for the surveillance of workers after occupational exposure to lung carcinogens were approved by the Haute Autorité de la Santé (French National Authority for Health) and the Institut National du Cancer (French National Cancer Institute) in December 2015 and the Recommendation R12 of these guidelines concerns the setting-up of a trial of low-dose chest computed tomography (CT) lung cancer screening in subjects occupationally exposed to lung carcinogens at high-risk of lung cancer (Expert consensus).

In LUCSO study, the investigators propose to conduct, under strictly defined conditions, a feasibility study of lung cancer screening in a population defined as being at high risk of lung cancer according to these good clinical practice guidelines. This population consists of smokers, aged from 55 to 74 years, currently or previously exposed to International Agency for Research on Cancer lung group 1 lung carcinogens.

The primary objective of this study is to evaluate the organization of lung cancer screening in the target population. This evaluation will focus on the following indicators:

• Screening activity indicator: screening coverage rate over two years
• Test quality indicator: validity of self-administered questionnaires to target the high-risk population
• Examination quality indicator: lung cancer detection rate, lung cancer detection rates by stage, validity of low-dose chest CT scan
• Follow-up indicator: smoking cessation rate, mortality rate

The secondary objectives of the study are:

• Describe the population recruited in each step of the protocol
• Develop a tool to identify subjects exposed to pulmonary carcinogens and with high-risk of lung cancer
• Evaluate the impact of the proposed screening programme on smoking cessation at one, two and three years.
• Evaluate the social impact of the screening campaign
• Conduct a cost-effectiveness analysis of the programme

The proposed study will take place in multidisciplinary and specialized reference centers (SRC) in various French districts participating in the programme, to welcome patients participating. It is organized into six workpackages (WP):

• WP1: Methodology - Epidemiology
• WP2: Evaluation of occupational exposure
• WP3: Imaging
• WP4: Lung cancer follow-up strategy
• WP5: Smoking cessation
• WP6: Medico-economic analysis Six specialized reference centers are proposed in four different regions in order to test a potential region effect and to allow the recruitment by each SRC of about 200 to 600 new eligible subjects per year and per department according to the population and the age pyramid of each department
• SRC1: Centre Intercommunal de Créteil for the Val-de-Marne (94), Seine-et-Marne (77), and Essonne (91) departments
• SRC2: Bordeaux University Hospital for the Gironde (33) department
• SRC3: Rennes University Hospital for the Ille-et-Vilaine (35) department
• SRC4: Brest University Hospital for the Finistère (29) department
• SRC5: Caen University Hospital for the Calvados (14) department
• SRC6: Rouen University Hospital for the Seine-Maritime (76) department

Each of these centers is voluntary and possesses the four essential prerequisites: an occupational health clinic - radiology team with specific skills in chest imaging - pulmonology team or network of pulmonologists specialized in lung cancer - smoking cessation team.

In view of the complexity of this organization, it is proposed to initially test the feasibility and acceptability of the screening programme sequentially for the first two years (24 months) in two SRCs (SRC1 and SRC2): "Phase 1: 2021-2023". It is expected to extend the study to the other SRCs after two years: "Phase 2: 2023-2029". Ad hoc adjustments will be decided for the creation of SRCs in the third year on the basis of the data acquired in the two pilot departments, especially on the expected target population participation rate. Mortality will be monitored at least until 2031.

The trial will be conducted in several steps:

• Identification of subjects currently or previously occupationally exposed to lung carcinogens by a screening invitation letter sent by Departmental Cancer Screening Centers to subjects aged from 55 to 74 years.
• Evaluation of occupational exposure to lung carcinogens
• Evaluation of the lung cancer risk level and verification of eligibility
• Screening procedure: Chest CT scans will be performed by centers specialized in chest imaging
• Lung cancer follow-up when an abnormality suggestive of lung cancer is demonstrated.

Inclusion criteria

Subjects at high risk of lung cancer: current smokers smoking 30 pack-years or more or ex-smokers smoking 30 pack-years or more and who have quit smoking for less than 15 years and currently or previously occupationally exposed to lung carcinogens. With an algorithm for determination of minimal duration of exposure to occupational carcinogens (according to the type and duration of occupational lung carcinogens)

Exclusion criteria

• Presence of clinical signs of lung cancer
• Subjects with a history of lung cancer
• Presence of serious short-term life-threatening comorbidities
• Absence of occupational exposure to lung carcinogens according to the predefined criteria
• Subjects already included in another prospective cohort study
• Subjects already assessed by chest CT scan during the previous year
• No tobacco exposure or insufficient tobacco exposure or smoking cessation for more than 15 years.