The surveillance of occupational cancers is a recognized national priority and is included in various government cancer plans. In France, the current surveillance system is based primarily on the analysis of cancer mortality rates by occupation. With the exception of mesotheliomas, there is no system for monitoring cancers linked to occupational activity and industry sector.

Santé publique France has studied the feasibility of developing such a system to supplement the indicators it produces and to reliably identify occupational groups at increased risk of cancer: this is the Sicapro project, whose pilot study results are published today.

Occupational Cancers in France

• In 2010, 12% of employees had been exposed to at least one carcinogenic hazard (chemical carcinogens, ionizing radiation, or night work for women).

• The proportion of cancer cases attributed to occupational factors is estimated at between 4% and 8.5%, or 15,000 to 33,000 new cases each year.

• It should be noted that several factors, such as the latency period between exposure and the onset of cancer, and lack of awareness of exposure, may indicate that a significant proportion of occupational cancers are not recognized as such.

What is the basis of the Sicapro study, and what are the results?

A linkage of data from cancer registries and data from the CNAV regarding occupational histories

The proposed surveillance system is based on the linkage, at the individual level, of medical data from cancer registries with data on professional careers from the National Old-Age Insurance Fund for employees under the general scheme (Cnav).

A pilot study was conducted with two participating registries (the General Cancer Registry of Lille and its region and the Tumor Registry of Doubs and the Belfort Territory), which provided data on all recorded cancer cases for the years 2010–2014. The objectives of this study were:

• to assess the performance of data matching using civil registry data on cancer patients from the registries and those included in the Cnav data;

• to identify the occupational history data available in the Cnav databases and to assess the quality of these administrative data for the purpose of epidemiological surveillance;

• to develop the various indicators that can be routinely generated for the final surveillance system and to assess the limitations of the approach, particularly regarding the identification of occupational exposures.

Ultimately, an expansion to all cancer registries and all employee pension schemes will allow for broader coverage with the aim of studying incidence for rarer cancer sites and/or for sectors of activity at a more granular level.

A reliable employment history covering the last 20 years of careers

In this pilot study, 96.9% of cancer cases were found in the Cnav databases, indicating an excellent matching rate between the databases. The reconstruction of career histories, carried out with the aim of assessing associations between cancer incidence and sector of activity, also proved very satisfactory starting in 1999.

This study shows that it is therefore possible to obtain a reliable employment history covering the last 20 years of a career, which appears sufficient even for studies on diseases with long latency periods, such as cancers. The socio-professional category (CSP), useful for producing cancer incidence indicators by CSP at the time of diagnosis, is also a parameter that can be utilized starting in 2012.

Sicapro: A Surveillance System Deemed Effective

Despite limitations identified during the pilot phase, the Sicapro surveillance system has proven effective in several respects:

• Little additional workload, as it is an integrated system based solely on pre-existing data of very high quality and completeness

• Minimization of all burdensome measures for patients and healthcare staff

• Comprehensive collection of cancer incidence data from regional registries

• Representative of the employed population covered by the general social security system and, eventually, representative of all employees

Moving toward expansion to all registries and all employees for nationwide coverage

Santé publique France aims to ensure the long-term viability of the Sicapro surveillance system by extending it to all registries for national coverage (including certain overseas departments—Guadeloupe, Martinique, and French Guiana) and to all employees. This latter goal is made possible by the Cnav’s implementation, starting in 2022, of the Single Career Management Directory (RGCU), which aims to centralize career data for insured individuals across all schemes.

Estimates of cancer incidence by occupation or industry sector provide valuable information for describing and understanding the relationships between occupational risk factors and the occurrence of cancer in the French population. They will help identify occupations or sectors of activity with high cancer incidence rates, as well as trends over time, in order to guide public policies aimed at improving and evaluating the prevention and recognition of work-related cancers.