This report presents the results of a feasibility study on the implementation of a surveillance system for the incidence of work-related cancers. Currently, no such surveillance system exists in France. 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 would make it possible to identify occupations or sectors of activity with a high incidence of cancer and changes over time, in order to guide public policies aimed at improving and evaluating the prevention and recognition of work-related cancers. The proposed surveillance system for cancer incidence linked to occupational activity (Sicapro), whose primary objective is to identify occupational groups at increased risk of cancer, 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 (Cnav). Initially, to test the feasibility of implementing such a surveillance system, a pilot study was conducted using two voluntary 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 pilot study were to evaluate the performance of data matching using civil registry data on cancer patients from the registries and those contained 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 examine the limitations of the approach, particularly regarding the identification of occupational exposures. Since the 1970s, France has maintained general and specialized cancer registries that enable local and national epidemiological surveillance of cancers by comprehensively recording all cancer cases occurring among the population residing in the territory covered by each registry. General cancer registries collect information on all cancers, whereas specialized cancer registries collect extensive information on certain cancers (digestive system, malignant hematological diseases, breast and other gynecological cancers, central nervous system, thyroid, mesothelioma) or concerning specific populations (children and adolescents). The two cancer registries that volunteered to participate in this pilot study (Lille and its region; Doubs and the Territoire de Belfort) are general registries, covering all cancer sites. The data collected by the Cnav contain all information pertaining to insured individuals’ work histories for the purpose of calculating their pensions. This includes all individuals with at least one period of employment subject to contributions to the general social security system, regardless of duration, and covers all individuals who have worked or are working in metropolitan France or overseas territories, including the foreign population. Information from other social security schemes (Agricultural Social Mutual Fund, Social Scheme for the Self-Employed, etc.) is reported to enable the calculation of pension entitlements, generally as retirement approaches, at the end of a person’s career. Data matching was performed by the National Old-Age Insurance Fund using civil registry data (last name, first name, date and place of birth) since the cancer registries did not collect the National Identification Number (NIR). The performance of this matching was satisfactory, as 96.9% of cancer cases were identified in the CNAV databases. Career histories were reconstructed using employer numbers, since the industry sector—directly accessible via the code for the primary activity performed—was systematically recorded only for the most recent years. The company number (Siret) recorded in the database allows the company’s industry sector (NAF) to be identified via INSEE’s Sirene® database. The feasibility of reconstructing employment histories for the purpose of analyzing associations between cancer incidence and industry sector was also found to be satisfactory starting in 1999. Starting with new cases from 2019, we will therefore have a reliable employment history covering the last twenty years of a person’s career, which appears sufficient even for studies on diseases with long latency periods, such as cancers. Reporting of the socio-professional category (SPC) by employers has been mandatory since 2008, but data reporting issues for the years 2009 to 2011 prevented the provision of indicators within the scope of this pilot study. Nevertheless, this information has been available since 2012 and will enable the provision of cancer incidence indicators by SOC at the time of diagnosis for the expanded surveillance system. Finally, two examples of possible uses for this data are presented here. The first study presents standardized incidence ratios for lung cancer by economic sector at the time of diagnosis among cases aged 20 to 64 years and recorded between 2010 and 2014 by the Doubs and Belfort Territory Cancer Registry. The second is a case-control study estimating the lifetime risk of developing lung cancer for both registries, considering as exposed individuals who worked for at least one year versus those who worked for less than one year in each industry sector. These results are put into perspective by calculating expected incidence disparity indices due to differences in smoking prevalence by industry sector, as smoking remains the primary risk factor for lung cancer. The main limitation identified in this study relates to the population covered by the National Old-Age Insurance Fund (CNAV). Indeed, the CNAV covers only employees under the general scheme, and data from other schemes are therefore complete only for retired individuals. Furthermore, the information reported by other schemes does not allow for the reconstruction of the sectors of activity occupied during a career or the socio-professional categories (CSP) for periods when individuals were self-employed or employees contributing to another scheme. This limitation could be addressed by the Cnav’s implementation of the Single Career Management Registry (RGCU), which aims to consolidate career data for each insured person from all schemes to ensure the completeness and consistency of this data. Real-time data entry into the RGCU by other schemes, scheduled for December 31, 2022, could thus make it possible to extend the population covered by the monitoring system to all working individuals, regardless of the scheme to which they belong. Despite the limitations identified during this pilot phase, the Sicapro surveillance system possesses the characteristics of an effective surveillance system: it does not require the collection of additional data, it has high sensitivity because the registries comprehensively capture incident cases in their respective regions, and it is representative of the employed population under the general scheme. The inclusion of all cancer registries in the surveillance system, covering nearly 20% of the population, will provide greater statistical power, enabling the study of incidence for rarer cancer sites and/or for sectors of activity at a more granular level. The surveillance system will also enable the production of indicators at the departmental level for departments fully covered by a registry, including certain overseas departments (Guadeloupe, Martinique, and French Guiana).