The Adisseo plant, located in Commentry in the Allier department, manufactures vitamins and amino acids through chemical synthesis. Following the observation of a cluster of kidney cancer cases among the plant’s employees, the Department of Occupational Health (DST) at the French Institute for Public Health Surveillance (InVS) undertook an epidemiological investigation through two complementary studies. A cohort study aims to analyze cause-specific mortality, particularly from cancer, among individuals who worked for a cumulative total of at least 6 months between January 1, 1960, and December 31, 2003. A case-control study nested within the cohort is designed to identify occupational characteristics associated with the risk of kidney cancer. This interim report provides a description of the data from the abdominal ultrasound screening program implemented by the occupational health service for the company’s employees, then reviews the progress and initial available results of the cohort study and the case-control study. Finally, it examines the feasibility of a study to assess the impact of abdominal ultrasound screening on the incidence rate of kidney cancer. The Screening Program - Between 1986 and 2003, 743 current or former employees of the plant participated in the annual abdominal ultrasound screening program implemented by the Occupational Health Service. In 1986, screening began among individuals exposed to vinyl chloride monomer (VCM) and was intended to detect liver angiosarcomas. In 1992, the program was expanded to include individuals exposed to C5 chloroacetate, an intermediate in vitamin A synthesis recognized as mutagenic in vitro. In 2001, all employees exposed to chemicals were invited to undergo screening. Since 2002, ultrasound screening has been offered to all factory employees who wish to participate. For two-thirds of employees who have had at least two ultrasounds, the average interval between two ultrasounds is 10.5 months. Nine cases of kidney cancer were diagnosed at a subclinical stage through this screening program. Cohort study—2,523 individuals worked a cumulative total of at least 6 months at Adisseo between January 1, 1960, and December 31, 2003. A regional survey of individuals with kidney cancer was conducted using data from healthcare facilities, computerized reports from pathology laboratories, and records of Long-Term Illnesses (ALD) covered by the general Social Security system. Cross-referencing patient lists with the list of current and former factory employees and reviewing medical causes of death identified 22 individuals with kidney cancer within the cohort. An analysis of cause-specific mortality in the cohort between January 1, 1968, and December 31, 2002, shows that overall mortality and mortality from cancerous tumors were lower than in the general French population for both men and women. No statistically significant excess of deaths from kidney cancer was observed among the factory’s employees. The study of kidney cancer incidence among factory employees between January 1, 1989, and December 31, 2003, shows a 5.3-fold increased risk of kidney cancer among men in the cohort compared to the general male population in France. This excess is statistically significant and is consistent with the standardized incidence ratio of 13.1 calculated in the preliminary report. The observation of an excess of kidney cancer in incidence but not in mortality is not contradictory. Indeed, the good survival of people with kidney cancer and the practice of ultrasound screening at the factory may explain this phenomenon. The analysis of mortality according to occupational parameters has not yet been carried out. Extensive logical imputation work is currently underway on the career histories of the cohort subjects to complete the missing occupational information, particularly the sector of activity within the factory. The feasibility of including employees of subcontracting companies in the cohort was tested and deemed unsatisfactory (feasibility study described in the appendix). Case-control study - Data collection for the case-control study is now complete; 18 individuals with kidney cancer and 82 controls matched by sex and age (+/- 2.5 years) were included in the study. The assessment of occupational exposures based on data collected via questionnaire is currently underway. For exposures specific to Adisseo, the assessment is being conducted by a team of evaluators from the DST and is based on a summary document describing the various buildings at the Commentry and Montluçon sites, as well as the production processes, synthesis phases, and products that have taken place in each building over time. This document was produced by a process engineer from the company for the purposes of the study; it was subsequently supplemented and validated by a working group composed of plant employees and the InVS team. General assessment guidelines were defined for personnel in production, maintenance, utilities, laboratories, and the pilot plant. Exposure for individuals working in other sectors is assessed on a case-by-case basis. For exposures not specific to Adisseo, the assessment is conducted by occupational hygienists from the DST and covers fifteen substances or categories of substances that may be risk factors for kidney cancer. A number of non-occupational factors were also collected via individual questionnaires. These data were analyzed using unconditional logistic regression, adjusted for sex and age. In the Adisseo case-control study, vital status at the time of the interview appears to be statistically linked to the risk of kidney cancer and likely influences the quality of the information collected. Having been included in the abdominal ultrasound screening program is associated with an increased risk of kidney cancer. The three risk factors for kidney cancer most consistently cited in the scientific literature—overweight, high blood pressure, and smoking—are associated in the Adisseo case-control study with an increased risk of kidney cancer. These initial results support the quality of the sampling and the data collected. Next steps - A draft study protocol to assess the impact of ultrasound screening on the incidence rate of kidney cancer is provided in the appendix. In this protocol, the incidence of kidney cancer among Adisseo employees who participated in the screening program would be compared to the incidence of kidney cancer among employees in the VCM polymerization sector, who have also been monitored via abdominal ultrasound since the mid-1980s. The study would require the collection and compilation of ultrasound surveillance data from CVM workers. Due to the significant financial and human resources it would require, the decision to undertake this study has been postponed to a later date. The final report on the epidemiological studies is scheduled for the end of 2007. For the cohort study, the ongoing imputation work on the payroll records is expected to be completed in May 2007, followed during the summer by a statistical analysis of mortality according to occupational characteristics. For the case-control study, the assessment of occupational exposures will be completed in May 2007 and will also be followed by a detailed statistical analysis of the risk of kidney cancer based on occupational exposures. (R.A.)