French recommendations for the medico-professional follow-up of workers currently or previously exposed to bladder carcinogens

Introduction
The SFMT (French Society for Occupational Health) has implemented, in association with the AFU (French Urology Association) and the SFC (French Cancer Society), a programme aimed at establishing, in France, recommendations for the medico-professional follow-up of workers currently or previously exposed to substances which are carcinogenic for the bladder.

Methods
The chosen method is the RPC "Clinical Practice Guidelines" method, recommended by the HAS (French National Authority for Health). A critical synthesis of the literature was conducted. Sectors of activity where workers are exposed to carcinogenic substances for the bladder (aromatic amines and certain polyaromatic hydrocarbons) were listed and classified according to the level of bladder cancer risk. Performance (sensitivity, specificity) of available techniques in view of targeted screening for bladder cancer were analysed, including a simulation of results among high-risk populations in France.

Results
The following parameters were selected to define a targeted screening protocol: the risk level for the professional group and the latency period between the start of exposure and the natural history of the disease. The NMP22BC test, exclusive haematuria testing, and combinations of urine cytology with, respectively, the NMP22BC test and haematuria test, generated an extremely high proportion of false positive results (around 20,000 false positives for 100,000 subjects, in each high-risk group category).

Discussion
Urine cytology is the test that offers the best specificity. Although poor, all stages combined, its sensitivity is better for high grades (80% on average), which are of poor prognosis when diagnosed at a late stage. These preliminary results suggest that urine cytology is the only technique that could be proposed in a first-intention targeted screening strategy for occupational bladder cancer. Recommendations will be established after consultation of a panel of about 80 critical readers.