CASCAP is a prospective cohort study. Two cohorts have been defined, one for determining who should be screened and the other for patients diagnosed as having CCA. The screening cohort, characterized in the upper zone of Fig. 1, is expected to include at least 150,000 individuals coming from highrisk areas for CCA, including the selfenrolment of persons who feel that they are in danger of developing CCA. The inclusion criteria include all endemic northeastern Thais of 40 years or over with any of the following: ever been infected by or treated for liver flukes or known to have eaten uncooked freshwater fish with scales. Once consent has been obtained, the participants will be enrolled in the program and their baseline information collected. If CCA has been diagnosed, the individual will automatically be moved to the second, patient cohort, characterized in the lower zone of Fig.