Interviews are conducted by trained health staff using a standardized questionnaire. Blood and urine samples (spot urine) are obtained. Cases are interviewed upon referral for a diagnostic biopsy (if possible) or as early as possible after diagnosis prior to any treatment. Controls are invited to the same clinic as the matched case to complete the same questionnaire and to provide samples. If the control cannot be invited to the clinical centre, a trained health staff technician or nurse visits the control at her place of residence to administer the interview and perform sample collection.