Thyroid Cancer Among Chornobyl Clean-up Workers in Ukraine: Pilot Study

Background: \- The Ukrainian Research Center for Radiation Medicine and the U.S. National Institutes of Health have been studying cancer risks and outcomes in individuals who participated in the decontamination clean-up process following the Chornobyl nuclear accident. Some of these individuals were exposed to external radiation at various levels, as well as radioactive iodine that may have affected the thyroid and increased the risk of developing thyroid cancer. Because more individual and comparative data are needed on the affected populations and clean-up workers associated with the Chornobyl accident, researchers are interested in collecting personal information and saliva samples from Chornobyl clean-up workers who have been diagnosed with thyroid cancer. Objectives: \- To assess the radiation-related risk of thyroid cancer among male Chornobyl clean-up workers and collect saliva samples for an initial study. Eligibility: \- Male Chornobyl clean-up workers from Kyiv and Donetsk oblasts who have been diagnosed with thyroid cancer. Design: * Participants will complete a standardized questionnaire during a personal interview. The questionnaire will ask for detailed information on the following areas of study: * Work history, conditions, and activities inside the 70-km clean-up and radiation calculation zone. * Residence history inside and outside the 30-km exclusion zone. * Milk consumption between April 26 and June 30, 1986 (to assess radioactivity from radioiodine fallout). * Potential non-radiation risk factors for thyroid cancer (e.g., smoking, alcohol consumption, family cancer history). * Participants will provide a saliva sample for pilot study testing....