Radiation exposure does not significantly contribute to the risk of recurrence of Chernobyl thyroid cancer.

Context: Papillary thyroid carcinoma (PTC) in patients exposed to environmental radioiodine after the Chernobyl accident is thought to have a relatively aggressive clinical course. Long-term results of treatment are not well known, especially in comparison with sporadic PTC.

Objective: The determination of risk factors for PTC recurrence in a controlled for baseline factors group of patients with radiation-related and sporadic PTC.

The Chernobyl childhood leukemia study: background & lessons learned.

Many challenges emerged during completion of a study to examine radiation dose and acute leukemia among children in areas of the former Soviet Union. In an era of globalization, our experiences might benefit others involved in multinational investigations.