Characteristics of young adults of Belarus with post-Chernobyl papillary thyroid carcinoma: a long-term follow-up of patients with early exposure to radiation at the 30th anniversary of the accident.

OBJECTIVES: Studies of thyroid cancer related to the Chernobyl accident have focused on children as they are the most vulnerable group with the highest risk of developing radiation-associated cancer. In contrast, our research aimed to look at the clinical and pathological features of patients with post-Chernobyl papillary thyroid carcinoma that were 2 years old or less at the time of the Chernobyl accident.

DESIGN: The study subjects were patients (n = 359) aged 0 to 2 at the time of the Chernobyl accident and aged ≥19 years at presentation/surgery who were treated in Belarus for papillary thyroid carcinoma during the period 2003-2013.

RESULTS: In conventional or oncocytic variant of papillary thyroid carcinoma, the prevalence of extra-thyroidal extension, nodal disease, infiltrative growth or lymphatic vessel invasion was above 50%. These features were less pronounced when compared to tall cell or diffuse sclerosing variants of papillary thyroid carcinoma. The highest frequency of central lymph node metastases was found in patients aged 1-2 years at exposure (P = 0·004). Subjects exposed in utero were characterized by absent/insignificant lymphocytic infiltration around the carcinoma (P = 0·025), predominance of conventional papillary architecture and an association with lymphocytic thyroiditis.

CONCLUSIONS: A number of features were associated with this group of patients that were very young at the time of radiation exposure. In addition, the incidence and basic characteristics of adult papillary thyroid carcinoma varied depending on the types of exposure conditions.