Childhood thyroid cancer in Belarus

The retrospective analysis was performed to compare the clinical course of radiogenic and sporadic childhood thyroid cancer. The entire series included 752 patients aged less than 15 years at diagnosis. Of them, 686 (91.2%) individuals had radiation history including 681 (90.6%) exposed at the time of the Chernobyl disaster and 5 (0.7%) children were previously treated for malignant lymphoma with an external beam therapy. The second group consisted of 66 (8.8%) unexposed patients. All the children underwent surgery and received suppressive thyroxine therapy with the mean dose of 2.0–2.5 μg/kg of body weight. Radioiodine therapy was performed in 464 (61.7%) cases. The comparison of patients with radiogenic and sporadic thyroid cancer did not reveal statistically significant differences in the distribution of tumor size, histological type or TNM stage. During follow-up time relapses were registered in 204 (27.1%) patients. The main sites of recurrence were the lung or lymph nodes whereas other lesions (thyroid remnants, the bone, soft tissues or CNS involvement) were uncommon. The disease-free survival ranged widely, 0–213 months after the date of primary surgery without significant difference between the radiogenic and sporadic cases. The observed 10-year survival was 99.5% for the entire series, including 99.5% and 99.7% in patients with radiogenic and sporadic carcinomas, respectively.