Thyroid carcinoma in children and adolescents in ukraine after the Chernobyl nuclear accident

Abstract

BACKGROUND The increase in the number of childhood thyroid carcinoma cases in Ukraine after the Chernobyl nuclear accident in 1986 prompted the development of a registry of thyroid carcinoma cases at the Institute of Endocrinology and Metabolism in Kiev. In the current study, the authors report the statistical data and clinicomorphologic features of the cases included in this registry. METHODS To study the incidence, and age and gender distribution of thyroid carcinoma in Ukraine, the authors compiled complete clinical information from cases diagnosed and treated at the Institute of Endocrinology and Metabolism and statistical reports submitted to the registry from 27 regions of Ukraine. Morphologic features of the resected tumors were examined and were included in the database. RESULTS During the 5 years preceding the Chernobyl nuclear accident, a total of 59 cases of thyroid carcinoma were identified in the birth to 18 years age group (25 in children age ≤ 14 years and 34 in adolescents ages 15–18 years). Between 1986 and 1997, the total number of thyroid carcinomas in Ukrainian children and adolescents was 577 (358 children and 219 adolescents). Morphologically, the thyroid tumors overwhelmingly were papillary carcinomas, and the majority of these also showed a follicular and/or solid growth pattern. Lymph node metastases and other extrathyroidal spread were common, thus necessitating total thyroidectomy and lymph node dissections in many patients. CONCLUSIONS Between 1990 and 1997, a significant increase in the incidence of thyroid carcinoma was noted in children and adolescents in Ukraine; the group most affected was comprised of the individuals who were age ≤ 5 years in 1986 (the year of the Chernobyl nuclear accident). The largest number of cases occurred in patients living in areas of thyroid radiation doses of ≥0.50 grays. The morphologic features of those thyroid tumors suggest that they are aggressive tumors with a high frequency of lymph node metastases, venous invasion, and extrathyroidal spread. Cancer 1999;86:149–56. © 1999 American Cancer Society.

A Radiation-Induced Gene Signature Distinguishes Post-Chernobyl from Sporadic Papillary Thyroid Cancers

“…It is interesting to note that increased levels were especially linked with PTC characterized by lymph node metastases and more aggressive behavior (40) and patients over the age of 45 (41). Again, post-Chernobyl PTC appeared more aggressive at presentation with lymph node metastasis (60-80%); other extrathyroidal spread and venous invasion were commonly observed (11)(12)(13). Our experimental design allowed us to compare the gene expression levels in the two groups characterized by aggressive behavior.…”

“…A solid papillary histological type was found in 93% of children in the Ukraine (8), and an increased prevalence of ultrasonographic thyroid abnormalities (nodules, cysts) was found (9,10). The tumors appeared to be more aggressive at presentation with lymph node metastasis in 60-80% of patients; other extrathyroidal spread and venous invasion were commonly observed (11,12). The tumors were shown to be more frequently associated with thyroid autoimmunity and developed after a short latent period of 4-5 years (13).…”

Thyroid carcinoma after Chernobyl latent period, morphology and aggressiveness

“…In Belarus, Northern Ukraine and parts of the Russian Federation, about 2000 cases of thyroid carcinoma can be attributed to exposure to fallout; nearly all are papillary carcinomas, and together they form the largest number of cases of cancer of a single type due to a known cause on a known date that have ever occurred (Williams, 2002). The cases vary in their age at exposure and latency; although over 95% of the cancers are classified as papillary carcinomas, they vary also in their morphology, ranging from a solid immature phenotype, lacking typical architectural differentiation and with limited thyroglobulin content, to welldifferentiated tumours dominated by either papillary or follicular architecture (Furmanchuk et al, 1992;Nikiforov and Gnepp, 1994;Bogdanova et al, 1995;Williams, 1996;Tronko et al, 1999). Many tumours contain a mixture of different patterns.…”

Pseudoangiomatous stromal hyperplasia of the breast

“…In reality they were even somewhat smaller" or "Tumors with a shorter latent period show more pronounced intra-and exrtathyroid spread. " (20) In a later study (32), the following figures were reported in regard to TNM staging of TC in children younger than 14 years diagnosed in Ukraine (Table I). It can be seen from the table that the stage T4 was diagnosed in about 50 % of all 244 post-Chernobyl pediatric TC cases.…”

“…It can be seen from the table that the stage T4 was diagnosed in about 50 % of all 244 post-Chernobyl pediatric TC cases. During the years 1981-1985 preceding the accident, only 3 TC were diagnosed in children, all T2 stage (32). To grow to a T4 stage, a tumor needs certain time.…”