Genetic Susceptibility to Radiation Induced Thyroid Cancer

6069 Background: To evaluate the clinical and patologic results of surgical treatment of children born after Chernobyl and to compare these findings with well-known data of the group of patients who were children at the time of Chernobyl. To compare the clinical and pathologic features of thyroid cancer of children born after the Chernobyl versus those born prior to 1986. Methods: Comparison of clinical and pathologic result of surgical treatment of 141 patients born after Chernobyl (Group 1) and 589 patients (Group 2) aged 0–18 at the time of the disaster (1986) among the single institution clinical cohort within years 1995–2005. Results: In Group 1 there were 31 cancers (22%) vs. 243 (41%) in Group 2 (p<0.05 between Group 1 and Group 2). The rate of extrathyroid invasion was 69% vs. 36% (p<0.05 between Group 1 and Group 2). In Group 1, 17/21(80%) patients with extrathyroid invasion were found to have regional neck metastases (8 unilateral, 9 bilateral).The mean age in this subgroup was 13.4 ± 2.11 years but in the “benign subgroup” of Group 1 the mean age is 16.2 ± 0.77 years.In Group 2, 49/88 (55%) patients with extrathyroid invasion only had regional metastases. The mean age in this subgroup is 31.1 ± 4.7 years (p<0.05 between Group 1 and Group 2). We found cancer multifocality in 1 patient (3%, Group 1) vs. 55 (23%, Group 2).There were 19 cases (13.5%) of atypical adenomas in Group 1 vs. 46 (8%) in Group 2 (p<0.05 between Group 1 and Group 2). Histological types: solid follicular variant of papillary carcinoma (typical for radiation-induced children carcinomas with short latency) was found in 3 cases in Group 1 (9.5%) vs. 76 (31%) in the Group 2 (p<0.05 between Group 1 and Group 2). There was only one case of follicular thyroid cancer in Group 1 (3%) vs. 9% in Group 2. We did not find any relationship of cases of cancer in Group 1 to the Chernobyl-polluted area (only 3 patients − 10% from the nearest to Chernobyl regions) vs. 192 patients (80%) in Group 2 (p<0.05 between Group 1 and Group 2). Among patients with tumors of uncertain malignant potential 9 patients (6%) were from Chernobyl-polluted area vs.72% in Group 2 (p<0.05 between Group 1 and Group 2). Conclusions: Our data demonstrates higher likelihood of aggressive well-differentiated thyroid cancer among a pediatric population independently from Chernobyl irradiation and connected with another etiological factors of genesis of tumor.The solid-follicular variant of papillary cancer and multifocality are typical for radiation-induced carcinoma in children. No significant financial relationships to disclose.

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ret/PTC1 and ret/PTC3 in thyroid tumors from Chernobyl liquidators: comparison with sporadic tumors from Ukrainian and French patients

Endocrine Related Cancer ◽

10.1677/erc.1.00884 ◽

2005 ◽

Vol 12 (1) ◽

pp. 173-183 ◽

Cited By ~ 16

Author(s):

J Di Cristofaro ◽

V Vasko ◽

V Savchenko ◽

S Cherenko ◽

A Larin ◽

...

Keyword(s):

Thyroid Cancer ◽

Genetic Susceptibility ◽

High Rate ◽

Thyroid Tumors ◽

Chernobyl Fallout ◽

Low Level ◽

High Prevalence ◽

Sporadic Tumors

Like children exposed to Chernobyl fallout, the workers who cleaned up after the accident, also known as liquidators, have exhibited an increased incidence of thyroid cancer. A high prevalence of ret/PTC3 rearrangement has been found in pediatric post-Chernobyl thyroid tumors, but this feature has not been investigated in liquidator thyroid tumors. In this study we analyzed the prevalence of ret/PTC1 and ret/PTC3 in thyroid tumors from 21 liquidators, 31 nonirradiated adult Ukrainian patients, and 34 nonirradiated adult French patients. ret rearrangements in carcinomas were found in 83.3% of liquidators, 64.7% of Ukrainian patients, and 42.9% of French patients. The prevalence of ret/PTC1 was statistically similar in the three groups. The prevalence of ret/PTC3 was significantly higher in liquidators than in French patients (P = 0.03) but it was also high in nonirradiated Ukrainian patients who exhibited values intermediate between liquidators and French patients. In adenomas the prevalence of rearrangement was significantly higher in all Ukrainians than in French patients (P = 0.004). Like children exposed to Chernobyl fallout, liquidators showed a high prevalence of ret/PTC3. This finding suggests that irradiation had the same effect regardless of age. However, given the high rate of ret/PTC3 in nonirradiated adult Ukrainians, the possibility of genetic susceptibility or low-level exposure to radiation in that group cannot be excluded.

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Comparison of early forecasts of the incidence of thyroid cancer in residents of the Russian Federation after the Chernobyl accident with observational data

Radiatsionnaya Gygiena = Radiation Hygiene ◽

10.21514/1998-426x-2021-14-4-45-59 ◽

2021 ◽

Vol 14 (4) ◽

pp. 45-59

Author(s):

I. A. Zvonova ◽

M. I. Balonov

Keyword(s):

Thyroid Cancer ◽

Thyroid Gland ◽

Children And Adolescents ◽

Russian Federation ◽

Chernobyl Accident ◽

Radioactive Fallout ◽

Radiation Induced ◽

The Russian Federation ◽

Regions Of Russia

A review of methods for assessing doses in the thyroid gland, predictions of the long-term consequences of its irradiation and the actual incidence of thyroid cancer in residents of four regions of the Russian Federation with the most significant radioactive fallout after the Chernobyl accident are presented. The method for assessing doses in the thyroid gland is based on the results of monitoring in May-June 1986 of radioiodine in the environment, food and in the body of residents. Thyroid doses in the population were used to justify medical and social protection measures, as well as epidemiological studies. In addition, the authorities needed forecasts of the possible morbidity of the population in order to organize adequate medical care. Most of the thyroid cancer cases were predicted among the adult population, which was not confirmed by observations 35 years after the accident. The prognosis of the incidence of thyroid cancer in preschool children differed in different studies due to the use of different coefficients of reducing the biological effectiveness of 131I radiation in the thyroid gland and long-term external and internal irradiation of the whole body with a low dose rate compared to the effect of acute exposure. The increase in the incidence of thyroid cancer among children began five years after the accident at the Chernobyl nuclear power plant. Examples of the dynamics of the incidence for children in the Bryansk region of the Russian Federation are given. The 2018 UNSCEAR Report showed that for 1986-2015, among children and adolescents under 18 years of age on the day of the accident in Belarus, Ukraine and four regions of Russia, more than 19 thousand thyroid cancer cases were detected, of which the share of radiation-induced diseases was estimated at 25%. For four regions of Russia, this amounts to 460 cases with a range of possible estimates from 130 to 900 cases. The highest morbidity was manifested among younger children exposed at the age of 0-4 years. In older children and adolescents, the proportion of radiation-induced diseases has significantly decreased 30 years after the accident. In general, early forecasts of radiation-induced thyroid cancer incidence in children in four regions of the Russian Federation with high levels of radioactive fallout are consistent with the data of subsequent 30-year epidemiological observations within an order of magnitude. With regard to thyroid cancer in adults, such a comparison is difficult, since no radiogenic increase in the incidence has been detected.

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