Ukrainian Consensus on Diagnosis and Management of Vitamin D Deficiency in Adults

Vitamin D deficiency (VDD) is a global problem, however, there were no Ukrainian guidelines devoted to its screening, prevention, and treatment, which became the reason for the Consensus creation. This article aimed to present the Consensus of Ukrainian experts devoted to VDD management. Following the creation of the multidisciplinary Consensus group, consent on the formation process, drafting and fine-tuning of key recommendations, and two rounds of voting, 14 final recommendations were successfully voted upon. Despite a recent decrease in VDD prevalence in Ukraine, we recommend raising awareness regarding VDD's importance and improving the strategies for its decline. We recommend screening the serum 25-hydroxyvitamin D (25(OH)D) level in risk groups while maintaining a target concentration of 75-125 nmol/L (30-50 ng/mL). We recommend prophylactic cholecalciferol supplementation (800-2000 IU/d for youthful healthy subjects, and 3000-5000 IU/d for subjects from the risk groups). For a VDD treatment, we recommend a short-term administration of increased doses of cholecalciferol (4000-10,000 IU/d) with 25(OH)D levels monitored after 4-12 weeks of treatment, followed by the use of maintenance doses. Additionally, we recommend assessing serum 25(OH)D levels before antiosteoporotic treatment and providing vitamin D and calcium supplementation throughout the full course of the antiosteoporotic therapy.

Characteristics and immune checkpoint status of radioiodine-refractory recurrent papillary thyroid carcinomas from Ukrainian Chornobyl Tissue Bank donors

Introduction

The radioiodine-refractory (RAI-R) recurrent papillary thyroid carcinomas (PTCs) are more frequent in elderly patients and have an unfavorable prognosis. Data on the prevalence and characteristics of RAI-R recurrent PTCs in patients of young and middle age with or without a history of radiation exposure in childhood are poorly described. The aim of the current study was: i) to determine the frequency of RAI-R recurrent PTCs among donors of the Chornobyl Tissue Bank (CTB) and analyze the clinicopathological features of primary tumors (PTs), primary metastases (PMTSs), recurrent metastases (RMTSs) and risk factors for RMTS, and ii) to determine the immune checkpoint status (ICS) of the RAI-R recurrent PTCs and to assess the factors associated with ICS positivity.

Methods

Sixty RAI-R recurrent PTCs (46 exposed to radiation and 14 non-exposed, 2.5% of all cases registered with the CTB) from the Ukrainian patients aged up to 48 years were identified.

Results

The clinicopathological characteristics of the PTs moderately to weakly resembled those of the PMTS and RMTS from the same patients while the metastatic tissues were highly similar. The multivariate model of RMTS included the dominant solid-trabecular growth pattern of the PT, cystic changes, N1b metastases, and the probability of a causation (POC) of PTC by radiation as risk factors. Among these factors, the lateral PMTS (N1b) had the strongest effect. The longer period of latency (a POC component) was the second statistically significant characteristic. ICS percent agreement between the PT and RAI-R RMTS was 91.5%; 23.7% of PTs and 28.8% of RMTSs had positive ICS (positive PD-L1 tumor epithelial cells (TECs) and positive PD-L1/PD1 tumor-associated immune cells). ICS positivity of PTs was associated with pronounced oncocytic changes and high density of the p16INK4A-positive TECs in the invasive areas of PTs. In RMTSs, ICS positivity was associated with pronounced oncocytic changes and Ki-67 labeling index ≥ 4.5% of PTs, and the dominant solid-trabecular growth pattern, Ki-67 labeling index ≥ 7.6% and p16INK4A-positivity of RMTS.

Discussion

The findings are of clinical relevance and may be useful for developing individual treatment approaches for patients with RAI-R recurrent PTCs possibly involving immunotherapy.

Female Papillary Thyroid Cancer Survivors Are at Increased Risk of Adenomyosis and Endometrial Hyperplasia

PURPOSE

Thyroid cancer (TC) is the most common endocrine cancer worldwide, affecting mainly women of reproductive age. However, no data exist about its association with endometrial or uterine disorders. This study aimed to assess the risk of hyperproliferative pathology of the reproductive system in female ТС survivors.

METHODS

This was a cross-sectional study of female patients aged 20-45 years diagnosed with papillary TC (PTC) from 1994-2018. Age-matched females with normal thyroid structures served as controls.

RESULTS

One hundred and sixteen patients (mean age 36.7±61 years) and 90 age-matched controls were included. PTC survivors demonstrated an increased risk for adenomyosis [odds ratio (OR) 2.5, 95% confidence interval (CI) 1.3-4.8] and endometrial hyperplasia (OR 3.9, 95% CI 1.1-14.3), compared with controls. The risk for adenomyosis was higher after the ten post-operative years (OR 5.3, 95% CI 2.29- 12.05) than during the first 5-10 years (OR 2.3, 95% CI 1.02-5.10) and increased with the number of RAI courses and the degree of TSH suppression. The risk of endometrial hyperplasia was most evident during the first five years post-thyroidectomy (OR 6.0, 95% CI 1.4-25.5), especially in patients with TSH <0.1 mU/L (OR 6.8, 95% CI 1.4-33.28) No difference in uterine leiomyomas or endometrial polyps was found between PTC survivors and controls.

CONCLUSIONS

Female PTC survivors are at increased risk of endometrial hyperplasia and adenomyosis compared with those with normal thyroid structures.

Exposure to the Thyroid from Intake of Radioiodine Isotopes after the Chornobyl Accident. Report I: Revised Doses and Associated Uncertainties for the Ukrainian-American Cohort

Thyroid doses from intake of radioiodine isotopes (131I, 132Te+132I, and 133I) and associated uncertainties were revised for the 13,204 Ukrainian-American cohort members exposed in childhood and adolescence to fallout from the Chornobyl nuclear power plant accident. The main changes related to the revision of the 131I thyroid activity measured in cohort members, the use of thyroid-mass values specific to the Ukrainian population, and the revision of the 131I ground deposition densities in Ukraine. Uncertainties in doses were assessed considering shared and unshared errors in the parameters of the dosimetry model. Using a Monte-Carlo simulation procedure, 1,000 individual stochastic thyroid doses were calculated for each cohort member. The arithmetic mean of thyroid doses from intake of 131I, 132Te+132I, and 133I for the entire cohort was 0.60 Gy (median = 0.22 Gy). For 9,474 subjects (71.6% of the total), the thyroid doses were less than 0.5 Gy. Thyroid doses for 42 cohort members (0.3% of the total) exceeded 10 Gy while the highest dose was 35 Gy. Intake of 131I contributed around 95% to internal thyroid exposure from radioiodine isotopes. The geometric standard deviation of individual stochastic thyroid doses varied among cohort members from 1.4 to 4.3 with an arithmetic mean of 1.6 and a median of 1.4. It was shown that the contribution of shared errors to the dose uncertainty was small. The revised thyroid doses resulted, in average, in around 40% decrease for cohort members from Zhytomyr Oblast and an increase of around 24% and 35% for the cohort members from Kyiv and Chernihiv Oblast, respectively. Arithmetic mean of TD20 doses for the cohort was around 8% less than that estimated in TD10, 0.60 Gy vs. 0.65 Gy, respectively; however, global median of TD20 doses somewhat increased compared to TD10: 0.22 Gy vs. 0.19 Gy, respectively. The difference between TD10 and TD20 was mainly due to a revision of the individual 131I thyroid activity measured in the cohort members.

RAAS inhibitors are associated with a better chance of surviving of inpatients with Covid-19 without a diagnosis of diabetes mellitus, compared with similar patients who did not require antihypertensive therapy or were treated with other antihypertensives

PURPOSE

The effect of renin-angiotensin-aldosterone system (RAAS) inhibitors in combination with COVID-19 and diabetes mellitus (DM) remains unknown. We assessed the risk of death in COVID-19 inpatients based on the presence or absence of DM, arterial hypertension (AH) and the use of RAAS inhibitors or other antihypertensives.

METHODS

The results of treatment of all adult PCR-confirmed COVID-19 inpatients (n = 1097, women 63.9%) from 02/12/2020 to 07/01/2022 are presented. The presence of DM at the time of admission and the category of antihypertensive drugs during hospital stay were noted. Leaving the hospital due to recovery or death was considered as a treatment outcome. Multivariable logistic regression analysis was used to assess the risk of death. Patients with COVID-19 without AH were considered the reference group.

RESULTS

DM was known in 150 of 1,097 patients with COVID-19 (13.7%). Mortality among DM inpatients was higher: 20.0% vs. 12.4% respectively (p=0.014). Male gender, age, fasting plasma glucose (FPG) and antihypertensives were independently associated with the risk of dying in patients without DM. In DM group such independent association was confirmed for FPG and treatment of AH. We found a reduction in the risk of death for COVID-19 inpatients without DM, who received RAAS inhibitors compared with the corresponding risk of normotensive inpatients, who did not receive antihypertensives: OR 0.22 (95% CI 0.07-0.72) adjusted for age, gender and FPG.

CONCLUSION

This result raises a question about the study of RAAS inhibitors effect in patients with Covid-19 without AH.

Breast cancer risk in Ukrainian women exposed to Chornobyl fallout while pregnant or lactating: standardized incidence ratio analysis, 1998 to 2016

The radiation-related risk of breast cancer among women following the Chornobyl accident remains uncertain. During pregnancy, there is rapid cell proliferation in the breast while radioactive iodine from fallout exposure can concentrate in lactating breast tissues. We conducted a standardized incidence ratio (SIR) analysis of breast cancer in a cohort of 2,631 women who were lactating and/or pregnant at any time during the 2-month period of radioiodine fallout (April 26, 1986-June 30, 1986). There were 37,151 person-years of follow-up, and 26 incident breast cancers were identified through linkage with the National Cancer Registry of Ukraine. Breast cancer rates among pregnant or lactating women were compared to the general population rates, and SIRs were adjusted for oblast, urban/rural, age, and calendar year. The SIR was not significant for women pregnant at the time of the accident (SIR = 0.75; 95% CI 0.44, 1.18) or for women lactating anytime within 2 months of the accident (SIR = 0.96; 95% CI 0.48, 1.68). However, there was a non-significantly elevated risk for women lactating at the time of accident (SIR = 1.30, 95% CI 0.40, 3.01). The increased SIR for breast cancer among lactating women is consistent with the results of a similar study in Belarus and indicates the need to quantify the radiation risk of breast cancer in a larger study of women lactating during the period of fallout exposure.

Clinicopathological Implications of the BRAF V600E Mutation in Papillary Thyroid Carcinoma of Ukrainian Patients Exposed to the Chernobyl Radiation in Childhood: A Study for 30 Years After the Accident

With time after the Chernobyl accident, the number of papillary thyroid carcinomas (PTCs) driven by the BRAF^V600E oncoprotein is growing in patients exposed to radiation at a young age. Clinicopathological associations of BRAF^V600E in PTCs from patients with internal radiation history have not been sufficiently studied so far. This work analyzes the structural characteristics, proliferative activity, invasive features, clinical information, and dosimetric data in the BRAF^V600E-positive and BRAF^V600E-negative PTCs from the Ukrainian patients exposed to Chernobyl radiation and treated over 30 years after the accident. The study included 428 PTCs from patients aged 4-49 years at surgery who lived in the six northern regions of Ukraine most contaminated by ¹³¹I, were ≤18 years of age at the time of exposure, and were operated on from 1990 to 2017. Immunohistochemical staining for BRAF^V600E was performed with the VE1 antibody. The probability of causation (POC) of a tumor due to radiation was determined using an interactive online NIH/NCI software. BRAF^V600E was detected in 136/428 (31.8%) PTCs. In comparison with the BRAF^V600E-negative PTCs, the BRAF^V600E-positivity was associated with older patient age at the accident and at surgery, a longer period of latency, and lower POC. The BRAF^V600E-positive PTCs were characterized by smaller tumor size, higher Ki67 labeling index, more frequent oncocytic changes, multifocality, and dominant papillary growth pattern. Tumor invasive features were less frequent in the BRAF^V600E-positive PTCs and did not change with POC level. Despite a less aggressive tumor phenotype, BRAF^V600E was a risk factor for recurrence, namely radioiodine-refractory (RAI-R) recurrent metastases. Multivariate models of RAI-R included BRAF^V600E and/or histopathological parameters closely correlating with BRAF^V600E such as tumor size, multifocality, dominant papillary growth pattern, or oncocytic changes. Thus, the BRAF^V600E-positive PTCs from patients from a high-risk group for radiogenic thyroid cancer diagnosed in the 30 years after the Chernobyl accident did not display higher invasiveness regardless of POC level, but in view of the prognostic impact of this genetic alteration, knowledge of the BRAF status may be beneficial for middle-aged patients with radiogenic PTC considered for RAI therapy, and suggests more careful follow-up of patients with the BRAF^V600E-positive tumors.

Assessment of internal exposure to 131I and short-lived radioiodine isotopes and associated uncertainties in the Ukrainian cohort of persons exposed in utero

This study revised the thyroid doses for 2582 Ukrainian in utero cohort members exposed to Chornobyl fallout (the Ukrainian in utero cohort) based on revision of: (i) 131I thyroid activity measured in the Ukrainian population, (ii) thyroid dosimetry system for entire Ukraine, and (iii) 131I ground deposition densities in Ukraine. Other major improvements included: (i) assessment of uncertainties in the thyroid doses considering shared and unshared error, and (ii) accounting for intake of short-lived radioisotopes of tellurium and iodine (132Te+132I and 133I). Intake of 131I was the major pathway for thyroid exposure, its median contribution to the thyroid dose was 97.4%. The mean prenatal and postnatal thyroid dose from 131I was 87 mGy (median = 17 mGy), higher than previous deterministic dose of 72 mGy (median = 12 mGy). For 39 individuals (1.5%) the dose exceeded 1.0 Gy, while the highest dose among the cohort members was 2.7 Gy. The geometric standard deviation (GSD) of 1000 individual stochastic doses varied from 1.9 to 5.2 with a mean of 3.1 and a median of 3.2. The lowest uncertainty (mean GSD = 2.3, median GSD = 2.2) was found for the subjects whose mothers were measured for 131I thyroid activity, while for individuals, whose mothers were not measured, the mean and median GSDs were 3.4. Uncertainties in thyroid doses were driven by shared errors associated with the parameters of the ecological model.

The high degree of similarity in histopathological and clinical characteristics between radiogenic and sporadic papillary thyroid microcarcinomas in young patients

The potential overtreatment of patients with papillary thyroid microcarcinoma (MPTC) has been an important clinical problem in endocrine oncology over the past decade. At the same time, current clinical guidelines tend to consider prior radiation exposure as a contraindication to less extensive surgery, even for low-risk thyroid carcinomas, which primarily include microcarcinomas. This study aims to determine whether there are differences in the behavior of MPTC of two etiological forms (radiogenic and sporadic), including invasive properties, clinical data, and recurrence in patients aged up to 30 years. For this purpose, 136 radiogenic (from patients aged up to 18 years at the time of the Chornobyl accident) and 83 sporadic (from patients born after the Chornobyl accident) MPTCs were selected and compared using univariate and multivariate statistical methods in a whole group and in age and tumor size subgroups. No evidence of more aggressive clinical and histopathological behavior of radiogenic MPTCs as compared to sporadic tumors for basic structural, invasive characteristics, treatment options, and postoperative follow-up results was found. Moreover, radiogenic MPTCs were characterized by the lower frequencies of oncocytic changes (OR = 0.392, p = 0.004), nodal disease (OR = 0.509, p = 0.050), and more frequent complete remission (excellent response) after radioiodine therapy (OR = 9.174, p = 0.008). These results strongly suggest that internal irradiation does not affect tumor phenotype, does not associate with more pronounced invasive properties, and does not worsen prognosis in pediatric or young adult patients with MPTC, implying that radiation history may be not a pivotal factor for determining treatment strategy in such patients.

The relationship of the clinicopathological characteristics and treatment results of post-Chornobyl papillary thyroid microcarcinomas with the latency period and radiation exposure

INTRODUCTION

A worldwide increase in the incidence of thyroid cancer during the last decades is largely due to papillary thyroid microcarcinomas (MPTCs), which are mostly low-risk tumors. In view of recent clinical recommendations to reduce the extent of surgery for low-risk thyroid cancer, and persisting uncertainty about the impact of radiation history, we set out to address whether clinicopathological characteristics and prognosis of post-Chornobyl MPTCs were changing with regard to: i) the latency period, ii) probability of causation (POC) of a tumor due to radiation, and iii) tumor size.

METHODS

Patients (n = 465) aged up to 50 years at diagnosis who lived in April, 1986 in six northern, most radiocontaminated regions of Ukraine were studied.

RESULTS

Latency period was statistically significantly associated with the reduction of POC level, tumor size and the frequency of fully encapsulated MPTCs. In contrast, the frequency of oncocytic changes and the BRAF^V600E mutation increased. Invasive properties and clinical follow-up results did not depend on latency except for a lower frequency of complete remission after postsurgical radioiodine therapy. The POC level was associated with more frequent extrathyroidal extension, and lymphatic/vascular invasion, less frequent oncocytic changes and BRAF^V600E , and did not associate with any clinical indicator. Tumor size was negatively associated with the latency period and BRAF^V600E , and had a statistically significant effect on invasive properties of MPTCs: both the integrative invasiveness score and its components such as lymphatic/vascular invasion, extrathyroidal extension and lymph node metastases increased. The frequency of total thyroidectomy, neck lymph node dissection and radioiodine therapy also increased with the larger tumor size. The duration of the latency period, POC level or tumor size did not associate with the chance of disease recurrence.

DISCUSSION

In summary, we did not observe overall worsening of the clinicopathological features or treatment results of radiogenic MPTCs that could be associated with the latency period or POC level, suggesting that radiation history did not strongly affect those in the analyzed MPTC patients. However, the increase in the invasive properties with tumor size indicates the need for individual risk stratification for each MPTC patient, regardless of radiation history, for treatment decision-making.

The BRAFV600E Mutation Is Not a Risk Factor for More Aggressive Tumor Behavior in Radiogenic and Sporadic Papillary Thyroid Carcinoma at a Young Age

Simple Summary

Analysis of the groups of young Ukrainian patients (aged ≤28 years) with radiogenic and sporadic papillary thyroid carcinomas (PTCs) showed that the frequency of BRAF^V600E was increasing with patient age, consistently remaining lower in radiogenic PTCs. In both etiopathogenic groups, the BRAF^V600E-positive PTCs more frequently had a dominant papillary growth pattern, smaller tumor size, higher Ki67 labeling index, and a frequency of the major indicators of tumor invasiveness that is lower than or equal to that of the BRAF^V600E-negative tumors. Comparison of the BRAF^V600E-positive PTCs across the groups found a virtual absence of differences, while the BRAF^V600E-negative tumors differed markedly and displayed a higher frequency of invasive tumor features in the radiogenic PTCs. Hence, there is evidence that BRAF^V600E does not confer a more aggressive course of PTC in young patients regardless of tumor etiology.

Abstract

Histopathological changes in the fusion oncogene-driven papillary thyroid carcinomas (PTCs) from children and adolescents exposed to Chernobyl fallout have been extensively studied. However, characteristics of the radiogenic BRAF^V600E-positive PTCs, whose proportion is growing with time, are not well described yet. We analyzed the relationship between the BRAF^V600E status (determined immunohistochemically with the VE1 antibody) and the clinicopathological features of 247 radiogenic and 138 sporadic PTCs from young Ukrainian patients aged ≤28 years. The frequency of BRAF^V600E was increasing with patient age, consistently remaining lower in radiogenic PTCs. In both etiopathogenic groups, the BRAF^V600E-positive PTCs more frequently had a dominant papillary growth pattern, smaller tumor size, higher Ki67 labeling index, and a frequency of the major indicators of tumor invasiveness that is lower than or equal to that of the BRAF^V600E-negative tumors. Comparison of the BRAF^V600E-positive PTCs across the groups found a virtual absence of differences. In contrast, the BRAF^V600E-negative radiogenic PTCs displayed less frequent dominant papillary and more frequent solid growth patterns, lower Ki67 labeling index, and higher invasiveness than the BRAF^V600E-negative sporadic tumors. Thus, BRAF^V600E is not associated with a more aggressive course of PTC in young patients regardless of etiology. The major clinicopathological differences between the radiogenic and sporadic PTCs are observed among the BRAF^V600E-negative tumors.

Relationship between hyperglycemia, waist circumference, and the course of COVID-19: Mortality risk assessment

An observational study was conducted in Ukraine to determine the independent mortality risks among adult inpatients with COVID-19. The results of treatment of COVID-19 inpatients (n = 367) are presented, and waist circumference (WC) was measured. Logistic regression analysis was applied to evaluate the effects of factors on the risk of mortality. Odds ratios and 95% CIs for the association were calculated. One hundred and three of 367 subjects had fasting plasma glucose level that met the diabetes mellitus criteria (≥7.0 mmol/L), in 53 patients, diabetes mellitus was previously known. Two hundred and eleven patients did not have diabetes or hyperglycemia. Diabetes mellitus/hyperglycemia odds ratio 2.5 (CI 1.0-6.1), p = 0.045 loses statistical significance after standardization by age, waist circumference or fasting plasma glucose. No effect on gender, body mass index-determined obesity, or hypertension was found. The fasting plasma glucose (>8.5 mmol/L), age (≥61 years), and waist circumference (>105 cm) categories were associated with ORs 6.34 (CI 2.60-15.4); 4.12 (CI 1.37-12.4); 8.93 (CI 3.26-24.5), respectively. The optimal model of mortality risk with AUC 0.86 (CI 0.81-0.91) included the diabetes/heperglycemia and age categories as well as waist circumference as a continued variable. Waist circumference is an independent risk factor for mortality of inpatients with COVID-19.

Abstract PO-055: Molecular characterization of papillary thyroid cancer in relation to ionizing radiation dose following the Chernobyl accident

The 1986 Chernobyl nuclear power plant accident increased papillary thyroid cancer (PTC) incidence in surrounding regions, particularly for 131I-exposed children. To investigate the contribution of environmental radiation to PTC characteristics and improve understanding of radiation-induced carcinogenesis, we analyzed genomic, transcriptomic, and epigenomic characteristics of 440 pathologically-confirmed fresh-frozen PTCs from Ukraine (359 with estimated childhood or in utero 131I exposure and 81 from unexposed children born after March 1987) and matched normal tissue (non-tumor thyroid tissue and/or blood). Mean age at PTC was 28.0 years (range: 10.0-45.6). Among 131I-exposed individuals, mean radiation dose was 250 mGy (range: 11.0-8,800). In multivariable models adjusted for age at PTC and sex, we observed radiation dose-dependent enrichment of fusion drivers (P=6.6 × 10−8), nearly all occurring in the MAPK pathway, as well as increases in small deletions (P=8.0 × 10−9) and simple/balanced structural variants (P=1.2 × 10−14). Further analyses demonstrated even stronger associations for those small deletions and simple/balanced structural variants that were clonal and bore hallmarks of non-homologous end-joining repair (deletions: P=4.9 × 10−31; simple/balanced structural variants: P=5.5 × 10−19). In contrast, radiation dose was not associated with subclonal small deletions (P=0.82) or subclonal simple/balanced structural variants (P=0.91). Additionally, radiation dose was not associated with TINS (locally templated insertions), which are characteristic of alt-end-joining repair (P=0.69). The effects of radiation on genomic alterations with more pronounced for those younger at exposure. Analyses generally were consistent with a linear radiation dose-response for all molecular characteristics except clonal small deletions. Analyses of transcriptomic and epigenomic features demonstrated strong associations with the PTC driver gene but not radiation dose. Our results point to DNA double-strand breaks as early carcinogenic events that subsequently enable PTC growth following environmental radiation exposure.

Citation Format: Lindsay M. Morton, Danielle Karyadi, Chip Stewart, Tetiana Bogdanova, Eric Dawson, Mia Steinberg, Jieqiong Dai, Stephen Hartley, Sara Schonfeld, Joshua Sampson, Yosi Maruvka, Vidushi Kapoor, Dale Ramsden, Juan Carvajal-Garcia, Chuck Perou, Joel Parker, Marko Krznaric, Meredith Yeager, Joseph Boland, Amy Hutchinson, Belynda Hicks, Casey Dagnall, Julie Gastier-Foster, Jay Bowen, Olivia Lee, Mitchell Machiela, Elizabeth Cahoon, Alina Brenner, Kiyohiko Mabuchi, Vladimir Drozdovitch, Sergii Masiuk, Mykola Chepurny, Liudmyla Yu Zurnadzhy, Maureen Hatch, Amy Berrington de Gonzalez, Gerry Thomas, Mykola Tronko, Gad Getz, Stephen Chanock. Molecular characterization of papillary thyroid cancer in relation to ionizing radiation dose following the Chernobyl accident [abstract]. In: Proceedings of the AACR Virtual Special Conference on Radiation Science and Medicine; 2021 Mar 2-3. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(8_Suppl):Abstract nr PO-055.

[HORMONAL AND METABOLIC ASPECTS OF DIABETES-ASSOCIATED OSTEOARTHRITIS]

Joint damage in patients with diabetes mellitus (DM) is a common complication and is associated with the induction of metabolic inflammation against the background of increased catabolic processes in various joint structures. The aim of our work was to study the level of insulin, leptin, osteocalcin, as well as biochemical markers of connective tissue metabolism in patients with diabetes-associated osteoarthritis. We examined 77 patients who were divided into groups by type of diabetes, the presence and severity of diabetic arthropathy. The content of insulin and leptin, osteocalcin in the blood serum was determined by the enzyme immunoassay, the level of glycosaminoglycans, hydroxyproline, hyaluronidase, collagenase according to traditional biochemical methods. Among the examined patients, diabetic arthropathy was diagnosed in more than 70%. Patients with diabetic arthropathy significantly increased levels of insulin (with type 1 diabetes by 38.5%, with type 2 diabetes by 55.6%) and leptin (with type 1 diabetes by 43.8%, with type 2 diabetes by 53.7,%), the level of osteocalcin (only with type 1 diabetes by 53.9%) There is a direct correlation between the severity of joint damage and the level of insulin and leptin. The severity of arthopathy in patients with type 2 diabetes is directly correlated with indicators of insulin resistance. In patients with diabetes-associated osteoarthritis, indicators that characterize catabolic processes in the connective tissue (hydroxyproline free and collagenase (p<0.001) are increased. The chances of detecting arthropathy with type 1 diabetes increase 3.8 times with an increase in insulin levels, with an increase in leptin 1.3 times, in patients with type 2 diabetes, 2.6 and 1.2 times, respectively. For this sample, it was found that the development of arthropathy does not depend on the type of diabetes. In women with type 2 diabetes, the chances of developing arthropathy are six times higher. 4 times than men. An increase in insulin and leptin levels can serve as a marker for the presence and progression of arthropathy in patients with diabetes. Patients with arthropathies have increased levels of hydroxyproline and collagenase, which reflects an increase in catabolic processes in the connective tissue, which may be one of the mechanisms for the development of joint structures in patients with diabetes.

Histopathological characteristics and post-operative follow-up of patients with potentially radiogenic papillary thyroid carcinoma depending on oncocytic changes availability in the tumor cells

AIM

To compare the frequency of main histopathological characteristics, 131І thyroid radiation doses, invasive properties and post-operative follow-up of patients of different age groups with potentially radiogenic papillary thyroid carcinoma (PTC) with the presence and absence of oncocytic changes in tumor cells.

MATERIALS AND METHODS

PTC removed in 483 patients from high risk age-group for radiogenic thyroid cancer development (children and adolescents at the time of Chornobyl accident who lived in the northern regions of Ukraine: Kyiv, Zhytomyr, and Chernihiv regions) have been studied microscopically.

RESULTS

The frequency of PTC with the presence of oncocytic changes (OCh) in tumor cells increased significantly with increasing of patients' age at the time of surgery: from 8.3% in children 4-14 years old to 54.3% in adults 39-48 years old (ptrend < 0.0001). The presence of such changes is associated with papillary and solid-trabecular dominant tumor growth pattern in more than 90% of cases in each age group. The mean 131І thyroid dose in the whole series of PTC patients with OCh was significantly lower compared to the same index in PTC patients without OCh (493.7 mGy and 765.8 mGy, respectively, p < 0.0001). In addition, regional metastases recurrences were revealed more frequently in patients with OCh in primary PTC compared with patients without OCh in primary tumor (7.2% vs 1.5%, p = 0.0022).

CONCLUSIONS

Significantly increasing age-trend of OCh in PTC of patients affected by the Chornobyl fallout and operated at age from 4 to 48 years, as well as opposite decreasing linear age-trend of 131І thyroid dose may reflect a gradual increase of sporadic PTCs frequency in the potentially radiogenic series with time elapsed since accident. The frequency of oncocytic insensitive to radioiodine therapy of lymph node metastases recurrences also increased with patients age and OCh availability in primary PTC.

Thyroid Cancer and Benign Nodules After Exposure In Utero to Fallout From Chernobyl

BACKGROUND

Children and adolescents exposed to radioactive iodine-131 (I-131) in fallout from the 1986 Chernobyl nuclear accident appear to be at increased risk of thyroid cancer and benign thyroid nodules. The prenatal period is also considered radiosensitive, and the fetal thyroid can absorb I-131 from the maternal circulation.

OBJECTIVES

We aimed to estimate the risk of malignant and benign thyroid nodules in individuals exposed prenatally.

METHODS

We studied a cohort of 2582 subjects in Ukraine with estimates of I-131 prenatal thyroid dose (mean = 72.6 mGy), who underwent two standardized thyroid screening examinations. To evaluate the dose-response relationship, we estimated the excess OR (EOR) using logistic regression.

RESULTS

Based on a combined total of eight cases diagnosed at screenings from 2003 to 2006 and 2012 to 2015, we found a markedly elevated, albeit not statistically significant, dose-related risk of thyroid cancer (EOR/Gy = 3.91, 95% CI: -1.49, 65.66). At cycle 2 (n = 1,786), there was a strong and significant association between I-131 thyroid dose and screen-detected large benign nodules (≥10 mm) (EOR/Gy = 4.19, 95% CI: 0.68, 11.62; P = 0.009), but no significant increase in risk for small nodules (<10 mm) (EOR/Gy = 0.34, 95% CI: -0.67, 2.24; P = 0.604).

CONCLUSIONS

The dose effect by nodule size, with I-131 risk for large but not small nodules, is similar to that among exposed children and adolescents in Belarus. Based on a small number of cases, there is also a suggestive effect of I-131 dose on thyroid cancer risk.

Neonatal outcomes following exposure in utero to fallout from Chernobyl

Iodine 131 (I-131), the principal component of nuclear fallout from the Chernobyl accident, concentrates in the thyroid gland and may pose risks to fetal development. To evaluate this, neonatal outcomes following the accident in April of 1986 were investigated in a cohort of 2582 in utero-exposed individuals from northern Ukraine for whom estimates of fetal thyroid I-131 dose were available. We carried out a retrospective review of cohort members' prenatal, delivery and newborn records. The relationships of dose with neonatal anthropometrics and gestational length were modeled via linear regression with adjustment for potentially confounding variables. We found similar, statistically significant dose-dependent reductions in both head circumference (-1.0 cm/Gy, P = 0.005) and chest circumference (-0.9 cm/Gy, P = 0.023), as well as a similar but non-significant reduction in neonatal length (-0.6 cm/Gy, P = 0.169). Gestational length was significantly increased with increasing fetal dose (0.5 wks/Gy, P = 0.007). There was no significant (P > 0.1) effect of fetal dose on birth weight. The observed associations of radioiodine exposure with decreased head and chest circumference are consistent with those observed in the Japanese in utero-exposed atomic bomb survivors.

Thyroid neoplasia risk is increased nearly 30 years after the Chernobyl accident

To evaluate risk of thyroid neoplasia nearly 30 years following exposure to radioactive iodine (I-131) from the 1986 Chernobyl nuclear accident, we conducted a fifth cycle of thyroid screening of the Ukrainian-American cohort during 2012-2015, following four previous screening cycles started in 1998. We identified 47 thyroid cancers (TC) and 33 follicular adenomas (FA) among 10,073 individuals who were <18 years at the time of the accident and had a mean I-131 dose of 0.62 Gy. We found a significant I-131 dose response for both TC and FA, with an excess odd ratio per Gy of 1.36 (95% CI: 0.39-4.15) and 2.03 (95% CI: 0.55-6.69), respectively. The excess risk of malignant and benign thyroid neoplasia persists nearly three decades after exposure and underscores the importance of continued follow-up of this cohort to characterize long-term pattern of I-131 risk.

Factors associated with serum thyroglobulin in a Ukrainian cohort exposed to iodine-131 from the accident at the Chernobyl Nuclear Plant

BACKGROUND

Serum thyroglobulin (Tg) is associated with the presence of thyroid disease and has been proposed as a biomarker of iodine status. Few studies have examined factors related to serum Tg in populations environmentally exposed to ionizing radiation and living in regions with endemic mild-to-moderate iodine deficiency.

METHODS

We screened 10,430 individuals who were living in Ukraine and under 18 years of age at the time of the 1986 Chernobyl Nuclear Power Plant accident for thyroid disease from 2001 to 2003. We estimated the percent change (PC) in serum Tg associated with demographic factors, iodine-131 thyroid dose, and indicators of thyroid structure and function using linear regression. We also examined these relationships for individuals with and without indications of thyroid abnormality.

RESULTS

Mean and median serum Tg levels were higher among participants with abnormal thyroid structure/function. Percent change in serum Tg increased among females, smokers and with older age (p-values<0.001), and Tg increased with increasing thyroid volume, and serum thyrotropin (p-values for trend<0.001). We found no evidence of significant associations between iodine-131 thyroid dose and Tg. Serum Tg levels were inversely associated with iodized salt intake (PC=-7.90, 95% confidence interval: -12.08, -3.52), and over the range of urinary iodine concentration, the odds of having elevated serum Tg showed a U-shaped curve with elevated Tg at low and high urinary iodine concentrations.

CONCLUSION

Serum Tg may be a useful indicator of population iodine status and a non-specific biomarker of structural and functional thyroid abnormalities in epidemiological studies.

Genomic copy number analysis of Chernobyl papillary thyroid carcinoma in the Ukrainian-American Cohort

One of the major consequences of the 1986 Chernobyl reactor accident was a dramatic increase in papillary thyroid carcinoma (PTC) incidence, predominantly in patients exposed to the radioiodine fallout at young age. The present study is the first on genomic copy number alterations (CNAs) of PTCs of the Ukrainian-American cohort (UkrAm) generated by array comparative genomic hybridization (aCGH). Unsupervised hierarchical clustering of CNA profiles revealed a significant enrichment of a subgroup of patients with female gender, long latency (>17 years) and negative lymph node status. Further, we identified single CNAs that were significantly associated with latency, gender, radiation dose and BRAF V600E mutation status. Multivariate analysis revealed no interactions but additive effects of parameters gender, latency and dose on CNAs. The previously identified radiation-associated gain of the chromosomal bands 7q11.22-11.23 was present in 29% of cases. Moreover, comparison of our radiation-associated PTC data set with the TCGA data set on sporadic PTCs revealed altered copy numbers of the tumor driver genes NF2 and CHEK2. Further, we integrated the CNA data with transcriptomic data that were available on a subset of the herein analyzed cohort and did not find statistically significant associations between the two molecular layers. However, applying hierarchical clustering on a 'BRAF-like/RAS-like' transcriptome signature split the cases into four groups, one of which containing all BRAF-positive cases validating the signature in an independent data set.

Dose-dependent expression of CLIP2 in post-Chernobyl papillary thyroid carcinomas

This study showed a clear dose-response relationship for the CLIP2 radiation marker in post-Chernobyl papillary thyroid carcinoma cohorts for young patients and hints to different molecular mechanisms in tumors induced at low doses compared to moderate/high doses.

A previous study on papillary thyroid carcinomas (PTC) in young patients who were exposed to ¹³¹iodine from the Chernobyl fallout revealed an exclusive gain of chromosomal band 7q11.23 in exposed cases compared to an age-matched control cohort. CLIP2, a gene located within band 7q11.23 was shown to be differentially expressed between exposed and non-exposed cases at messenger RNA and protein level. Therefore, a standardized procedure for CLIP2 typing of PTCs has been developed in a follow-up study. Here we used CLIP2 typing data on 117 post-Chernobyl PTCs from two cohorts of exposed patients with individual dose estimates and 24 non-exposed controls to investigate a possible quantitative dose-response relationship of the CLIP2 marker. The ‘Genrisk-T’ cohort consisted of 45 PTCs and the ‘UkrAm’ cohort of 72 PTCs. Both cohorts differed in mean dose (0.59 Gy Genrisk-T, 1.2 Gy UkrAm) and mean age at exposure (AaE) (2 years Genrisk-T, 8 years UkrAm), whilst the median latency (16 years Genrisk-T, 18 years UkrAm) was comparable. We analyzed the association between the binary CLIP2 typing and continuous thyroid dose with logistic regression. A clear positive dose-response relationship was found for young PTC cases [age at operation (AaO) < 20 years, AaE < 5 years]. In the elder age group a higher proportion of sporadic tumors is assumed due to a negligible dose response, suggesting different molecular mechanisms in sporadic and radiation-induced cases. This is further supported by the association of elder patients (AaO > 20 years) with positivity for BRAF V600E mutation.

Non-thyroid cancer in Northern Ukraine in the post-Chernobyl period: Short report

The Chernobyl nuclear power plant accident in Ukraine in 1986 led to widespread radioactive releases into the environment - primarily of radioiodines and cesium - heavily affecting the northern portions of the country, with settlement-averaged thyroid doses estimated to range from 10 mGy to more than 10 Gy. The increased risk of thyroid cancer among exposed children and adolescents is well established but the impact of radioactive contamination on the risk of other types of cancer is much less certain. To provide data on a public health issue of major importance, we have analyzed the incidence of non-thyroid cancers during the post-Chernobyl period in a well-defined cohort of 13,203 individuals who were <18 years of age at the time of the accident. The report is based on standardized incidence ratio (SIR) analysis of 43 non-thyroid cancers identified through linkage with the National Cancer Registry of Ukraine for the period 1998 through 2009. We compared the observed and expected number of cases in three cancer groupings: all solid cancers excluding thyroid, leukemia, and lymphoma. Our analyses found no evidence of a statistically significant elevation in cancer risks in this cohort exposed at radiosensitive ages, although the cancer trends, particularly for leukemia (SIR=1.92, 95% confidence interval: 0.69; 4.13), should continue to be monitored.

Morphological difference in adult thyroid papillary carcinoma between Japan and Ukraine

Geographic differences have been reported to affect the morphological and molecular features of papillary thyroid carcinomas (PTCs). The area around Chernobyl is well-known to be iodine-deficient in contrast to Japan, an iodine-rich country. We reviewed histological differences in adult PTC between Ukraine and Japan. In total, 112 PTCs from age- and sex-matched adults (Ukraine 56, Japan 56) were evaluated histologically for several factors including tumor size, capsulation, tumor components (papillary, follicular, solid, trabecular), lymph node metastasis, extrathyroid invasion, lymphocytic infiltration, oxyphilic metaplasia, and MIB-1 index. We demonstrated that tumors were smaller (1.56 vs. 2.13 cm, p<0.05) and more solid and that lymph node metastasis was less frequent (14.3% vs. 48.2%, p<0.001) in Ukrainian cases. PTC subtype distribution was significantly different between the two groups. Solid variant (8.9% vs. 1.8%) and mixed subtypes with solid components were more frequent in Ukrainian patients. In contrast, classical papillary carcinomas were more frequent in Japanese cases (10.7% vs. 50.0%, p<0.001). Marked oxyphilic metaplasia was more common in Ukrainian cases (33.9 % vs. 8.9 %, p<0.001). MIB-1 index was significantly higher in Ukrainian cases (2.9% vs. 1.8%, p<0.001). However, the frequencies of tumor capsule formation and background lymphoid follicle formation around the tumor were similar between groups. Morphological differences in adult PTCs were similar to those in pediatric PTCs as reported previously, suggesting that morphogenesis of PTC is influenced by environmental factors, especially dietary iodine, as well as genetic factors.

Reconstruction of individual thyroid doses to the Ukrainian subjects enrolled in the Chernobyl Tissue Bank

The Chernobyl Tissue Bank (CTB) is an organisation that collects and stores samples of tumoral thyroid tissue obtained from Ukrainian and Russian subjects who were treated surgically for a thyroid cancer and had been exposed to (131)I from the Chernobyl accident. By 2012, the CTB had collected specimens of thyroid tissue from 2267 residents of Ukraine for the purpose of radiation research. Arithmetic mean thyroid doses and uncertainties have been estimated for all but 24 subjects for whom residence at the time of exposure was not found. The subjects have been classified into six groups or sub-groups according to the type of dosimetry-related information that is available for each of them. Excluding the 325 subjects with negligible radiation exposure, the arithmetic mean of the thyroid dose over all subjects is estimated as 0.4 Gy, with individual values ranging from <1 mGy to 13 Gy. The uncertainties in the individual thyroid dose estimates, characterised by the geometric standard deviations of their probability distributions, range from 1.3 to 8.7, with an arithmetic mean of 3.2.

Abstract 3599: Prevalance and spectrum of chromosomal rearrangements in post-Chernobyl thyroid cancer

Introduction: After the Chernobyl disaster, a strong association between childhood I-131 exposure and papillary thyroid carcinoma (PTC) was observed. Our previous study of PTCs from a Ukrainian cohort who were &lt; 18 y.o. at the time of Chernobyl and received 0.008-8.6 Gy of I-131 to the thyroid revealed that RET/PTC rearrangement was the most common mutation and correlated with I-131 dose (Cancer, in press). Common forms of rearrangement and point mutation were detected in 37 (60%) of these tumors. The aim of this study was to examine the remaining tumors for rare rearrangements known to occur in thyroid cancer and for novel chromosomal rearrangements.

Design: Twenty-five mutation-negative PTCs were analyzed. RT-PCR was used to search for BRAF/AKAP9 fusion and differential real-time PCR to search for all types of RET and NTRK1 rearrangements. After screening for these rearrangements, RNA from 12 tumors lacking all known mutation or rearrangement were used to create libraries and perform whole RNA sequencing on the Illumina HiSeq2000. Thyroid dose estimation was based on radioactivity measurements, environmental transport models, and interview data.

Results: Chromosomal rearrangements and point mutations identified in this cohort are shown, with patient characteristics, in Table 1. Additionally, through RNA-seq, a novel chromosomal rearrangement was identified in several tumors that lack known alteration and were associated with a mean thyroid dose of 2.39 Gy. This novel rearrangement is being validated and characterized.

Table 1. Chromosomal rearrangements and corresponding patient characteristics Genetic Alteration Mutation frequency I-131 dose, mean (Gy) Age at exposure, mean (yrs) Latency, mean (yrs) RET/PTC1 and 3 22 (36%) 1.22 6.4 15.9 Other RET/PTC 1 (1.6%) 0.01 11.5 14.2 PAX8/PPARγ 2 (3%) 0.62 12.2 13.5 BRAF/AKAP9 1 (1.6%) 0.27 11.2 20.8 NTRK1 rearrangement 1 (1.6%) 0.44 6.8 15.7 BRAF or RAS mutation 14 (22%) 0.27 10.5 17.6 None (or newly discovered) 22 (35%) 2.05 7.7 16.5 Overall 62 (100%) 1.27 8.1 16.5

Conclusions: Our results demonstrate the occurrence, although with low frequency, of NTRK1, BRAF/AKAP9, and rare types of RET/PTC rearrangements in this post-Chernobyl cohort. In addition, a novel chromosomal rearrangement was identified in tumors associated with high mean I-131 dose, which should further elucidate the genetic mechanisms of radiation-induced thyroid carcinogenesis.

Citation Format: Rebecca J. Leeman-Neill, Alina J. Brenner, Mark P. Little, Tetiana Bogdanova, Maureen Hatch, Kiyohiko Mabuchi, Mykola Tronko, Yuri E. Nikiforov. Prevalance and spectrum of chromosomal rearrangements in post-Chernobyl thyroid cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3599. doi:10.1158/1538-7445.AM2013-3599

Thyroid cancer in Ukraine after the Chernobyl accident (in the framework of the Ukraine-US Thyroid Project)

As a result of the accident at the Chernobyl Nuclear Power Plant, millions of residents of Belarus, Russia, and Ukraine were exposed to large doses of radioactive iodine isotopes, mainly I-131. The purpose of the Ukraine-American (UkrAm) and Belarus-American (BelAm) projects are to quantify the risks of thyroid cancer in the framework of a classical cohort study, comprising subjects who were aged under 18 years at the time of the accident, had direct measurements of thyroid I-131 radioactivity taken within two months after the accident, and were residents of three heavily contaminated northern regions of Ukraine (Zhitomir, Kiev, and Chernigov regions). Four two-year screening examination cycles were implemented from 1998 until 2007 to study the risks associated with thyroid cancer due to the iodine exposure caused during the Chernobyl accident. A standardised procedure of clinical examinations included: thyroid palpation, ultrasound examination, blood collection followed by a determination of thyroid hormone levels, urinary iodine content test, and fine-needle aspiration if required. Among the 110 cases of thyroid cancer diagnosed in UkrAm as the result of four screening examinations, 104 cases (94.5%) of papillary carcinomas, five cases (4.6%) of follicular carcinomas, and one case (0.9%) of medullary carcinoma were diagnosed.

Prevalence of hyperthyroidism after exposure during childhood or adolescence to radioiodines from the chornobyl nuclear accident: dose-response results from the Ukrainian-American Cohort Study

Relatively few data are available on the prevalence of hyperthyroidism (TSH concentrations of <0.3 mIU/liter, with normal or elevated concentrations of free T4) in individuals exposed to radioiodines at low levels. The accident at the Chornobyl (Chernobyl) nuclear plant in Ukraine on April 26, 1986 exposed large numbers of residents to radioactive fallout, principally to iodine-131 ((131)I) (mean and median doses  =  0.6 Gy and 0.2 Gy). We investigated the relationship between (131)I and prevalent hyperthyroidism among 11,853 individuals exposed as children or adolescents in Ukraine who underwent an in-depth, standardized thyroid gland screening examination 12-14 years later. Radioactivity measurements taken shortly after the accident were available for all subjects and were used to estimate individual thyroid doses. We identified 76 cases of hyperthyroidism (11 overt, 65 subclinical). Using logistic regression, we tested a variety of continuous risk models and conducted categorical analyses for all subjects combined and for females (53 cases, n  =  5,767) and males (23 cases, n  =  6,086) separately but found no convincing evidence of a dose-response relationship between (131)I and hyperthyroidism. There was some suggestion of elevated risk among females in an analysis based on a dichotomous dose model with a threshold of 0.5 Gy chosen empirically (OR  =  1.86, P  =  0.06), but the statistical significance level was reduced (P  =  0.13) in a formal analysis with an estimated threshold. In summary, after a thorough exploration of the data, we found no statistically significant dose-response relationship between individual (131)I thyroid doses and prevalent hyperthyroidism.

Radiation induced thyroid cancer: fundamental and applied aspects

AIM

To describe the epidemiology and pathology of thyroid cancer in Ukraine, and to perform the molecular analysis of genetic alterations more frequently found to be associated to papillary carcinomas (PTC) in a selected group of PTC.

MATERIALS AND METHODS

Relationship between the thyroid cancer incidence and gender, age, and place of residence of subjects aged 0-18 years at the time of the Chernobyl accident (5427 subjects of thyroid cancer, among which 3996 (73.6%) were children aged 0 to 14 years at the time of the accident, and 1431 (26.3%) were adolescents aged 15 to 18 years was studied. Pathologically analyzed thyroid carcinomas were obtained from 640 patients (20-40 years old at the time of surgery and born before the Chernobyl accident), and from 90 patients (11-22 years old at the time of surgery and born after the accident). All patients were operated during 2006-2008. RET/PTC rearrangements and BRAF(V600E) mutation were analyzed in 35 cases of PTC.

RESULTS

A comparison between the thyroid cancer incidence rates in the 6 highest contaminated regions of Ukraine and in the other 21 regions shows the most significant difference between the rates for the last three years of follow-up, which confirms that a direct relationship is still present between the rise in thyroid cancer incidence and the post Chernobyl radiation exposure. Much lower incidence of thyroid cancer in subjects, who were born after the accident, additionally confirmed a direct relationship between the Chernobyl accident and thyroid cancer development at least in those who were aged up to 18 years at the time of the nuclear accident. Pathological results showed that with increasing latency the decrease has been noted in the percentage of PTC with solid structure, a decrease in invasive properties of tumors, as well as an increase in the percentage of PTC with papillary-follicular structure, encapsulated forms, and <<small>> carcinomas measuring up to 1 cm. Molecular-biological studies of PTC revealed more common RET/PTC1 and RET/PTC3 rearrangements (34.3% of cases), than BRAFV600E mutation (24%cases).

CONCLUSION

After 22 years from the Chernobyl nuclear accident the number and incidence of thyroid cancer cases in Ukraine was steadily increased in the cohort of those who were children and adolescents at the time of the accident. Most common thyroid tumors (PTC) were characterized by significant changes in histological structure with increasing latency. PTC with any RET/PTC rearrangements had more aggressive behavior than BRAF(V600E)-positive tumors or PTC without gene alterations.

Frequency of undetected thyroid nodules in a large I-131-exposed population repeatedly screened by ultrasonography: results from the Ukrainian-American cohort study of thyroid cancer and other thyroid diseases following the Chornobyl accident

BACKGROUND

Imperfect detection on screening tests can lead to erroneous conclusions about the natural history of thyroid nodules following radiation exposure. Our objective was to assess in a repeatedly screened I-131-exposed population the frequency with which a thyroid nodule could be retrospectively identified on ultrasonography studies preceding the one on which it was initially detected.

METHODS

A cohort of over 13,000 young people exposed to fallout from Chornobyl underwent ultrasonography screening at 2-year intervals from 1998 to 2007. The study group consisted of screening examinations on which a thyroid nodule was detected following one or more prior negative examinations. In the study group there were 48 cancers and 92 benign nodules. For each of these 140 index studies a comparison set was created containing all available prior studies plus (to test for bias) negative studies from control subjects. While viewing the index study, three independent reviewers scored the comparison studies for the presence and size of a preexisting nodule. Detection rates were compared for true priors versus controls, for cancer versus benign, and for histologic subtypes of papillary carcinoma.

RESULTS

A preexisting nodule was identified by at least one reviewer in 24.0% of the true prior versus 8.3% of the controls and by all three reviewers in 11% versus 1% (Fisher's exact test, p < 0.0001). There was no significant difference in detection rates between cancers and benign nodules (22.4% vs. 24.7%, p = 0.411). There was no correlation between time from prior to index study and change in nodule size for either malignant or benign nodules (r = 0.01, NS). There were no differences in detection rates or size among papillary cancer subtypes. Reviewers could not distinguish between true priors and controls.

CONCLUSIONS

These findings, showing significant rates of undetected benign and malignant nodules and no evidence for rapid growth, suggest that conclusions drawn from screening studies about the frequency of late-developing, rapidly growing thyroid nodules following radiation exposure should be interpreted with caution.

Glibenclamide-related excess in total and cardiovascular mortality risks: data from large Ukrainian observational cohort study

OBJECTIVE

To compare mortality risks among type 2 diabetes (T2D) patients being treated with glibenclamide, gliclazide, or glimepiride.

METHODS

Retrospective observational cohort studies of primary care-based diabetes register were carried out. Risk of total and cardiovascular (CVD) mortality was evaluated in cohort of T2D patients that were treated with either glibenclamide (n=50,341), glimepiride (n=2479) or gliclazide (n=11,368). Cox regression was used for multifactor evaluation. A cross-sectional evaluation of oral anti-diabetic drug (OAD) structure for 2005 and 2007 was also performed, as well as age at the time of death was compared in the timeframe between 2002 and 2007.

RESULTS

Total mortality was lower for gliclazide and glimepiride, vs. glibenclamide cohort: HRs 0.33 (95% CI 0.26-0.41), p<0.001 and 0.605 (95% CI 0.413-0.886), p<0.01 respectively. CVD mortality risk reduction vs. glibenclamide was significant only in gliclazide cohort: 0.29 (95% CI 0.21-0.38), p<0.001. Glibenclamide prescriptions had changed from 64.0% (95% CI 63.5-64.5) to 59.5% (95% CI 9.7-10.4). Age at the time of death for OAD-treated patients increased by 6.27 (95% CI 3.67-8.87)yrs, p<0.001.

CONCLUSION

Glibenclamide treatment of T2D is associated with greater risk of all-cause mortality, vs. gliclazide or glimepiride treatment, and CVD mortality, vs. gliclazide treatment.

Correlation between the prevalence of type 1 diabetes with the daily insulin dose and the autoimmune process against glutamic acid decarboxylase in adults

In this study, we compared the rate of insulin requirement among adults with type 1 diabetes (T1D) in 24 Ukrainian regions. The glutamic acid decaroxylase 65 antibody (GADA), insulin antibody (IA), and plasma c-peptide levels were investigated. The data included the prevalent cases of T1D in Ukraine at the end of 2006. Only persons aged over 14 years at the time of inclusion into the Ukrainian register and diagnosed with diabetes before 30 years of age were included in this study (n=26796). A total of 86 T1D patients (42 males; 44 females) with a mean age of 27.5 years (0.86) and a mean diabetes duration of 10.3 (0.72) years (SE), were randomly selected from four regional diabetes registers. The GADA, IA, and the plasma c-peptide levels were also determined. The logistic regression model was used, and the odds ratio (OR) and 95% confidence interval (CI) were calculated. Furthermore, the differences in the T1D prevalence among the 24 Ukrainian regions were obtained (p<0.001). In the "minimal" regional cluster (MIC), the prevalence rate was 6 (5-6), and in the "maximal" (MAC) regional cluster, it was -9 (8-9) per 10000 adults. For patients with a disease duration (DD) of up to 15 years (n=13677), the daily insulin dose (DID) was observed to increase linearly with DD (R=0.899, p<0.001). The median insulin doses were standardized according to DD, and the values were lowest in the MIC and highest in the MAC populations: 45.89 (45.28-47.19) and 56.59 (53.33-57.88) U/24 h, respectively (p<0.01). Furthermore, the level of HbA1c in the MAC of T1D patients was observed to be higher than that in the MIC (9.52+/-2.24%, n=240, and 8.57+/-3.29%, n=111, respectively; p<0.01). In addition, the GADA levels and persistence in the MAC patients (n=38) were higher than that in the MIC patients (n=48): 14.1+/-4.6 and 3.2+/-1.2 U/ml, respectively, mean+/-SE; p=0.028; OR=9.66 (3.31-28.17), p<0.001. Adjusting for age, gender, and duration of diabetes affected the results only slightly. Furthermore, the IA and c-peptide levels and their persistence were not observed to be associated with TD1 prevalence.

Subclinical hypothyroidism after radioiodine exposure: Ukrainian-American cohort study of thyroid cancer and other thyroid diseases after the Chornobyl accident (1998-2000)

BACKGROUND

Hypothyroidism is the most common thyroid abnormality in patients treated with high doses of iodine-131 (131I). Data on risk of hypothyroidism from low to moderate 131I thyroid doses are limited and inconsistent.

OBJECTIVE

This study was conducted to quantify the risk of hypothyroidism prevalence in relation to 131I doses received because of the Chornobyl accident.

METHODS

This is a cross-sectional (1998-2000) screening study of thyroid diseases in a cohort of 11,853 individuals < 18 years of age at the time of the accident, with individual thyroid radioactivity measurements taken within 2 months of the accident. We measured thyroid-stimulating hormone (TSH), free thyroxine, and antibodies to thyroid peroxidase (ATPO) in serum.

RESULTS

Mean age at examination of the analysis cohort was 21.6 years (range, 12.2-32.5 years), with 49% females. Mean 131I thyroid dose was 0.79 Gy (range, 0-40.7 Gy). There were 719 cases with hypothyroidism (TSH > 4 mIU/L), including 14 with overt hypothyroidism. We found a significant, small association between (131)I thyroid doses and prevalent hypothyroidism, with the excess odds ratio (EOR) per gray of 0.10 (95% confidence interval, 0.03-0.21). EOR per gray was higher in individuals with ATPO < or = 60 U/mL compared with individuals with ATPO > 60 U/mL (p < 0.001).

CONCLUSIONS

This is the first study to find a significant relationship between prevalence of hypothyroidism and individual (131)I thyroid doses due to environmental exposure. The radiation increase in hypothyroidism was small (10% per Gy) and limited largely to subclinical hypothyroidism. Prospective data are needed to evaluate the dynamics of radiation-related hypothyroidism and clarify the role of antithyroid antibodies.

A screening study of thyroid cancer and other thyroid diseases among individuals exposed in utero to iodine-131 from Chernobyl fallout

BACKGROUND

Like stable iodine, radioiodines concentrate in the thyroid gland, increasing thyroid cancer risk in exposed children. Data on exposure to the embryonic/fetal thyroid are rare, raising questions about use of iodine 131 (I-131) in pregnant women. We present here estimated risks of thyroid disease from exposure in utero to I-131 fallout from the Chernobyl nuclear accident.

METHODS

We conducted a cross-sectional thyroid screening study (palpation, ultrasound, thyroid hormones, and, if indicated, fine needle aspiration) from 2003 to 2006. Participants were 2582 mother-child pairs from Ukraine in which the mother had been pregnant at the time of the accident on April 26, 1986, or 2 months after the time during which I-131 fallout was still present (1494 from contaminated areas, 1088 in the comparison group). Individual cumulative in utero thyroid dose estimates were derived from estimated I-131 activity in the mother's thyroid (mean 72 mGy; range 0-3230 mGy).

RESULTS

There were seven cases of thyroid carcinoma and one case of Hurthle cell neoplasm identified as a result of the screening. Whereas the estimated excess odds ratio per gray for thyroid carcinoma was elevated (excess odds ratio per gray 11.66), it was not statistically significant (P = 0.12). No radiation risks were identified for other thyroid diseases.

CONCLUSION

Our results suggest that in utero exposure to radioiodines may have increased the risk of thyroid carcinoma approximately 20 yr after the Chernobyl accident, supporting a conservative approach to medical uses of I-131 during pregnancy.

The joint effects of different types of glucose-lowering treatment and duration of diabetes on total and cardiovascular mortality among subjects with type 2 diabetes

OBJECTIVE

To compare the joint effects of different types of glucose-lowering treatment (oral drugs, insulin, and both) and duration of diabetes on total and cardiovascular mortality among diabetic patients.

METHODS

Study cohorts included 30,534 Ukrainian males and 58,909 females with type 2 diabetes. During the mean follow-up of 2.7 years, 7804 deaths were recorded.

RESULTS

The multivariate-adjusted hazard ratios (HRs) for total mortality among diabetic patients, who used oral glucose-lowering drug (OGLD) only, insulin only, both insulin and OGLD, were 1.00, 2.34, and 2.22 in men, and 1.00, 2.12, and 2.20 in women, respectively. The multivariate-adjusted HRs for total mortality across categories of duration of diabetes (<5, 5-9, 10-14, 15-19, and >/=20 years) were 1.00, 1.17, 1.32, 1.43, and 1.57 (p(trend)<0.001) in men, and 1.00, 1.13, 1.34, 1.74, and 1.68 (p(trend)<0.001) in women, respectively. Diabetic patients who used insulin and reported longer duration of diabetes had the highest risk of total mortality.

CONCLUSION

Type 2 diabetic patients treated with insulin show a greater risk of death than those treated with OGLD only. Increasing duration of diabetes is associated with an increased death risk. The combination of insulin treatment and longer duration of diabetes identifies a particular high death risk.

Body mass index and the risk of total and cardiovascular mortality among patients with type 2 diabetes: a large prospective study in Ukraine

BACKGROUND

Several prospective studies have evaluated the association between body mass index (BMI) and cardiovascular mortality among patients with type 2 diabetes; however, the results are controversial.

OBJECTIVE

To investigate the association of different BMI distributions with total and cardiovascular mortality among diabetic patients.

METHODS

A total of 30 534 Ukrainian men and 58 909 women with type 2 diabetes from the nationwide population-based diabetes register were included in this study.

RESULTS

During a mean follow-up of 2.7 years, 7804 deaths were recorded, of which 3320 were due to cardiovascular disease. After adjustment for age, smoking and alcohol drinking, the hazard ratios across the five BMI categories (<23, 23-24.9, 25-29.9 (reference group), 30-34.9 and >or=35 kg/m2) among diabetic men were 1.57 (95% CI 1.42 to 1.74), 1.16 (1.05 to 1.28), 1.0, 1.01 (0.91 to 1.12) and 1.24 (1.02 to 1.50) for total mortality, and 1.67 (95% CI 1.42 to 1.95), 1.30 (1.12 to 1.51), 1.0, 1.13 (0.96 to 1.34) and 1.54 (1.16 to 2.05) for cardiovascular mortality, respectively. The respective hazard ratios among diabetic women were 1.34 (95% CI 1.22 to 1.47), 1.00 (0.91 to 1.10), 1.0, 1.04 (0.97 to 1.12) and 1.27 (1.14 to 1.41) for total mortality, and 1.36 (95% CI 1.18 to 1.57), 1.06 (0.92 to 1.21), 1.0, 1.12 (1.01 to 1.25) and 1.35 (1.15 to 1.59) for cardiovascular mortality. Additional adjustment for systolic blood pressure, total cholesterol, history of cardiovascular disease, diabetes treatments and duration of diabetes affected the results only slightly.

CONCLUSIONS

This study indicated a U-shaped association between BMI and total and cardiovascular mortality among diabetic men and women.

Primary care diabetes in Ukraine

People with diabetes in Ukraine are cared for by endocrinology specialists. Implementation of the National Diabetes Plan solved the problem of free insulin supply. However, many problems of diabetic care, including increase of accessibility to some laboratory tests and treatments, are still unresolved. An increase of life expectancy among diabetic patients has been noted during the past 5 years.

Gene expression and the biological phenotype of papillary thyroid carcinomas

The purpose of this paper is to correlate the molecular phenotype of papillary thyroid carcinoma (PTC) to their biological pathology. We hybridized 26 PTC on microarrays and showed that nearly 44% of the transcriptome was regulated in these tumors. We then combined our data set with two published PTC microarray studies to produce a platform- and study-independent list of PTC-associated genes. We further confirmed the mRNA regulation of 15 genes from this list by quantitative reverse transcription-PCR. Analysis of this list with statistical tools led to several conclusions: (1) there is a change in cell population with an increased expression of genes involved in the immune response, reflecting lymphocyte infiltration in the tumor compared to the normal tissue. (2) The c-jun N-terminal kinase pathway is activated by overexpression of its components. (3) The activation of ERKK1/2 by genetic alterations is supplemented by activation of the epidermal growth factor but not of the insulin-like growth factor signaling pathway. (4) There is a downregulation of immediate early genes. (5) We observed an overexpression of many proteases in accordance with tumor remodeling, and suggested a probable role of S100 proteins and annexin A2 in this process. (6) Numerous overexpressed genes favor the hypothesis of a collective migration mode of tumor cells.

[Permanent hypoparathyroidism due to thyroid cancer surgical procedures in patients exposed to radiation in the Chernobyl, Ukraine, nuclear reactor accident]

BACKGROUND AND OBJECTIVE

Postoperative hypoparathyroidism is a rare, but complex endocrine disorder. The purpose of this case series study was to evaluate the symptoms, signs and sequelae of the disease in a major homogeneous patient group after the Chernobyl accident in the Ukraine.

PATIENTS AND METHODS

This study is based on a random sample of 25 patients with symptomatic permanent hypoparathyroidism after surgical procedures on the thyroid for carcinoma following the Chernobyl accident in May 1986. They underwent physical examination and their parathyroid hormone and calcium levels in serum were determined. The signs, symptoms and sequelae of their disease were systematically assessed by a validated specific questionnaire. The extent of individual distress by the symptoms and signs were analysed by using a Likert scale (points between 1 = no and 5 = maximal distress).

RESULTS

In 14 patients (56%) (age at time of operation: 18.24 +/- 4.26 years) paresthesias occurred at least every third day. Very frequent general symptoms were joint pains and hair loss (in 17 patients / 68%). 19 patients (76%) had enamel defects, 17 (68%) increasingly dry skin since the operation. Psychical symptoms like excitability (20 patients / 80%) and depressed mood since the operation (16 patients / 64%) were strikingly frequent. The patients were affected more by dry skin (2,76 on the Likert scale) than by paraesthesias (2,56) or joint pains (2,68) and most of all by depressive mood (2.96) and excitability (3.38). 4 patients (16%) had kidney stones, while osteoporosis and osteosclerosis occurred in 7 (28%) respectively 3 persons (12%). 6 patients (24%) had cataracts and 3 (12%) had basal ganglia calcification. Interestingly, 1/3 of all patients had only non-characteristic symptoms of the disease consistent with a latent form of hypoparathyroidism.

CONCLUSIONS

Our data partly show a severe form of hypoparathyroidism of very young persons in the Chernobyl region, a finding which strongly supports the need of exact diagnosis and interdisciplinary treatment options of this postoperative disorder.

Iodine excretion in regions of Ukraine affected by the Chornobyl Accident: experience of the Ukrainian-American cohort study of thyroid cancer and other thyroid diseases

Urinary iodine concentrations were measured in 11,926 subjects who are participants in the Ukrainian-American Cohort Study of Thyroid Cancer and Other Thyroid Diseases Following the Chornobyl Accident. Measurements were made in two time periods corresponding to the first and second thyroid screening cycles (1998-2000, 2001-2003). These time periods fall before and after initiation of a government program to increase iodine sufficiency. Median urinary iodine concentrations did increase in the later time period compared to the earlier [47.5 microg/L, 95% confidence interval (CI) 46.5-48.9 microg/L versus 41.7 microg/L, 95% CI 40.4-42.5 microg/L], but levels remained in the mild-to-moderate iodine deficiency range as defined by the World Health Organization (WHO), indicating the need for further efforts at iodination. In both time periods, urinary iodine levels were found to vary by place of residence and were lower in rural compared to urban areas. Iodine status needs to be considered when evaluating risk of thyroid cancer and other thyroid diseases.

Effects of N-acylethanolamines and various antimitotic agents on apoptotic DNA fragmentation in conventionally normal and tumor tissue of human adrenals

AIM

To study effects of N-acylethanolamines (NAE) and various antimitotic agents: taxol, colchicine, and cytochalasin B on the DNA fragmentation extent in conventionally normal (CNT) and tumor tissue of human adrenal cortex.

METHODS

Six types of adrenal tumor tissue of 84 patients were analyzed. Slices of tissue was incubated at 37 degrees C for 3 h in the presence of NAEs and antimitotics, DNA was extracted and analysed in agarose gel.

RESULTS

It was established that NAEs enhanced apoptosis in conventionally normal and tumor tissue of adrenal glands. In general, tumor tissue was more sensitive to NAEs and antimitotic compounds than conventionally normal tissue. NAEs in combination with colchicine and cytochalasin B enhanced DNA fragmentation in some types of tumor tissue and did not influence, or even reduced it in CNT. Taxol revealed selective action depending on tumor tissue type. Considerable individual differences were reported in sensitiveness of different types of tumors to the NAEs and antimitotic agents.

CONCLUSIONS

Taxol and combination of NAEs with colchicine and cytochalasin B are inductors of apoptosis in the adrenal tumor cells and thus promising for further investigation.

Frequency of BRAF T1796A mutation in papillary thyroid carcinoma relates to age of patient at diagnosis and not to radiation exposure

In this study, the frequency of BRAF mutation was investigated in a series of 67 cases of papillary thyroid cancer (PTC) in patients from Ukraine. Thirty-two patients were aged 30 years or older at the time of diagnosis and 35 were under 16. Tumour was microdissected from paraffin wax-embedded sections, DNA extracted, and the presence of the BRAF T1796A mutation demonstrated by two different methods: PCR followed by restriction enzyme digestion or primer extension assay and detection using MALDI-TOF mass spectrometry. Eighteen (58%) of the adult cases, but only one of the 35 cases aged less than 16 harboured a BRAF T1796A mutation. There was complete agreement between the two methods used, suggesting that the MALDI-TOF assay is a robust alternative to conventional mutation analysis. RET rearrangement was also examined in the young cohort. The overall frequency of RET rearrangement was 45.7%. Eight of the younger group of patients were born after 1 December 1986 and were therefore not exposed to radioiodine in fallout from Chernobyl. None of the PTCs from these eight patients were positive for BRAF mutation. The frequency of RET rearrangement was 44% in the 27 cases exposed to radiation and 50% in the eight not exposed. These results suggest that the different molecular biological profiles observed are associated with the age of the patient at diagnosis with PTC, rather than being associated with radiation exposure.

BRAF mutations are not a major event in post-Chernobyl childhood thyroid carcinomas

The BRAF gene has been shown to be a major target for mutations in papillary thyroid carcinoma (PTC) (36-69%), which forms almost all of the over 2000 cases of thyroid carcinoma that have occurred in Chernobyl. BRAF is activated by point mutation, and were it to occur at a high frequency in Chernobyl-related tumors, it would challenge the dominant role of double-strand breaks in radiation-induced PTC. In a previous study, we detected the BRAF V600E mutation in 46% (23 of 50) of sporadic adult PTC. Using the same methodology, we have analyzed 34 post-Chernobyl PTC and detected RET/PTC rearrangements in 14 (41%) and BRAF mutations (V600E) in four (12%). These two alterations did not coexist in any PTCs. The mean age at exposure of patients with PTC showing BRAF mutation was higher than that of patients with tumors without BRAF mutation irrespective of their RET status. We have also analyzed 17 sporadic cases of childhood PTC and found that only one (6%) harbored the BRAF V600E mutation. We conclude that the frequency of BRAF mutations is significantly lower (P = 0.0008) in post-Chernobyl PTC than in adult sporadic PTC, whereas no significant difference was found between post-Chernobyl and sporadic childhood PTCs.

Single nucleotide polymorphism analysis in the human phosphatase PTPrj gene using matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry

Data derived from analysis of single nucleotide polymorphisms (SNPs) are being applied in many diverse fields, from medical studies of disease mechanisms and individual drug response, to population genetics for tracking migration and mixing of ancestral groups and also in forensic science for the identification of human remains and identification of individuals from bodily samples. All these applications have in common the need to generate data for multiple loci from large numbers of samples. Matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOFMS) is a promising platform for the generation of such data and we present a simple, flexible and robust technique for SNP determination. We demonstrate these features by typing two SNPs (Q276P and R326Q) in the human phosphatase gene PTPrj, which has been implicated in the aetiology of colon, lung, breast and thyroid cancers. A nucleotide depletion primer extension assay using no commercial kits or dideoxyNTPs was used to genotype a panel of DNAs derived from thyroid cancer patients and normal volunteers. The results obtained were in perfect agreement with those generated via restriction fragment length polymorphism analysis. No significant association was noted between possession of either allelic variant and a disease state, but the technique was validated as simple, flexible and appropriate for application in this context. Furthermore, it was highly cost-effective and required minimal optimisation, rendering it ideal for this type of pilot study.

Post-surgical ablation of thyroid residues with radioiodine in Ukrainian children and adolescents affected by post-Chernobyl differentiated thyroid cancer

Post-surgical ablation of thyroid residues with 131-iodine (131-I) is usually recommended after near-total thyroidectomy in high-risk patients, including children, with differentiated thyroid cancer (DTC). We report here the results of post-surgical radioiodine thyroid ablation in 249 children and adolescents of Ukraine with post-Chernobyl DTC initially treated with near-total thyroidectomy at the Institute of Endocrinology and Metabolism in Kiev, during a 2-year period. The patients' age at the time of the Chernobyl accident (1986), ranged from <1 to 14 yr in 223 subjects (children) and from 15 to 18 yr in 26 subjects (adolescents). Six weeks after surgery a diagnostic 131-I whole body scan revealed the presence of residual thyroid tissue in all cases. All patients received one or more courses of radioiodine therapy, for a total of 468 courses. One hundred and twenty-nine out of 249 patients (51.8%) were successfully ablated. The total number of treatment courses needed in these patients was 219. Most patients required multiple doses of radioiodine, only 63 required a single dose. One hundred and twenty patients (48.2%) treated with radioiodine were not ablated and are still under treatment program. The clinical features and the amount of thyroid residue were not different in ablated or not-ablated patients. Our results indicate that in this particular population of post-Chernobyl thyroid carcinomas, thyroid ablation is a rather difficult task. Only 51.8% were successfully ablated. Possible explanation for this finding may be the young age of the patients, other particular features of post-Chernobyl thyroid carcinoma or technical aspects, such as less radical surgical procedures.