Increase In Incidence Of Thyroid Cancer Research Articles

Per- and polyfluoroalkyl substances (PFAS) exposure and thyroid cancer: systematic review and meta-analysis.

Per- and polyfluoroalkyl substances (PFAS) exposure is a potential risk factor for thyroid cancer and may be a contributor to the increasing thyroid cancer incidence rates. A systematic review and meta-analysis was performed to summarize all human studies to date investigating the association between PFAS exposure and thyroid cancer. A search of the National Library of Medicine and National Institutes of Health PubMed and Scopus databases was done to identify relevant articles published in English through January 2024. Studies reporting the association between PFAS exposure and thyroid cancer using odds ratios (OR) were included in the meta-analysis with summary estimate calculated using a random effects model (n=5). Perfluorooctanoic acid (PFOA) was the most investigated PFAS. Results of the included studies varied, ranging from significant positive to significant negative associations with thyroid cancer incidence for different PFAS. Meta-analyses of PFOA, Perfluorooctanesulfonic acid (PFOS), perfluorononanoic acid (PFNA), perfluorohexanesulfonic acid (PFHxS) were not significant. This comprehensive review of the current literature highlights the limited knowledge and inconsistent results of this association. Large longitudinal cohort studies with varying time between sample collection and thyroid cancer diagnosis are needed to better understand the role of PFAS exposure on thyroid carcinogenesis.

Secular Increasing Trends in Female Thyroid Cancer Incidence in Taiwan

Background: Thyroid cancer incidence has increased globally in recent decades, especially in females, although its trends in Taiwan have not been studied extensively. This study aimed to investigate changes in female incidence and possible causes of thyroid cancer in Taiwan. Methods: Using the Taiwan Cancer Registry (TCR) Database, age-standardized incidence rates, age-specific incidence rates and birth cohorts were calculated. Correlation between female thyroid cancer incidence and cohort fertility rates were examined. Results: Thyroid cancer incidence increased in Taiwanese female, with age-adjusted rates per 100,000 people increasing from 7.37 during 1995–1999 to 20.53 during 2015–2019; the annual percentage change (APC) was 5.9% (95% CI, 5.3–6.5). Age-specific incidence rates increased with age, with peak rates occurring at younger ages. The APCs in the 50–54 age group were the highest (6.8%, 95% CI, 6.1–7.5). Incidence rates also increased with later birth cohorts. We observed a significant negative correlation between thyroid cancer incidence and fertility rates in the same birth cohort. Conclusions: We hypothesize that overdiagnosis may be a main reason for the rapidly increasing thyroid cancer incidence in Taiwanese females. Notably, we observed a strong negative correlation between fertility and thyroid cancer incidence. However, our study is limited by the absence of individual-level cancer data in the TCR database. These associations with fertility will be an important subject for future thyroid cancer research.

Controversy and boundary in the diagnose and treatment of thyroid cancer

In recent years, the incidence of thyroid cancer has rapidly increased, whereas the mortality rate has not risen correspondingly. Therefore, scholars at home and abroad have proposed the view of overdiagnosis in thyroid cancer, sparking intense debates about the phenomenon of overdiagnosis and overtreatment. A historical review and discussion of the primary reasons for the increase in thyroid cancer incidence and the improvement in treatment outcomes are beneficial. It helps clarify that the real increase in thyroid cancer is primarily due to the higher incidence rate, rather than overdiagnosis. Additionally, it allows us to reevaluate which factors guarantee favorable efficacy in thyroid cancer.

Investigating the Association of Polygenic Risk Scores With Thyroid Cancer Susceptibility in a Han Chinese Population.

Thyroid cancer, the leading endocrine tumor with a rising global incidence, especially in women, is influenced by both genetic and environmental factors. This study examines the relationship between polygenic risk scores (PRS) and thyroid cancer susceptibility in the Han Chinese population, as well as the impact of genetic variants on clinical outcomes. Analyzing data from 57 257 participants in the Taiwan Precision Medicine Initiative, the study employed the Affymetrix Genome-Wide TWB 2.0 SNP Array for genotyping. PRS were calculated using single nucleotide polymorphisms (SNPs) from prior genome-wide association studies, specifically PGS000087 and PGS000797, and correlated with clinical parameters like age, sex, comorbidities, and treatment methods. Among 4063 participants with thyroid tumors (839 malignant, 3224 benign), higher PRS quartiles correlated significantly with increased thyroid cancer incidence. The highest quartile showed a 1.15-fold (PGS000797) and 1.14-fold (PGS000087) greater risk than the lowest quartile. Key findings included an association between higher PRS quartiles and younger onset age, along with a notable link to chronic kidney disease and thyroid hormone levels in specific SNPs. The study demonstrates PRS's utility in predicting thyroid cancer risk in the Han Chinese population, with higher PRS associated with increased risk and distinct clinical features. While this study focuses on the Han Chinese population, we recognize the importance of comparing PRS performance across different ancestries to fully understand ethnic genetic diversity in cancer risk assessment. Future studies should aim to include such comparative analysis.

Do electromagnetic fields significantly affect thyroid cells and their functions? – A systematic review

Background: This review aimed to emphasize the effects, mechanisms involved, conditions required to trigger impacts, and the adapted responses of EMF on thyroid gland. Methods: The included literatures were collected from the Oceania Radiofrequency Scientific Advisory Association (ORSAA) database which were published before April 2021. The searched was then refined with keyword ‘thyroid’. Results: A total of 15 experimental studies, 10 observational studies, 4 review articles, and 1 medical hypothesis were included. Hypothyroidism is the most reported functional abnormality. The identified morphological abnormalities of the thyroid gland include increased follicular epithelial and interfollicular tissue, decreased colloid volume of cubic cells, follicular fluid, interfollicular space, changes in lysosomes, granular endoplasmic reticulum, cell nuclei, changes in glandular structures including cell hypotrophy, glandular hypertrophy, and increased apoptosis via caspase-dependent pathways. The observational studies reported an increase in thyroid cancer incidence and the diameter of the left anteroposterior of the thyroid gland. Postulation that thyroid cancer is associated with thyroid cancer EMF exposure, is suggested by a medical hypothesis paper. The possibilities of hypothyroidism, thyroid cancer, and cell apoptosis due to EMF exposure have been highlighted in the review articles. Conclusion: Despite these findings, critical elements, such as the effects and mechanisms of EMF exposure on thyroid hormone transporters, genomic and non-genomic actions, conditions required for the effect to occur, and the resultant adapted responses, have not been explored suggesting the need of further research.

No Change in Complications Following Thyroidectomy Despite Increase in Thyroid Cancer Surgeries: A Meta-Regression Analysis.

The increase in thyroid cancer incidence has inevitably led to an increase in thyroid cancer surgeries. This meta-regression analysis aimed to determine if the rate of post-thyroidectomy complications changes by year. PubMed and Embase databases were used to perform a systematic literature search of studies published from January 1, 2005, using the keywords "thyroidectomy" and "complication." A meta-regression was performed for post-thyroidectomy hypocalcemia and bleeding. This meta-analysis included 25 studies involving 927751 individuals. Through the years of publications in this study, there was no significant difference in the proportion of post-thyroidectomy hypocalcemia and bleeding (p=0.9978, 0.6393). Although the number of thyroid surgeries has recently increased, the incidence of post-thyroidectomy hypocalcemia and bleeding did not significantly increase.

Prediction model of cervical lymph node metastasis based on clinicopathological characteristics of papillary thyroid carcinoma: a dual-center retrospective study.

The overall prevalence of papillary thyroid carcinoma (PTC) patients is expanding along with an ongoing increase in thyroid cancer incidence. Patients with PTC who have lymph node metastases have a poor prognosis and a high death rate. There is an urgent need for indicators that can predict lymph node metastasis (LNM) before surgery as current imaging techniques, such as ultrasonography, do not have sufficient sensitivity to detect LNM. To predict independent risk factors for Central lymph node metastasis (CLNM) or Lateral lymph node metastasis (LLNM), we therefore developed two nomograms based on CLNM and LLNM, separately. In two centers, the Second Affiliated Hospital of Nanchang University and Yichun People's Hospital, we retrospectively analyzed clinicopathological characteristics of PTC patients. We utilized multivariate analysis to screen for variables that might be suspiciously related to CLNM or LLNM. Furthermore, we developed nomograms to graphically depict the independent risk valuables connected to lymph node metastasis in PTC patients. Ultimately, 6068 PTC patients in all were included in the research. Six factors, including age<45, male, mETE, TSH>1.418, tumor size>4cm, and location (multicentric and lobe), were observed to be related to CLNM. Age<45, male, mETE (minimal extrathyroidal extension), multifocality, TSH≥2.910, CLNM positive, and tumor size>4cm were regarded as related risk factors for LLNM. The two nomograms developed subsequently proved to have good predictive power with 0.706 and 0.818 and demonstrated good clinical guidance functionality with clinical decision curves and impact curves. Based on the successful establishment of this dual-institution-based visual nomogram model, we found that some clinical features are highly correlated with cervical lymph node metastasis, including CLNM and LLNM, which will better help clinicians make individualized clinical decisions for more effectively rationalizing managing PTC patients.

Thyroid Cancer Incidence and Mortality by Socioeconomic Level in the State of São Paulo, Brazil 2001-2017

ObjectiveThyroid cancer is rising largely due to greater detection of indolent or slow-growing tumors; we sought to compare the incidence and mortality profiles of thyroid cancer in the State of São Paulo by socioeconomic status (SES). MethodsData on thyroid cancer cases diagnosed from 2003 to 2017 in the Barretos Region and from 2001 to 2015 in the municipality of São Paulo were obtained from the respective cancer registries. Corresponding death data were obtained from a Brazilian public government database. Age-standardized rates were calculated and presented as thematic maps. The rates were also calculated by SES and spatial autocorrelation was assessed by global and local indices. ResultsThere were 419 cases of thyroid cancer and 21 deaths in Barretos, contrasting with the highly populated São Paulo, with 30 489 cases and 673 deaths. The overall incidence rates in São Paulo (15.9) were three times higher than in Barretos (5.7), while incidence rates in women were close to five times higher in Barretos and four times higher in São Paulo than in men. Mortality rates were, in relative terms, very low in both regions. A clear stepwise gradient of increasing thyroid cancer incidence with increasing SES was observed in São Paulo, with rates in very high SES districts four times those of low SES (31.6 vs 8.1). In contrast, the incidence rates in Barretos presented little variation across SES levels. ConclusionThyroid cancer incidence varied markedly by SES in São Paulo, with incidence rates rising with increasing socioeconomic index. Overdiagnosis is likely to account for a large proportion of the thyroid cancer burden in the capital.

Lindane use and the incidence of thyroid cancer in the United States; an ecological study

Introduction: The increased thyroid cancer incidence rate may potentially be partially attributable to exposure to chemicals with endocrine disruptive properties. Lindane is an organochlorine pesticide with endocrine disruptive properties that has been classified as carcinogenic to humans. The aim of this ecological study was to evaluate potential correlation between Lindane exposure and thyroid cancer incidence in the United States (US). Methods: Data on age-adjusted thyroid cancer incidence rate (per 100,000 people) was obtained from the Centers for Disease Control and Prevention for all US states for 2018. Lindane use was obtained from the US Geological Survey and presented in quintiles for the years 1992 and 2007 to consider latency period. Trend of Lindane use between 1992 and 2007 was calculated using Mann Kendall correlation test. Lindane use estimates per cropland (kg/acres cropland) were overlaid on the map of age-adjusted thyroid cancer incidence rate using ArcGIS. Correlation between statewide Lindane use and age-adjusted thyroid cancer incidence rates was calculated using Spearman correlation. Results: Overall Lindane use decreased significantly between 1992 and 2007 (T= -0.617; p &amp;#x3c;0.001). Statewide differences in the patterns of Lindane use as well as thyroid cancer were found, with high rates of thyroid cancer and Lindane use reported in several states including Delaware and Georgia. There was no statistically significant correlation between thyroid cancer incidence rates in 2018 and Lindane use in 1992 (r=0.075; p=0.689) nor Lindane use in 2007 (r=0.01; p=0.935), among males and females combined. Conclusion: Restrictions clearly seem to be effective in reducing Lindane use. While, overall, there was no evidence of a correlation between thyroid cancer and Lindane use, more research is needed to explore this further specifically in highly exposed populations (e.g. rural areas) with longitudinal studies that assess the effects of long-term exposure to Lindane and other organochlorine pesticides.

Evaluating the Rising Incidence of Thyroid Cancer and Thyroid Nodule Detection Modes

There is epidemiologic evidence that the increasing incidence of thyroid cancer is associated with subclinical disease detection. Evidence for a true increase in thyroid cancer incidence has also been identified. However, a true increase in disease would likely be heralded by an increased incidence of thyroid-referable symptoms in patients presenting with disease. To evaluate whether modes of detection (MODs) used to identify thyroid nodules for surgical removal have changed compared with historic data and to determine if MODs vary by geographic location. This was a retrospective analysis of pathology and medical records of 1328 patients who underwent thyroid-directed surgery in 16 centers in 4 countries: 4 centers in Canada, 1 in Denmark, 1 in South Africa, and 12 in the US. The participants were the first 100 patients (or the largest number available) at each center who had thyroid surgery in 2019. The MOD of the thyroid finding that required surgery was classified using an updated version of a previously validated tool as endocrine condition, symptomatic thyroid, surveillance, or without thyroid-referable symptoms (asymptomatic). If asymptomatic, the MOD was further classified as clinician screening examination, patient-requested screening, radiologic serendipity, or diagnostic cascade. The MOD of thyroid nodules that were surgically removed, by geographic variation; and the proportion and size of thyroid cancers discovered in patients without thyroid-referable symptoms compared with symptomatic detection. Data analyses were performed from April 2021 to February 2022. Of the 1328 patients (mean [SD] age, 52 [15] years; 993 [75%] women; race/ethnicity data were not collected) who underwent thyroid surgery that met inclusion criteria, 34% (448) of the surgeries were for patients with thyroid-related symptoms, 41% (542) for thyroid findings discovered without thyroid-referable symptoms, 14% (184) for endocrine conditions, and 12% (154) for nodules with original MOD unknown (under surveillance). Cancer was detected in 613 (46%) patients; of these, 30% (183 patients) were symptomatic and 51% (310 patients) had no thyroid-referable symptoms. The mean (SD) size of the cancers identified in the symptomatic group was 3.2 (2.1) cm (median [range] cm, 2.6 [0.2-10.5]; 95% CI, 2.91-3.52) and in the asymptomatic group, 2.1 (1.4) cm (median [range] cm, 1.7 [0.05-8.8]; 95% CI, 1.92-2.23). The MOD patterns were significantly different among all participating countries. This retrospective analysis found that most thyroid cancers were discovered in patients who had no thyroid-referable symptoms; on average, these cancers were smaller than symptomatic thyroid cancers. Still, some asymptomatic cancers were large, consistent with historic data. The substantial difference in MOD patterns among the 4 countries suggests extensive variations in practice.

Complication Rates of Total Thyroidectomy vs Hemithyroidectomy for Treatment of Papillary Thyroid Microcarcinoma

Papillary thyroid microcarcinomas (PTMCs) have been associated with increased thyroid cancer incidence in recent decades. Total thyroidectomy (TT) has historically been the primary treatment, but current guidelines recommend hemithyroidectomy (HT) for select low-risk cancers; however, the risk-benefit ratio of the 2 operations is incompletely characterized. To compare surgical complication rates between TT and HT for PTMC treatment. SCOPUS, Medline via the PubMed interface, and the Cochrane Central Register of Controlled Trials (CENTRAL); through January 1, 2021, with no starting date restriction. Terms related to papillary thyroid carcinoma and its treatment were used for article retrieval. This meta-analysis used the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guideline and was written according to the Meta-analysis of Observational Studies in Epidemiology (MOOSE) proposal. Original investigations of adults reporting primary surgical treatment outcomes in PTMC and at least 1 complication of interest were included. Articles evaluating only secondary operations or non-open surgical approaches were excluded. Study selection, data extraction, and risk of bias assessment were performed by 2 independent reviewers and conflicts resolved by a senior reviewer. Pooled effect estimates were calculated using a random-effects inverse-variance weighting model. Cancer recurrence and site, mortality (all-cause and disease-specific), vocal fold paralysis, hypoparathyroidism, and hemorrhage/hematoma. Risk of bias was assessed using the McMaster Quality Assessment Scale of Harms scale. In this systematic review and meta-analysis, 17 studies were analyzed and included 1416 patients undergoing HT and 2411 patients undergoing TT (HT: pooled mean [SD] age, 47.0 [10.0] years; 1139 [84.6%] were female; and TT: pooled mean [SD] age, 48.8 [10.0] years; 1671 [77.4%] were female). Patients undergoing HT had significantly lower risk of temporary vocal fold paralysis compared with patients undergoing TT (3.3% vs 4.5%) (weighted risk ratio [RR], 0.4; 95% CI, 0.2-0.7), temporary hypoparathyroidism (2.2% vs 21.3%) (weighted RR, 0.1; 95% CI, 0.0-0.4), and permanent hypoparathyroidism (0% vs 1.8%) (weighted RR, 0.2; 95% CI, 0.0-0.8). Contralateral lobe malignant neoplasm recurrence was 2.3% in the HT group, while no such events occurred in the TT group. Hemithyroidectomy was associated with a higher overall recurrence rate (3.8% vs 1.0%) (weighted RR, 2.6; 95% CI, 1.3-5.4), but there was no difference in recurrence in the thyroid bed or neck. The results of this systematic review and meta-analysis help characterize current knowledge of the risk-benefit ratio of HT vs TT for treatment of PTMC and provide data that may have utility for patient counseling surrounding treatment decisions.

Individual Dose Response and Radiation Origin of Childhood and Adolescent Thyroid Cancer in Fukushima, Japan

Background: After the Fukushima Nuclear Power Plant accident in 2011, thyroid ultrasound screening was carried out as part of the Fukushima health management survey (FHMS) on all residents of ages≤18 years at the accident. The results of the 1st (2011-2013) and 2nd (2014-2015) round screening showed dozens of times excess thyroid cancer detection compared to the expected from the cancer registry. Both FHMS and the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) summarized that thyroid cancer cases detected in Fukushima were unlikely to be attributed to radiation exposure from the absence of dose-response relation. We elucidated the response of thyroid cancer incidence to individual external doses and found the dominant radiation effect on the increased thyroid cancer incidence after the accident. Method: Association between average individual external dose based on FHMS basic survey and thyroid cancer incidence rate of dose groups was analysed by the linear regression analysis. Thyroid dose estimated in UNSCEAR 2020/2021 for 10-year-old children was used for comparison. Results: Incidence proportions of dose groups in the 2nd round showed a linear response to mean individual external dose under 2.5 mSv range. A rough estimate of the excess relative risk per gray (Gy) was ERR/Gy =213 (95%CI: 129, 297) (p=0.02). Conclusion: Childhood and adolescent thyroid cancer in Fukushima was associated with individual external dose estimated in FHMS basic survey. Increased childhood and adolescent thyroid cancer in Fukushima could most probably be attributed to radiation exposure from the nuclear accident.

Fertility drugs and incidence of thyroid cancer in a Danish nationwide cohort of 146 024 infertile women.

Do fertility drugs increase the risk of thyroid cancer among infertile women? The use of most types of fertility drugs was not associated with an increased risk of thyroid cancer. The incidence of thyroid cancer is higher for women than men, especially during reproductive years, indicating that reproductive hormones may be involved in the development of thyroid cancer. Only a few previous studies have examined the association between the use of fertility drugs and incidence of thyroid cancer and the results are inconclusive. A retrospective, population-based cohort study including all 146 024 infertile women aged 20-45 years and living in Denmark in the period 1995-2017. The women were followed from the date of entry in the cohort (i.e. date of first infertility diagnosis) until the occurrence of thyroid cancer or any other cancer (except non-melanoma skin cancer), death, emigration, total thyroidectomy or the end of follow-up (31 December 2018), whichever occurred first. The median length of follow-up was 11.3 years. In total, 167 women were diagnosed with thyroid cancer during the follow-up period. Information on the use of specific fertility drugs (clomiphene citrate, gonadotropins, hCGs, GnRH receptor modulators and progesterone), thyroid cancer, covariates and vital status was obtained from the Danish Infertility Cohort and various Danish national registers. Cox proportional hazard regression models were used to calculate hazard ratios (HRs) and 95% CIs for thyroid cancer overall and for papillary thyroid cancer. After adjustment for the calendar year of infertility diagnosis, the highest obtained level of education, parity status, obesity or thyroid disease and mutual adjustment for other registered fertility drugs, no marked associations were observed between the use of clomiphene citrate, hCG, gonadotropins or GnRH receptor modulators and risk of overall or papillary thyroid cancer. However, ever use of progesterone was associated with an increased rate of both overall (HR 1.63; 95% CI 1.07-2.48) and papillary (HR 1.66, 95% CI 1.04-2.65) thyroid cancer after mutual adjustment for other specific fertility drugs. For most specific fertility drugs, we observed a tendency toward higher associations with thyroid cancer within the first 5 years after the start of drug use than after 5 years from the start of use. No marked associations were detected according to the cumulative dose for any of the specific fertility drugs. Despite a large study population, the statistical precision in some subgroup analyses may be affected due to the low number of thyroid cancer cases. Although we were able to adjust for a number of potential confounders, residual and unmeasured confounding may potentially have affected the observed associations, as we could not adjust for some factors that may influence the association between fertility drugs and thyroid cancer, including age at menarche and BMI. Although this study, which is the largest to date, provides reassuring evidence that there is no strong link between the use of fertility drugs and thyroid cancer incidence, we observed a modest increased thyroid cancer incidence after the use of progesterone. However, we cannot rule out that this is a chance finding and the potential association between the use of progesterone and thyroid cancer should therefore be investigated further in large epidemiological studies. The results of the present study provide valuable knowledge for clinicians and other health care personnel involved in the diagnosis and treatment of infertility. The study was supported by research grants from the Jascha Foundation and the Aase and Ejner Danielsens Foundation. B.N. received honoraria and/or non-financial support by Gedeon Richter Nordics AB, IBSA Nordic APS and Merck KGAA. The remaining authors have no competing interests. N/A.

LATE ONCOLOGICAL AFTEREFFECTS OF RADIATION EXPOSURE CAUSED BY THE CHORNOBYL ACCIDENT.

Studies of the longterm oncological consequences after the Chornobyl accident show a significant impact of radiation exposure on the cancer incidence rate in affected population in Ukraine. This is supported by the increased radiation risk of leukaemia in liquidators, which exceeds national population rates, and its value is comparable to the data on hibakushi, who were subjected to Abombings. For the first time in the cleanup workers cohort the radiation dependence of chronic lymphoid leukaemia was established. There are radiation associated risks of leukemia in children who have been exposed to radiation from the Chornobyl accident. There has been registered an increase of thyroid cancer incidence in children and adults (liquidators, evacuees from the 30km exclusion zone and residents of the most contaminated territories). There is an excess of breast cancer in female liquidators. The frequency of all forms of malignant neoplasms decreases over time but still exceeds national rates. Further monitoring of malignant neoplasms in the groups of affected population will allow evaluating the radiation risks of cancer forms whose radiationassociated manifestation is already known from previous studies or can be expected in the future.

Papillary Thyroid Carcinoma: Current Position in Epidemiology, Genomics, and Classification.

Papillary thyroid carcinoma is the most common type of thyroid malignancy both in adults and pediatric population. Since the 1980s, there are changes in criteria in labelling thyroid lesions as "papillary thyroid carcinomas." Radiation exposure is a well-established risk factor for papillary thyroid carcinoma. Other environmental risk factors include dietary iodine, obesity, hormones, and environmental pollutants. Papillary thyroid carcinomas could occur in familial settings, and 5% of these familial cases have well-studied driver germline mutations. In sporadic papillary thyroid carcinoma, BRAF mutation is common and is associated with clinicopathologic and prognostic markers. The mutation could aid in the clinical diagnosis of papillary thyroid carcinoma. Globally, thyroid cancer is among the top ten commonest cancer in females. In both adult and pediatric populations, there are variations of prevalence of thyroid cancer and rising incidence rates of thyroid cancer worldwide. The increase of thyroid cancer incidence was almost entirely due to the increase of papillary thyroid carcinoma. The reasons behind the increase are complex, multifactorial, and incompletely understood. The most obvious reasons are increased use of diagnostic entities, change in classification of thyroid neoplasms, as well as factors such as obesity, environmental risk factors, and radiation. The prognosis of the patients with papillary thyroid carcinoma is generally good after treatment. Nevertheless, cancer recurrence and comorbidity of second primary cancer may occur, and it is important to have awareness of the clinical, pathological, and molecular parameters of papillary thyroid carcinoma.

Динамика заболеваемости раком щитовидной железы населения России: основные факторы риска

According to GLOBOCAN 2020 Statistics based on estimates for 36 cancers incidence and mortality in 185 countries produced by the International Agency for Research on Cancer (IARC) in 2020, the total number of cancer cases increased by 19.3 million new cases and the number of cancer deaths increased by 10 million new cancer deaths. According to statistics, 1 of 5 people develops cancer during their life, and one of 8 men and one of 11 women die from the disease. The cancer burden to 2040 is expected to increase by 28.4 million cases. The dynamics of incidence and mortality from malignant neoplasms in the Russia is registered by the P. Hertsen Moscow Oncology Research Institute (MORI), branch of the National Medical Research Radiolog-ical Centre of the Ministry of Health of the Russian Federation. The data received in 2019 and 2010 were compared. The increase in cancer incidence over 10 years was 24%. However, thyroid cancer incidence surpasses other cancers incidence by 58%. The following main risk factors for potential regional induction of thyroid cancer are: the environmental situation in regions of Russia, the effects of the Chernobyl accident, and health effects of population exposed to radiation, approved with modern medical equipment. Based on epidemiological studies, it has been numerically proven that the above listed main risk factors are responsible for the significant increase in thyroid cancer incidence in Russia.

Pesticides and the risk of thyroid cancer, 50 years after restricted organochlorine pesticide use

BACKGROUND AND AIM: The incidence rate of thyroid cancer has increased significantly in recent decades in the United States (US) and worldwide. Exposure to endocrine disruptive chemicals, including pesticides, has been suggested to potentially contribute to this increase. Although many organochlorine pesticides have been restricted or banned in the US since the 1970s, these pesticides are stable and lipophilic, allowing them to remain in tissues for years potentially exerting carcinogenic effects. The objective of present study was therefore to assess time trends of thyroid cancer incidence and pesticide use in the US from 1975 to 2017. METHODS: Using data from the United States Department of Agriculture (USDA) and Surveillance, Epidemiology, and End Results Program (SEER), trends of pesticides use between years 1975-2008 and incidence of thyroid cancer between years 1975-2017 in the US were assessed. The Mann-Kendall test was used to assess whether there was a significant, monotonic up- or downward trend, expressed as Kendall’s Tau b correlation coefficient. RESULTS:There was a significant increased thyroid cancer incidence rate from 4.85 cases per 100,000 per year in 1975, to 13.68 cases per 100,000 per year in 2017 (correlation coefficient: 0.873; p= 0.001). Pesticide use increased significantly from 448.9 million pounds in year 1975 to 631.9 million pounds in year 1981 (correlation coefficient: 0.809; p= 0.016). After 1981, pesticide use decreased to 516.1 million pounds in 2008, however this was a non-significant decrease (correlation coefficient: -0.207; p= 0.128). CONCLUSIONS:The simultaneous increase in pesticide use and thyroid cancer incidence rate suggests a potential negative health effect of pesticide exposure, although longitudinal studies are needed to investigate causality. Surveillance of the general population is needed to explore the impact of pesticide exposure in the US as no significant decrease in pesticide use is seen to date. KEYWORDS: Pesticides, cancer and cancer precursors

Thyroid cancer overdiagnosis revisited

BackgroundEvidence has accumulated showing that an increase in thyroid cancer incidence reflects overdiagnosis of clinically unimportant lesions due to the rise in the use of neck ultrasonography. In the manuscript we examine the hypothesis that the rise in thyroid cancer incidence in Russia is largely caused by overdiagnosis. Materials and methodsIncidence and mortality rates of thyroid cancer for Russia overall and its administrative regions were abstracted from the statistical database of the Ministry of Health of Russia. For incidence trends, we calculated the percentage change, linear regression coefficient and p-value. The calculation of excess cases was based on expected age-specific distributions assuming that the incidence of thyroid cancer increases exponentially with age, as predicted by the multistage model of carcinogenesis. FindingsOver the study period (1989–2015) the age standardized incidence of thyroid cancer has tripled in Russian women and doubled in men. Strong support for the hypothesis that the increase in thyroid cancer incidence may be artificial is evident from age-specific incidence trends: increases in incidence in middle age but not in older ages, thereby altering the age curves from the expected exponential shape to an “inverted U” shape. The number of observed cases of thyroid cancer exceeded the expected number by 138, 325 or 70 % of all cases diagnosed with thyroid cancer. We attribute the excess cases to detection by ultrasonography clinically unimportant lesions. This is supported by a very high incidence –to-mortality ratio, low case fatality, high and growing prevalence of thyroid cancer. ConclusionAlthough there is an evidence that exposure to iodine 131 (131I) is an important cause of the increase in incidence of thyroid cancer in high-risk populations, we have shown that this increase could largely be attributed to overdiagnosis associated with ultrasonography screening. Overdiagnosis is the only explanation of the increase in thyroid cancer incidence in low-risk regions.

Whether iodized salt consumption increases thyroid cancer incidence.

This study aimed to explore the correlation between population-based iodine intake from iodized salt (iodine-IS) and thyroid cancer (TC) incidence. The TC incidence data were collected from the annual reports issued by China's National Central Cancer Registry. The iodine- IS data were extracted from the National Iodized Salt Surveys and National IDD Surveys (NIDDs). The time lag effect of iodine-IS on TC incidence was examined by using a polynomial distributed lag (PDL) model. Iodine-IS consumption peaked in 1999, declined to approximately 60% of 1999 in 2018, but remained close to 142.2 μg/person/day. After 2000, TC incidence increased notably on an annual basis. Iodine-IS and the age-standardized rate adjusted to the world population of TC incidence were significantly negatively correlated (p<0.05). The PDL model revealed that iodine-IS had a significant 6-year time lag effect on TC incidence (p<0.05). Iodine nutrition, as indicated by iodine-IS, exhibited a steady decline. The populationbased iodine-IS was adequate, however, TC incidence continued increasing. Although the 6-year cumulative effect of iodine-IS was considered, a negative correlation between iodine-IS and TC incidence was observed. Iodine- IS may not be a major risk factor for TC because universal salt iodization is maintaining adequate iodine nutrition in the population. The increasing TC incidence may reduce public willingness to consume iodized salt.

Increased Incidence of Thyroid Cancer in Occupational Radiation Epidemiology: Attribution to Screening among Radiation Workers.

In most studies on radiation workers, the incidence of thyroid cancer was determined to be higher than among the general population; this is generally assumed to be due to overdiagnosis through thyroid screening. However, there is a lack of evidence on the association between thyroid screening and increased thyroid cancer incidence in most occupational studies. In this study, we compared thyroid cancer screening rates between the general population and radiation workers with various occupations and examined the relationship between these rates and thyroid cancer incidence. We compared thyroid screening rates between radiation workers and the general population with age- and sex-standardized screening ratios (SSRs) using data from two national surveys conducted during 2015-2017 in Korea, and assessed the correlation between these ratios and age- and sex-standardized incidence ratios (SIRs) for thyroid cancer. Screening rates were higher among radiation workers than among the general population, with an overall SSR of 1.58 (95% confidence interval: 1.54-1.62). When various types of occupations were compared, those with an increased SSR also had an increased SIR. SSRs remained high even when the screening period was restricted to the year preceding the survey (the year after the establishment of guidelines for thyroid cancer screening aimed at reducing overdiagnosis). In conclusion, the increased incidence of thyroid cancer among radiation workers compared to that among the general population can be attributed mainly to increased thyroid screening rates. Additional efforts are needed to reduce unnecessary thyroid cancer screening in occupational populations, particularly in those with better access to healthcare, in terms of clinical rationale and for assessing the true increase in thyroid cancer incidence.