The correlation between small papillary thyroid cancers and gamma radionuclides Cs-137, Th-232, U-238 and K-40 using spatially-explicit, register-based methods.

A steep increase of small papillary thyroid cancers (sPTCs) has been observed globally. A major risk factor for developing PTC is ionizing radiation. The aim of this study is to investigate the spatial distribution of sPTC in Sweden and the extent to which prevalence is correlated to gamma radiation levels (Caesium-137 (Cs-137), Thorium-232 (Th-232), Uranium-238 (U-238) and Potassium-40 (K-40)) using multiple geospatial and geostatistical methods. The prevalence of metastatic sPTC was associated with significantly higher levels of Gamma radiation from Th-232, U-238 and K-40. The association is, however, inconsistent and the prevalence is higher in densely populated areas. The results clearly indicate that sPTC has causative factors that are neither evenly distributed among the population, nor geographically, calling for further studies with bigger cohorts. Environmental factors are believed to play a major role in the pathogenesis of the disease.

Safety and efficacy of CT-guided radioactive iodine-125 seed implantation as a salvage treatment for recurrent head and neck cancer after two or more courses of radiotherapy.

BACKGROUND: In the past, patients with recurrent head and neck cancer (rHNC) who had previously received a high dose of radiation and were unable to undergo surgery were mainly treated with palliative chemotherapy due to the high incidence of side effects from re-irradiation. With the development of radiotherapy technology, re-irradiation of recurrent lesions by radioactive iodine-125 seed implantation (RISI) has been proposed as a feasible therapeutic approach. This study aimed to investigate the safety and efficacy of computed tomography (CT)-guided RISI in the treatment of rHNC after two or more courses of radiotherapy, and to analyze the prognostic factors. METHODS: Data of 33 patients with rHNC who received CT-guided RISI after two or more courses of radiotherapy were collected and statistically analyzed. The median cumulative dose of the previous radiotherapy was 110 Gy. Short-term efficacy was assessed by Response Evaluation Criteria in Solid Tumors (version 1.1) criteria, while adverse events were evaluated by Common Terminology Criteria for Adverse Events (version 5.0) criteria. RESULTS: The median gross tumor volume (GTV) was 29.5 cc, and the postoperative median dose to 90% of target volume (D90) was 136.8 Gy. For adverse reactions, enhanced pain was found in 3 (9.1%) patients, followed by grade 1 to 2 acute skin reactions in 3 (9.1%) patients, grade 2 to 3 late skin reactions in 2 (6.1%) patients, grade 1 to 2 early mucosal reactions in 4 (12.1%) patients, and mandibular osteonecrosis in 1 (3.0%) patient. Regarding the treatment efficacy, the 1- and 2-year local control (LC) rates were 47.8% and 36.4% (median LC time, 10 months), and the 1- and 2-year overall survival (OS) rates were 41.3% and 32.2% (median OS time, 8 months). The absence of adverse events was associated with better LC. CONCLUSIONS: CT-guided RISI, as a salvage therapy, demonstrated acceptable safety and efficacy in the treatment of rHNC after two or more courses of radiotherapy. TRIAL REGISTRATION: This study was registered at Chinese Clinical Trial Register database (Registration No. ChiCTR2200063261 ) in September 2, 2022.

Impact of Modified Thoracic Breast Approach Lumpectomy on Prognosis of Recurrence in Radical Thyroid Carcinoma Patients.

Objective: This study aimed to compare the efficacy and safety of endoscopic radical thyroidectomy (ERT) via modified breast approach (MBA) with conventional open thyroidectomy in treating thyroid carcinoma (TC). Methods: One hundred patients with TC were randomized into a research group (treated with modified thoracic breast approach lumpectomy) and a control group (treated with traditional open surgery). Clinical efficacy, adverse effects, operative time, intraoperative bleeding, postoperative drainage, and length of stay (LOS) were compared between the groups. Serum calcium and parathyroid hormone levels were measured preoperatively and on postoperative days 1 and 5. Patients were followed up for 1-year prognosis, including prognostic survival, TC recurrence rate, and factors affecting their prognosis. Results: There was no difference in total treatment efficiency between the groups, but the incidence of adverse effects, intraoperative bleeding, postoperative drainage, and LOS were lower in the research group, while the operative time was higher in the control group. Serum calcium and parathyroid hormone were insufficient in both groups on postoperative day 1 compared to preoperative levels, with higher levels in the research group. On postoperative day 5, there was no difference between the groups. TC recurrence was lower in the research group, and logistic regression analysis showed that age and surgical method were independent factors affecting prognostic recurrence in TC patients. Conclusion: Modified thoracic breast approach lumpectomy for radical TC is a safe and effective technique that can improve patients' prognosis of recurrence. It is recommended for clinical practice.

Dietary selenium intake and thyroid cancer risk in postmenopausal women.

OBJECTIVE: It has been suggested that higher selenium intake and consumption of supplements protect against several cancers. To our knowledge, epidemiologic evidence is rare and inconsistent on the association of selenium level and the risk for thyroid cancer. Therefore, the aim of this study was to examine the association between selenium intake and thyroid cancer risk in postmenopausal women using the Women's Health Initiative (WHI) database. METHODS: The WHI recruited 161 808 postmenopausal women 50 to 79 y of age between September 1, 1993 and December 31, 1998. The present study included 147 348 women 63.15 y of age (SD = 7.21) at baseline. The main exposure was baseline total selenium intake including dietary selenium measured by food frequency questionnaire (FFQ) and supplemental selenium. The outcome was thyroid cancer, which was adjudicated by trained physicians. Cox proportional hazard models were used to analyze the association. RESULTS: During a mean follow-up of 16.4 y until September 30, 2020, 442 thyroid cancer cases were identified. There was no significant association between total selenium intake and thyroid cancer risk after adjusting for multiple covariates (highest versus lowest quartile: hazard ratio [HR], 0.88; 95% confidence interval [CI], 0.60-1.29). Association between total selenium intake and the risk for papillary thyroid cancer was also not significant (highest versus lowest quartile: HR, 1.02; 95% CI, 0.66-1.52). CONCLUSIONS: The present data did not support that either total or dietary selenium intake was associated with the risk for thyroid cancer or the papillary subtype in postmenopausal women ages 50 to 79 y in the United States.

Lenvatinib-induced hypocalcaemia due to transient primary hypoparathyroidism.

CONTEXT: Radioiodine refractory differentiated thyroid cancer can be effectively treated with multi-tyrosine-kinase inhibitors (MKIs). Hypocalcaemia has been reported among the side effects of these drugs, but little is known about its pathophysiology and clinical relevance. CASE REPORT: We report the case of a 78-years-old woman with an aggressive papillary thyroid cancer infiltrating perithyroidal structures. The extent of surgery was limited to hemithyroidectomy, RAI treatment could not be performed, and she started lenvatinib treatment. After 4 months of therapy, the patient accessed the Emergency Department for a grade III hypocalcaemia (corrected serum calcium: 6.6 mg/dL, n.v. 8.1-10.4 mg/dL), due to primary hypoparathyroidism (serum PTH: 12.6 ng/L, n.v. 13-64 ng/L). The patient was treated with intravenous calcium infusions and vitamin D supplementation. After discharge, the oral dose of carbonate calcium (CaCO3) was of 6 g/day, and was titrated according to blood exams. Two weeks after discharge, while taking CaCO3 at the dose of 3 g/day, the patient experienced symptomatic grade II hypercalcemia (corrected serum calcium: 11.6 mg/dL), associated to the spontaneous reprise of PTH secretion, and leading to oral calcium withdrawal. During the subsequent follow-up, the patient remained eucalcemic without calcium supplementation. CONCLUSIONS: Though hypocalcaemia has been described as potential side effect of MKI treatment, this is the first report of a lenvatinib-induced primary hypoparathyroidism, in a patient with a documented normal parathyroid function after surgery. The periodical assessment of calcium-phosphorus metabolism is thus warranted to prevent this potentially lethal side effect, in both post-surgical hypoparathyroid and euparathyroid patients.

The Iodine Rush: Over- or Under-Iodination Risk in the Prophylactic Use of Iodine for Thyroid Blocking in the Event of a Nuclear Disaster.

Iodine is an essential element for the production of thyroid hormones (THs). Both deficient and excess iodine intakes may precipitate in adverse thyroidal events. Radioactive iodine (RI) is a common byproduct of nuclear fission processes. During nuclear emergencies RI may be released in a plume, or cloud, contaminating the environment. If inhaled or ingested, it may lead to internal radiation exposure and the uptake of RI mainly by the thyroid gland that absorbs stable iodine (SI) and RI in the same way. A dose of radiation delivered to the thyroid gland is a main risk factor for the thyroid cancer development. The SI prophylaxis helps prevent childhood thyroid cancer. The thyroid gland saturation with prophylactic SI ingestion, reduces the internal exposure of the thyroid by blocking the uptake of RI and inhibiting iodide organification. However, negative impact of inadequate SI intake must be considered. We provide an overview on the recommended iodine intake and the impact of SI and RI on thyroid in children and adolescents, discussing the benefits and adverse effects of the prophylactic SI for thyroid blocking during a nuclear accident. The use of SI for protection against RI may be recommended in cases of radiological or nuclear emergencies, moreover the administration of iodine for prophylactic purposes should be cautious. Benefits and risks should also be considered according to age. Adverse effects from iodine administration cannot be excluded. Precise indications are mandatory to use the iodine for thyroid blocking. Due to this natural adaption mechanism it's possible to tolerate large doses of iodine without clinical effects, however, a prolonged assumption of the iodine when not needed can be dangerous and may precipitate in severe thyroidal and non-thyroidal negative effects.

Is thyroid hormone supplementation avoidable for patients with low-risk papillary thyroid cancer after thyroid lobectomy? A two-center observational study.

OBJECTIVE: Changing insights regarding the extent of surgery for low-risk papillary thyroid cancer (PTC) stir up discussions on the benefits and harms of thyroid lobectomy versus total thyroidectomy. The chance of needing postoperative thyroid hormone supplementation after thyroid lobectomy is still unclear. The purpose of this retrospective two-center study was to identify the incidence and risk factors of postoperative thyroid-stimulating hormone (TSH) elevation (>2.0 µIU/ml) after thyroid lobectomy for low-risk PTC. DESIGN AND METHODS: Medical records of 201 consecutive patients with low-risk PTC from two tertiary centers who underwent thyroid lobectomy between 2015 and 2019 were retrospectively reviewed. Postoperative thyroid function tests were measured regularly and patients were prescribed levothyroxine if the TSH level was higher than 2.0 µIU/ml. Multivariable regression models were used to evaluate potential risk factors associated with postoperative TSH elevation after thyroid lobectomy. RESULTS: At 6 weeks postoperatively, 85% had TSH level of >2 µIU/ml; this increased to 88% by 3-6 months. Receiver operating characteristic analysis identified preoperative TSH cut-off (>1.7 µIU/ml) to predict postoperative TSH elevation. Multivariate analysis revealed that only a high preoperative TSH level (>1.7 µIU/ml) was an independent risk factor for a postoperative TSH level of >2 µIU/ml (odds ratio = 7.71; p < .001). CONCLUSION: Nearly 90% of the patients who underwent thyroid lobectomy for low-risk PTC had a postoperative TSH level of >2 µIU/ml, necessitating thyroid hormone supplementation in accordance with current guidelines. This finding highlights that preoperative patient counseling should also focus on raising awareness about postoperative thyroid hormone supplementation for low-risk PTC patients seeking thyroid lobectomy.

Adjuvant radiotherapy and radioiodine treatment for locally advanced differentiated thyroid cancer: systematic review and meta-analysis.

BACKGROUND: Treatment for locally advanced differentiated thyroid cancer is surgery followed by radioiodine while the role of adjuvant external beam radiotherapy (EBRT) is debated. METHODS: The panel of the Italian Association of Radiotherapy and Clinical Oncology developed a clinical recommendation on the addition of EBRT to radioiodine after surgery for locally advanced differentiated thyroid cancer by using the Grades of Recommendation, Assessment, Development, and Evaluation methodology and the Evidence to Decision framework. A systematic review with meta-analysis about this topic was conducted with a focus on outcome of benefits and toxicity. RESULTS: Locoregional control was improved by EBRT while no considerable toxicity impact was reported. CONCLUSION: The panel judged uncertain the benefit/harms balance; final recommendation was conditional both for EBRT + radioiodine and radioiodine alone in the adjuvant setting.

Nutritional status and follicular-derived thyroid cancer: An update.

The incidence of differentiated thyroid cancer has been increasing in the last decades all over the world. Such a steady growth cannot be entirely attributable to more intensive thyroid nodule screening and more sensitive diagnostic procedures. Several environmental factors have changed with sufficient rapidity in the same time frame and may represent credible candidates for this increase. They include modified iodine intake, lifestyle-associated risk factors, exposure to various toxic compounds, pollutants and xenobiotics, nutritional deficiencies, eating habits and comorbidities. Foremost, nutritional patterns have gained high interest as possible promoters and modifiable risk factors for thyroid cancer in recent years. The aim of this narrative review is to focus on the relationship between thyroid cancer and nutritional factors, dietary habits and obesity. Low iodine intake has been associated to increased risk of thyroid cancer, favoring the development of more aggressive histotypes. Moreover, correction of iodine deficiency can shift thyroid cancer subtypes toward less aggressive forms, without affecting the overall risk for cancer. Actually, evidence regarding the association between selenium and vitamin D deficiency and thyroid cancer is very limited, despite their well-known anti-cancer potentials, and the clinical usefulness of their supplementation is still uncertain in this setting. Albeit the relationship between single foods and thyroid cancer is difficult to examine, fish and iodine-rich foods, vegetables, and fruits might exert protective effects on thyroid cancer risk. Conversely, no clear association has been found for other foods to date. Lastly, a clear association between obesity and the risk of thyroid cancer, with more aggressive behavior, seems to emerge from most studies, likely involving variations in thyroid function and chronic inflammation mediated by cytokines, insulin, leptin and adiponectins. Although no definite association between dietary factors and thyroid cancer has been firmly established so far, some nutritional patterns, together with excessive weight, seem to play a relevant role in thyroid cancer carcinogenesis as well as in its severity and aggressiveness. These effects may play an additive role to the well-established one exerted by environmental carcinogens, such as pollutants and radiation exposure.

Phytoestrogens and Thyroid Cancer Risk: A Population-Based Case-Control Study in Connecticut.

BACKGROUND: Very few previous studies have examined the relationship between thyroid cancer risk and intake of phytoestrogens (PE); furthermore, these studies have reached inconsistent results. METHODS: We analyzed data from a population-based case-control study in Connecticut from 2010 to 2011, including 387 histologically confirmed thyroid cancer cases and 433 population-based controls, with compound data available concerning specific PEs. Multivariate unconditional logistic regression models were used to estimate the associations between specific PEs and the risk of thyroid cancer, adjusting for potential confounders. RESULTS: An elevated risk of thyroid cancer was associated with moderate to high levels of coumestrol intake [OR = 2.48, 95% confidence interval (CI), 1.39-4.43 for 40-80 µg/day; OR = 2.41, 95% CI, 1.32-4.40 for 80-130 µg/day; and OR = 2.38, 95% CI, 1.26-4.50 for >200 µg/day compared with <40 µg/day], and the main elevation in risk appeared among microcarcinomas (≤1 cm). A decreased risk of papillary macrocarcinomas (>1 cm; OR = 0.26, 95% CI, 0.08-0.85 for 1,860-3,110 µg/day compared with <760 µg/day) was associated with moderate genistein intake among women. CONCLUSIONS: Our study suggests that high coumestrol intake increases the risk of thyroid cancer, especially microcarcinomas, whereas moderate amounts of genistein intake appear to be protective for females with thyroid macrocarcinomas. IMPACT: The study highlights the importance of distinguishing between microcarcinomas and macrocarcinomas in future research on the etiology of thyroid cancer.

Vitamin D deficiency and its relationship to cancer stage in patients who underwent thyroidectomy for papillary thyroid carcinoma.

PURPOSE: As imaging technology improves and more thyroid nodules and malignancies are identified, it is important to recognize factors associated with malignancy and poor prognosis. Vitamin D has proven useful as a prognostic tool for other cancers and may be similarly useful in thyroid cancer. This study explores the relationship of Vitamin D to papillary thyroid carcinoma stage while accounting for socioeconomic covariates. MATERIALS AND METHODS: The medical records of all patients who underwent thyroidectomy at one institution between 2000 and 2015 were reviewed. Subjects with non-papillary thyroid cancer pathology, prior malignancy, and without Vitamin D levels were excluded. The remaining 334 patient records were examined for cancer stage, Vitamin D levels, Vitamin D deficiency listed in history, and demographic and comorbid factors. RESULTS: Vitamin D laboratory values showed no significant relationship to cancer stage (p = 0.871), but patients with Vitamin D deficiency documented in the medical record were more likely to have advanced disease (28.6% versus 14.7%; p = 0.028). The patients with documented Vitamin D deficiency also had lower 25-hydroxyvitamin D nadirs (21.5 ng/mL versus 26.5 ng/mL, p = 0.008) and were more likely to be on Vitamin D supplementation (92.6% versus 41.8%, p < 0.001). CONCLUSIONS: The results suggest that Vitamin D deficiency may have value as a negative prognostic indicator in papillary thyroid cancer and that pre-operative laboratory evaluation may be less useful. This is important because Vitamin D deficiency is modifiable. While different racial subgroups had different rates of Vitamin D deficiency, neither race nor socioeconomic status showed correlation with cancer stage.

[Factors related to thyroid carcinoma in Zhejiang province: a matched case-control study].

Objective: To explore the influencing factors related to thyroid carcinoma. Methods: Matched by sex, age and original residential areas, 659 pairs of cases and controls were recruited and studied. Methods including both single factor analysis and multivariate conditional logistic regression analysis were carried out to identify the influencing factors. Results: Multivariate conditional logistic regression analysis showed that higher education, being diabetic, alcohol intake, tea drinking, occupational physical activity and the frequency of eating fishes/eggs etc., were potentially protective to thyroid carcinoma. Depression, personal history of CT examination and less salt intake seemed to be risk factors on thyroid carcinoma. For males, factors as alcohol intake, tea drinking, occupational physical activity and frequent egg-eating appeared protective. For females, higher education, diabetes, tea drinking, occupational physical activity, frequent consumption of fishes/eggs, short duration of menstruation appeared as possibly protective. Conclusion: Higher education, diabetes, alcohol intake, tea drinking, occupational physical activity, frequent consumption of fishes/eggs, depression, personal history of CT examination and less salt intake served as potential influencing factors to thyroid carcinoma.

The risk of thyroid cancer and obesity: A nationwide population-based study using the Korea National Health Insurance Corporation cohort database.

INTRODUCTION: In recent years, the incidence of thyroid cancer and obesity has increased rapidly worldwide. Many studies have been conducted on the relationship between thyroid cancer and obesity; however, the potential mechanisms are not well understood, and few studies have been performed in Asia. This study aimed to identify the relationship between the risk of thyroid cancer and obesity in the Korean population based on a large cohort of data. METHOD: We analyzed clinical data from a total of 351,402 individuals (males: 181,709, females: 169,693) aged over 20 years who received medical examinations arranged by the national insurance program from 2003 to 2008. Newly diagnosed thyroid cancer was identified using insurance claims data. The median follow-up duration was 7.01 years. RESULTS: The mean body mass index (BMI) of the subjects was 23.6 ±â€¯3.2 kg/m2 (males, 24 ±â€¯3; females, 23.1 ±â€¯3.3). A total of 3308 individuals (0.94%) developed thyroid cancer during the study period. The risk of thyroid cancer was higher with increasing BMI in both men and women. Hazard ratios (95% confidence interval) for obese (25-29.9 kg/m2) and extremely obese (≥30 kg/m2) groups were 1.23 (1.13-1.34) and 1.26 (1.02-1.50), respectively, compared to the normal group (18.5-22.9 kg/m2). In particular, the association between the risk of thyroid cancer and BMI was more remarkable in the male group than female group. CONCLUSION: Our findings show that higher BMI is positively associated with the risk of thyroid cancer. Furthermore, this study supports the positive association between obesity and the increased incidence of thyroid cancer.

Factors related to thyroid carcinoma in Zhejiang province: a matched case-control study / 中华流行病学杂志

Objective: To explore the influencing factors related to thyroid carcinoma. Methods: Matched by sex, age and original residential areas, 659 pairs of cases and controls were recruited and studied. Methods including both single factor analysis and multivariate conditional logistic regression analysis were carried out to identify the influencing factors. Results: Multivariate conditional logistic regression analysis showed that higher education, being diabetic, alcohol intake, tea drinking, occupational physical activity and the frequency of eating fishes/eggs etc., were potentially protective to thyroid carcinoma. Depression, personal history of CT examination and less salt intake seemed to be risk factors on thyroid carcinoma. For males, factors as alcohol intake, tea drinking, occupational physical activity and frequent egg-eating appeared protective. For females, higher education, diabetes, tea drinking, occupational physical activity, frequent consumption of fishes/eggs, short duration of menstruation appeared as possibly protective. Conclusion: Higher education, diabetes, alcohol intake, tea drinking, occupational physical activity, frequent consumption of fishes/eggs, depression, personal history of CT examination and less salt intake served as potential influencing factors to thyroid carcinoma.

Japanese Food Data Challenge the Claimed Link between Fukushima's Releases and Recently Observed Thyroid Cancer Increase in Japan.

Internal, high-dose exposure with radioiodine is known to increase the risk for thyroid cancer in children and adolescents. Ingestion of contaminated food is generally regarded a dominant route of internal exposure. We analyzed the huge data set of the post-Fukushima food monitoring campaign and deployed a conservative model for the estimation of the doses to the general public in a worst-case scenario. Our data suggest that the committed equivalent ingestion doses to the thyroids of the affected Japanese public, even in the utmost conservative approach, remained below the limit on ingestion of radioiodine in foodstuffs and beverages of 50 mSv (as thyroid equivalent dose). This level of 50 mSv is also the intervention level for the administration of stable iodine, mainly after inhalation. Our study hence suggests that, based on the food data, the internal exposure of Japanese residents was too low to cause a statistically discernible increase in thyroid cancer, even if the contribution from inhalation is taken into account. The data also indicate that the governmental efforts in the food monitoring campaign were successful and cut the thyroid doses to the public by a factor of approximately 3 compared to a scenario without any monitoring.

Effect of excess iodine intake on thyroid on human health.

The recommended daily intake of iodide, is 150 µg for adolescents and adults, 250 µg for pregnancy and lactation. Thyroid gland is an effective collector of iodine. The active iodine uptake along the basolateral membrane of thyroid cell is followed by its transport to the apical edge of the cell and then to the follicle lumen. TSH acts through cAMP and stimulates NIS gene expression and protein synthesis. The major proportion of iodine in the thyroid gland is bound to Thyroglobulin. The non-organic intrathyroidal iodine is usually low, but significantly greater compared to plasma. Large doses of iodine reduce both the uptake and the organification (Wolff-Chaikoff effect) and cause partial inhibition of Tg proteolysis. The thyroid gland has several protective mechanisms resulting on the maintenance of normal thyroid function despite wide fluctuations of the daily iodine intake. Ingestion of several commonly used drugs and food conservatives results in acute or chronic excessive iodine intake. Failure to escape from the iodine induced organification inhibition can cause hypothyroidism, which is temporary and subsides after iodine exposure ceases. Iodine excess may also establish a status of excessive thyroid hormone synthesis and release, thus inducing autonomic thyroid function in iodopenic areas or can contribute to the development of iodine-induced hyperthyroidism in iodine abundant areas. The anti-arrhythmic Amiodarone, is a benzofuranic product with a very high iodine content, is associated with either hypo- or hyperthyroidism development. In the presence of defective auto-protective mechanisms, excessive iodine ingestion can divert the normal thyroid function.

Bone mineral density in treated at a young age for differentiated thyroid cancer after Chernobyl female patients on TSH-suppressive therapy receiving or not Calcium-D3 supplementation.

Long-term management of patients with differentiated thyroid cancer (DTC) commonly includes TSH-suppressive therapy with L-T4 and, in case of postsurgical hypoparathyroidism, Calcium-D3 supplementation, both of which may affect skeletal health. Experience with female patients treated for DTC at a young age and who were then receiving long-term therapy with L-T4 and Calcium-D3 medication is very limited to date. This cross-sectional study set out to investigate effects of Calcium-D3 supplementation and TSH-suppressive therapy on bone mineral density (BMD) in 124 young female patients treated for DTC at a mean age of 14 years and followed-up for an average of 10 years. BMD was found to be significantly higher in patients receiving Calcium-D3 medication than in patients not taking supplements. The level of ionized calcium was the strongest factor determining lumbar spine BMD in patients not receiving Calcium-D3 supplementation. Pregnancy ending in childbirth and HDL-cholesterol were associated with a weak adverse effect on spine and femoral BMD. No evidence of adverse effects of L-T4 and of radioiodine therapies on BMD was found. We conclude that Calcium-D3 medication has a beneficial effect on BMD, and that TSH-suppressive therapy does not affect BMD in women treated for DTC at young age, at least after 10 years of follow-up.

Mammography and the risk of thyroid and hematological cancers: a nationwide population-based study.

To investigate the association between thyroid cancer as well as the most radiosensitive hematological cancers and radiation exposure from mammography. This study used information from a random sample of two million persons enrolled in the nationally representative Taiwan National Health Insurance (NHI) Research Database. The exposed group was composed of women aged 18-65 who had undergone diagnostic mammography between 2000 and 2007. The nonexposed control group was composed of women in the NHI database who had never undergone diagnostic mammography. There were 25,362 women in the exposed group and 203,317 women in the nonexposed group. After adjusting for age and comorbidities, the patients who had been exposed to radiation from mammography did not have a significantly higher risk of developing thyroid cancer and hematological cancers (adjusted HR, 1.201; 95% CI, 0.813-1.774 for thyroid cancer and adjusted HR, 1.228; 95% CI, 0.838-1.800 for hematological cancers). The scattered radiation dose delivered by mammography should be cautiously handled, but no additional concerns about the risk of thyroid cancer developing malignancy should be emphasized.

Lack of association between fingernail selenium and thyroid cancer risk: a case-control study in French Polynesia.

BACKGROUND: Numerous studies have suggested that selenium deficiency may be associated with an increased risk for several types of cancer, but few have focused on thyroid cancer. MATERIALS AND METHODS: We examined the association between post-diagnostic fingernail selenium levels and differentiated thyroid cancer risk in a French Polynesian matched case-control study. Conditional logistic regression models were used to estimate odds ratios and 95% confidence intervals. RESULTS: The median selenium concentration among controls was 0.76 µg/g. Significantly, we found no association between fingernail selenium levels and thyroid cancer risk after conditioning on year of birth and sex and additionally adjusting for date of birth (highest versus lowest quartile: odds-ratio=1.12, 95% confidence interval: 0.66-1.90; p-trend=0.30). After additional adjustment for other covariates, this association remained non-significant (p-trend=0.60). When restricting the analysis to thyroid cancer of 10 mm or more, selenium in nails was non-significantly positively linked to thyroid cancer risk (p-trend=0.09). Although no significant interaction was evidenced between iodine in nails and selenium in nails effect (p=0.70), a non-significant (p-trend =0.10) positive association between selenium and thyroid cancer risk was seen in patients with less than 3 ppm of iodine in nails. The highest fingernail selenium concentration in French Polynesia was in the Marquises Islands (M=0.87 µg/g) and in the Tuamotu-Gambier Archipelago (M=0.86 µg/g). CONCLUSIONS: Our results do not support, among individuals with sufficient levels of selenium, that greater long-term exposure to selenium may reduce thyroid cancer risk. Because these findings are based on post-diagnostic measures, studies with prediagnostic selenium are needed for corroboration.

Controversies about radioactive iodine-131 remnant ablation in low risk thyroid cancers: are we near a consensus?

Well differentiated thyroid cancers (WDTC), including papillary (80%) and follicular (10%) types, are the most common endocrine cancers globally. Over the last few decades most the diagnosed cases have fallen into low risk categories. Radioactive iodine-131 (RAI) has an established role in reducing recurrence and improving the survival in high risk patients. In patients with primary tumor size <1 cm, RAI is not recommended by many thyroid societies. However, low risk WDTC has been an arena of major controversies, most importantly the role and dose of adjuvant RAI for remnant ablation to minimize chances of recurrence and improving survival. This review is an attempt to update readers about the previous and existing practice based on results of non- randomized trials and evolving trends fueled by recently published randomized studies.