Tumor Size and Presence of Metastases in Differentiated Thyroid Cancer - Comparing Cohorts from Two Countries

OBJECTIVE

Incidence of thyroid cancer varies widely, even across neighboring countries. Data on this phenomenon is largely lacking, but are likely related to differences in health care systems. Therefore, we explored whether there are differences between populations from these two countries with respect to the relationship between tumor size and advanced disease.

METHODS

We retrospectively studied two cohorts of adult DTC patients from a Dutch and a German university hospital. We analyzed the presence of lymph node metastases with respect to tumor size for PTC, and the presence of distant metastases for DTC, and PTC and FTC separately.

RESULTS

We included 1771 DTC patients (80% PTC,20% FTC; 24% lymph node and 8% distant metastases). For PTC, the proportion of patients with lymph node metastases was significantly higher in the Dutch than in the German population for tumors ≤1cm (45% vs. 14%; p<0.001). For DTC, distant metastases occurred particular significantly more frequently in the Dutch than in the German population for tumors ≤2cm (7% vs. 2%; p=0.004).

CONCLUSION

The presence of lymph node and distant metastases is significantly higher in pT1 DTC cases in the Dutch compared to the German cohort, which might be caused by differences in the indication for and application of diagnostic procedures eventually leading to DTC diagnosis. Our results implicate that one should be cautious when extrapolating results and guidelines from one country to another.

Second primary malignancies induced by radioactive iodine treatment of differentiated thyroid carcinoma - a critical review and evaluation of the existing evidence

PURPOSE

Concern is growing about long-term side effects of differentiated thyroid cancer treatment, most notably radioactive iodine (RAI) therapy. However, published studies on the subject have had heterogeneous cohorts and conflicting results. This review seeks to provide an updated evaluation of published evidence, and to elucidate the risk of second primary malignancies (SPMs), especially secondary hematologic malignancies (SHMs), attributable to RAI therapy.

METHODS

An extensive literature search was performed in Ovid MEDLINE, Ovid MEDLINE and In-Process & Other Non-Indexed Citations, Ovid MEDLINE Epub Ahead of Print, Cochrane Central Register of Controlled Trials (CENTRAL) and PubMed. Studies regarding RAI-induced SPMs or a dose-response relationship between RAI therapy and SPMs were identified, 10 of which were eligible for the analysis. We evaluated risk of bias in each study and judged quality of evidence (QOE) across all studies using the Grading of Recommendations, Assessment, Development and Evaluations approach.

RESULTS

For the outcome "SPM", the relative effect (relative risk, hazard ratio, or odds ratio) of RAI vs. no RAI ranged from 1.14 to 1.84 across studies, but most results were not statistically significant. For the outcome "SHM", reported relative effects ranged from 1.30 to 2.50, with 2/3 of the studies presenting statistically significant results. In 7/8 of the studies, increased risk for SPM was shown with increasing cumulative RAI activity. QOE was "very low" regarding SPM after RAI and regarding a dose-response relationship, and "low" for SHM after RAI.

CONCLUSION

Based on low quality evidence, an excess risk for the development of SPM cannot be excluded but is expected to be small.

Individualized treatment of differentiated thyroid cancer: The value of surgery in combination with radioiodine imaging and therapy - A German position paper from Surgery and Nuclear Medicine

A consensus statement about indications for post-surgical radioiodine therapy (RIT) in differentiated thyroid cancer patients (DTC) was recently published by the European Thyroid Association (ETA) 1. This publication discusses indications for RIT on the basis of an individual risk assessment. Many of the conclusions of this consensus statement are well founded and accepted across the disciplines involved. However, especially from the perspective of nuclear medicine, as the discipline responsible for indicating and executing RIT, some of the recommendations may require further clarification with regard to their compatibility with established best practice and national standards of care. Assessment of the indications for RIT is strongly dependent on the weighing up of benefits and risks. On the basis of longstanding clinical experience in nuclear medicine, RIT represents a highly specific precision medicine procedure of proven efficacy with a favorable side-effect profile. This distinguishes RIT significantly from other adjuvant oncological therapies and has resulted in the establishment of this procedure as a usually well-tolerated, standard safety measure. With regard to its favorable risk/benefit ratio, this procedure should not be unnecessarily restricted, in the interest of offering reassurance to the patients. Both patients' interests and regional/national differences need to be taken into account. We would therefore like to comment on the recent consensus from the perspective of authors and to provide recommendations based on the respective published data.

Evaluating the use of a two-step age-based cutoff for the UICC/AJCC TNM staging system in patients with papillary or follicular thyroid cancer

BACKGROUND

The joint Union International Contre le Cancer and American Joint Committee on Cancer (UICC/AJCC) Tumor, Node, Metastasis (TNM) staging system for differentiated thyroid cancer (DTC) involves a single age cutoff as a prognostic criterion. Because a single cutoff is a dichotomization of what might be a sliding scale, using multiple age cutoffs might result into a better stage definition. The aim of our study was to investigate if using a two-step age-based cutoff would improve the TNM staging system regarding disease-specific survival (DSS).

METHODS

We retrospectively studied two cohorts of adult DTC patients from The Netherlands and Germany. DSS was analyzed for papillary (PTC) and follicular thyroid cancer (FTC) separately, investigating several two-step age-based cutoffs for those with distant metastases; below lower threshold classified as stage I, between lower and upper threshold as stage II, and above upper threshold as stage IV.

RESULTS

We included 3074 DTC patients (77% PTC). For PTC, an age cutoff of 45 with 50 years had the best statistical model performance, while this was 25 with 40 years for FTC. However, differences with the optimal single age cutoffs of 50 years for PTC and 40 years for FTC were small.

CONCLUSIONS

The optimal two-step age-based cutoff to predict DSS is 45 with 50 years for PTC and 25 with 40 years for FTC, rather than 55 years currently used for DTC. Although these two-step age-based cutoffs were marginally better from a statistical point of view, from a clinical point of view, the recently defined optimal single age cutoffs of 50 years for PTC and 40 years for FTC might be preferable.

Responsivity of the Striatal Dopamine System to Methylphenidate-A Within-Subject I-123-β-CIT-SPECT Study in Male Children and Adolescents With Attention-Deficit/Hyperactivity Disorder

BACKGROUND

Methylphenidate (MPH) is the first-line pharmacological treatment of attention-deficit/hyperactivity disorder (ADHD). MPH binds to the dopamine (DA) transporter (DAT), which has high density in the striatum. Assessments of the striatal dopamine transporter by single positron emission computed tomography (SPECT) in childhood and adolescent patients are rare but can provide insight on how the effects of MPH affect DAT availability. The aim of our within-subject study was to investigate the effect of MPH on DAT availability and how responsivity to MPH in DAT availability is linked to clinical symptoms and cognitive functioning.

METHODS

Thirteen adolescent male patients (9-16 years) with a diagnosis of ADHD according to the DSM-IV and long-term stimulant medication (for at least 6 months) with MPH were assessed twice within 7 days using SPECT after application of I-123-β-CIT to examine DAT binding potential (DAT BP). SPECT measures took place in an on- and off-MPH status balanced for order across participants. A virtual reality continuous performance test was performed at each time point. Further clinical symptoms were assessed for baseline off-MPH.

RESULTS

On-MPH status was associated with a highly significant change (-29.9%) of striatal DAT BP as compared to off-MPH (t = -4.12, p = 0.002). A more pronounced change in striatal DAT BP was associated with higher off-MPH attentional and externalizing symptom ratings (Pearson r = 0.68, p = 0.01). Striatal DAT BP off-MPH, but not on-MPH, was associated with higher symptom ratings (Pearson r = 0.56, p = 0.04).

CONCLUSION

Our findings corroborate previous reports from mainly adult samples that MPH changes striatal DAT BP availability and suggest higher off-MPH DAT BP, likely reflecting low baseline DA levels, as a marker of symptom severity.

High-dose radiation exposure and hypothyroidism: aetiology, prevention and replacement therapy

Without any doubt, high dose radiation exposure can induce hypothyroidism. However, there are open questions related to the mechanisms of its induction, corresponding dose thresholds and possible countermeasures. Therefore, this review addresses the aetiology, prevention and therapy of radiation induced hypothyroidism. External beam radiotherapy with several 10 Gy to the head and neck region and radioiodine therapy with several 100 Gy thyroid absorbed dose can destroy the thyroid gland and can induce autoantibodies against thyroid tissue. According to recent literature, clinical hypothyroidism is observed at threshold doses of ∼10 Gy after external beam radiotherapy and of ∼50 Gy after radioiodine therapy, children being more sensitive than adults. In children and adolescents exposed by the Chernobyl accident with mean thyroid absorbed doses of 500-800 mGy, subclinical hypothyroidism has been detected in 3%-6% of the cases with significant correlation to thyroid absorbed doses above 2.5 Gy. In case of nuclear emergencies, iodine thyroid blocking (ITB) is the method of choice to keep thyroid absorbed doses low. Large doses of stable iodine affect two different steps of internalization of radioiodine (transport and organification); perchlorate affecting the transport only may be an alternative to iodine. Administered before radioiodine incorporation, the effect of 100 mg iodide or more is still about 90% after 1 days, 80% after 2 days, and 50% or less after 3 days. If administered (too) late after exposure to radioiodine, the theoretically expected protective effect of ITB is about 50% after 6 h, 25% after 12 h, and about 6% after 24 h. In case of repeated or continuous exposure, repeated administration of 50 mg of iodide daily is indicated. If radiation-induced hypothyroidism cannot be avoided, thyroid hormone replacement therapy with individualized dosing and regular monitoring in order to maintain thyroid-stimulating hormone levels within the normal range ensures normal life expectancy.

Finding the Optimal Age Cutoff for the UICC/AJCC TNM Staging System in Patients with Papillary or Follicular Thyroid Cancer

Background: Differentiated thyroid cancer (DTC) is the only cancer entity for which the UICC/AJCC (Union for International Cancer Control and American Joint Committee on Cancer) TNM (tumor-node-metastasis) staging system involves an age cutoff as a prognostic criterion. However, the optimal age cutoff has not yet been determined in detail. The aim of our study was therefore to investigate the optimal age cutoff for the TNM staging system to predict disease-specific survival (DSS) with a focus on differences between patients with papillary thyroid cancer (PTC) and follicular thyroid cancer (FTC). Methods: We retrospectively studied two large well-described cohorts of adult DTC patients from a Dutch and a German university hospital. DSS was analyzed for DTC overall, and for PTC and FTC separately, using several age cutoffs (per 5-year increment between 20 and 85 years and subsequently 1-year increments between 35 and 55 years), employing the histopathological criteria from the TNM staging system, eighth edition. Results: We included 3074 DTC patients (77% PTC and 23% FTC; mean age at diagnosis was 49 years). Median follow-up was seven years. For DTC and for PTC and FTC separately, the majority of the age cutoffs had a better statistical model performance than a model with no age cutoff. For DTC overall and for PTC, an age cutoff of 50 years had the best statistical model performance, while it was 40 years for FTC. Conclusions: In this large European population of DTC patients, when employing the histopathological criteria of the TNM system (eighth edition), the optimal age cutoff to predict DSS is 50 years rather than the 55 years currently in use. With the optimal age cutoff being 50 years for PTC and 40 years for FTC, there was a substantial difference in age cutoff for the respective histological entities. Therefore, implementation of different age cutoffs for PTC and FTC could improve the predictive value of the TNM staging system.

Hypothyroidism after radiation exposure: brief narrative review

The thyroid gland is among the organs at the greatest risk of cancer from ionizing radiation. Epidemiological evidence from survivors of radiation therapy, atomic bombing, and the Chernobyl reactor accident, clearly shows that radiation exposure in childhood can cause thyroid cancer and benign thyroid nodules. Radiation exposure also may induce hypothyroidism and autoimmune reactions against the thyroid, but these effects are less well-documented. The literature includes only a few, methodologically weak animal studies regarding genetic/molecular mechanisms underlying hypothyroidism and thyroid autoimmunity after radiation exposure. Rather, evidence about radiation-induced hypothyroidism and thyroid autoimmunity derives mainly from follow-up studies in patients treated with external beam radiotherapy (EBRT) or iodine-131, and from epidemiological studies in the atomic bombing or nuclear accident survivors. Historically, hypothyroidism after external irradiation of the thyroid in adulthood was considered not to develop below a 10-20 Gy dose threshold. Newer data suggest a 10 Gy threshold after EBRT. By contrast, data from patients after iodine-131 "internal radiation therapy" of Graves´ disease indicate that hypothyroidism rarely occurs below thyroid doses of 50 Gy. Studies in children affected by the Chernobyl accident indicate that the dose threshold for hypothyroidism may be considerably lower, 3-5 Gy, aligning with observations in A-bomb survivors exposed as children. The reasons for these dose differences in radiosensitivity are not fully understood. Other important questions about the development of hypothyroidism after radiation exposure e.g., in utero, about the interaction between autoimmunity and hypofunction, and about the different effects of internal and external irradiation still must be answered.

Clinical considerations for the treatment of secondary differentiated thyroid carcinoma in childhood cancer survivors

The incidence of differentiated thyroid carcinoma (DTC) has increased rapidly over the past several years. Thus far, the only conclusively established risk factor for developing DTC is exposure to ionizing radiation, especially when the exposure occurs in childhood. Since the number of childhood cancer survivors (CCS) is increasing due to improvements in treatment and supportive care, the number of patients who will develop DTC after surviving childhood cancer (secondary thyroid cancer) is also expected to rise. Currently, there are no recommendations for management of thyroid cancer specifically for patients who develop DTC as a consequence of cancer therapy during childhood. Since complications or late effects from prior cancer treatment may elevate the risk of toxicity from DTC therapy, the medical history of CCS should be considered carefully in choosing DTC treatment. In this paper, we emphasize how the occurrence and treatment of the initial childhood malignancy affects the medical and psychosocial factors that will play a role in the diagnosis and treatment of a secondary DTC. We present considerations for clinicians to use in the management of patients with secondary DTC, based on the available evidence combined with experience-based opinions of the authors.

MON-508 Clinicopathological Features of Papillary Thyroid Cancer After Fukushima and Chernobyl Accidents

The phenomenon of a sharp increase in the incidence of thyroid cancer worldwide is now under debate. Screening activity, diagnostic improvements or real rise in incidence as a result of unknown carcinogens are discussed. Studies in Belarus after Chernobyl showed that the synergistic influence of radiation and nitrates might lead to an increased thyroid cancer (TC) risk in children. For better understanding of the etiology, we compared the published clinical data of pediatric TC patients after the nuclear emergency of Fukushima with the observations we made after the Chernobyl accident.

In a large-scale survey after the Fukushima accident, 300,476 subjects were screened and by September 2018, 191 subjects were diagnosed with thyroid malignancy or suspected malignancy by fine needle aspiration. Mean age of TC patients was 17.8 years at presentation. Mean tumor size was 14.9 mm. Postoperative lymph node metastasis, extra-thyroidal invasion, and pulmonary metastasis were detected in 79%, 45%, and 2.1% of all cases, respectively. Only 4.8% TC cases were staged as low risk pT1aN0M0 (Suzuki et al. 2018). For comparison, in Belarus patients mean age was 13.0 years at presentation (1078 cases), mean tumor size 14.4 mm. Lymph node metastases were observed in 74%, pulmonary metastasis in 11% and extra-thyroidal extension in 48.5 - 64.1% (with respect to latency period). The low risk (pT1aN0M0) TC patients were diagnosed in 19.2% cases.

The most of TC cases from Japan and Belarus were clinically significant, not “overdiagnosed” and screened on time. Given that the accidental thyroid doses were very low in Japanese cases, it would be very important to evaluate and compare the exposure to endocrine disruptors as e.g. nitrates and low radiation doses from diagnostic procedures (dental X-ray examination and computed tomography).

Referece:

Suzuki S, Matsumoto Y, Ookouchi C, Nakano K, Iwadate M, Suzuki S, Nakamura I, Fukushima T, Mizunuma H, Yamashita S, Takenoshita S. The clinicopathological features of childhood and adolescent thyroid cancer in Fukushima after the Fukushima Daiichi nuclear power plant accident. Thyroid. 2018; Supplement 1, (Poster 136).

Feasibility Study Shows Multicenter, Observational Case-Control Study Is Practicable to Determine Risk of Secondary Breast Cancer in Females With Differentiated Thyroid Carcinoma Given Radioiodine Therapy in Their Childhood or Adolescence; Findings Also Suggest Possible Fertility Impairment in Such Patients

Objective: This single-center, observational case-control feasibility study sought to test key elements of a protocol for an eventual long-term international observational case-control study of a larger patient cohort, to evaluate the risk of breast cancer as a second primary malignancy in females with differentiated thyroid cancer (DTC) given radioiodine therapy (RAI) during childhood or adolescence. Patients: Females developing DTC after the Chernobyl accident in Belarus and ≤19 years old at the time of thyroid surgery were enrolled: patients given RAI (n = 111) and controls of similar age not given RAI (n = 90). Results: One case of breast cancer was newly diagnosed among the RAI patients, but none in controls. Patients given RAI significantly less frequently needed 2^nd surgeries than did controls (23%, 26/111 vs. 39%, 35/90, P < 0.05); the main indication for such procedures usually is suspicion of local recurrence. RAI patients appeared to have had more frequent reproductive difficulties than did controls: 78% (87/111) of the former vs. 93% (84/90) of the latter had a history of pregnancy (P < 0.01), and the mean number of pregnancies was 1.5 ± 1.2 in RAI patients vs. 1.9±1.1 in controls (P < 0.05). Most notably, infertility was observed in 23% (26/111) of RAI patients vs. 4% (4/90) of controls (P < 0.01). In conclusion, a international observational case-control study on breast cancer after DTC in patients given RAI vs. not given RAI appears to be feasible. Additional research and everyday clinical attention should be devoted to reproductive function after RAI in young females.

Breast Cancer After Treatment of Differentiated Thyroid Cancer With Radioiodine in Young Females: What We Know and How to Investigate Open Questions. Review of the Literature and Results of a Multi-Registry Survey

Published studies on the risk of radiation-induced second primary malignancy (SPM) after radioiodine treatment (RAI) of differentiated thyroid cancer (DTC) refer mainly to patients treated as middle-aged or older adults and are not easily generalizable to those treated at a younger age. Here we review available literature on the risk of breast cancer as an SPM after RAI of DTC with a focus on females undergoing such treatment in childhood, adolescence, or young adulthood. Additionally, we report the results of a preliminary international survey of patient registries from academic tertiary referral centers specializing in pediatric DTC. The survey sought to evaluate the availability of sufficient patient data for a potential international multicenter observational case-control study of females with DTC given RAI at an early age. Our literature review identified a bi-directional association of DTC and breast cancer. The general breast cancer risk in adult DTC survivors is low, ~2%, slightly higher in females than in males, but presumably lower, not higher, in those diagnosed as children or adolescents than in those diagnosed at older ages. RAI presumably does not substantially influence breast cancer risk after DTC. However, data from patients given RAI at young ages are sparse and insufficient to make definitive conclusions regarding age dependence of the risk of breast cancer as a SPM after RAI of DTC. The preliminary analysis of data from 10 thyroid cancer registries worldwide, including altogether 6,449 patients given RAI for DTC and 1,116 controls, i.e., patients not given RAI, did not show a significant increase of breast cancer incidence after RAI. However, the numbers of cases and controls were insufficient to draw statistically reliable conclusions, and the proportion of those receiving RAI at the earliest ages was too low.In conclusion, a potential international multicenter study of female patients undergoing RAI of DTC as children, adolescents, or young adults, with a sufficient sample size, is feasible. However, breast cancer screening of a larger cohort of DTC patients is not unproblematic for ethical reasons, due to the likely, at most slightly, increased risk of breast cancer post-RAI and the expected ~10% false-positivity rate which potentially produced substantial "misdiagnosis."

The time point of completion thyroidectomy has no prognostic impact in patients with differentiated thyroid cancer

BACKGROUND

After partial resection of the thyroid gland, a second operation referred to as "completion thyroidectomy" may be required if histopathological analysis indicates the presence of differentiated thyroid cancer (DTC). Although there is little evidence, it is assumed that the time point of completion thyroidectomy is not critical for oncological prognosis of patients with DTC. We assessed whether patients with total thyroidectomy (TTx) in a two-step procedure have an equal long-term prognosis with regard to disease-specific survival (DSS) compared to patients immediately undergoing total thyroidectomy in a one-step procedure.

METHODS

A database study using the Würzburg thyroid cancer database with 2258 patients with pT1a-pT4b tumours DTC who were operated between 1980 and 2016 was carried out.

RESULTS

A total of 277 patients with papillary microcarcinoma pT1aN0M0 were treated by hemithyroidectomy. TTx as one-step procedure was performed in 1114 patients compared to 867 with TTx as a two-step procedure. Patients with papillary thyroid cancer more frequently had a TTx as one-step procedure than follicular thyroid cancer patients (59.4% vs 47%; P < 0.001). Compared to a one-step thyroidectomy, overall complication rate was not different compared to patients undergoing a single operation. Multivariate analysis showed that the presence of distant metastases, T-stage and age at diagnosis were the only independent determinants for DTC-specific survival, regardless of a one- or two-time thyroidectomy.

CONCLUSION

The present study on the largest of such patient collectives provides evidence that a delayed completion operation does not affect DSS in DTC, nor does it lead to a significant increase in complication rates.

The effects of the Union for International Cancer Control/American Joint Committee on Cancer Tumour, Node, Metastasis system version 8 on staging of differentiated thyroid cancer: a comparison to version 7

OBJECTIVE

To assess the changes resulting from the changes from UICC/AJCC TNM version 7 to version 8 and to subsequently determine whether TNM version 8 is an improvement compared to previous iterations of the TNM system and other staging systems for differentiated thyroid cancer (DTC) with regard to prognostic power.

DESIGN

Database study of DTC patients treated in our centre between 1978 up to and including 1 July 2014. Results were compared to our previous comparison of prognostic systems using the same data set.

PATIENTS

2257 DTC patients.

MEASUREMENTS

Staging in accordance with TNM 7 and TNM 8. Thyroid cancer-specific mortality; comparison was based on p-values of univariate Cox regression analyses as well as analysis of the proportion of variance explained (PVE).

RESULTS

There is a redistribution from stage 3 to lower stages affecting 206 (9.1%) patients. DTC-related mortality according to Kaplan-Meier for younger and older patients in TNM 7 had a slightly lower prognostic power than that in accordance with TNM 8 (P = 8.0 10^-16 and P = 1.5 10^-21 , respectively). Overall staging is lower in 627/2257 (27.8%) patients. PVE (TNM 7: 0.29; TNM 8: 0.28) and the P-value of Cox regressions (TNM 7: P = 7.1*10^-52 ; TNM 8: P = 3.9*10^-49 ) for TNM version 8 are marginally lower than that for TNM version 7, but still better than for any other DTC staging system.

CONCLUSION

TNM 8 results in a marked downstaging of patients compared to TNM 7. Although some changes, like the change in age boundary, appear to be associated with an improvement in prognostic power, the overall effect of the changes does not improve the predictive power compared to TNM 7.

Low or Undetectable Basal Thyroglobulin Levels Obviate the Need for Neck Ultrasound in Differentiated Thyroid Cancer Patients After Total Thyroidectomy and 131I Ablation

BACKGROUND

Neck ultrasound (NUS) is currently seen as a main component of follow-up of differentiated thyroid cancer (DTC) and is usually performed regardless of non-stimulated thyroglobulin (Tg) levels. The aim of this study was to determine whether there is a clinical benefit from such a routine NUS in DTC patients.

METHODS

A retrospective database study was conducted of 3176 cervical ultrasound exams performed in 773 patients between June 15, 1996, and July 1, 2012. The accuracy of ultrasound results was assessed based on the results of further diagnostic and/or therapeutic procedures within six months of a particular ultrasound.

RESULTS

A total of 2199 NUS exams were classified as true negative, 216 as true positive, 692 as false positive in 339 (43.9%) individual patients, 170 of whom were low risk, and 69 as false negative. Thus, overall sensitivity, specificity, positive predictive value, negative predictive value, and accuracy [confidence interval] were 75.8% [70.1-81.5%], 76.1% [74.3-77.8%], 23.8% [18.1-29.5%], 97.0 [96.2-97.7%], and 76.0% [74.3-77.7%], respectively. No significant differences were found between low- and high-risk patients. There were no significant differences between patients with an undetectable and a low detectable (<1 μg/L) Tg level. However, these two groups both showed significantly lower positive predictive value and higher negative predictive value than patients with a Tg ≥1 μg/L. From January 2007 onwards, true-positive and false-negative neck ultrasounds were no longer observed in patients with Tg <1 μg/L.

CONCLUSION

After total thyroidectomy and ¹³¹I ablation, neck ultrasound should be reserved only for anti-Tg antibody negative patients with a Tg level of ≥1 μg/L.

Thyroid Cancer Induction: Nitrates as Independent Risk Factors or Risk Modulators after Radiation Exposure, with a Focus on the Chernobyl Accident

In recent decades, differentiated thyroid cancer (DTC) incidence has been increasing worldwide. The important contributions to this phenomenon of "overdiagnosis" driven by wider use of improved ultrasound systems are amply documented, notwithstanding the "real" carcinogenic effects of ionizing radiation, e.g., from the Chernobyl accident or health care interventions. Less well understood is the role of nitrates - as environmental pollutants, in diet, and in medication - in thyroid carcinogenesis. Increasing exposure to nitrates is associated with rising incidence of esophageal, stomach, bladder, and colon cancers. Recent data suggest that in agricultural areas with higher mean nitrate levels in groundwater, DTC risk is also elevated. Our work in Belarus after Chernobyl has shown that children in districts with high nitrate concentrations in drinking water had significantly higher thyroid cancer incidence after irradiation than did their counterparts in areas with lower nitrate concentrations. Notwithstanding thyroid shielding, increasing use of computed tomography and dental X-rays heightens radiation exposure of the salivary glands in the general population, especially in children and adolescents. When nitrate intake is increased, salivary gland irradiation may potentially result in carcinogenic elevations in plasma nitric oxide concentrations. In conclusion, excess nitrate intake seems to be an independent risk factor for DTC. Additionally, we hypothesize from our data that high nitrate levels modulate the carcinogenic effect of radiation on the thyroid. Cohort studies, case-control studies, or both, are needed to quantify the effects of nitrates on DTC risk in the presence or absence of radiation exposure, e.g., that associated with diagnostic or therapeutic health care interventions.

Inkorporationsmessungen bei Angehörigen von Radioiodtherapiepatienten nach Therapie benigner Erkrankungen der Schilddrüse

Ziel: Patienten exhalieren 1-131 nach Radioiodtherapie. Ziel der vorliegenden Studie ist die Bestimmung der von Angehörigen von Radio- iodtherapiepatienten nach Entlassung aus der Therapiestation inkorporierten Aktivität und der daraus resultierenden Schilddrüsendosis.

Methoden: Bei 31 Angehörigen von Radioiodtherapiepatienten wurde die Schilddrüsenaktivität mittels der Schilddrüsensonde eines Ganzkörperzählers gemessen und daraus Dosiswerte bestimmt.

Ergebnisse: Bei 11 der 31 Messungen wurde keine Aktivität oberhalb der Nachweisgrenze von 13 Bq festgestellt. Im Mittel wurde bei den restlichen Personen 104 Bq gemessen, entsprechend einer daraus resultierenden mittleren Schilddrüsendosis von 0,2 mSv (Maximalwert: 2 mSv). Schlußfolgerung: Die Zufuhr von 1-131 bei Angehörigen von Radioiodtherapiepatienten nach deren Entlassung ist gering und führte in keinem Fall zu einer effektiven Dosis von mehr als 1 mSv.

Effects of Thyrotropin on Peripheral Thyroid Hormone Metabolism and Serum Lipids

BACKGROUND

Subclinical hypothyroidism is associated with dyslipidemia and atherosclerosis. Whether these effects are in part mediated via direct effects of thyrotropin (TSH) on peripheral thyroid hormone (TH) metabolism and/or concentrations of serum lipids is not clear.

OBJECTIVE

This study examined whether TSH has direct effects on peripheral TH metabolism and serum lipids.

METHODS

Eighty-two patients with differentiated thyroid cancer were retrospectively analyzed. All patients had undergone total thyroidectomy and ¹³¹I remnant ablation. During follow-up, two successive injections of recombinant human TSH (rhTSH) were administered to patients on a stable dose of levothyroxine. In all patients, TSH, thyroxine (T4), free T4 (fT4), triiodothyronine (T3), reverse T3 (rT3), total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, apolipoprotein B, lipoprotein(a), and triglyceride levels were measured immediately before the first and approximately 72 hours after the second injection of rhTSH.

RESULTS

After rhTSH stimulation, T3 values decreased (from 1.91 to 1.81 nmol/L; p < 0.001). T4, fT4, and rT3 did not change. After rhTSH, median apolipoprotein B increased from 0.90 to 0.92 g/L (p = 0.03), lipoprotein(a) from 0.21 to 0.24 g/L (p < 0.001), and triglycerides from 1.98 to 2.50 mmol/L (p < 0.001). Serum high-density lipoprotein cholesterol decreased from 0.98 to 0.81 mmol/L (p < 0.001). Multiple regression analysis showed that the changes in lipids were most closely associated with the decrease in T3 levels.

CONCLUSIONS

TSH has direct effects on peripheral TH metabolism by decreasing T3 levels in levothyroxine-treated thyroidectomized patients. This decrease in T3 levels is accompanied by unfavorable changes in serum lipids.

Verfahrensanweisung für die nuklear medizinische Wächter-Lymphknoten-Diagnostik

The authors present a procedure guideline for scintigraphic detection of sentinel lymph nodes in malignant melanoma and other skin tumours, in breast cancer, in head and neck cancer, and in prostate and penile carcinoma. Important goals of sentinel lymph node scintigraphy comprise reduction of the extent of surgery, lower postoperative morbidity and optimization of histopathological examination focussing on relevant lymph nodes. Sentinel lymph node scintigraphy itself does not diagnose tumorous lymph node involvement and is not indicated when lymph node metastases have been definitely diagnosed before sentinel lymph node scintigraphy. Procedures are compiled with the aim to reliably localise sentinel lymph nodes with a high detection rate typically in early tumour stages. Radiation exposure is low so that pregnancy is not a contraindication for sentinel lymph node scintigraphy. Even with high volumes of scintigraphic sentinel lymph node procedures surgeons, theatre staff and pathologists receive a radiation exposure < 1 mSv/year so that they do not require occupational radiation surveillance.

Nuclear medical inpatient treatment in Germany

All public licensed hospitals of Germany are obligated since 2004 to establish and to publish a structured biennial quality report. The aim of this study was to analyse the quality reports from 2008 of clinics with nuclear-medicine therapy ward and to investigate developments for the inpatient nuclear-medicine therapy by comparing the results with the quality reports of the years 2004 and 2006. Methods: All available structured quality reports of clinics with a nuclear-medicine therapy ward of the years 2004, 2006 and 2008 were evaluated. Results: The total number of inpatient treatment cases in 2008 amounted to 54 190 (2006: 54 884; 2004: 57 366). This corresponds to a decrease of 5.5% in comparison to 2004. The number of the therapy wards decreased at the same time to currently 117 (2006: 120; 2004: 124). Remarkable changes were found in the spectrum of the main diagnosis. Thus, the most frequent diagnosis with the ICD-code E05 (hyperthyroidism) decreased continuously from 37 747 treatments in 2004 and 34 764 in 2006 to 31 756 in the year 2008. In contrast, the ICD-diagnoses for thyroid cancer (C73, Z08) with 14 761 cases in 2008 increased with time (2006: 13 426; 2004: 12 581). Conclusions: In analogy to the observations from Europe after introduction of an iodine prophylaxis the improved iodine supply in Germany has led to a decline of the radioiodine therapy due to hyperthyroidism.

Procedure guideline for iodine-131 whole-body scintigraphy for differentiated thyroid cancer (version 2)

The version 2 of the procedure guideline for iodine-131 whole-body scintigraphy for differentiated thyroid cancer is an update of the procedure guideline published in 1999. The following statements are added or modified: The two alternatives of an endogenous TSH-stimulation by the withdrawal of the thyroidal hormone medication and of an exogenous TSH-stimulation by the injection of the recombinant human TSH (rhTSH) have an equal sensitivity for the diagnostic use of radioiodine and for the measurement of thyroglobulin. Image acquisition under rhTSH is obtained approximately 48 h after the radioiodine administration, while an interval of about 72 h is preferred under endogenous TSH-stimulation. If iodine-negative metastases are expected, the feasibility of scintigraphy using 99mTc sestamibi or preferably positron emission tomography using 18F-fluorodeoxyglucose should be considered. The sensitivity of FDG-PET is increased by TSH-stimulation. Before planning the iodine-131 scintigraphy the patient has to avoid iodine-containing medication and the possibility of additives of iodine in vitamin- and electrolyte-supplementation has to be considered.

Guideline for in vivo- and in vitro procedures for thyroid diseases (version 2)

The version 2 of the guideline for diagnostic standards of thyroid disorders is an update of the guideline published in 1999 and describes standards of in vitro and in vivo procedures. The following statements are modified: In vitro procedures: When measurement of the TSH-receptor antibodies is indicated, the guideline recommends the use of a second generation assay (recombinant human TSH-receptor as antigen). The functional assay sensitivity for the measurement of thyroglobulin should reach a value ≤1 ng/ml. Moleculargenetic tests (RET proto-oncogen) are indicated in patients with a newly diagnosed medullary thyroid cancer and in the relatives of patients with hereditary medullary thyroid cancer. In vivo procedures: The sonographic examination should use a probe with a frequency of at least 7.5 MHz. Indications for the thyroid scintigraphy: nodule size ≥1 cm in diameter, autonomous goitre/nodule with clinical or subclinical hyperthyroidism, necessity of a differentiation between Graves’ disease and chronic lymphocytic thyroiditis, therapy control after a definitive treatment and – in individual cases – the follow-up of untreated autonomous nodules.

Procedure guideline for radioiodine test (version 2)

The version 2 of the procedure guideline for radioiodine test is an update of the guideline published in 1999. The following statements were added or modified: The procedure guideline discusses the pros and cons of a single measurement or of repeated measurements of the iodine-131 uptake and their optimal timing. Different formulas are described when one, two or three values of the radioiodine kinetic are available. The probe with a sodium iodide crystal, alternative or additionally the gamma-camera using the ROI-technique are instrumentations for the measurement of iodine-131 uptake. A possible source of error is an inappropriate measurement (sonography) of the target volume. The patients’ preparation includes the withdrawal of antithyroid drugs 2-3 days before radioiodine administration. The patient has to avoid iodine-containing medication and the possibility of additives of iodide in vitamin- or electrolyte-supplementation has to be considered.

Improved follow-up of patients with differentiated thyroid carcinoma

Aim: Physicians typically are unaware of the radioiodine uptake (RIU) detection limit (LoD) on scintigrams of differentiated thyroid carcinoma (DTC) patients. We evaluated a novel method to determine LoD as a quantitative upper limit for RIU in negative scans and as a value to contextualize faint visible uptake. Patients, methods: To test whether LoD is related to physicians’ ratings, RIU and LoD were calculated from scintigraphic count statistics for 120 static planar neck scans and were compared with the ratings of five nuclear medicine specialists blinded to patient/ scan characteristics regarding visible cervical uptake. Scans were acquired on days 1 (d1) and 2 (d2) post-administration of 298 ± 30 MBq iodine-131 in 60 consecutive DTC patients after recombinant human thyrotropin (rhTSH) or thyroid hormone withdrawal (THW) (n = 30 each). Results: Indicating good inter-observer agreement, ≥ 4 readers concurred regarding 56 (93.3%) [54 (90.0%)] d1[d2] scans. Seventeen scans from 12 patients received ≥ 3 positive votes; in 15 (88.2%), RIU exceeded LoD. RIU assessed from regions-of-interest over former thyroid beds in scans with ≤ 2 positive votes was typically below the LoD (99/103 scans, 96.1%). In 48 patients with ≤ 2 positive votes in both scans, LoD was a median 0.0094% (0.0050%) in d1(d2) images and was significantly lower (p < 0.01) on early or late scans in 22 euthyroid rhTSH patients versus 26 hypo thyroid THW patients. Conclusion: LoD data obtained by the proposed method closely reflect nuclear medicine specialists’ scan ratings and provide comparators in serial scintigrams, improving diagnostic 131I imaging accuracy in differentiated thyroid carcinoma.

Procedure guideline for thyroid scintigraphy (version 3)

The version 3 of the procedure guideline for thyroid scintigraphy is an update of the procedure guideline previously published in 2003. The interpretation of the scintigraphy requires the knowledge of the patients' history, the palpation of the neck, the laboratory parameters and of the sonography. The interpretation of the technetium-99m uptake requires the knowledge of the TSH-level. As a consequence of the improved alimentary iodine supply the 99mTc-uptake has decreased; 100 000 counts per scintigraphy should be acquired. For this, an imaging time of 10 minutes is generally needed using a high resolution collimator for thyroid imaging.

Procedure guideline for radioiodine therapy and 131iodine whole-body scintigraphy in paediatric patients with differentiated thyroid cancer

The procedure guideline for radioiodine (131I) therapy and 131I whole-body scintigraphy of differentiated thyroid cancer in paediatric patients is the counterpart to the procedure guidelines (version 3) for adult patients and specify the interdisciplinary guideline for thyroid cancer of the Deutsche Krebsgesellschaft concerning the nuclear medicine part. Characteristics of thyroid cancer in children are the higher aggressiveness of papillary thyroid cancer, the higher frequency of extrathyroidal extension and of disseminated pulmonary metastases as well as the high risk of local recurrences. Radioiodine therapy is generally recommended in children, the 131I activity depends on the children's body weight. Radioiodine ablation in children with small papillary cancer (≤1 cm) should be considered. TSH stimulation is reached two weeks (children) or three weeks (adolescents) after withdrawal of thyroid hormones. Anti-emetic drugs are highly recommended. CT of the chest and examination of pulmonary function are clearly indicated if there is any suspicion on metastases. 3–6 months after 131I ablation, the 131I whole-body scintigraphy is highly recommended as lymph node metastases are frequently detected in paediatric patients. Follow-up care should be arranged in shorter intervals than in adults to test the compliance and to adapt dosage of thyroid hormones to the children's body weight. Reference values of fT3 are higher in children than in adults. Evidence is insufficient to describe in which constellation the TSH may be kept within the low normal level. Therefore, TSH suppression is generally recommended.

Procedure guideline for iodine-131 whole-body scintigraphy for differentiated thyroid cancer (version 3)

Version 3 of the procedure guideline for 131I whole-body scintigraphy (WBS) is the counterpart to the procedure guideline for radioiodine therapy (version 3) and specify the interdisciplinary guideline for thyroid cancer of the Deutsche Krebsgesellschaft concerning the nuclear medicine part. 131I WBS 3–6 months after 131I ablation remains a standard procedure in an endemic area for thyroid nodules and the high frequency of subtotal surgical procedures. Follow-up without 131I WBS is only justified if the following preconditions are fulfilled: low-risk group pT1–2, pN0 M0 with histopathologically confirmed pN0, 131I uptake <2%, 131I WBS during ablation without any suspicious lesion, stimulated thyroglobulin (Tg)-level 3–6 months after ablation <2 ng/mL, and absence of anti-thyroglobulin- antibodies with normal recovery-testing. If patients from the low-risk group show normal 131I WBS 3–6 months after ablation and stimulated Tg is of <2 ng/mL, there will be no need for additional routine 131I WBS. If patients from the high-risk group show normal 131I WBS and stimulated Tg-level of <2 ng/mL 3–6 months after ablation, the follow- up care should include repeated stimulated Tgmeasurements. If the Tg-level remains below 2 ng/mL, an additional 131I WBS will be not necessary. The recommended intervals for stimulated Tg-testing are adapted to the prior intervals for 131I WBS-testing in the high-risk group. Increased anti-thyroglobulin-antibodies or incomplete recovery-testing make an individual strategy of follow- up care necessary, which include 131I WBS.

Procedure guideline for radioiodine test (Version 3)

The version 3 of the procedure guideline for radioiodine test is an update of the guideline previously published in 2003. The procedure guideline discusses the pros and cons of a single measurement or of repeated measurements of the iodine-131 uptake and their optimal timing. Different formulas are described when one, two or three values of the radioiodine kinetic are available. The probe with a sodiumiodine crystal, alternatively or additionally the gammacamera using the ROI-technique are instrumentations for the measurement of iodine-131 uptake. A possible source of error is an inappropriate measurement (sonography) of the target volume. The patients' preparation includes the withdrawal of antithyroid drugs 2–3 days before radioiodine administration. The patient has to avoid iodine-containing medication and the possibility of additives of iodine in vitamin- and electrolyte-supplementation has to be considered.

Stationäre nuklearmedizinische Therapie 2010 bis 2012 in Deutschland

Das Ziel dieser Analyse war es, deutschlandweite Daten über den Status und die Entwicklung der stationären nuklearmedizinischen Therapie zu ermitteln. Als Datenquelle wurden die gesetzlichen Qualitätsberichte der Krankenhäuser verwendet. Methodik: Die vom Gemeinsamen Bundesausschuss (G-BA) aus den maschinenverwertbaren XML-Daten der Qualitätsberichte erstellten Referenzberichte aller Kliniken Deutschlands mit nuklearmedizinischer Therapiestation wurden für die Jahre 2010 und 2012 analysiert. Für die Beurteilung der längerfristigen Entwicklung dienten Ergebnisse aus eigenen Voruntersuchungen der strukturierten Qualitätsberichte für die Jahre 2004, 2006 und 2008. Zur Ermittlung der deutschlandweiten Häufigkeit von Schilddrüsenoperationen und der Radioiodtherapie wurden öffentliche Datenbanken des Instituts für das Entgeltsystem im Krankenhaus (InEK) für die Jahre 2004 bis 2012 ausgewertet. Ergebnisse: Die Gesamtzahl der stationären nuklearmedizinischen Behandlungsfälle hat von 2010 mit 50 363 Patienten bis 2012 auf 47 314 Patienten gering abgenommen. Im längeren Verlauf von 2004 bis 2012 findet sich ein deutlicher Rückgang der Fälle von 17,5%. Der Rückgang ist vor allem durch eine Abnahme an Erkrankungen mit Hyperthyreose (ICD-Code E05) bedingt. Seit 2009 ist auch die Anzahl der Schilddrüsenoperationen rückläufig. Ein moderater Anstieg der Fallzahlen von 23,7% zeigt sich für die Diagnose Schilddrüsenkarzinom (ICD-Code C73) von 2004 bis 2012. Schlussfolgerungen: Vermutlich führt die verbesserte Iodversorgung in Deutschland zu einem Rückgang an stationären Patienten mit Hyperthyreose in der Nuklearmedizin und in der Folge zu einer Abnahme sowohl der Anzahl an Radioiodtherapien als auch der Schilddrüsenoperationen in der Chirurgie. Im Gegensatz hierzu ist die Anzahl der Patienten mit der Diagnose Schilddrüsenkarzinom auf nuklearmedizinischen Therapiestationen moderat ansteigend, dies korreliert mit der weltweit zu beobachtenden Steigerung der Inzidenz des Schilddrüsenkarzinoms.

Only a Rapid Complete Biochemical Remission After 131I-Therapy is Associated with an Unimpaired Life Expectancy in Differentiated Thyroid Cancer

The objective of the work was to investigate the relationship between thyroglobulin doubling time (TgDT) as a marker of speed of response to ¹³¹I-therapy and the differentiated thyroid cancer (DTC) recurrence rate, DTC specific mortality rate, and relative survival rate in a DTC population followed over a long period of time after ¹³¹I-therapy. From our database, data of 1354 patients were reviewed. TgDT could be calculated in 174 patients, however, 376 patients did not have sufficient Tg values available for TgDT calculation and 804 patients reached biochemical remission before a sufficient number of Tg measurements for TgDT calculation was acquired. Main outcome measures were recurrence-free, DTC specific, and relative survival rates. In patients<45 years, TgDT in multivariate analysis was identified as the solitary significant determinant of DTC specific and relative survival. In patients≥45 years of age at diagnosis, TgDT is an independent, but not the only determinant of recurrence free, DTC specific, and relative survival. Importantly, in this age group life expectancy is normal in patients reaching rapid biochemical remission (i. e., before TgDT can be calculated); it was reduced in patients with a negative TgDT, which normally is deemed a marker of response to therapy. Only DTC patients with a rapid biochemical remission have a very good prognosis with a normal life expectancy. If no rapid biochemical remission occurs, both biochemically progressive disease and a slower biochemical remission of disease are associated with a reduced prognosis, especially in older DTC patients.

Prevalence of thyroid disorders in elderly people in Germany. A screening study in a country with endemic goitre

AIM

In a screening study on people of working age the prevalence of morphological thyroid disorders was 33.1 %. It is not known precisely whether this further increases after retirement. The present study aimed to establish whether the increase in the prevalence of morphological and functional thyroid disorders continues beyond working age in elderly citizens.

METHODS

223 participants were recruited in an institute for geriatric rehabilitative medicine. All patients were screened by thyroid ultrasound, measurement of serum levels of thyroid hormones and thyroid related autoantibodies as well as measurement of urinary iodine excretion.

RESULTS

The median thyroid volume was 17 ml (range 4-41 ml) in men and 16 ml (range 0.4-73 ml) in women. 27/59 (46 %) of the men (median age [range]: 77 [58-87] years) and 85/139 (61 %) of the women (median age [range]: 77 [52-97] years), or a total of 112/198 (57 %) residents, showed morphological thyroid abnormalities. There was no clear increase with age. 85 % of the participants without a history of thyroid treatment were euthyroid. 12 % showed a subclinical hyperthyroidism whereas 1 % showed a biochemically manifest hyperthyroidism. 2 % were biochemically hypothyroid. Tg-antibodies was elevated in 10 (5 %) and TPO-antibodies in 18 (9 %) of the patients. Median iodine excretion was 129 µg/l. 41.5 % of the patients showed iodine excretion values below 100 µg/l whereas only 7 % of the patients showed a severe iodine deficiency with an excretion below 50 µg/l.

CONCLUSION

Compared to a previously described population of working age, the prevalence of morphological thyroid disorders does not further increase above the age of 65; thyroid function abnormalities in this iodine sufficient screening population were relatively rare.

[Not Available]

In the last 60 years dramatically increased the content of nitrates in groundwater due to intensive use of nitrogen fertilizers in agriculture. Research in post-Chernobyl period has shown that a sharp increase in the incidence of thyroid cancer depends not only on the level of thyroid dose, but also on the level of nitrates in groundwater.

The First Meeting of the WHO Guideline Development Group for the Revision of the WHO 1999 Guidelines for Iodine Thyroid Blocking

The meeting held in May 2014 in Würzburg, Germany, discussed the scope of the revision of the 1999 WHO guidelines for iodine thyroid blocking (ITB) by following the WHO handbook for guideline development. This article describes the process and methods of developing the revised, evidence-based WHO guidelines for ITB following nuclear and radiological accidents, the results of the kick-off meeting as well as further steps taken to complete the revision.

Thyroglobulin fluctuations in patients with iodine-refractory differentiated thyroid carcinoma on lenvatinib treatment - initial experience

Tyrosine kinase inhibitors (TKI) have shown clinical effectiveness in iodine-refractory differentiated thyroid cancer (DTC). The corresponding role of serum thyroglobulin (Tg) in iodine-refractory DTC has not been investigated yet. 9 patients (3 female, 61 ± 8y) with progressive iodine-refractory DTC starting on lenvatinib were considered. Tumor restaging was performed every 2–3 months including contrast-enhanced computed tomography (CT, RECIST 1.1). Serum Tg was measured and compared to imaging findings. After treatment initiation, serum Tg levels dropped in all patients with a median reduction of 86.2%. During long-term follow-up (median, 25.2 months), fluctuations in Tg could be observed in 8/9 subjects. According to RECIST, 6/9 subjects achieved a partial response or stable disease with the remaining 3/9 experiencing progressive disease (2/3 with Tg levels rising above baseline). All of the patients with disease progression presented with a preceding continuous rise in serum Tg, whereas tumor marker oscillations in the subjects with controlled disease were only intermittent. Initiation of lenvatinib in iodine-refractory DTC patients is associated with a significant reduction in serum Tg levels as a marker of treatment response. In the course of treatment, transient Tg oscillations are a frequent phenomenon that may not necessarily reflect morphologic tumor progression.

Selected single-nucleotide polymorphisms in FOXE1, SERPINA5, FTO, EVPL, TICAM1 and SCARB1 are associated with papillary and follicular thyroid cancer risk: replication study in a German population

Several single-nucleotide polymorphisms (SNPs) have been associated with papillary and follicular thyroid cancer (PTC and FTC, respectively) risk, but few have replicated. After analyzing 17525 tag SNPs in 1129 candidate genes, we found associations with PTC risk in SERPINA5, FTO, HEMGN (near FOXE1) and other genes. Here, we report results from a replication effort in a large independent PTC/FTC case-control study conducted in Germany. We evaluated the best tagging SNPs from our previous PTC study and additionally included SNPs in or near FOXE1 and NKX2-1 genes, known susceptibility loci for thyroid cancer. We genotyped 422 PTC and 130 FTC cases and 752 controls recruited from three German clinical centers. We used polytomous logistic regression to simultaneously estimate PTC and FTC associations for 79 SNPs based on log-additive models. We assessed effect modification by body mass index (BMI), gender and age for all SNPs, and selected SNP by SNP interactions. We confirmed associations with PTC and SNPs in FOXE1/HEMGN, SERPINA5 (rs2069974), FTO (rs8047395), EVPL (rs2071194), TICAM1 (rs8120) and SCARB1 (rs11057820) genes. We found associations with SNPs in FOXE1, SERPINA5, FTO, TICAM1 and HSPA6 and FTC. We found two significant interactions between FTO (rs8047395) and BMI (P = 0.0321) and between TICAM1 (rs8120) and FOXE1 (rs10984377) (P = 0.0006). Besides the known associations with FOXE1 SNPs, we confirmed additional PTC SNP associations reported previously. We also found several new associations with FTC risk and noteworthy interactions. We conclude that multiple variants and host factors might interact in complex ways to increase risk of PTC and FTC.

The TNM system (version 7) is the most accurate staging system for the prediction of loss of life expectancy in differentiated thyroid cancer

OBJECTIVE

Many prognostic systems have been developed for differentiated thyroid cancer. It is unclear which one of these performs 'best'. Our aim was to compare staging systems applicable to our patient database to identify which best predicts DTC-related loss of life expectancy and DTC-specific mortality.

DESIGN

Database study of patients with DTC treated in our centre between 1978 (earliest available data) up to and including 1 July 2014. All were staged in accordance with the AMES, Clinical Class, Memorial Sloan Kettering, Ohio State University, TNM versions 5 and 6/7, University of Alabama, University of Münster and qTNM systems.

PATIENTS

A total of 2257 patients with differentiated thyroid cancer.

MEASUREMENTS

Loss of life expectancy expressed as relative survival and thyroid cancer-specific mortality. Comparison was based on P values of univariate Cox regression analyses as well as analysis of the proportion of variance explained (PVE).

RESULTS

Median available follow-up time was 7·2 years (range: 0-35·1 years). Three hundred and twenty-seven patients died, 149 of whom died of DTC. Version 7 of the TNM system was best for predicting DTC-related mortality (P = 7·1 × 10^-52 ; PVE = 0·296), followed by TNM version 5 (P = 6·7 × 10^-44 ; PVE = 0·255). For prediction of loss of life expectancy, version 7 of the TNM system was also best, closely followed by the Clinical Class system (P both < 2 × 10^-16 ).

CONCLUSIONS

The UICC/AJCC TNM system version 7 outperforms other prognostic classification systems based on extent of disease at the start of treatment both for prediction of differentiated thyroid cancer-related death and for prediction of loss life expectancy.

Prognostic Value of Serum Tumor Markers in Medullary Thyroid Cancer Patients Undergoing Vandetanib Treatment

Tyrosine kinase inhibitors (TKIs) such as vandetanib have shown clinical effectiveness in advanced medullary thyroid cancer (MTC). During TKI treatment, fluctuations in the tumor markers carcinoembryonic antigen (CEA) and calcitonin (CTN) are frequently observed. Their role for treatment monitoring and the decision-making process has not been fully elucidated yet.Twenty-one patients (male, 16, female, 5; mean age, 49 ± 13 years) with progressive MTC receiving vandetanib (300 mg orally per day) were considered. Tumor restaging was performed every 3 months including contrast-enhanced computed tomography (CT). Response was assessed according to recent criteria (Response Evaluation Criteria in Solid Tumors, RECIST 1.1). Additionally, CEA and CTN were measured at the day of CT imaging and alterations observed in tumor markers were compared to respective imaging findings (partial response, PR; stable disease, SD; progressive disease, PD).During long-term follow-up (510 ± 350 days [range, 97-1140 days]), CTN and CEA levels initially dropped in 71.4% and 61.9% of the patients followed by fluctuations in serum marker levels. A rise in CTN ≥39.5% between 2 subsequent measurements (defined by ROC analysis) had a sensitivity of 70.6% and a specificity of 83.2% in predicting PD with an accuracy of 82.0% (area under the curve (AUC), 0.76). Oscillations in CEA levels were not predictive for PD.Whereas tumor marker fluctuations in MTC patients undergoing TKI treatment are a frequent phenomenon, a significant rise in CTN ≥40% turns out to as an early indicator of tumor progression.

Evidence of impaired carbohydrate assimilation in euthyroid patients with Hashimoto's thyroiditis

BACKGROUND/OBJECTIVES

Hashimoto's thyroiditis (HT) represents a wide-spread autoimmune disease. In euthyroid patients with HT, an impaired assimilation of common carbohydrates has been observed. Our objectives were to compare the frequency of (1) fructose (FM), lactose (LM) and sorbitol malassimilation (SM), (2) gastrointestinal symptoms (GS) following carbohydrate ingestion and (3) recurrent GS relevant to the participants' daily lives.

SUBJECTS/METHODS

We conducted a prospective case-control study of 45 ambulatory patients with HT and 38 healthy volunteers, matched with regard to age, gender and area of origin. Hydrogen breath tests with fructose, lactose, sorbitol and glucose were performed, the lactose testing additionally comprising measurements of capillary blood glucose (cBG). GS during the tests and recurrent GS concerning the participants' daily lives were assessed. A food-frequency questionnaire was administered.

RESULTS

FM was diagnosed in 48.9% of patients compared with 26.3% of the control group (P=0.035). In all, 42.2% of patients with HT and 21.1% of healthy controls showed LM (P=0.04). FM and/or LM was present in 73.3% of the patients and in 42.1% of healthy controls (P=0.004). GS after the ingestion of fructose (P=0.003) or lactose (P=0.025) and recurrent GS were significantly more prevalent in the case group. The consumption of free fructose, lactose or sorbitol did not differ.

CONCLUSIONS

Carbohydrate malassimilation and gastrointestinal complaints are frequent in euthyroid patients with HT, leading to novel clinical and pathophysiological considerations and concepts.

Major Factors Affecting Incidence of Childhood Thyroid Cancer in Belarus after the Chernobyl Accident: Do Nitrates in Drinking Water Play a Role?

One of the major health consequences of the Chernobyl Nuclear Power Plant accident in 1986 was a dramatic increase in incidence of thyroid cancer among those who were aged less than 18 years at the time of the accident. This increase has been directly linked in several analytic epidemiological studies to iodine-131 (¹³¹I) thyroid doses received from the accident. However, there remains limited understanding of factors that modify the ¹³¹I-related risk. Focusing on post-Chernobyl pediatric thyroid cancer in Belarus, we reviewed evidence of the effects of radiation, thyroid screening, and iodine deficiency on regional differences in incidence rates of thyroid cancer. We also reviewed current evidence on content of nitrate in groundwater and thyroid cancer risk drawing attention to high levels of nitrates in open well water in several contaminated regions of Belarus, i.e. Gomel and Brest, related to the usage of nitrogen fertilizers. In this hypothesis generating study, based on ecological data and biological plausibility, we suggest that nitrate pollution may modify the radiation-related risk of thyroid cancer contributing to regional differences in rates of pediatric thyroid cancer in Belarus. Analytic epidemiological studies designed to evaluate joint effect of nitrate content in groundwater and radiation present a promising avenue of research and may provide useful insights into etiology of thyroid cancer.