Guideline Compliance in Surgery for Thyroid Nodules - A Retrospective Study

Diagnostic guidelines for thyroid nodules focus on malignancy risk assessment to avoid unnecessary diagnostic operations. These guidelines recommend a combination of tests in form of a diagnostic algorithm. The present study analyzed the recommended algorithm and its implementation by different medical professionals. Preoperative diagnostic procedures, laboratory tests and histopathological findings of patients who underwent thyroid surgery between 2006 and 2013 were analyzed. The results were stratified by the assignation by specialized endocrinologists (ENP), general practitioners (GP) or Goethe-University Hospital Frankfurt (UKF). 677 patients were enrolled, of these 62% were assigned by UKF, 18.5% by an ENP and 19.5% by a GP. Ultrasonography rate was significantly higher in UKF (97.6%) compared to patients assigned by GP (90.9%, p<0.0001). Rates for fine-needle aspiration cytology ranged between 47.6% in UKF and 23.2% in ENP (p<0.0001). In over 93% of the patients an analysis of thyroid-stimulating hormone and triiodothyronine/thyroxin was realized. The overall malignancy rate was 11.82%. The malignancy rate was significantly higher if a FNA biopsy was performed (16.35 vs. 8.94%; p=0.0048). A higher malignancy rate could only be seen if the preoperative diagnostic workup included FNA. Besides this, the grade of algorithm adherence showed no effect on the malignancy rate.

Comparative study evaluating the efficiency of cooled and uncooled single-treatment MWA in thyroid nodules after a 3-month follow up

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cMWA and uMWA both lead to a significant reduction of thyroid nodule volume.

•

Patient pain level during uMWA is significantly higher than during cMWA.

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cMWA reduces the risk of side effects.

•

Single-treatment session shows comparable results to multiple treatment sessions.

Objective

The aim of this study was to evaluate and compare the efficacy of single-treatment cooled and uncooled microwave ablation in thyroid nodules.

Methods

Eighteen patients (11 women) with an average age of 62 years (range: 41–80) with 18 cold, mainly solid or solid thyroid nodules were treated with cooled or uncooled microwave ablation. Pain during the treatment was measured on a 10-point score. Side effects revealed by ultrasound or patients’ complaints were documented. Laboratory data was evaluated before, 24 h and three months after MWA. Nodule volumes were measured before and three months after MWA.

Results

Cooled MWA was better tolerated than uncooled MWA. A significant reduction of thyroid nodule volume was observed in all cases. The reduction after cMWA was higher (40%) than after uMWA (29%). Pain intensity during cMWA was significantly lower than after uMWA. CMWA and uMWA led to a significant decrease of nodule blood circulation and echogenicity and to a significant increase of nodule elasticity. Thyroid function remained intact in all cases. The energy (kJ/s) administered into the nodules in relation to the ablation time during cMWA was higher than during uMWA.

Conclusions

CMWA leads to a slightly higher but statistically not significant nodule volume reduction than uMWA. Patient comfort during cMWA is higher than during uMWA. The risk of unintended side effects is less in cMWA. A Single-treatment provides sufficient results.

[Radioiodine therapy for benign thyroid diseases (version 5). German Guideline]

The version 5 of the guideline for radioiodine therapy of benign thyroid disorders is an update of the version 4, which was published by the German Society of Nuclear Medicine (Deutsche Gesellschaft für Nuklearmedizin, DGN) in co-ordination with the German Society of Endocrinology (Deutsche Gesellschaft für Endokrinologie, DGE, Sektion Schilddrüse) and the German Society of General- and Visceral-Surgery (Deutsche Gesellschaft für Allgemein- und Viszeralchirurgie, DGAV) in 2007. This guideline was harmonized with the recommendations of the European Association of Nuclear Medicine (EANM). According to the German "Directive on Radiation Protection in Medicine" the physician specialised in nuclear medicine ("Fachkunde in der Therapie mit offenen radioaktiven Stoffen") is responsible for the justfication to treat with radioiodine. Therefore, relevant medical indications for radioiodine therapy and alternative therapeutic options are discussed within the guideline. This procedure guideline is developed in the consensus of a representative expert group. This fulfils the level S1 (first step) within the German classification of Clinical Practice Guidelines.

Cooled microwave ablation of thyroid nodules: Initial experience

OBJECTIVE

To evaluate if internally cooled microwave ablation (cMWA) is a safe and effective method for treatment of benign and malign thyroid nodules.

METHODS

9 patients with 11 symptomatic cold benign thyroid nodules and 1 recurrent thyroid carcinoma ranging in volume from 9.1 to 197ml (mean size 52± 57ml) were treated with cMWA. The mean age of the patients was 59 years. Pain during the treatment was measured on a 10-point scale. Side effects revealed by ultrasound or patients' complaints were documented. Periablative efficacy was measured 24h after cMWA as change (Δ) in serum thyreoglobulin (Tg). Nodule elasticity was measured on a 4-point scale, blood circulation and echogenicity on a 3-point scale.

RESULTS

All patients tolerated cMWA well. Median pain intensity averaged 2.1±0.8 (range: 1-3). Postablative hematoma was observed in all cases. In no cases ablation led to hoarseness, superficial burns, nodule ruptures, vagal reactions or dysphagia. cMWA lead to a significant decrease of blood circulation, nodule echogenicity and a significant increase of elasticity (Δ = 1.1 ± 0.33; 0.8 ± 0.4 and 1.1 ± 0.6 points)(p<0.05). An average increase of 4495ng/ml Tg was measured (p<0.05).

CONCLUSIONS

cMWA is an effective and secure method for treatment of thyroid nodules.

[131I and 99mTc-Uptake in focal thyroid autonomies. Development in Germany since the 1980s]

Germany has developed into a country with a nationwide largely sufficient iodine supply due to improved alimentary iodine supply. The reduction of iodine uptake in focal autonomies induced by reduced iodine avidity was evaluated by Gotthardt et al. 2006, showing a significant decline of pertechnetate uptake up to the year 2004.

AIM

This study was intended to carry this investigation forward to the present day to analyze the course of a conjectural stabilization of iodine uptake values.

PATIENTS, MATERIAL, METHODS

283 patients who underwent radioiodine therapy for focal thyroid were analyzed retrospectively. Pertechnetate uptake was measured scintigraphically, thyroid volume sonographically and iodine uptake by iodine uptake test. The uptake percentage in the autonomous volume was correlated with autonomous volume and the resulting values tracked over a time period of seven years.

RESULTS

Mean thyroid volume ranged from 24 to 29 ml, autonomous volume from 7.2 to 9.4 ml. Pertechnetate uptake ranged from 0.2 to 0.25%/ml autonomous volume. Iodine uptake values ranged from 3.2 to 4.2%/ml autonomous volume. None of the changes observed were statistically significant (all p>0.05).

CONCLUSION

Prophylactic measures towards improvement of the general public´s iodine supply in Germany had led to a decline of pertechnetate and iodine uptake in the thyroid up until the turn of the millennium. The here presented data show a stabilization of ^99mTc-Uptake. Our study could also show that actual iodine uptake has stabilized at a steady level over the preceding seven years.

[Procedure guidelines for radioiodine therapy of differentiated thyroid cancer. Version 4]

The procedure guideline for radioiodine therapy of differentiated thyroid cancer (version 4) was developed in the consensus of a representative expert group. This fulfils the level S1 (first step) within the AWMF classification of Clinical Practice Guidelines (AWMF, Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften, Germany). This procedure guideline completed the guideline for surgical management of thyroid cancer (level S2) with the aspects from nuclear medicine. Controversies over ablative radioiodine therapy in small papillary thyroid cancers and in minimally invasive follicular cancer without angioinvasion, over empirical standard doses for ablative radioiodine therapy, and over the kind of TSH-stimulation were described and the guideline formulated a corridor of good clinical practice. The text has included the recent results from the National Cancer database and the SEER database (both from the USA), indicating that the ablative radioiodine therapy has improved the survival rate even in low risk patients. Such a statistically significant benefit can be detected only by a national cancer registry with long-term follow-up data.

Bipolar radiofrequency ablation of benign thyroid nodules using a multiple overlapping shot technique in a 3-month follow-up

Purpose The aim of this study was to evaluate the decrease of benign thyroid nodules after bipolar radiofrequency ablation (RFA) in a 3-month follow-up using a multiple overlapping shot technique ('MOST'). Methods A total of 18 patients with 20 symptomatic benign thyroid nodules (17 cold nodules, 3 hyperfunctioning nodules) were treated in one single session by bipolar RFA. Bipolar ablation was performed using MOST. The nodule volumes were measured prior to ablation and 3 months after the procedure using ultrasound. The population consisted of either solid (>80% solid tissue within the volume of interest), complex, or cystic nodules (<20% solid tissue within the volume of interest). Results Bipolar RFA resulted in a highly significant (p < 0.0001) decrease of nodule volume (ΔV), median 5.3 mL (range 0.13-43.1 mL), corresponding to a relative reduction in mean of 56 ± 17.9%. Median initial volume was 8 mL (range 0.48-62 mL); 3 months after ablation a median volume of 2.3 mL (range 0.3-32 mL) was measured. Nodule growth ≥50% occurred in 70% (14 nodules). At the follow-up no complications such as infections, persisting pain, nerve injuries or immunogen stimulation occurred. Patients with cold nodules (15) remained euthyroid, with hyperfunctioning nodules either euthyroid (2) or latent hypofunctional (1). Conclusion The use of bipolar RFA is an effective, safe and suitable thermoablative technique to treat benign thyroid nodules. Combined with the multiple overlapping shot technique it allows sufficient ablation.

[German Society of Nuclear Medicine procedure guideline on beta-amyloid brain PET imaging]

Recently, a number of positron emission tomography (PET) radiotracers have been approved for clinical use. These tracers target cerebral beta-amyloid (Aβ) plaques, a hallmark of Alzheimer's disease. Increasing use of this method implies the need for respective standards. This German Society of Nuclear Medicine guideline describes adequate procedures for Aβ plaque PET imaging. It not only discusses the tracers used for that purpose, but also lists measures for correct patient preparation, image data generation, processing, analysis and interpretation. With that, this "S1" category (according to the German Association of the Scientific Medical Societies standard) guideline aims at contributing to quality assurance of nuclear imaging in Germany.

Focal colorectal uptake in (18)FDG-PET/CT: maximum standard uptake value as a trigger in a semi-automated screening setting

BACKGROUND

Focal colorectal uptake in (18)FDG-PET/CT may be associated with a malignancy and can be quantified. This provides the basis for an automatic trigger threshold above which cases are flagged for colonoscopic evaluation and below which for individual assessment.

PURPOSE

To determine the lowest maximum standard uptake (SUVmax) in colorectal cancer that could be used as a threshold to trigger endoscopic evaluation and to evaluate whether the SUVmax needs to be further normalised to a priori known extrinsic factors.

METHODS

The SUVmax was measured in 54 colorectal carcinomas and correlated with gender, age, blood glucose level, injected activity, body mass index and time to scan using t test or correlation coefficients (Pearson or Spearman, according to distribution).

RESULTS

There was no correlation between SUVmax and any of the extrinsic factors mentioned above. The lowest SUVmax value was 5 [mean ± SD (range): 11.1 ± 4.8 (5.0-24.6)].

CONCLUSION

In contrast to most other screening techniques, semi-automation in colorectal screening seems possible with PET/CT. This opens the door for further study into the feasibility of automated screening. Independent from extrinsic factors, an SUVmax ≥5.0 in a focal colorectal uptake in (18)FDG-PET/CT should automatically trigger for endoscopic evaluation, if not contraindicated. Cases with SUVmax <5 should be assessed individually before referral for endoscopy. Thus, more interpretation time could be spent on those cases with a lower uptake and more ambiguous diagnosis.

Bipolar Radiofrequency Ablation of Benign Symptomatic Thyroid Nodules: Initial Experience

PURPOSE

To determine the safety and efficacy of bipolar radiofrequency ablation (RFA) in benign thyroid nodules.

METHODS

23 patients with 24 symptomatic benign thyroid nodules (21 regressive, 3 adenomas) ranging in volume from 0.5 to 112 ml (mean ± sd: 18 ± 24.4 ml) underwent bipolar RFA. Pain during the procedure was measured on a 10-point scale. Side-effects revealed by ultrasound or patients' complaints were documented. Periablative efficacy was measured 24 hours after RFA as change (Δ) in serum thyreoglobulin (Tg) and sonographic criteria (echogenity, Doppler blood flow and elasticity) categorized on a 3-point scale (echogenity, Doppler blood flow) or 4-point scale (elasticity). Efficacy in the 3 autonomous adenomas was measured as normalization of (99 m)Tc-pertechnate scintigraphy.

RESULTS

Bipolar RFA was well tolerated by all patients with a median pain score of 3 ± 1.5 (range: 1 - 7). Side-effects were hematomas in 4 of 23 patients (17 %). Bipolar RFA resulted in a significant (p < 0.01) decrease in echogenity, blood flow, elasticity (Δ = 1 ± 0.28, 1 ± 0.46 and 1 ± 0.85 points, respectively), a median increase in Tg of 403 ± 2568 ng/ml as well as in a normalization of scintigraphy.

CONCLUSION

Bipolar RFA is a safe and effective treatment option for symptomatic benign thyroid nodules.

KEY POINTS

• Bipolar RFA is a safe and effective treatment for benign thyroid nodules.• Ultrasound imaging allows guidance during bipolar radiofrequency ablation.• (99 m)Tc-pertechnetate is able to detect the ablation area of autonomous adenomas. Citation Format: • Korkusuz Y, Erbelding C, Kohlhase K et al. Bipolar Radiofrequency Ablation of Benign Symptomatic Thyroid Nodules: Initial experience with Bipolar Radiofrequency. Fortschr Röntgenstr 2016; 188: 671 - 675.

Volume reduction of benign thyroid nodules 3 months after a single treatment with high-intensity focused ultrasound (HIFU)

Background

High-intensity focused ultrasound (HIFU) is a promising, non-invasive technique in treating benign thyroid nodules (TNs). The aim of this study was to evaluate the efficacy of HIFU to induce clinically meaningful shrinkage in benign predominantly solid TNs and to identify variables that influence or predict the magnitude of TN volume reduction.

Methods

For each of ten subjects, HIFU treatment was conducted on a single nodule. Nodular volume was measured sonographically at baseline and at 3 months post-procedure. Nodular function and early treatment assessment was done scintigraphically.

Results

Median nodular volume reduction was 0.7 ml absolute and 48.8% relative to pre-interventional size (p < 0.05). Absolute shrinkage was negatively correlated with the average treatment depth (τ = −0.61, p < 0.05). Absolute nodular volume was positively correlated with the scintigraphic nodular uptake reduction (τ = 0.66, p < 0.05).

Conclusions

HIFU treatment of benign predominantly solid TNs appears to be safe and effective for inducing nodular shrinkage. Despite potential for improvement, a single treatment session with HIFU is already a viable alternative to more standard methods. The feasibility of multiple HIFU treatments requires further investigation. Due to the small sample size, the findings of this analysis need conformation by larger studies.

Age and body composition influence TSH concentrations after administration of rhTSH

AIM

Previous studies listed body surface area (BSA), lean body mass (LBM), and age as modifying factors on the TSH concentrations after administration of recombinant human thyrotropin (rhTSH). The purpose of this study was to identify the main modifying factors on serum TSH levels and to compare the stimulation via single rhTSH injection after a short thyroid hormone withdrawal (THW) with that of the standard stimulating protocol.

PATIENTS, METHODS

106 patients with differentiated thyroid cancer (DTC) undergoing radioiodine therapy (RIT) after rhTSH administration were obtained through chart review. Two groups were evaluated: Group I was treated with a single rhTSH administration after two weeks of T3 therapy followed by one week of THW. Group II was stimulated according to the international standard protocol via rhTSH injections for two consecutive days. Serum TSH concentrations were documented prior to rhTSH administration (day 1 TSH), one day after (day 3 TSH) and 3-6 days after (mean 4.2 days, day 6 TSH) the last rhTSH injection. The following data was collected: age, gender, weight, height, BMI, LBM, BSA, residual thyroid tissue, CRP, creatinine, GFR, liver enzymes, alkaline phosphatase, cholesterol, and triglycerides.

RESULTS

Group I: Age combined with anthropometric factors like BMI (TSH increase and day 6 TSH), BSA (TSH decrease), and gender (day 6 TSH) are the main modifying factors on serum TSH concentrations after rhTSH administration. Group II: Age and lean body mass (LBM) showed a significant impact on day 3 TSH, TSH increase (day 3-day 1), and TSH decrease (day 6-day 3). Day 6 TSH was found to be influenced by GFR (group II).

CONCLUSION

Age and anthropometric parameters have significant independent influence on TSH concentrations after rhTSH injection in both groups. Anthropometric parameters (BSA, LBM) and demographic parameters (female gender) show strong influence on TSH concentrations. Further research should be conducted to examine the influence of body compartments on TSH levels through measuring total body water.

Can peptide receptor radionuclide therapy be safely applied in florid bone metastases? A pilot analysis of late stage osseous involvement

AIM

Highly advanced metastatic bone disease with extensive osseous infiltration of neuroendocrine tumours (NET) may preclude patients from treatment with peptide receptor radionuclide therapy (PRRT) in concern about haematotoxicity. This study aims to assess the safety and efficacy of PRRT with 177Lu-octreotate in a patient cohort with this condition.

PATIENTS, METHODS

41 PRRT courses were performed in 11 patients with gastroenteropancreatic neuroendocrine tumours (GEP-NET) and florid bone metastases (severely advanced widespread metastatic bone disease). A mean activity of 6.95 GBq 177Lu-octreotate was administered per treatment cycle, aimed at four courses with standard intervals of 3 months. Haematological parameters were determined prior to each treatment course, in 2-4 weeks intervals between the courses, 8-12 weeks after the last course of PRRT and in 3 monthly intervals thereafter. Toxicity was recorded using Common Terminology Criteria for Adverse Events v3.0. Restaging was performed 3 months after termination of PRRT with CT/MRI and functional imaging (modified MDA criteria).

RESULTS

Significant (grade III-IV), reversible haematotoxicity occurred in 4 (35%) patients and after 10 (24%) administrations. It either resolved spontaneously (1 patient) or was controlled by supportive measures (3 patients), such as blood transfusions (3 patients) or deferral of the subsequent therapy cycle (1 patient). Patients returned to baseline blood values within up to 23 months after termination of PRRT. The observed treatment response of bone metastases consisted of a partial response in 2, a minor response in 1, stable disease in 7, and progressive disease in 1 patient. Of the 4 patients with metastatic bone pain, 1 experienced complete and 3 partial resolution of symptoms within 3-10 weeks after commencement of PRRT.

CONCLUSION

These preliminary data indicate that PRRT with 177Lu-octreotate can be safely applied even in florid bone metastases with extensive, severely advanced osseous replacement. The higher myelosuppression rate was not associated with serious complications and should not preclude patients from being treated and potentially experiencing remarkable treatment efficacy despite the very advanced stage.

Local thyroid tissue ablation by high-intensity focused ultrasound: effects on thyroid function and first human feasibility study with hot and cold thyroid nodules

OBJECTIVE

The aim of this study was to assess whether high-intensity focused ultrasound (HIFU), a new and promising method for the treatment of benign hot and cold thyroid nodules using thermal ablation, has an impact on thyroid function, and to evaluate its feasibility in outpatient settings. Additionally, a possible difference in the treatment of solid and complex thyroid nodules was evaluated.

METHOD

Ten patients with one thyroid nodule each (six cold and four hot nodules) underwent HIFU in January 2014. Four nodules were solid and six nodules were complex. Serum levels of triiodothyronine (T3), thyroxine (T4), thyrotropin (TSH), thyroglobulin (hTg) and additionally antibodies against hTg (TAK), TSH receptors (TRAK) and thyroid peroxidase (TPO) were measured at enrolment and 24 h after the HIFU treatment. The pre- and post-thyroglobulin reduction was measured to evaluate the scale of ablation. In addition, patients' pain was recorded on a numeric rating scale from 0 to 10.

RESULTS

The HIFU treatment did not affect thyroid function, since hormone levels stayed stable (p < 0.05). No serious immune reaction was induced. Thyroglobulin serum levels increased significantly (p < 0.05) and were correlated to the total energy emitted by HIFU (p < 0.1). The results of complex thyroid nodules did not differ from solid thyroid nodules. Similarly, the results of hot thyroid nodules did not differ from cold thyroid nodules. All patients tolerated the whole treatment and no severe complications were observed.

CONCLUSION

HIFU is a safe and effective method to treat benign, solid, complex, hot and cold thyroid nodules preserving thyroid function. Further developments of the system are needed to gain suitability for daily use.

Early assessment of high-intensity focused ultrasound treatment of benign thyroid nodules by scintigraphic means

Background

High-intensity focused ultrasound (HIFU) allows to inflict intracorporal thermal lesions without penetrating the skin or damaging the surrounding tissue. This analysis intends to assess the magnitude of HIFU-induced ablations within benign thyroid nodules using scintigraphic imaging with ^99mTc.

Methods

Ten cold, hot, or indifferent nodules were treated using multiple pulses of HIFU to induce temperatures of around 85°C within the ablation zone. Pre- and posttreatment, uptake values of ^99mTc-pertechnetate or ^99mTc-MIBI were recorded. The pre-post reduction of nodular uptake was evaluated to assess ablation magnitude.

Results

Relative nodular uptake in relation to total thyroidal uptake decreased after one session of HIFU in all cases. Median ^99mTc-MIBI uptake reduction was 35.5% (ranging from 11% to 57%; p < 0.1), while ^99mTc-pertechnetate scintigraphy showed a median uptake reduction of 27% (range 10% to 44%; p < 0.1). No major complications were observed.

Conclusions

HIFU appears to be safe and is an easy to perform means of thermal ablation. This study shows that HIFU treatment in thyroidal nodules can be evaluated by scintigraphic means shortly after the intervention. Due to small sample size, the exact magnitude of HIFU ablation efficiency in thyroidal nodules remains a value to be assessed in a larger study.

Evaluation of fear of radiation and isolation before and after radioiodine therapy

BACKGROUND

Prior to undergoing radioiodine therapy (RIT), patients regularly have concerns about isolation on the ward (mandatory for RIT for at least 48 hours in Germany due to radiation protection legislation) as well as fear of the presence of radioactive substances. In this study, these fears were investigated before and after RIT.

METHODS

A questionnaire was developed for completion both before and after radioiodine therapy. Questions included: (i) "Are you afraid of a therapy with radioactive substances?" (ii) "Do you have reservations about contact with radioactive substances?" and (iii) "Are you anxious about isolation?" Possible answers were made in a qualitative representation using a scale of 1-4 (4=full agreement, 3=mostly agreement, 2=partial agreement, and 1=no agreement). Further questions included, for example, sources of information used prior to therapy. A total of 209 patients treated by single or preplanned multiple RIT were surveyed over a period of 8 months (return 109). Analysis was done in subgroups according to age, education, disease, and number of RITs.

RESULTS

Question 1, "Are you afraid of a therapy with radioactive substances?" showed a similar statistically relevant decline in each subgroup (p<0.05), except for patients with multiple RIT (p=0.81). Asked about the handling of radioactive substances and their perception about the safety in this regard, the entire collective showed a highly statistically significant (p<0.01) decrease with little variability between the groups. The question concerning fear of isolation resulted in a significant decrease (p<0.05) in all subgroups, except for patients with multiple RIT (p=0.13). Analysis of sources of information before RIT showed that older patients preferred printed material and rarely used online resources, while younger patients used the internet more frequently, in addition to printed materials. Finally, most patients would undergo radioiodine therapy again (medical indication provided), with 54% fully agreeing and only 4% not agreeing.

CONCLUSIONS

The survey demonstrates a reduction in concerns about nuclear radiation, use of unsealed radioactive materials, and isolation on the ward after RIT. Surprisingly, concerns rise again before a subsequent therapy.

FOXE1 association with differentiated thyroid cancer and its progression

BACKGROUND

Single nucleotide polymorphisms (SNPs) near thyroid transcription factor genes (FOXE1 rs965513/NKX2-1 rs944289) have been shown to be associated with differentiated thyroid cancer (DTC) in Caucasoid populations. We investigated the role of those SNPs in German patients with DTC and also extended our analysis to tumor stages and lymphocytic infiltration of the tumors (ITL).

METHODS

Patients with DTC (n=243; papillary, PTC; follicular, FTC) and healthy controls (HC; n=270) were analyzed for the rs965513 and rs944289 SNPs.

RESULTS

The case-control analysis for rs965513 SNP showed that the genotypes "AA," "AG," and minor allele "A" were more frequent in patients with DTC than in HC (pronounced in PTC p(genotype)=0.000084, p(allele)=0.006 than FTC p(genotype)=0.29 and p(allele)=0.06). Furthermore, subgroup analysis of the DTC patients stratified for primary tumor stage (T1-T2, T3-T4), the absence or presence of regional lymph node metastases (N0, N1), for distant metastases (M0, M1), as well as for ITL, showed an association of rs965513 with stages T1-T2, T1-T3, N1, and absence of ITL. The NKX2-1 SNP rs944289, however, was not associated with DTC.

CONCLUSION

Our results confirm that the FOXE1 rs965513 SNP confers an increased risk for DTC in the German population, particularly allele "A" and the genotypes "AA" and "AG" for PTC. This increased risk was also observed in advanced tumor stages and absence of ITL, which may reflect the course of a more aggressive disease. The NKX2-1 rs944289 SNP, however, appears to play a secondary role in the development of DTC in the German population.