In thyroidectomized patients with thyroid cancer, a serum thyrotropin of 30 μU/mL after thyroxine withdrawal is not always adequate for detecting an elevated stimulated serum thyroglobulin

Quality of Life of Survivors of Thyroid Cancer Is Not Inferior to That in Subjects without Cancer: Long-Term after Over 5 Years

BACKGRUOUND

Patients with thyroid cancer undergo less extensive surgery and additional therapies compared to those with other cancers. We aimed to compare the quality of life (QoL) between patients with thyroid cancer and healthy subjects using representative data from Korea. Differences in QoL of thyroid cancer survivors according to the duration after cancer diagnosis was also evaluated.

METHODS

This population-based cohort study included 50,278 subjects who participated in the Korea National Health and Nutrition Examination Survey between 2007 and 2017. QoL was compared between patients with thyroid cancer and healthy subjects using self-reported data from the EuroQoL (EQ)-5 dimension (5D) and EQ-visual analog scale (VAS). Propensity score matching was used to match thyroid cancer survivors to healthy subjects (1:5 matching).

RESULTS

Linear regression with univariate analysis showed that the presence of thyroid cancer was positively correlated with better EQ-5D index scores (β-coefficient=0.010, p=0.046). After adjusting for multiple covariables, statistical significance was maintained. EQ-VAS fails to demonstrate any significant correlation. Among the EQ-5D categories, patients with thyroid cancer showed better self-care than healthy subjects. Thyroid cancer duration did not correlate with the EQ-5D index score. In subgroup analyses, compared to patients with thyroid cancer duration of <5 years, no significant difference was observed in the correlation between the EQ-5D index score and survival duration in those with thyroid cancer duration of 5 to 9 years and ≥10 years.

CONCLUSION

Using a large-scale nationwide population-based database, our study demonstrated better QoL, especially in terms of self-care, among thyroid cancer survivors than among healthy subjects without cancer.

miR-30b-5p inhibits proliferation, invasion, and migration of papillary thyroid cancer by targeting GALNT7 via the EGFR/PI3K/AKT pathway

Background

Papillary thyroid carcinoma (PTC) is a common endocrine tumor. Increasing evidence has shown that microRNA dysfunction is involved in the occurrence and development of cancer. The expression of MicroRNA-30b-5p (miR-30b-5p) was down-regulated in PTC; however, its role in the development of PTC is not clear. Hence, this study aimed to explore the role and mechanism of miR-30b-5p in the occurrence and development of PTC.

Methods

The qRT-PCR assay was used to detect the expression of miR-30b-5p in 60 cases of papillary thyroid carcinoma along with their matched non-cancerous tissues. This study explored the biological function of miR-30b-5p by the functional gain and loss experiments in vitro and vivo. The direct target gene of miR-30b-5p and its signaling pathway was identified through bioinformatics analysis, qRT-PCR, western blot, rescue experiments, and double luciferase 3'-UTR report analysis.

Results

This study demonstrated that the low expression of miR-30b-5p is related to poor clinicopathological features. Functionally, the overexpression of miR-30b-5p inhibited the proliferation, invasion, and migration of PTC cells. Bioinformatics and luciferase analysis showed that GALNT7 is the direct and functional target of miR-30b-5p. Moreover, miR-30b-5p inhibited the proliferation of PTC in vivo by inhibiting the expression of GALNT7. The studies on the mechanism have shown that GALNT7 promotes cell proliferation and invasion by activating EGFR/PI3K/AKT kinase pathway, which can be attenuated by the kinase inhibitors.

Conclusions

Overall, miR-30b-5p inhibited the progression of papillary thyroid carcinoma by targeting GALNT7 and inhibiting the EGFR/PI3K/AKT pathway.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02323-x.

Systematic review of health-related quality of life following thyroid cancer

This systematic review provides a summary of all studies published between 2000 and 2019 using a health-related quality of life (HRQOL) patient-completed questionnaire to report outcomes following diagnosis and treatment of thyroid cancer. The search terms were “thyroid cancer” or “thyroid carcinoma,” “quality of life” or “health related quality of life,” and “questionnaire” or “patient reported outcome.” EMBASE, PubMed, Medline, PsycINFO, CINAHL, and HaNDLE-On-QOL search engines were searched between 2 February and 23 February 2020. A total of 811 identified articles were reduced to 314 when duplicates were removed. After exclusion criteria (not thyroid specific, no quality of life questionnaires, and conference abstracts) were applied, 92 remained. Hand searching identified a further 2 articles. Of the 94 included, 16 had a surgical, 26 a primarily medical, and 52 a general focus. There were articles from 27 countries. A total of 49 articles were published from 2015 through 2019 inclusive. A total of 72 questionnaires were used among the articles and a range of 7 to 2215 participants were included within each article. This review demonstrated an increasing number of publications annually. The scope of enquiry into aspects of HRQOL following thyroid cancer is broad, with relatively few addressing surgical aspects and many focusing on the impact of radio-iodine. More research is required into shared decision-making in initial management decisions and HRQOL and interventions aimed specifically at addressing long-term HRQOL difficulties.

Circulating biomarkers for the detection of tumor recurrence in the postsurgical follow-up of differentiated thyroid carcinoma

PURPOSE OF REVIEW

To discuss advances and challenges in thyroglobulin and Tg-antibody (TgAb) measurement and their impact on clinical management of differentiated thyroid carcinoma (DTC).

RECENT FINDINGS

Basal high-sensitive Tg (hsTg) measurement avoids the need for stimulation and greatly simplifies DTC patients' management. In addition, patients with undetectable hsTg after thyroid ablation are at a very low risk of recurrence and can be safely managed by periodic hsTg measurement alone. When TgAb is present, its trend over time serves as primary (surrogate) tumor marker. However, an undetectable hsTg measurement appears to indicate a complete remission of DTC even in the presence of TgAb. Finally, reliable reference values are not yet available for low-risk DTC who are treated with less than total thyroid ablation, and caution is needed before well-designed studies addressing these issues have been published.

SUMMARY

The use of hsTg assays has changed paradigms for DTC monitoring even in the presence of TgAb, and greatly reduced patients' discomfort and overall case-management costs. Reliable Tg interpretation criteria are urgently needed for patients treated with less than total thyroid ablation.

Recombinant human thyrotropin versus thyroid hormone withdrawal in an Asian population

CONTEXT

To prepare for radioactive iodine therapy in post total thyroidectomy patients with well-differentiated thyroid cancer (WDTC), either thyroid hormone withdrawal (THW) or administration of recombinant human thyrotropin (rhTSH) can be performed.

OBJECTIVE

Our objective is to compare quality of life (QoL) parameters using the SF-36v2 questionnaire (Short Form health survey) and a self-evaluated item, and the hypothyroid status using modified Billewicz scores in an Asian population undergoing either THW or rhTSH for remnant ablation or adjuvant treatment following total thyroidectomy for WDTC. We will also assess the proportion of patients achieving TSH level of >30 mU/L after 4 weeks of thyroid hormone withdrawal.

RESULTS

Patients in the rhTSH group were better in the QoL domains of physical functioning, role functioning/physical and bodily pain, while patients in THW group were better in mental health. This was however, not statistically significant. Modified Billewicz scores were higher in patients in THW group as compared with rhTSH group and statistically significant. A total of 96.3% of patients achieved TSH level >30 mU/L after 4 weeks of THW.

CONCLUSION

Clinical symptoms and signs of hypothyroidism as assessed with modified Billewicz scores were statistically significantly higher in the THW group. However, there was no statistically significant difference in QoL in the rhTSH group.

Clinical utility of an ultrasensitive thyroglobulin assay in the follow-up of patients with differentiated thyroid cancer: can the stimulation test be avoided in patients with an intermediate recurrence risk?

SUMMARY

Serum thyroglobulin (Tg) measurement during suppression with levothyroxine (LT4) using an ultrasensitive assay (OnT4-Tg) has been proposed as a replacement of TSH-stimulated Tg measurement (OffT4-Tg) in management of patients with differentiated thyroid cancer (DTC). The aim of this study is to evaluate the capacity of an ultrasensitive Tg assay in predicting an OffT4-Tg > 2.0 ng/mL based on the OnT4-Tg in patients with DTC and an intermediate recurrence risk. We analysed 101 patients with DTC and an intermediate (n = 92) or high risk of recurrence (n = 9) who were treated with total thyroidectomy and ablation with ¹³¹I, and followed for an average of 6 years. OnT4-Tg was undetectable in 64 of 101 patients; OffT4-Tg was #x003C; 2.0 ng/mL in 61 of these 64 patients, all with negative imaging results. Furthermore, 37 of 101 patients had detectable OnT4-Tg; 32 of these 37 patients also presented OffT4-Tg > 2.0 ng/mL, and only 3 of these 32 patients had metastases detected by neck ultrasound. Considering a cutoff point of 0.1 ng/mL for OnT4-Tg, the assay had a sensitivity of 91%, specificity of 92%, positive predictive value (PPV) of 86% and the negative predictive value (NPV) of 95% when predicting an OffT4-Tg > 2.0 ng/mL (biochemical disease). The use of an ultrasensitive Tg assay allows prediction of which patients will remain disease-free even if they are at an intermediate risk of recurrence, and to decrease the need for stimulated Tg assays in two-thirds of these patients.

Indirect Basal Metabolism Estimation in Tailoring Recombinant Human TSH Administration in Patients Affected by Differentiated Thyroid Cancer: A Hypothesis-Generating Study

PURPOSE

Recombinant human TSH (rhTSH) is currently used in follow-up of patients affected by differentiated thyroid cancer (DTC). Age, sex, weight, body mass index, body surface area (BSA) and renal function are known factors affecting serum TSH peak levels, but the proper rhTSH dose to deliver to single patient remains elusive. In this study, the correlations of basal metabolic rates with serum TSH peak following rhTSH administration were investigated.

METHODS

We evaluated 221 patients affected by thyroid cancer that received a standard dose rhTSH. Blood samples were collected at pre-established time points. Data on body weight, height, and BSA were collected. The Mifflin-St Jeor and Fleisch equations were used to assess basal metabolism.

RESULTS

The median value (range) of serum TSH peaks was 142 ± 53 μU/ml. Serum TSH peaks were significantly lower in males than in females (p = 0.04). TSH values also increased with age. Data showed a significant decrease of TSH peak levels at day 3 from the administration of rhTSH when basal metabolic rates increased (p = 0.002 and p = 0.009, respectively). Similar findings were observed at day 5 (p = 0.004 and p = 0.04, respectively). A multivariate analysis of several factors revealed that patients' basal metabolism (obtained using the Mifflin-St Jeor but not Fleisch equation) predicts serum TSH level peak at day 3 (p < 0.001). These results were used to generate a new formula based on Mifflin-StJeor equation which reveals as a promising tool in tailoring rhTSH dose.

CONCLUSION

Basal metabolism appears an improving factor in tailoring diagnostic rhTSH dose in patients affected by DTC.

Thyroglobulin levels and thyroglobulin/thyrotropin ratio could predict the success of the ablative/therapeutic 131I in the differentiated thyroid cancers

BACKGROUND

Stimulated thyroglobulin (STg) levels in patients with differentiated thyroid carcinomas (DTCs) after total thyroidectomy (TT) and before radioactive iodine (¹³¹I) ablation/therapy (RIT) are predictive of therapeutic success but can be influenced by the thyroid-stimulating hormone (TSH) level.

OBJECTIVES

This study compared the reliability of the STg/TSH ratio and STg measurement in predicting the success of RIT.

METHODS

Sixty-three DTC patients submitted to TT were assessed retrospectively to compare the ability of STg level and the STg/TSH ratio to predict successful RIT.

RESULTS

In this study 48 (76.2%) patients had successful RIT. The successful and unsuccessful groups received different ¹³¹I doses and had different STg levels and STg/TSH ratios. The STg and STg/TSH ratio cutoff values that predicted successful RIT were 4.41 ng/mL (sensitivity of 86.7% and specificity of 77%) and 0.093 (sensitivity of 80% and specificity of 79.2%), respectively. Age, STg level, STg/TSH ratio, and ¹³¹I dose were associated with successful RIT, but after multivariate analysis only STg remained associated (p < 0.05).

CONCLUSION

In conclusion, our data suggest that the STg/TSH ratio and measurement of STg are equally reliable in predicting successful RIT in DTC patients.

Prediction of radioactive iodine remnant ablation failure in patients with differentiated thyroid cancer: A cohort study of 740 patients

BACKGROUND

The purpose of this study was to detect parameters that could serve as predictors of radioactive iodine (I-131) ablation failure in patients with low-risk and intermediate-risk differentiated thyroid carcinoma (DTC).

METHODS

Our cohort study included 740 patients with DTC who received postoperative I-131 remnant ablation. Anthropometric, biochemical, and pathohistological parameters were analyzed and correlated with ablation outcome using multivariable logistic regression models.

RESULTS

Treatment failure rates were higher in patients <53 years, with N1a classification, and lymph node capsular invasion. In patients with N1a disease, thyroglobulin (Tg) > 2.4 ng/mL predicted treatment failure with 93.8% sensitivity and 52.5% specificity, and in patients with N1b disease, Tg > 14.9 ng/mL with 77.8% sensitivity and 92.9% specificity. I-131 activity was not associated with treatment outcome.

CONCLUSION

Patients < 53 years old, with higher Tg levels, N1a classification, and lymph node capsular invasion have a higher risk of ablation failure. Stimulated Tg is an excellent predictor of treatment failure in patients with N1 disease. © 2016 Wiley Periodicals, Inc. Head Neck 39: 109-115, 2017.

Serum thyrotropin level of 30 μIU/mL is inadequate for preablative thyroglobulin to serve as a prognostic marker for differentiated thyroid cancer

PURPOSE

Preablative-stimulated thyroglobulin (ps-Tg) has manifested its potential for predicting prognosis in patients with differentiated thyroid carcinoma (DTC), but its level can be affected by thyrotropin (TSH). The objective of this study was to evaluate the utility of ps-Tg in predicting individual response after radioactive iodine (RAI) therapy, and further explore the appropriate TSH level for ps-Tg to serve as a prognostic marker in DTC without initial distant metastasis (DM).

METHODS

A total of 208 consecutive non-DM DTC patients with serial ps-Tg, TSH, and anti-Tg antibody (TgAb) measured simultaneously were enrolled. The initial and last measurements of ps-Tg were marked as Tg1 and Tg2, respectively, with a median interval of 8 days, so does TSH. Clinical response was retrospectively evaluated as excellent, indeterminate, biochemical incomplete, or structural incomplete response (ER, IDR, BIR, or SIR) after a mean follow-up of 21.5 months. Tg1 and Tg2 were tested and compared for their performances in predicting ER and incomplete response (IR, including BIR and SIR) by receiver operating characteristic (ROC) curve analysis. The 416 ps-Tg levels (Tg1 and Tg2) were then categorized by their corresponding TSH grouping of 30-<60 (n = 100), 60-<90 (n = 131), 90-<120 (n = 99), and ≥120 μIU/mL (n = 86), and the predictive performances were further compared among TSH groups.

RESULTS

Tg2, with a higher corresponding TSH level than Tg1 (median: 104.763 vs. 65.046 μIU/mL), presented higher area under the ROC curve (AUC) in predicting both ER and IR (ER: 0.889 vs. 0.836, P = 0.003; IR: 0.925 vs. 0.869, P = 0.046). The performances of ps-Tg in predicting ER and IR were both improved significantly as TSH rose from 30-<60 to 60-<90 μIU/mL, with an increase in AUC from 0.810 to 0.888 in predicting ER (P = 0.006) and from 0811 to 0.937 in predicting IR (P = 0.014), respectively. However, this kind of benefit was not further enlarged as TSH rose from 60-<90 to 90-<120 μIU/mL (both P > 0.05).

CONCLUSION

In comparison with the TSH context of 30 μIU/mL, a higher preablative TSH level of 60-<90 μIU/mL might be more appropriate for ps-Tg to serve as a prognostic marker for DTC.

Is Very High Thyroid Stimulating Hormone Level Required in Differentiated Thyroid Cancer for Ablation Success?

Objective:

Remnant ablation with radioactive iodine (I-131) is a successful form of treatment that aims to destroy the remaining residual tissue and/or metastatic tissue after total thyroidectomy in differentiated thyroid cancer (DTC) patients. High level of thyroid stimulating hormone (TSH) (≥30 mIU/L) is recommended for success of ablation treatment. In this retrospective study, our aim was to investigate whether the TSH levels at the time of ablation effect the success of radioactive iodine remnant ablation.

Methods:

Patients who were diagnosed with DTC, treated with bilateral total/near total thyroidectomy and who were referred for I-131 remnant ablation were included in this study. Patients with undetectable TSH-stimulated serum thyroglobulin (Tg) level, normal physical examination, negative results on whole body scan with I-131, and no evidence of neck lymph node metastasis on ultrasound were defined as disease-free. The correlation between TSH level at the time of ablation and ablation success was assessed.

Results:

Two hundred sixty one consecutive patients were included in the present study. Mean TSH level was 19.47±6 mIU/L in the 34 patients with TSH <30 mIU/L, while mean TSH level was 73.65±27 mIU/L in the 227 patients with TSH ≥30 mIU/L during I-131 remnant ablation. Ablation was unsuccessful in only one patient with TSH <30 mIU/L who had lung metastasis. Ablation was unsuccessful in 5.1% of patients with TSH ≥30 mIU/L. The effect of TSH level was not significant on ablation success (p=0.472).

Conclusion:

In conclusion, we think that a high TSH serum level alone is not a factor for the success of ablation. Age, presence of metastasis, extent of residual thyroid mass should also be considered. Especially, in the presence of metastatic tissue, obtaining adequate increase in TSH level is not always possible. The success of ablation at lower levels of TSH elevations may be sufficient for patients, and long-term hypothyroidism may not be required.

Structured review of papers reporting specific functions in patients with cancer of the head and neck: 2006 - 2013

Health-related quality of life (HRQoL) focuses on 4 core domains: physical and psychological function, social interaction, disease, and treatment-related symptoms, and is a key outcome in patients with cancer of the head and neck. We reviewed papers published between 2006 and 2013 that used validated questionnaires to report functional outcome in this group. A total of 572 papers were identified and 118 of them concerned function. Specific outcomes included anxiety, chewing, maxillectomy, mucositis, pain, shoulder function, and trismus. The specific functions most often identified were xerostomia, speech or voice, and swallowing or dysphagia. A considerable body of evidence has now accumulated on HRQoL and functional outomes although the precise role of HRQoL during the planning of treatment remains controversial. Over time, the emphasis of the studies included has tended to move away from the reporting of outcomes in general to more hypothesis-driven and group-specific work.

Correlation of Consecutive Serum Thyroglobulin Levels During Hormone Withdrawal and Failure of Initial Radioiodine Ablation in Thyroid Cancer Patients

OBJECTIVE

The aim of this study was to evaluate the value of thyroglobulin (Tg) kinetics during preparation of radioiodine ablation for prediction of initial radioiodine ablation failure in thyroid cancer patients.

METHODS

Thyroid cancer patients after total thyroidectomy who underwent radioiodine ablation with 3-4 weeks of hormone withdrawal between May 2011 and January 2012 were included. Consecutive serum Tg levels 5-10 days before ablation (Tg1) and on the day of ablation (Tg2) were obtained. The difference between Tg1 and Tg2 (ΔTg), daily change rate of Tg (ΔTg/day) and Tg doubling time (Tg-DT) were calculated. Success of initial ablation was determined by the results of the follow-up ultrasonography, diagnostic radioiodine scan and stimulated Tg level after 6 to 20 months.

RESULTS

A total of 143 patients were included. Failed ablation was reported in 52 patients. Tg2 higher than 5.6 ng/ml and Tg-DT shorter than 4.2 days were significantly related to a high risk of ablation failure. ΔTg and ΔTg/day did not show significant correlation with ablation failure.

CONCLUSIONS

Thyroglobulin kinetics on consecutive blood sampling during hormone withdrawal may be helpful in predicting patients with higher risk of treatment failure of initial radioiodine ablation therapy in thyroid cancer patients.

Comparison of conventional L-thyroxine withdrawal and moderate hypothyroidism in preparation for whole-body 131-I scan and thyroglobulin testing

PURPOSE

After thyroidectomy for thyroid cancer, patients often withdraw L-T4 for diagnostic or therapeutic purposes, showing signs and symptoms of hypothyroidism. A slighter hypothyroidism (reducing L-T4 to one-half) has been proposed to limit these inconveniences. We evaluated half-dose L-T4 protocol, in comparison to conventional L-T4 withdrawal, in terms of effectiveness and improvement of clinical and biochemical disorders.

METHODS

We randomized 55 thyroid cancer patients into two groups: 29 patients underwent 5 weeks of half-dose of previous L-T4 treatment (HD group); 26 patients replaced L-T4 with L-T3 for 3 weeks followed by 2 weeks of withdrawal (TW group). Clinical features (Zulewsky clinical score) and biochemical parameters (lipids, liver, and muscle enzymes) were evaluated in all patients at baseline and after 5 weeks.

RESULTS

Total cholesterol, creatine kinase, lactate dehydrogenase, aspartate aminotransferase, and alanine aminotransferase increased at 5 weeks in both groups, but significantly more in TW, but no difference was found by clinical score. Patients who achieved the thyroid-stimulating hormone (TSH) target value (25 µU/ml) were 92.3% in TW group and 48.3% in HD group (p < 0.001). In the HD group, only basal TSH statistically correlated with the achievement of the TSH target. Receiver operating characteristic curves indicated that a basal TSH ≥0.52 μU/ml is required to reach an adequate TSH level.

CONCLUSIONS

Half-dose L-T4 protocol, compared to conventional L-T4 withdrawal, is associated with less biochemical disorders but no significant clinical advantage. Therefore, the half-dose protocol reaches an adequate TSH target in 48.3% of patients and is not effective unless basal serum TSH is ≥0.52 μU/ml.

Analysis of Clinical Factors for the Determination of Optimal Serum Level of Thyrotropin After Recombinant Human Thyroid-Stimulating Hormone Administration

PURPOSE

To determine the optimal levels of thyroid-stimulating hormone (TSH) levels after administration of recombinant human TSH (rhTSH) to patients with differentiated thyroid cancer (DTC), we have analyzed the clinical parameters that affected the degree of the increase in serum levels of TSH.

METHODS

We retrospectively analyzed 276 patients with differentiated thyroid cancer (DTC), post-thyroidectomy and remnant ablation. Pearson's correlation coefficient test was used to evaluate the correlation between serum levels of TSH after rhTSH stimulation and various clinical factors, including age, sex, height, weight, body mass index (BMI), body surface area (BSA), serum blood urea nitrogen, creatinine, and estimated glomerular filtration rate (GFR). Linear regression analysis was used to determine the predictors of the degree of increase in serum TSH level after rhTSH stimulation.

RESULTS

After the rhTSH injections, all subjects achieved TSH levels of >30 μU/mL, with a mean of 203.8 ± 83.4 μU/mL. On univariate analysis, age (r = 0.255) and serum creatinine (r = 0.169) level were positive predictors for higher levels of serum TSH after rhTSH stimulation, while weight (r = -0.239), BMI (r = -0.223), BSA (r = -0.217), and estimated GFR (r = -0.199) were negative predictors. Multiple linear regression analysis revealed that serum creatinine was the most powerful independent predictor for serum levels of TSH, followed by age, BSA, and BMI.

CONCLUSIONS

An increment in serum TSH after rhTSH stimulation was significantly affected by age, BSA, BMI, and creatinine, with creatinine being the most powerful predictor. By understanding the difference in the increased levels of TSH in various subjects, their dose of rhTSH can be adjusted during scheduling for radioiodine ablation, or during follow-up (recurrence surveillance) after surgery and ablation.

Superiority of delayed risk stratification in differentiated thyroid cancer after total thyroidectomy and radioactive iodine ablation

AIM

The aim of this study was to validate the effectiveness of delayed risk stratification (DRS) in predicting structural progression and compare the predictive value of American Thyroid Association (ATA) risk stratification with that of DRS in patients with differentiated thyroid cancer (DTC).

METHODS

A total of 398 patients with DTC who underwent surgery followed by radioactive iodine ablation were enrolled. Patients were categorized as having excellent response, acceptable response, biochemical incomplete response, or structural incomplete response at 8-15 months' evaluation after radioactive iodine ablation for DRS. Effectiveness of DRS was evaluated according to structural progression-free survival (PFS; median follow-up, 10.7 years).

RESULTS

A total of 229 patients (57.5%) were classified as having excellent response, 78 (19.6%) as having acceptable response, 62 (15.6%) as having biochemical incomplete response, and 29 patients (7.3%) as having structural incomplete response. After DRS, 60.2% of intermediate-risk patients and 20.5% of high-risk patients were shifted to the excellent response category. Sixty-nine patients (17.3%) showed structural progression. DRS showed statistical difference in PFS (hazard ratio, 4.268; 95% confidence interval, 3.258-5.477; P<0.001). In multivariate analysis of ATA risk stratification and DRS, DRS was significantly associated with PFS (hazard ratio, 4.383; 95% confidence interval, 3.250-5.912; P<0.001), but ATA risk stratification was not. There was no significant difference in deviances between the use of DRS alone and the use of both DRS and ATA risk stratification (χ=0.103, d.f.=1, P=0.748).

CONCLUSION

DRS is superior to ATA risk stratification in predicting structural disease progression for DTC patients.

Thyroglobulin measurement using highly sensitive assays in patients with differentiated thyroid cancer: a clinical position paper

Differentiated thyroid cancer (DTC) is the most common endocrine cancer and its incidence has increased in recent decades. Initial treatment usually consists of total thyroidectomy followed by ablation of thyroid remnants by iodine-131. As thyroid cells are assumed to be the only source of thyroglobulin (Tg) in the human body, circulating Tg serves as a biochemical marker of persistent or recurrent disease in DTC follow-up. Currently, standard follow-up for DTC comprises Tg measurement and neck ultrasound combined, when indicated, with an additional radioiodine scan. Measurement of Tg after stimulation by endogenous or exogenous TSH is recommended by current clinical guidelines to detect occult disease with a maximum sensitivity due to the suboptimal sensitivity of older Tg assays. However, the development of new highly sensitive Tg assays with improved analytical sensitivity and precision at low concentrations now allows detection of very low Tg concentrations reflecting minimal amounts of thyroid tissue without the need for TSH stimulation. Use of these highly sensitive Tg assays has not yet been incorporated into clinical guidelines but they will, we believe, be used by physicians caring for patients with DTC. The aim of this clinical position paper is, therefore, to offer advice on the various aspects and implications of using these highly sensitive Tg assays in the clinical care of patients with DTC.

Thyrotropin in the development and management of differentiated thyroid cancer

Thyrotropin (TSH) is the major regulator and growth factor of the thyroid. TSH may be important in the development of human thyroid cancer, with both suggestive animal models and clinical evidence, although definitive proof is still required. Applications for TSH in thyroid cancer management include TSH stimulation of radioiodine uptake, enhancement of biochemical monitoring through thyroglobulin measurement, and long-term suppression of TSH with supraphysiologic levothyroxine. This review synthesizes current knowledge of TSH in both the development and management of differentiated thyroid cancer.

Low but measurable stimulated serum thyroglobulin levels <2 µg/L frequently predict incomplete response in differentiated thyroid cancer patients

INTRODUCTION

The study was aimed to determine the response and predictive risk factors of differentiated thyroid cancer (DTC) with measurable (0.4-2.0 µg/L) stimulated serum thyroglobulin (sTg) during the 10-24 months after radioiodine remnant ablation (RRA) and their long-term outcomes.

METHODS

Out of 839 retrospectively reviewed patients, 95 eligible DTC patients were included. Patients were classified as having incomplete response or no evidence of disease (NED). The sTg cut-off values with highest predicted accuracy for incomplete response at 10-24 months were calculated with receiver operator characteristics curve analysis.

RESULTS AND CONCLUSION

At 10-24 months after RRA, incomplete response was identified in 54 patients (57%) and 38/54 (70.4%) patients were found with structural evidence of disease. The remaining 16 patients (29.6%) had biochemical evidence of disease without structural evidence of disease. Forty-one patients (43%) were classified as having NED at 10-24 months after RRA and 27 patients (66%) did not receive further radioactive iodine (RAI) therapy and remained disease free at median follow-up of 6.5 years. Fourteen patients received second RAI treatment after 6 months and before the 10-24 months assessment time point. Of these, 2 had persistent tumor 6 years later. The sTg >0.6 µg/L at 6-10 months after RRA had optimal sensitivity (83.3%), specificity (56%) and negative predictive value (72%) of detecting incomplete response at 10-24 months after RRA. A total of 23/43 patients in the American Thyroid Association low-risk category had incomplete response after first RRA and 5/23 (21.7%) had recurrent/persistent disease at long-term follow-up.

Detectable thyroglobulin with negative imaging in differentiated thyroid cancer patients

In the absence of autoantibodies against thyroglobulin (Tg), Tg measurement nowadays is the cornerstone of clinical management of differentiated thyroid cancer patients. DTC patients presenting with a positive Tg measurement without an anatomical correlate on anatomic imaging provide a management challenge to the attending physician.

Based on the literature we will provide an overview of the most important steps to undertake in such patients and their potential clinical consequences.