Comparing the Prognostic Value of the Eighth Edition of the American Joint Committee on Cancer/Tumor Node Metastasis Staging System Between Papillary and Follicular Thyroid Cancer

Comparison of 8th and 7th editions of TNM staging in terms of mortality, persistent disease, and response to treatment in patients with differentiated thyroid cancer

OBJECTIVE

To compare the eighth and seventh editions of TNM staging (TNM-8 and TNM-7) on disease-related mortality, persistent disease, and response to treatment in patients with differentiated thyroid cancer (DTC).

METHODS AND MATERIALS

We studied 400 patients (79% female) with DTC with a mean age of 40.93±14.11 years. TNM staging was recorded according to the 7th and 8th editions and patients were followed for at least 1 year and response to therapy was recorded according to ATA response categorization.

RESULTS

The mean follow up time was 42.5±15.24 months. Overall, 108 patients (27%) were down-staged using the TNM-8, mainly due to the changes in the age cut-off (14.5%), N (9.25%), and T categorization (3.25%). All patients in stage III and 82.8% in stage IV were down-staged. The mean Tg levels were significantly higher in stages III and IV in TNM-8 compared to TNM-7. Four disease-related death were recorded during follow up, all in stage IV according to TNM-7, while one was in stage II according to TNM-8. One year after treatment, persistent disease was detected in 12% and 77% of patients in stage III according to the 7th and 8th editions, respectively (P= 0.04). Similarly, biochemical incomplete response one year after treatment was seen in 7.3% and 87% in stage III disease using 7th and 8th editions (P = 0.006) that fell to 2.4% and 22% in the last visit respectively (P = 0.04).

CONCLUSION

Persistent disease and incomplete response to therapy were more common in stages III and IV in TNM-8 compared to TNM-7. The eighth edition was a better predictor of persistent disease in stages III and IV disease.

Risk factors for cervical lymph node metastasis of papillary thyroid cancer in elderly patients aged 65 and older

Objective

To assess the risk factors of cervical lymph node metastasis in elderly patients aged 65 years and older diagnosed with papillary thyroid cancer (PTC).

Design and method

In this retrospective analysis, we included a total of 328 elderly patients aged 65 years and older diagnosed with PTC. We thoroughly examined clinical features from these patients. Utilizing univariate and multivariate logistic regression analyses, we aimed to identify factors contributing to the risk of central and lateral lymph node metastasis (CLNM/LLNM) in this specific population of PTC patients aged 65 years and older.

Results

In the univariate analysis, CLNM was significantly associated with tumor size, multifocality, bilaterality, and microcalcification, while only tumor size ≥ 1cm (OR = 0.530, P = 0.019, 95% CI = 0.311 - 0.900) and multifocality (OR = 0.291, P < 0.001, 95% CI = 0.148 - 0.574) remained as risk factors in the multivariate analysis. LLNM was confirmed to be associated with male (OR = 0.454, P < 0.020, 95% CI = 0.233 - 0.884), tumor size ≥ 1cm (OR = 0.471, P = 0.030, 95% CI = 0.239 - 0.928), age ≥ 70 (OR = 0.489, P = 0.032, 95% CI = 0.254 - 0.941), and microcalcification (OR = 0.384, P = 0.008, 95% CI = 0.189 - 0.781) in the multivariate analysis. In elderly PTC patients with CLNM, male gender (OR = 0.350, P = 0.021, 95% CI = 0.143 - 0.855), age ≥ 70 (OR = 0.339, P = 0.015, 95% CI = 0.142 - 0.810), and bilaterality (OR = 0.320, P = 0.012, 95% CI = 0.131 - 0.779) were closely associated with concomitant LLNM in both univariate and multivariate analyses.

Conclusion

For elderly PTC patients aged 65 and older, tumor size ≥ 1cm and multifocality are significant risk factors for CLNM. Meanwhile, male, tumor size ≥ 1cm, age ≥ 70, and microcalcification are crucial predictors for LLNM. In patients already diagnosed with CLNM, male, age ≥ 70, and bilaterality increase the risk of LLNM.

Novel molecular typing reveals the risk of recurrence in patients with early-stage papillary thyroid cancer

BACKGROUND

Papillary thyroid cancer (PTC) is an indolent disease with a favorable prognosis but characterized by a high recurrence rate. We aimed to improve precise stratification of recurrence risk in PTC patients with early stage using multi-gene signatures.

PATIENTS AND METHODS

The present study was performed using data from The Cancer Genome Atlas (TCGA) and multi-center datasets. Unsupervised consensus clustering was used to obtain the optimal molecular subtypes and least absolute shrinkage and selection operator (LASSO) analysis was performed to identify potential genes for the construction of recurrence signature. Kaplan-Meier survival analysis and the log-rank test was used to detect survival differences. Harrells concordance index (C-index) was used to assess the performance of the DNA damage repair (DDR) recurrence signature.

RESULTS

Through screening 8 candidate gene sets, the entire cohort was successfully stratified into two recurrence-related molecular subtypes based on DDR genes: DDR-high subtype and DDR-low subtype. The recurrence rate of DDR-high subtype was significantly lower than DDR-low subtype [HR = 0.288 (95%CI, 0.084-0.986), P = 0.047]. Further, a two-gene DDR recurrence signature was constructed, including PER1 and EME2. The high-risk group showed a significantly worse recurrence-free survival (RFS) than the low-risk group [HR = 10.647 (95%CI, 1.363-83.197), P = 0.024]. The multi-center data demonstrated that proportion of patients with low expression of PER1 and EME2 was higher in the recurrence group than those in the non-recurrence group.

CONCLUSIONS

These findings could help accurately and reliably identify PTC patients with high risk of recurrence so that they could receive more radical and aggressive treatment strategies and more rigorous surveillance practices.

Patient's age with papillary thyroid cancer: Is it a key factor for cervical lymph node metastasis?

BACKGROUND

Age is one of the important prognostic indicators of papillary thyroid cancer (PTC). However, the distinct metastatic patterns and prognosis of age-related lymph node metastasis (LNM) are unclear. This study aims to investigate the impact of age on LNM.

METHODS

We conducted two independent cohort studies to assess age-nodal disease association using logistic regression analysis and a restricted cubic splines model. A multivariable Cox regression model was utilized to test the impact of nodal disease on cancer-specific survival (CSS) after age stratification.

RESULTS

For this study, we included 7572 and 36,793 patients with PTC in Xiangya and SEER cohorts, respectively. After adjustment, advanced age was linearly associated with decreasing risk of central LNM. Patients of age ≤18 years (OR = 4.41, P < 0.001) and 19-45 years (OR = 1.97, P = 0.002) had a higher risk of developing lateral LNM than patients of age >60 years in both cohorts. Furthermore, CSS is significantly reduced in N1b disease (P < 0.001), not N1a disease, regardless of age. The incidence of high-volume LNM (HV-LNM) was significantly higher in patients of age ≤18 years and 19-45 years than in those of age >60 years (P < 0.001), in both cohorts. In addition, CSS was compromised in patients with PTC of age 46-60 years (HR = 1.61, P = 0.022) and those of age >60 (HR = 1.40, P = 0.021) after developing HV-LNM.

CONCLUSIONS

Patient age is significantly associated with LNM and HV-LNM. Patients with N1b disease or patients with HV-LNM of age >45 years have significantly shorter CSS. Age can, thus, be a useful guide for determining treatment strategies in PTC.

Multi-Omics and Management of Follicular Carcinoma of the Thyroid

Follicular thyroid carcinoma (FTC) is the second most common cancer of the thyroid gland, accounting for up to 20% of all primary malignant tumors in iodine-replete areas. The diagnostic work-up, staging, risk stratification, management, and follow-up strategies in patients who have FTC are modeled after those of papillary thyroid carcinoma (PTC), even though FTC is more aggressive. FTC has a greater propensity for haematogenous metastasis than PTC. Furthermore, FTC is a phenotypically and genotypically heterogeneous disease. The diagnosis and identification of markers of an aggressive FTC depend on the expertise and thoroughness of pathologists during histopathological analysis. An untreated or metastatic FTC is likely to de-differentiate and become poorly differentiated or undifferentiated and resistant to standard treatment. While thyroid lobectomy is adequate for the treatment of selected patients who have low-risk FTC, it is not advisable for patients whose tumor is larger than 4 cm in diameter or has extensive extra-thyroidal extension. Lobectomy is also not adequate for tumors that have aggressive mutations. Although the prognosis for over 80% of PTC and FTC is good, nearly 20% of the tumors behave aggressively. The introduction of radiomics, pathomics, genomics, transcriptomics, metabolomics, and liquid biopsy have led to improvements in the understanding of tumorigenesis, progression, treatment response, and prognostication of thyroid cancer. The article reviews the challenges that are encountered during the diagnostic work-up, staging, risk stratification, management, and follow-up of patients who have FTC. How the application of multi-omics can strengthen decision-making during the management of follicular carcinoma is also discussed.

Role of 131I in low-risk differentiated thyroid cancer

Differentiated thyroid cancer (DTC) is the most frequent endocrine neoplasm, with an increase in recent decades. Papillary carcinoma is the most frequent histological subtype and a large number of cases are related to tumors of small size and with little clinical repercussion, detected incidentally or as a consequence of the availability of diagnostic techniques. The "good prognosis" of the majority of cases has maintained for years the controversy in the approach to these patients, especially in two basic aspects of the therapeutic protocol: surgery and the administration of radioiodine. While in metastatic and high-risk patients, the administration of ¹³¹I therapy is widely accepted, in intermediate-low risk patients its use is highly questioned. In this paper we review the available evidence on radioiodine therapy in low-risk patients.

Evaluating Disease Specific Survival Prediction of Risk Stratification and TNM Systems in Differentiated Thyroid Cancer

BACKGROUND

Many countries have national guidelines for the management of differentiated thyroid cancer (DTC), including a risk stratification system to predict recurrence of disease. Studies whether these guidelines could also have relevance, beyond their original design, in predicting survival are lacking. Additionally, no studies evaluated these international guidelines in the same population, nor compared them to the TNM system. Therefore, we investigated the prognostic value of six stratification systems employed by ten International guidelines, and the TNM system with respect to predicting disease specific survival (DSS).

METHODS

We retrospectively studied adult patients with DTC from a Dutch university hospital. Patients were classified using the risk classification described in the British, Dutch, French, Italian, Polish, Spanish, European Society of Medical Oncology, European Thyroid Association, and 2009 and 2015 American Thyroid Association (ATA) guidelines, and the latest TNM system. DSS was analyzed using the Kaplan-Meier method, and the statistical model performance using the C-index, AIC, BIC and PVE.

RESULTS

We included 857 patients with DTC (79% PTC, 21% FTC). Median follow-up was 9 years, and 67 (7.8%) died due to DTC. The Dutch guideline had the worst statistical model performance, while the 2009 ATA/2014 British guideline had the best. However, the (adapted) TNM system outperformed all stratification systems.

CONCLUSIONS

In a European population of patients with DTC, out of ten International guidelines employing six risk of recurrence stratification systems and one mortality based stratification system, our optimized age-adjusted TNM system (8th edition) outperformed all other systems.

Treatment strategies for low-risk papillary thyroid carcinoma: a position statement from the Thyroid Department of the Brazilian Society of Endocrinology and Metabolism (SBEM)

Increasingly sensitive diagnostic methods, better understanding of molecular pathophysiology, and well-conducted prospective studies have changed the current approach to patients with thyroid cancer, requiring the implementation of individualized management. Most patients with papillary thyroid carcinoma (PTC) are currently considered to have a low risk of mortality and disease persistence/recurrence. Consequently, current treatment recommendations for these patients include less invasive or intensive therapies. We used the most recent evidence to prepare a position statement providing guidance for decisions regarding the management of patients with low-risk PTC (LRPTC). This document summarizes the criteria defining LRPTC (including considerations regarding changes in the TNM staging system), indications and contraindications for active surveillance, and recommendations for follow-up and surgery. Active surveillance may be an appropriate initial choice in selected patients, and the criteria to recommend this approach are detailed. A section is dedicated to the current evidence regarding lobectomy versus total thyroidectomy and the potential pitfalls of each approach, considering the challenges during long-term follow-up. Indications for radioiodine (RAI) therapy are also addressed, along with the benefits and risks associated with this treatment, patient preparation, and dosage. Finally, this statement presents the best follow-up strategies for LRPTC after lobectomy and total thyroidectomy with or without RAI.

Comparison of the prognostic value of AJCC cancer staging system 7th and 8th editions for differentiated thyroid cancer

BACKGROUND

In the last American Joint Committee on Cancer/Tumor, Node, Metastasis (AJCC/TNM) 8th edition (TNM8), several changes were introduced to this risk stratification system to improve the prognosis of differentiated thyroid cancer (DTC).

AIM

To validate the impact of TNM8 vs. TNM 7th edition (TNM7) in DTC in terms of predictive value in two hospitals from Buenos Aires, Argentina.

METHODS

Retrospective study of DTC patients from two institutions. Reclassification from TNM7 to TNM8, disease-specific survival (DSS), and final clinical outcomes at the end of follow-up (recurrent/persistent structural disease) (median 5 years) were analyzed. The proportion of variation explained (PVE) was used to compare the predictive capability of DSS of both classification systems.

RESULTS

Reclassification of 245 patients, aged (mean ± SD) 55 ± 15.36 years, 91% women, to TNM8 from TNM7 showed: 82% vs 57% stage I (SI), 10% vs 8.5% SII, 5% vs 22% SIII, 3% vs 12% SIV (p < 0.01). Forty percent of the population was downstaged with TNM8. Ten-year DSS rates for SI, SII, SIII and SIV in TNM7 were 100, 100, 100 and 74%, respectively and in TNM8: 97.6, 100, 100 and 37.5%, respectively. Out of 4 disease-specific deaths in SIV TNM7, one was subclassified to SI TNM8, corresponding to a 53-year-old patient with structural persistence. PVE for TNM8 (29%) was more than twice that of TNM7 (13%).

CONCLUSION

In this Argentinian DTC patients sample, it was confirmed that the new TNM8 classification is more accurate in predicting survival attributable to cancer than its previous version.

Diagnostic and Treatment Considerations for Thyroid Cancer in Women of Reproductive Age and the Perinatal Period

Thyroid cancer is one of the most common cancers diagnosed in women of reproductive age and during pregnancy. This leads to important questions about thyroid cancer prognosis and treatment, but also fertility and risk for adverse obstetric and/or fetal and neonatal outcomes. The benefits of thyroid cancer treatment should be weighed against its harms, as various options may adversely impact maternal and fetal health. In the current review, the authors focus on perinatal-specific clinical considerations related to the care of patients with thyroid cancer.

Assessment of Radiofrequency Ablation for Papillary Microcarcinoma of the Thyroid: A Systematic Review and Meta-analysis

IMPORTANCE

Papillary microcarcinomas of the thyroid (mPTCs) account for an increasing proportion of thyroid cancers in past decades. The use of radiofrequency ablation (RFA) has been investigated as an alternative to surgery. The effectiveness and safety of RFA has yet to be determined.

OBJECTIVE

To evaluate the effectiveness and safety of RFA for low-risk mPTC.

DATA SOURCES

Embase, MEDLINE via Ovid, Web of Science Core Collection, Cochrane Central Register of Controlled Trials, and the top 100 references of Google Scholar were searched from inception to May 28, 2021.

STUDY SELECTION

Articles reporting on adult patients with mPTC treated with RFA were included. Studies that involved patients with pre-ablation lymph node or distant metastases, recurrence of disease, or extrathyroidal extension were excluded. Final article selection was conducted by multiple reviewers based on consensus. The proportion of eligible articles was 1%.

DATA EXTRACTION AND SYNTHESIS

This meta-analysis was conducted in accordance with the MOOSE guidelines. Random and fixed-effect models were applied to obtain pooled proportions and 95% CIs.

MAIN OUTCOMES AND MEASURES

The primary outcome was the complete disappearance rate of mPTC. Secondary outcomes were tumor progression and complications.

RESULTS

Fifteen studies were included in this meta-analysis. A total of 1770 patients (1379 women [77.9%]; mean [SD] age, 45.4 [11.4] years; age range, 42.5-66.0 years) with 1822 tumors were treated with RFA; 49 tumors underwent 1 additional RFA session and 1 tumor underwent 2 additional RFA sessions. Mean (SD) follow-up time was 33.0 (11.4) months (range, 6-131 months). The pooled complete disappearance rate at the end of follow-up was 79% (95% CI, 65%-94%). The overall tumor progression rate was 1.5% (n = 26 patients), local residual mPTC in the ablation area was found in 7 tumors (0.4%), new mPTC in the thyroid was found in 15 patients (0.9%), and 4 patients (0.2%) developed lymph node metastases during follow-up. No distant metastases were detected. Three major complications occurred (2 voice changes lasting >2 months and 1 cardiac arrhythmia). Minor complications were described in 45 patients.

CONCLUSIONS AND RELEVANCE

The findings of this systematic review and meta-analysis suggest that RFA is a safe and efficient method to treat selected low-risk mPTCs. Radiofrequency ablation could be envisioned as step-up treatment after local tumor growth under active surveillance for an mPTC or initial treatment in patients with mPTCs with anxiety about active surveillance.

Risk factors associated with disease-specific mortality in papillary thyroid cancer patients with distant metastases

PURPOSE

Papillary thyroid carcinoma (PTC) is among the most curable cancer types. Even though uncommon, some patients present distant metastatic disease at diagnosis or during the follow-up and most of them have long-term survival. However, there continues to be controversies regarding what clinicopathological features are associated with mortality in these patients. This paper evaluates the factors related to poor disease-specific survival (DSS) in patients with metastatic PTC.

METHODS

A retrospective cohort study included PTC patients with distant metastasis from a tertiary public oncological center. Clinicopathological features, treatment modalities, and outcome were reviewed.

RESULTS

Between 1986 and 2014, 108 patients were diagnosed with metastatic PTC. In the multivariate analysis male sex (HR = 2.65; 95%CI: 1.08-6.53; P = 0.033), radioiodine refractory disease (HR = 9.50; 95%CI: 1.23-73.38; P = 0.031) and metastasis at multiple sites (HR = 5.91; 95%CI: 1.80-19.32; P = 0.003) were independent risk factors for death in patients with metastatic PTC.

CONCLUSION

Male patients with metastatic PTC, with radioiodine refractory disease and metastasis at multiple sites have a high risk of death.

Concepts of Pathological Staging and Prognosis in Papillary Thyroid Carcinoma

American Joint Committee on Cancer (AJCC)/Union for International Cancer Control (AJCC/UICC) staging and American Thyroid Association (ATA) risk predication system are the best predicators of mortality and cancer recurrence, respectively, in patients with differentiated thyroid carcinoma, including papillary thyroid carcinoma. In ATA risk stratification of differentiated thyroid carcinomas, clinical features, nodal features, and pathological features are assessed. Many of the features are also assessed in pathological staging. The prognostic stage grouping of papillary thyroid carcinoma in AJCC/UICC depends on the age of the patients as well as the standard parameters-extent of tumor (T), lymph node status (N), and presence of distant metastasis (M). Major changes noted in the current pathological staging protocol include the cut-off age from 45-year to 55-year in grouping of patients, use of gross invasion of strap muscles instead of minimal microscopic extrathyroidal extensions as T3b and downstage of many prognostic groups such as those with lymph node metastases (without distant metastases) from Stage III to Stage II. The staging protocol have moved many patients with papillary thyroid carcinoma into good prognostic groups for better predication of patients' survival rates and to avoid unnecessary treatment. This new approach has been verified by different groups globally, although modifications could be expected in the future for better prognostic assessment in patients with papillary thyroid carcinoma.

Global Hotspots and Prospects of I-131 Therapy in Thyroid Carcinoma via Bibliometric Analysis

Background

Hundreds of studies have reported the application of iodine-131 (I-131) in thyroid carcinoma (THCA) in past years. However, the status of research in the field and other related topics have not been investigated. This study aimed to identify the cooperation of authors, countries, and institutions, as well as explore the hot topics and prospects regarding I-131 therapy in THCA based on previous studies.

Methods

Publications from 2010 to 2020 were retrieved from Web of Science Core Collection according to research strategy. Bibliometric analyses were performed using VOSviewer 1.6.15 and CiteSpace 5.7.3 to evaluate and visualize the cooperation network, hot topic, and research frontier.

Results

The number of publications showed a trend of fluctuation between 2010 and 2020. We identified 1387 publications related to I-131 therapy in THCA, which were published by 1628 institutions from 82 countries. The largest proportion of publications were emanated from the USA, and the majority of papers were published by Thyroid. Shanghai Jiao Tong University of China contributed the most papers. Although many authors participated in the research of this field, high-yield authors were few. Co-occurrence analysis classified keywords into five clusters, including assessment, efficacy measurement, monitoring, hormone regulation, and guidelines of I-131 therapy. The terms “bone marrow dosimetry and time” were among the latest hotspots. The research frontier topic in I-131 therapy focused on the “P53 and anti-Müllerian hormone”.

Conclusion

The attention to I-131 therapy in THCA should be increased considerably. It was necessary to construct active co-operations between authors, countries, and institutions to promote the development of this field. Recent researches referred to the timing and dose assessment of I-131 therapy in THCA. Future studies likely focused on targeted therapy and adverse effects evaluation were worthy of research as well.

Overall survival is improved with total thyroidectomy and radiation for male patients and patients older than 55 with T2N0M0 Stage 1 classic papillary thyroid cancer

BACKGROUND

We examine whether surgery extent and radiation administration affect overall survival for cT2N0M0 classic papillary thyroid cancer according to age and sex.

METHODS

Patients with cT2N0M0 classic papillary thyroid cancer tumors in the National Cancer Data Base (2004-2016) were selected. Multivariable Cox regression analysis compared patients (combined male + female cohorts) having lobectomy to those having total thyroidectomy with or without radiation (primarily radioactive iodine) for ages: 18 to 45, 46 to 55, and >55 years. In addition, 1:1 propensity score matching and Kaplan-Meier curves with 10-year overall survival estimates, and log-rank test were stratified by age and sex.

RESULTS

Lobectomy had equivalent overall survival to total thyroidectomy without and with radiation for patients (combined male + female cohorts) aged 18 to 45 and 46 to 55 years on multivariable analysis. On propensity score matching there was overall survival advantage for total thyroidectomy with radiation over both lobectomy and total thyroidectomy for men (ages 18-90+ combined) and overall survival advantage in patients (combined male + female cohort) aged >55 years having total thyroidectomy with radiation versus lobectomy. On propensity score matching there were no overall survival differences in women (ages 18-90+ combined) or patients (combined male + female cohort) aged 18 to 45 and 46 to 55 years having either lobectomy, total thyroidectomy, or total thyroidectomy with radiation.

CONCLUSION

For cT2N0M0 classic papillary thyroid cancer, total thyroidectomy with radiation improves 10-year overall survival for patients (combined male + female cohort) aged >55 years and men (ages 18-90+ combined).

The prognostic value of lymph node metastasis and the eighth edition of AJCC for patients with anaplastic thyroid cancer

OBJECTIVE

The eighth edition of the American Joint Committee on Cancer (AJCC-v8) for anaplastic thyroid cancer (ATC) made a revision in staging for patients with lymph node metastasis (LNM) based on the seventh edition of AJCC (AJCC-v7). Our study aimed to evaluate the predictive ability of AJCC-v8 for survival in patients with ATC by exploring the association between lymph node stage and prognosis of ATC patients.

METHODS

Retrospective study of ATC in Surveillance, Epidemiology and End Results (SEER) database. The association between LNM and survival of ATC was estimated by the Kaplan-Meier method and Cox regression model. The predictive performances of the AJCC-v8 and AJCC-v7 were estimated through C-index, Akaike information criterion (AIC) and Bayesian information criterion (BIC).

RESULTS

A total of 313 patients with ATC were included in our analysis. Notably, LNM was identified as an independent risk factor for ATC mortality (adjusted HR, 1.47, 95% CI, 1.10-1.96; p = .009), while the risk of mortality in N1a group was comparable to that in N1b group according to univariate (HR, 1.30, 95% CI, 0.92-1.82; p = .133) and multivariate (adjusted HR 0.87, 95% CI, 0.60-1.27; p = .467) cox analyses. Applying the AJCC-v8, the survival of migration population staged T1-3aN1M0 was significantly worse than that of T1-3aN0M0 patients (IVA stage), while was not different from that of T3b-T4bN0/N1M0 patients (IVB stage). With a higher C-index (0.60 vs. 0.59), lower AIC (2728 vs. 2732) and BIC (2732 vs. 2735), AJCC-v8 was demonstrably a more favourable prediction model than AJCC-v7.

CONCLUSIONS

This study demonstrated that LNM was independently associated with poor prognosis of ATC, and AJCC-v8 with the modified staging of patients with LNM showed better survival predictive performance in ATC patients than AJCC-v7.

How to identify indolent thyroid tumors unlikely to recur and cause cancer death immediately after surgery-Risk stratification of papillary thyroid carcinoma in young patients

Current histopathological diagnosis methods cannot distinguish the two types of thyroid carcinoma: clinically significant carcinomas with a potential risk of recurrence, metastasis, and cancer death, and clinically insignificant carcinomas with a slow growth rate. Both thyroid tumors are diagnosed as "carcinoma" in current pathology practice. The clinician usually recommends surgery to the patient and the patient often accepts it because of cancer terminology. The treatment for these clinically insignificant carcinomas does not benefit the patient and negatively impacts society. The author proposed risk stratification of thyroid tumors using the growth rate (Ki-67 labeling index), which accurately differentiates four prognostically relevant risk groups based on the Ki-67 labeling index, ≥30%, ≥10 and <30%, >5 and <10%, and ≤5%. Indolent thyroid tumors with an excellent prognosis have the following four features: young age, early-stage (T1-2 M0), curatively treated, and low proliferation index (Ki-67 labeling index of ≤5%), and are unlikely to recur, metastasize, or cause cancer death. Accurate identification of these indolent tumors helps clinicians select more conservative treatments to avoid unnecessary aggressive (total thyroidectomy followed by radio-active iodine) treatments. Clinicians can alleviate the fears of patients by confirming these four features, including the low proliferation rate, in a pathology report immediately after surgery when patients are most concerned.

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.

TERT Promoter Mutations and the 8th Edition TNM Classification in Predicting the Survival of Thyroid Cancer Patients

Simple Summary

In a cohort study involving 393 patients with differentiated thyroid cancer, TERT promoter mutations were found to act as an independent poor prognostic factor based on the American Joint Committee on Cancer (AJCC) tumor-node-metastasis 8th edition (TNM-8) in differentiated thyroid carcinoma (DTC) patients, regardless of the histological types or stage at diagnosis. Since the current AJCC TNM-8 is insufficient to distinguish the risk of mortality in patients with differentiated thyroid cancer, a proposal for a new survival prediction model that includes the TERT promoter mutational state is required.

Abstract

Our research group has previously shown that the presence of TERT promoter mutations is an independent prognostic factor, by applying the TERT mutation status to the variables of the AJCC 7th edition. This study aimed to determine if TERT mutations could be independent predictors of thyroid cancer-specific mortality based on the AJCC TNM 8th edition, with long-term follow-up. This was a retrospective study of 393 patients with pathologically confirmed differentiated thyroid carcinoma (DTC) after thyroidectomy at a tertiary Korean hospital from 1994 to 2004. The thyroid cancer-specific mortality rate was 6.9% (5.2% for papillary and 15.2% for follicular cancers). TERT promoter mutations were identified in 10.9% (43/393) of DTC cases (9.8% of papillary and 16.7% of follicular cancer) and were associated with older age (p < 0.001), the presence of extrathyroidal invasion (p < 0.001), distant metastasis (p = 0.001), and advanced stage at diagnosis (p < 0.001). The 10-year survival rate in mutant TERT was 67.4% for DTC patients (vs. 98% for wild-type; adjusted hazard ratio (HR) of 9.93, (95% CI: 3.67–26.90)) and 75% for patients with papillary cancer (vs. 99%; 18.55 (4.83–71.18)). In addition, TERT promoter mutations were related to poor prognosis regardless of histologic type (p < 0.001 for both papillary and follicular cancer) or initial stage (p < 0.001, p = 0.004, and p = 0.086 for stages I, II, and III and IV, respectively). TERT promoter mutations comprise an independent poor prognostic factor after adjusting for the clinicopathological risk factors of the AJCC TNM 8th edition, histologic type, and each stage at diagnosis, which could increase prognostic predictability for patients with DTC.

Changes in Stage Distribution and Disease-Specific Survival in Differentiated Thyroid Cancer with Transition to American Joint Committee on Cancer 8th Edition: A Systematic Review and Meta-Analysis

BACKGROUND

Recent revision significantly changed the American Joint Committee on Cancer (AJCC) staging criteria for differentiated thyroid cancer (DTC). To quantitatively evaluate resulting changes in patient stage distribution and the associated disease-specific survival (DSS) incorporating diverse populations, we performed a meta-analysis of studies comparing the AJCC 7th edition (AJCC-7) with 8th edition (AJCC-8) staging for DTC.

MATERIALS AND METHODS

After PROSPERO registration (#CRD42019123657), publications in English reporting DSS of DTC with AJCC-7 and AJCC-8 from inception to June 2019 were identified by search of MEDLINE and PubMed. Random-effects meta-analyses were conducted to compare differences in survival between AJCC-7 and AJCC-8. Pooled hazard ratios, 10-year DSS, and corresponding interval estimates were calculated for AJCC subgroups. Differences in survival between editions were assessed using subgroup analysis with nonoverlapping confidence intervals indicating statistical significance.

RESULTS

Final analysis included six studies with 10,850 subjects and median follow-up from 55 to 148 months. Use of AJCC-8 shifted classification to earlier stages: stage I, from 60% to 81%; stage II, from 5% to 13%; stage III, from 21% to 2%; stage IV, from 10% to 3%. Ten-year DSS was significantly lower in AJCC-8 versus AJCC-7 in patients with stage II (88.6%, 95% confidence interval [CI] 82.7-94.6% vs. 98.1%, 95% CI 96.6-99.6%, respectively) and stage III disease (70.5%, 95% CI 59.1-83.9% vs. 96.8%, 95% CI 94.1-99.64%, respectively).

CONCLUSION

Meta-analysis of revised AJCC staging for DTC, incorporating diverse populations, demonstrates redistribution of patients toward earlier clinical stages and better stratification of disease-specific mortality risk, specifically among patients now classified with stage II and III disease.

IMPLICATIONS FOR PRACTICE

This study provides updated estimates of disease-specific survival for patients with differentiated thyroid cancer determined by the American Joint Committee on Cancer staging system that are generalizable to broader populations and support improved stratification using the recently revised criteria.

A Comparison of the Seventh and Eighth Editions of the AJCC Staging Systems to Predict Recurrence in Papillary Thyroid Microcarcinoma

BACKGROUND

The incidence of papillary thyroid microcarcinoma has been constantly rising in recent decades. The tumor, node, metastasis staging system is designed to predict prognosis in patients with papillary thyroid carcinoma. Recent studies have shown that the American Joint Committee on Cancer (AJCC) 8th edition is superior to the 7th edition for predicting tumor recurrence in PTC patients. To date, whether the 8th edition is also better able to predict recurrence in papillary thyroid microcarcinoma (PTMC) remains unclear.

METHOD

We enrolled 1007 cases from our thyroid cancer database in the First Affiliated Hospital, Zhejiang University School of Medicine, from 1997 to 2011. Univariable and multivariate Cox hazard regression analyses were used to identify the association between variables and recurrence. Disease-free survival was calculated using the Kaplan-Meier method and compared using the log-rank test.

RESULTS

A total of 1007 PTMC patients were enrolled, with a median follow-up of 67 months. Of 93 (9.2%) patients downstaged by the changes in versions, 49 (52.7%) were downstaged because the age-at-diagnosis cut-off used for staging increased from 45 to 55 years, while 35 (37.6%) were downstaged due to the weakening of the effects of lymph node metastasis. The recurrence rate of PTMC was 4.17%. Univariate Cox hazards regression analyses showed that TNM stage according to the AJCC 8th edition was significantly associated with recurrence, while the recurrence survival curves showed that TNM stage (stage I vs. stage II-IV) according to the AJCC 8th edition, but not the 7th edition, was significantly associated with disease-free survival (p < 0.05).

CONCLUSIONS

The AJCC 8th edition has better ability to predict recurrence in PTMC patients than the 7th edition.

How Does The AJCC/TNM Staging System Eighth Edition Perform in Thyroid Cancer at A Major Middle Eastern Medical Center?

OBJECTIVE

The American Joint Committee on Cancer tumor node metastasis (TNM) staging system eighth edition (TNM-8) for differentiated thyroid cancer (DTC) has been introduced as a replacement for tumor node metastasis staging system seventh edition (TNM-7). We present the first study from a Middle Eastern population comparing these 2 versions of the TNM staging system.

METHODS

We compared TNM-8 with TNM-7 in 701 patients with DTC seen during a 3-year period with a median age of 37 years (6-83) and a female-to-male ratio of 558 (79.6%) to 143 (20.4%).

RESULTS

The number (%) of patients within each stage in TNM-7 and TNM-8, respectively, are as follows: stage I = 503 (71.6%) and 583 (83.2%), stage II = 52 (7.4%) and 81 (11.4%), stage III = 53 (7.6%) and 6 (0.9%), and stage IV = 93 (13.2%) and 31 (4.6%). Overall, 172 patients (24.5%) were downstaged in TNM-8 compared to that in TNM-7, as follows: 26, 30, and 24 patients from stages II, III, and IV in TNM-7 to stage I in TNM-8; 23 and 32 patients from TNM-7 stages III and IV to TNM-8 stage II; 6 patients from stage IVa in TNM-7 to stage III in TNM-8; and 31 patients from stage IVc in TNM-7 to stage IVb in TNM-8. TNM-7 and TNM-8 predicted the long-term outcome well (median follow-up, 7.9 years), but Kaplan-Meier analysis showed better separation of cancer-specific survival in TNM-8 compared to TNM-7.

CONCLUSIONS

Compared with TNM-7, TNM-8 approximately downstaged a quarter of DTC patients and was more robust in separating the outcome of different stages over time.

Evaluation of Clinicopathological and Molecular Parameters on Disease Recurrence of Papillary Thyroid Cancer Patient: A Retrospective Observational Study

Simple Summary

Papillary thyroid cancer (PTC) patients are staged according to the Tumor-Node-Metastasis staging system (TNM). This work was aimed at comparing the usefulness of the 8th edition of TNM (TNM-8), currently used, and that of the previous one (TNM-7) for predicting disease-free interval (DFI) in a cohort of 1148 patients. Moreover, clinicopathological and molecular factors were statistically evaluated in order to determine which of these was/were the best predictor(s) of DFI. Results obtained from the multivariate analysis indicated that advanced tumor stages were independent risk factors for a lower DFI regardless of TNM, but the statistical model created with the TNM-7 was most accurate. When stage-determining factors were included individually in the multivariate analysis, LN metastases, tall cell variant, and age emerged as independent risk factors for a shorter DFI, with lateral LN metastases being the most relevant. No molecular parameters could improve the prediction of DFI provided by LN metastases.

Abstract

The American Joint Committee on Cancer has revised the Tumor-Node-Metastasis (TNM) staging system for papillary thyroid cancer (PTC) patients. We examined the impact of this new classification (TNM-8) on patient stratification and estimated the prognostic value of clinicopathological features for the disease-free interval (DFI) in a cohort of 1148 PTC patients. Kaplan–Meier analyses showed that all clinicopathological parameters analyzed, except age and multifocality, were associated significantly with DFI. Cox regression identified tall cell PTC variant and stage as independent risk factors for DFI. When the stage was replaced with age, tumor size, and lymph node (LN) metastases in the set of covariates, the lateral LN metastases stood out as the strongest independent predictor of DFI, followed by tall cell variant and age. A noteworthy result emerging from these analyzes is that regression models had lower Akaike and Bayesian information criterions if variables were categorized based on the TNM-7. In addition, we examined data from a different PTC patient cohort, acquired from The Cancer Genome Atlas database, to verify whether the DFI prediction could be enhanced by further clinicopathological and molecular parameters. However, none of these was found to be a significant predictor of DFI in the Cox model.

New paradigms in the treatment of low-risk thyroid cancer

INTRODUCTION

Thyroid cancer is the most common endocrine malignancy. Multiple different staging systems have been introduced and used for differentiated thyroid carcinoma (DTC).

AREAS COVERED

In this literature review we provide an overview of the standard options for management of patients with low risk differentiated thyroid cancer.

EXPERT OPINION

Surgery is considered the first and most important step in managing DTC with goal to remove all the malignant foci in order to achieve cure and increase the survival with least chance of recurrence. Many studies have been conducted to determine the best surgical approaches and how aggressive surgeries should be in order to achieve the best outcomes regarding efficacy as well as safety. Radioactive iodine (RAI) therapy has also been a part of the treatment regimen and is used for different purposes with three main goals: post-surgical ablation, adjuvant therapy and persisted/recurrent disease treatment. Radiation therapy, on the other hand, is still not recommended to be used routinely in DTC because of the conflicting data of its benefit.

Predictors of recurrence after total thyroidectomy plus neck dissection and radioactive iodine ablation for high-risk papillary thyroid carcinoma

BACKGROUND

American Thyroid Association (ATA) proposed management guidelines for differentiated thyroid cancer, including a three-tiered risk stratification system for structural recurrence. This study aimed to compare the various 2015 ATA criteria for the strength of association with the recurrence of high-risk papillary thyroid carcinoma (PTC).

STUDY DESIGN

This study included 545 consecutive patients who underwent total thyroidectomy plus neck dissection and radioactive iodine ablation (RAI) for previously untreated high-risk PTC. The association of recurrence-free survival (RFS) with clinicopathological factors was evaluated by univariate and multivariate Cox proportional hazard regression analyses.

RESULTS

During a follow-up median period of 89 months, 90 (16.5%) patients had any-site recurrence. Of the high-risk factors, high stimulated thyroglobulin (sTg) level and >3-cm sized lymph nodes (LNs) were significantly associated with recurrence (all P < .005). Sex, tumor size, lymphovascular invasion, multifocality, number of positive LNs, extranodal extension, T and N classifications, and overall tumor-node-metastasis stage were also significantly associated with recurrence (all P < .05). In multivariate analyses, high sTg level [adjusted hazard ratio (HR) = 7.18] and N1b (adjusted HR = 3.27) were independent factors predictive of recurrence (all P ≤ .001).

CONCLUSIONS

Postoperative high serum sTg level might be the most important predictor of PTC recurrence after total thyroidectomy plus neck dissection and RAI.

Role of [99mTc]Tc-Galacto-RGD2 SPECT/CT in identifying metastatic differentiated thyroid carcinoma after thyroidectomy and radioactive iodine therapy

PURPOSE

Integrin αvβ3, a member of the arginine-glycine-aspartate (RGD)-binding subfamily, is associated with tumor angiogenesis and metastasis. The aim of study is to investigate the clinical role of [^99mTc]Tc-Galacto-RGD₂ SPECT/CT in high-risk differentiated thyroid carcinoma (DTC) after thyroidectomy and radioactive iodine (RAI) therapy.

METHODS

Thirty-six patients with high-risk DTC (20 males, 16 females; mean age: 59.9 ± 16.6 y) who underwent thyroidectomy and RAI therapy were consecutively enrolled in this study. All patients underwent [^99mTc]Tc-Galacto-RGD₂ SPECT/CT and diagnostic ¹³¹I whole-body scan 6 months after the last RAI treatment. A region of interest (ROI) was drawn and the ratio of tumor/non-target (T/NT) was calculated. Per-patient and per-lesion analysis was performed to evaluate the diagnostic efficacy. The final diagnosis was confirmed by histopathology and follow-up. Integrin αvβ3, CD31, and Ki-67 expression in the tumor were also analyzed for evaluation of angiogenesis and proliferation.

RESULTS

Out of 36 patients, twenty-two had metastatic disease. By per-patient analysis, the area under the curve of [^99mTc]Tc-Galacto-RGD₂ SPECT/CT was marginally significantly higher than that of ¹³¹I whole-body scan and morphological imaging (P = 0.0034 and 0.0006). For per-lesion analysis, [^99mTc]Tc-Galacto-RGD₂ SPECT/CT identified 67 metastatic lymph nodes in 14 patients, 12 lung metastases in four patients, and 12 bone metastases in six patients; its sensitivity was significantly higher than that of ¹³¹I whole-body scan in detection of lymphatic (90.54% vs. 55.41%, P = 0.0124) and bone metastasis (92.31% vs. 30.77%, P = 0.046). The ratio of T/NT in metastatic lesions increased with the DTC upstaging.

CONCLUSIONS

[^99mTc]Tc-Galacto-RGD₂ SPECT/CT has high sensitivity in the detection of metastasis in high-risk DTC and further contributes to evaluation of tumor angiogenesis and radio‑iodine refractory status.

Radioactive Iodine Therapy in Differentiated Thyroid Cancer: 2020 Update

OBJECTIVE. The paradigm of theranostics is based on tailoring therapy for the purpose of optimizing outcomes. This principle is being applied to radioactive iodine therapy. Consequently, thyroid cancer therapy protocols are evolving. The purpose of this article is to promote a modern approach to radioiodine therapy. CONCLUSION. This article highlights guidelines and position statements, summarizes the prognostication systems of thyroid cancer, and reviews which prescribed activities of ¹³¹I.

Contemporary considerations in adjuvant radioiodine treatment of adults with differentiated thyroid cancer

Differentiated thyroid cancer (DTC) is the most common endocrine malignancy with a growing incidence worldwide. The initial conventional management is surgery, followed by consideration of ¹³¹ I treatment that includes three options. These are termed remnant ablation (targeting benign thyroid remnant), adjuvant (targeting presumed microscopic DTC) and known disease (targeting macroscopic DTC) treatments. Some experts mostly rely on clinicopathologic assessment for recurrence risk to select patients for the ¹³¹ I treatment. Others, in addition, apply radioiodine imaging to guide their treatment planning, termed theranostics (aka theragnostics or radiotheragnostics). In patients with low-risk DTC, remnant ablation rather than adjuvant treatment is generally recommended and, in this setting, the ATA recommends a low ¹³¹ I activity. ¹³¹ I adjuvant treatment is universally recommended in patients with high-risk DTC (a primary tumor of any size with gross extrathyroidal extension) and is generally recommended in intermediate-risk DTC (primary tumor >4 cm in diameter, locoregional metastases, microscopic extrathyroidal extension, aggressive histology or vascular invasion). The optimal amount of ¹³¹ I activity for adjuvant treatment is controversial, but experts reached a consensus that the ¹³¹ I activity should be greater than that for remnant ablation. The main obstacles to establishing timely evidence through randomized clinical trials for ¹³¹ I therapy include years-to-decades delay in recurrence and low disease-specific mortality. This mini-review is intended to update oncologists on the most recent clinical, pathologic, laboratory and imaging variables, as well as on the current ¹³¹ I therapy-related definitions and management paradigms, which should optimally equip them for individualized patient guidance and treatment.

Longitudinal Analysis of the Effect of Radioiodine Therapy on Ovarian Reserve in Females with Differentiated Thyroid Cancer

Background: Although international guidelines have become more conservative on the use of radioactive iodine (RAI) therapy, it is still one of the cornerstones of the treatment of patients with advanced differentiated thyroid cancer (DTC). As a large proportion of females diagnosed with DTC is in their reproductive years, knowledge about the effect of RAI on their gonadal and reproductive function is important. Earlier studies evaluating Anti-Müllerian hormone (AMH) as a representative of ovarian reserve were either cross-sectional, had relatively low numbers, had no patients with multiple RAI therapies, or had a relatively short follow-up. The primary aim of our study was, therefore, to prospectively evaluate the effect of RAI on AMH in women undergoing treatment for DTC. Methods: We included females, aged 16 years until menopause, who were scheduled to undergo their first RAI treatment for DTC at our hospital. Serum AMH was measured before initial therapy and regularly thereafter. Repeated measurement analysis was used to assess the changes of AMH concentrations over time, and how this is influenced by age and cumulative RAI dose. Results: Longitudinal AMH assessments were available in 65 patients (mean age 32 years, median of five measurements during median follow-up of 34 months). AMH concentrations changed nonlinear over time, decreased until 12 months in the single RAI group (-55%), and stabilized thereafter. In the multiple RAI group, after stabilization, a further decrease occurred (-85% after 48 months). Age in both RAI groups significantly influenced AMH change over time, with younger patients (<35 years of age) showing a less steep decrease. Conclusions: In a population of female DTC patients treated with total thyroidectomy and a single RAI therapy, AMH concentrations significantly dropped during the first year after initial therapy, and thereafter they remained stable. In patients receiving multiple RAI therapies, a further decrease was seen. Age at baseline significantly influenced AMH change over time. These results support a less aggressive treatment with RAI in low-risk patients as is advocated in the current American Thyroid Association (ATA) guidelines, especially in females older than 35 years of age with the desire to have a child.

Evaluation of the 2015 ATA Guidelines in Patients With Distant Metastatic Differentiated Thyroid Cancer

CONTEXT

Current American Thyroid Association (ATA) Management Guidelines for the treatment of differentiated thyroid cancer (DTC) stratify patients to decide on additional radioiodine (RAI) therapy after surgery, and to predict recurring/persisting disease. However, studies evaluating the detection of distant metastases and how these guidelines perform in patients with distant metastases are scarce.

OBJECTIVE

To evaluate the 2015 ATA Guidelines in DTC patients with respect to 1) the detection of distant metastases, and 2) the accuracy of its Risk Stratification System in patients with distant metastases.

PATIENTS AND MAIN OUTCOME MEASURES

We retrospectively included 83 DTC patients who were diagnosed with distant metastases around the time of initial therapy, and a control population of 472 patients (312 low-risk, 160 intermediate-risk) who did not have a routine indication for RAI therapy. We used the control group to assess the percentage of distant metastases that would have been missed if no RAI therapy was given.

RESULTS

Two hundred forty-six patients had no routine indication for RAI therapy of which 4 (1.6%) had distant metastases. Furthermore, among the 83 patients with distant metastases, 14 patients (17%) had excellent response, while 55 (67%) had structural disease after a median follow-up of 62 months. None of the 14 patients that achieved an excellent response had a recurrence.

CONCLUSIONS

In patients without a routine indication for RAI therapy according to the 2015 ATA Guidelines, distant metastases would initially have been missed in 1.6% of the patients. Furthermore, in patients with distant metastases upon diagnosis, the 2015 ATA Guidelines are an excellent predictor of both persistent disease and recurrence.

Effect of prophylactic central neck dissection on the surgical outcomes in papillary thyroid cancer: experience in a single center

PURPOSE

Morbidity due to papillary thyroid carcinoma (PTC) is increased mostly due to lymph node (LN) metastases, which lead to reoperations and complications associated with these operations. The aim is to compare the outcomes of PTC having total thyroidectomy and prophylactic central lymph node dissection (TT + PCND) with patients having total thyroidectomy (TT) alone.

METHODS

This study is a retrospective cohort analysis of 358 PTC patients that were operated by a single surgeon in a single center. Data about the patients were extracted from the medical records.

RESULTS

Of the patient cohort, 258 patients had TT + PCND (42.5 ± 11.3 years) and 100 patients (41.2 ± 11.9 years) had only TT. Total number of LN extracted in the TT + PCND group was 8.1 ± 6.9. The mean number of metastatic LN were 2.2 ± 1.9. Percentage of patients that had RAI were less in the TT + PCND group compared to the TT group. Seven patients (2.7%) in the TT + PCND group and 19 (19.0%) in TT group had recurrent disease (p < 0.0001). Of the complications, only transient hypoparathyroidism was increased in TT + PCND group compared to TT group (26.7% vs 10%, p < 0.0001).

CONCLUSION

TT + PCND performed by an experienced surgeon seems to decrease the number of LN recurrences, and the need for reoperations.

TUMOR SIZE IS AN INDEPENDENT PREDICTOR OF MORTALITY RISK IN DIFFERENTIATED THYROID CANCER PATIENTS WITH T4 DISEASE

Objective: The eighth edition of the American Joint Committee on Cancer (AJCC) guideline on the tumor-node-metastasis staging system has been applied in clinical practice for thyroid cancer since 2018. However, using these criteria, a few studies have shown no significant difference between stage III and IV diseases amongst the differentiated thyroid cancer (DTC) patients. Thus, we aimed to study the underlying reason behind this observation. Methods: Patients were selected from the Surveillance, Epidemiology, and End Results database between 2004 and 2015. The Cox proportional hazards regression model was used for the univariate and multivariate analyses to plot the Kaplan-Meier survival curves for overall survival (OS) and disease-specific survival (DSS). Results: A total of 1,431 patients had a median tumor size of 3.0 cm (range: 0.1 to 50 cm). When stratified by tumor size (≤2 cm, 2 to 4 cm, and >4 cm), lower survival rates were observed in patients with stage III (T4a) cancer and large tumor size than in those with stage IVA (T4b) cancer and small tumor size. Univariate and multivariate analyses showed that tumor size (≤4 cm versus >4 cm) is an independent prognostic factor for OS (P<.001) and DSS (P<.001) in DTC patients with T4a and T4b diseases. Conclusion: Tumor size is an independent prognostic factor for OS and DSS in DTC patients with T4 disease; tumor size-related modification of the T4 category can improve the AJCC staging system for DTC patient with stage III-IV diseases. Abbreviations: AJCC = American Joint Committee on Cancer; CI = confidence interval; DSS = disease-specific survival; DTC = differentiated thyroid cancer; FTC = follicular thyroid cancer; HR = hazard ratio; OS = overall survival; PTC = papillary thyroid cancer; SEER = Surveillance, Epidemiology, and End Results; TNM = tumor-node-metastasis.

The BRAF V600E mutation is a predictor of the effect of radioiodine therapy in papillary thyroid cancer

Objective: To investigate the correlation between the BRAF V600E gene mutation and clinicopathological features and thyroid function after iodine-131 treatment in patients with papillary thyroid cancer (PTC). Methods: A total of 128 PTC patients who underwent iodine-131 treatment after a total thyroidectomy from February 2015 to November 2016 at Hunan Cancer Hospital, China, were recruited. There were 25 males and 103 females. The age range was 11 to 73 years old. The BRAF V600E mutation in tumor tissues was detected by amplification-restriction mutation system polymerase chain reaction (ARMS-PCR), and the serum levels of Tg, TSH, Tg-Ab, and Tpo-Ab were measured by chemiluminescence after iodine-131 treatment. The BRAF V600E mutation was shown to be associated with clinicopathological characteristics and thyroid function indicators after iodine-131 treatment. Results: BRAF V600E mutation was detected in 75 of the 128 patients (58.6%) and was observed more frequently in cases with elevated Tg levels (Tg>1.00) at 3, 6, 12, and 18 months after treatment compared with patients without any BRAF mutations (P<0.05). Patients with BRAF V600E mutation had significant lower level of Tg-Ab at 3 and 12 months after treatment with iodine-131 than patients without BRAF V600E mutation (P<0.05). Among the 75 BRAF V600E patients, no significant association was found between the levels of TSH and Tpo-Ab after iodine-131 treatment (P>0.05). The BRAF V600E mutation was closely associated with the high-risk and age of the patient (≥45 years old) (P<0.05), but there was no significant correlation with gender, clinical stage, and distant metastasis. Conclusion: The BRAF V600E mutation is closely related to serum Tg elevation after treatment with iodine-131 in papillary thyroid cancer. These findings suggest that this BRAF mutation may be a predictor of the efficacy of iodine-131 treatment for papillary thyroid cancer.

Treatment of Differentiated Thyroid Carcinomas

Differentiated thyroid cancer (DTC) is the most common thyroid cancer and is frequently encountered in clinical practice. The incidence of DTC has increased significantly over the past three decades. Surgical resection, radioactive iodine (RAI), and levothyroxine suppression therapy remain the primary modalities for DTC treatment. Active surveillance for low-risk thyroid cancer may be an alternative to immediate surgery for appropriately selected patients. Patient characteristics influence treatment selection and intensity. In the subset of patients with progressive distant metastatic disease, not amenable to treatment with surgery or RAI, novel agents, including targeted therapies and immunotherapy, should be considered.

Risk Stratification in Differentiated Thyroid Cancer: From Detection to Final Follow-Up

CONTEXT

Modern management of differentiated thyroid cancer requires individualized care plans that tailor the intensity of therapy and follow-up to the estimated risks of recurrence and disease-specific mortality.

DESIGN

This summary is based on the authors' knowledge and extensive clinical experience, supplemented by review of published review articles, thyroid cancer management guidelines, published staging systems, and original articles identified through a PubMed search, which included terms such as risk stratification, staging, clinical outcomes, and differentiated thyroid cancer.

MAIN OUTCOME MEASURES

In the past, risk stratification in differentiated thyroid cancer usually referred to a static estimate of disease-specific mortality that was based on a small set of clinicopathological features available within a few weeks of completing initial therapy (thyroidectomy, with or without radioactive iodine). Today, risk stratification is a dynamic, active process used to predict the appropriateness for minimalistic initial therapy, disease-specific mortality, risk of recurrence, and the most likely response to initial therapy. Rather than being a static prediction available only after initial therapy, modern risk stratification is a dynamic, iterative process that begins as soon as a suspicious nodule is detected and continues through final follow-up.

CONCLUSIONS

Dynamic risk assessment should be used to guide all aspects of thyroid cancer management, beginning before a definitive diagnosis is made and continuing through the final follow-up visit.

Risk of Recurrence in Differentiated Thyroid Cancer: A Population-Based Comparison of the 7th and 8th Editions of the American Joint Committee on Cancer Staging Systems

BACKGROUND

Differentiated thyroid cancer (DTC) survival is excellent, making recurrence a more clinically relevant prognosticator. We hypothesized that the new American Joint Committee on Cancer (AJCC) 8th edition improves on the utility of the 7th edition in predicting the risk of recurrence in DTC.

METHODS

A population-based retrospective review compared the risk of recurrence in patients with DTC according to the AJCC 7th and 8th editions using the Surveillance, Epidemiology, and End Results-based Kentucky Cancer Registry from 2004 to 2012.

RESULTS

A total of 3248 patients with DTC were considered disease-free after treatment. Twenty percent of patients were downstaged from the 7th edition to the 8th edition. Most patients had stage I disease (80% in the 7th edition and 94% in the 8th edition). A total of 110 (3%) patients recurred after a median of 27 months. The risk of recurrence was significantly associated with stage for both editions (p < 0.001). In the 7th edition, there was poor differentiation between lower stages and better differentiation between higher stages (stage II hazard ratio [HR] 0.91, 95% confidence interval [CI] 0.39-2.11; stage III HR 3.72, 95% CI 2.29-6.07; stage IV HR 11.66, 95% CI 7.10-19.15; all compared with stage I). The 8th edition better differentiated lower stages (stage II HR 4.06, 95% CI 2.38-6.93; stage III HR 13.07, 95% CI 5.30-32.22; stage IV 11.88, 95% CI 3.76-37.59; all compared with stage I).

CONCLUSIONS

The AJCC 8th edition better differentiates the risk of DTC recurrence for early stages of disease compared with the 7th edition. However, limitations remain, emphasizing the importance of adjunctive strategies to estimate the risk of recurrence.

Assessment of the prognostic value and N1b changes of the eighth TNM/AJCC staging system for differentiated thyroid carcinoma

BACKGROUND

The aim of this study was to evaluate the prognostic veracity for disease-specific survival (DSS) of the eighth edition of the American Joint Committee on Cancer/Union for International Cancer Control tumor-node-metastasis staging system (TNM-8) compared with the seventh edition (TNM-7) in a Chinese population of patients with differentiated thyroid carcinoma (DTC) and to evaluate the impact of N1b redefinition and reclassification on prediction of survival.

METHODS

A total of 569 DTC patients who underwent thyroid surgery in two Chinese hospitals were included in analysis to assess the predictive accuracy and N1b changes of TNM-8. Data from the Surveillance, Epidemiology and End Results (SEER) program were applied to validate the findings on N1b changes of TNM-8. Unadjusted DSS was calculated using the Kaplan-Meier method. Multivariable Cox proportional hazards models were used to evaluate the association of stage and lymph node metastasis (LNM) status with survival. The proportion of variation explained (PVE), Akaike information criterion (AIC), and Bayesian information criterion (BIC) were evaluated to compare model performance.

RESULTS

When TNM-8 was applied, 39.7% of patients were downstaged relative to TMN-7. In comparison of TNM-7 and TMN-8, the PVE was 18.68% and 22.33%, the AIC was 704.22 and 680.50, and the BIC was 702.98 and 679.24, respectively. In 569 Chinese patients with DTC, levels I-V LNM was significantly related to poorer DSS compared with N0 and level VI LNM. Among patients aged ≥ 55 years, those with levels I-V and VII LNM had significantly worse DSS than those with N0 and Level VI LNM. In the SEER dataset, patients with levels I-V and VII LNM had significantly worse DSS compared with those with N0 and Level VI LNM, especially in older patients (age ≥ 55 years).

CONCLUSIONS

TNM-8 staged a significant number of Chinese patients into lower stages and improved the accuracy of predicting DSS compared with TNM-7. However, changes in lateral LNM definition and classification of TNM-8 have a significant prognostic implication for patients with DTC, especially older patients (≥ 55 years). Our data suggest that a modified TNM staging system would be more useful for predicting mortality and determining a proper treatment strategy in patients with DTC.

Evaluating the 2015 American Thyroid Association Risk Stratification System in High-Risk Papillary and Follicular Thyroid Cancer Patients

Background: The 2015 American Thyroid Association (ATA) Risk Stratification System for differentiated thyroid cancer (DTC) is designed to predict recurring/persisting disease but not survival. Earlier studies evaluating this system evaluated the 2009 edition, comprised a low number of patients with ATA high-risk, had low numbers of patients with follicular thyroid cancer (FTC), or did not distinguish between papillary and FTC. Therefore, we evaluated the prognostic value of the 2015 ATA Risk Stratification System in a large population of high-risk thyroid cancer patients, which included a substantial proportion of FTC patients. Methods: We retrospectively studied adult patients with DTC who were diagnosed and/or treated at a Dutch university hospital between January 2002 and December 2015. All patients fulfilled the 2015 ATA high-risk criteria. Overall survival and disease-specific survival (DSS) were analyzed using the Kaplan-Meier method. Logistic regression and Cox proportional hazards models were used to estimate the effects of DTC subtype and ATA high-risk criteria on response to therapy, recurrence, as well as survival. Results: We included 236 patients with high-risk DTC (32% FTC) with a mean age of 56 years. Median follow-up was 6 years. At final follow-up, 69 patients (29%) had excellent response, while 120 (51%) had structural disease. All high-risk criteria, except large pathologic lymph nodes, were inversely related to excellent response and positively related to structural disease at final follow-up. During follow-up, 14% of the 79 patients who achieved excellent response developed a recurrence. Finally, 10-year DSS was much higher in the initial excellent response than in the initial structural disease group (100% vs. 61%, respectively). Conclusions: In a population of high-risk DTC patients harboring a large subset of FTC patients, the 2015 ATA Risk Stratification System is not only an excellent predictor of persisting disease but also of survival. As much as 14% of the high-risk patients who had an excellent response upon dynamic risk stratification experienced a recurrence during follow-up. Clinicians should thus be aware of the relatively high recurrence risk in these patients, even after an excellent response to therapy.

Association of the Cumulative Dose of Radioactive Iodine Therapy With Overall Survival in Patients With Differentiated Thyroid Cancer and Pulmonary Metastases

Purpose: The optimal cumulative dose of radioactive iodine therapy (RAIT) for patients with differentiated thyroid cancer (DTC) and pulmonary metastases (PM) is not known, therefore we evaluated the association between the cumulative dose of RAIT and overall survival (OS). Methods: A total of 202 patients with DTC and PM who underwent thyroidectomy and RAIT were analyzed in this study. The median cumulative dose of RAIT was 530 mCi. OS was compared with an age- and sex-matched general population from China to assess relative survival. Multivariable proportional hazards model smoothing by penalized spline was applied to identify independent predictors and examine the adjusted non-linear association of cumulative dose of RAIT and patient age with mortality. Results: The observed survival and relative survival at 10 years was 54.96 and 60.81%, respectively, with the standardized mortality ratio being 5.34. The cumulative dose of RAIT was associated with mortality in a dose-dependent fashion without an apparent cutoff point after adjustment of other variables. A linear but moderate association was found in the dose of 300 to 1,000 mCi. Cumulative dose of RAIT, patient age, diameter of pulmonary metastases, and extrapulmonary metastases were identified as independent predictors for OS. The increasing patient age was associated with mortality in a non-linear pattern, with the optimal threshold being 40 years. With advancing age, the risk of death increases rapidly in patients aged 40 years and younger, but slowly in patients over 40 years. Conclusions: RAIT should be assigned to RAI-avid patients until disease has been controlled or RAIT becomes refractory after consideration of the potential long-term side-effects. Patient age was associated with OS in a non-linear pattern, with a threshold at 40 years. Consideration of age as a binary variable could elucidate a more accurate prognosis in such patients.

Clinical Assessment and Risk Stratification in Differentiated Thyroid Cancer

Thyroid cancer management is rapidly evolving to a personalized management approach. Risk stratification systems are designed to assist in personalized management. Differentiating patients who may benefit from aggressive therapy and intense follow-up as opposed to those who can be successfully treated with minimalized initial management options and follow-up is crucial to the development of the right treatment plan for the right patient in order to optimize initial therapy and follow-up testing. This article aims to describe and discuss the risk stratification systems currently recommended for differentiated thyroid cancer.

Survival in Papillary Thyroid Microcarcinoma: A Comparative Analysis Between the 7th and 8th Versions of the AJCC/UICC Staging System Based on the SEER Database

Background: Considerable modifications have been introduced in the new edition of the American Joint Committee on Cancer/Union for International Cancer Control (AJCC/UICC) TNM staging system. Based on the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) database, this study aimed to compare the 7th and 8th editions of the AJCC/UICC TNM staging system for patients with papillary thyroid microcarcinoma (PTMC) and follicular variant papillary thyroid microcarcinoma (FVPTMC). Methods: A Data from 2004 to 2014 of 39,032 patients registered in the SEER database were included. The 7th and 8th editions of the AJCC/UICC staging system were compared in terms of TNM staging, age cutoff, and clinical staging. Patient survival was evaluated using Kaplan-Meier and multivariable Cox proportional hazards models. The American Thyroid Association (ATA) risk stratification system was integrated with the AJCC/UICC staging system for further investigation. Receiver operating characteristic (ROC) curves, Harrell's C-index, Akaike information criterion (AIC), and the Bayesian information criterion (BIC) were used to assess the models' performances. Results: Revised TNM categories, age cutoff, and clinical staging in the 8th edition resulted in reclassification of the overall stage. Applying the 8th edition, 1,278 stage III and 425 stage IV patients were reclassified as stage I; 950 stage III and 459 stage IV patients were reclassified as stage II; 77 stage IV patients were reclassified as stage III; and only 88 patients remained in stage IV. All patients in stage I, according to the 7th edition, remained in this stage when using the 8th edition. Patients classified into higher stages (III and IV) in the 8th edition showed a worse prognosis than those classified into same stages in the 7th edition. The 8th edition proved to be a better model with higher prognostic efficacy survival (higher AUC and C-index, lower AIC and BIC) than the 7th edition. When integrated with the ATA risk stratification system, the 8th edition still showed better discriminative power for patients in the higher risk group. Conclusion: Based on the SEER database, the 8th edition of the AJCC/UICC staging system has better prognostic efficacy than the 7th edition for patients with PTMC and FVPTMC.

A comparison of the 7th and 8th editions of the AJCC staging system in terms of predicting recurrence and survival in patients with papillary thyroid carcinoma

OBJECTIVES

The recently published 8th edition of the American Joint Committee on Cancer (AJCC) tumour-node-metastasis (TNM) staging system was significantly updated following the thyroid cancer-related guidelines to provide better predictability of survival but not focus on recurrence. Therefore, we compared the predictive values of the 7th and 8th editions of the AJCC staging systems for recurrence-free survival (RFS) and overall survival (OS) after thyroidectomy for papillary thyroid carcinoma (PTC).

METHODS

This retrospective study included 2930 patients who underwent thyroidectomy and neck dissection for previously untreated PTC between 2006 and 2014. TNM stage was defined according to 7th and 8th editions. Univariate and multivariate Cox proportional hazard regression analyses were used to identify associations between variables and RFS or OS. Multivariate models for the AJCC TNM stages were adjusted for clinical and pathological variables.

RESULTS

A significant number of patients classified as T3 with overall TNM stages II-IV in the AJCC 7th edition were down-staged in the 8th edition. Unadjusted T classification and overall TNM staging in both the 7th and 8th editions were significantly associated with RFS and OS rates (P < 0.001). After adjustment for clinicopathological factors, the overall TNM stage according to the AJCC 8th edition, but not the 7th edition, remained significantly associated with RFS and OS (P < 0.05), with better predictability of recurrence and survival, in patients with PTC.

CONCLUSIONS

The 8th edition AJCC staging system down-staged a large proportion of PTC patients, resulting in better predictability of recurrence and survival compared to the previous staging system.

CONDENSED ABSTRACT

This study compared the abilities of the 7th and 8th edition AJCC staging systems to predict recurrence and overall survival in 2930 patients with papillary thyroid carcinoma. The updated guidelines down-staged a large proportion of patients, resulting in better prediction of recurrence and survival than the previous staging system.