An International Multi-Institutional Validation of Age 55 Years as a Cutoff for Risk Stratification in the AJCC/UICC Staging System for Well-Differentiated Thyroid Cancer

Thyroid cancer, recent advances in diagnosis and therapy

Over the past several decades, the approach to the diagnosis and management of patients with follicular cell-derived thyroid cancer has evolved based on improved classification of patients better matching clinical outcomes, as well as advances in imaging, laboratory, molecular technologies and knowledge. While thyroid surgery, radioactive iodine therapy and TSH suppression remain the mainstays of treatment, this expansion of knowledge has enabled de-escalation of therapy for individuals diagnosed with low-risk well-differentiated thyroid cancer; better definition of treatment choices for patients with more aggressive disease; and improved ability to optimize treatments for patients with persistent and/or progressive disease. Most recently, the advancement of knowledge regarding the molecular aspects of thyroid cancer has improved thyroid cancer diagnosis and has enabled individualized therapeutic options for selected patients with the most aggressive forms of the disease. Guidelines from multiple societies across the world reflect these changes, which focus on taking a more individualized approach to clinical management. In this review, we discuss the current more personalized approach to patients with follicular cell-derived thyroid cancer and point toward areas of future research still needed in the field.

A population-based study of the three major variants of papillary thyroid carcinoma

Objective

To explore the clinicopathological features and relative prognostic risks of the three major variants of papillary thyroid carcinoma (PTC).

Methods

We retrospectively analyzed the clinicopathological characteristics and prognoses of patients with the three major PTC variants, conventional papillary thyroid carcinoma (CPTC), follicular-variant papillary carcinoma (FVPTC), and tall-cell papillary thyroid carcinoma (TCPTC), based on data from the Surveillance, Epidemiology, and End Results database from 2005 to 2009.

Results

A total of 29,555 patients were enrolled. In terms of their demographic and clinicopathological characteristics, TCPTC had the highest prevalence of older patients, men, patients with locally advanced stage (T stage and N stage), and mortality, while FVPTC had the lowest prevalence in relation to these factors. The three variants differed significantly in terms of 5-year overall survival and 5-year disease-specific survival. Cox regression analysis identified male sex, age ≥45 years, and higher American Joint Committee on Cancer and TNM stage as independent factors predicting a poor prognosis in relation to both overall and disease-specific survival.

Conclusions

CPTC, FVPTC, and TCPTC have different clinicopathological characteristics and prognoses, indicating the need for different treatment strategies for these three variants of PTC.

Impacts of the American Joint Committee on Cancer (AJCC) 8th edition tumor, node, metastasis (TNM) staging system on outcomes of differentiated thyroid cancer in Thai patients

Background

In 2018, the American Joint Committee on Cancer (AJCC) 8^th edition (AJCC8) was introduced to replace the previous version (AJCC7) due to superiority of AJCC8 over AJCC7 for better prediction of survival from thyroid cancer.

Aim

To compare AJCC staging systems with the American Thyroid Association (ATA) risk classification for the prediction of 5-year disease-free survival (DFS), and 5-year disease-specific survival (DSS) in Thai patients.

Methods

We retrospectively reviewed all patients with histopathologic diagnosis of DTC who were treated at Theptarin Hospital, Bangkok, Thailand from 1987 to 2019.

Results

The study cohort included 262 differentiated thyroid cancer (DTC) patients (papillary thyroid cancer 89.7% with a median time of follow-up 7.8 years). The number (%) of patients within each stage group by AJCC7 and AJCC8 respectively are as follows: Stage I: 173 (66.0%) vs. 232 (88.5%), Stage II: 33 (12.6%) vs. 24 (9.2%), Stage III: 36 (13.7%) vs. 2 (0.8%), Stage IV: 20 (7.7%) vs. 4 (1.5%). The ATA high risk group was found in 24.3% of AJCC7 Stage I compared with 23.7% of AJCC8 Stage I. The 5-year DFS rates in patients classified as stages I, II, III, and IV by AJCC8 were 87.9%, 45.8%, 0% and 25%, respectively. The 5-year DSS rates in patients classified as stages I, II, III and IV by AJCC8 were 98.7%, 100%, 100% and 0%, respectively. AJCC8 was more predictive of DFS rate than AJCC7.

Conclusions

Our study is in accord with previous studies that AJCC8 downstage a significant percentage of patients with DTC and correlated with better prognostic validity. However, even a person at low risk for mortality can be at high risk for recurrence.

Prediction of ipsilateral lateral cervical lymph node metastasis in papillary thyroid carcinoma: a combined dual-energy CT and thyroid function indicators study

BACKGROUND

Predicting the possibility of ipsilateral lateral cervical lymph node metastasis (ipsi-LLNM) was crucial to the operation plan for patients with papillary thyroid carcinoma (PTC). This study aimed to investigate the independent risk factors for ipsi-LLNM in PTC patients by combining dual-energy computed tomography (DECT) with thyroid function indicators.

METHODS

We retrospectively enrolled 406 patients with a pathological diagnosis of PTC from Jan 2016 to Dec 2019. Ensure the DECT images were clear and the thyroid function indicators were complete. Univariate and multivariate logistic analyses explored the independent risk factors for ipsi-LLNM. To evaluate the cutoff value of each risk factor by using receiver operating characteristic (ROC) curves.

RESULTS

A total of 406 patients with PTC were analyzed, including 128 with ipsi-LLNM and 278 without ipsi-LLNM. There were statistical differences of parameters between the two groups (P < .0001), including serum Tg, Anti-Tg, Anti-TPO, the volume of the primary lesion, calcification, extrathyroidal extension (ETE), and iodine concentration (IC) in the arterial and the venous phases. Independent risk factors for ipsi-LLNM included serum Tg, Anti-Tg, ETE, and IC in the arterial and the venous phases (P < .05). The combined application of the above independent risk factors can predict the possibility of ipsi-LLNM, with an AUC of 0.834. Ipsi-LLNM was more likely to occur when the following conditions were met: with ETE, Tg >  100.01 ng/mL, Anti-Tg >  89.43 IU/mL, IC in arterial phase > 3.4 mg/mL and IC in venous phase > 3.1 mg/mL.

CONCLUSIONS

The combined application of DECT quantitative parameters and thyroid function indicators can help clinicians accurately predict ipsi-LLNM before surgery, thereby assisting the individualized formulation of surgical procedures.

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.

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.

Risk Factors for Contralateral Occult Carcinoma in Patients With Unilateral Papillary Thyroid Carcinoma: A Retrospective Study and Meta-Analysis

BACKGROUND

Bilateral lesions are common in papillary thyroid carcinoma (PTC). For patients with unilateral PTC, occult carcinoma that is not detected preoperatively, but pathologically after surgery, might remain in the contralateral lobe. In this situation, inadequate surgical extent could cause relapse and even lead to re-operation. Here, we explore the frequency and investigate the risk factors of contralateral occult PTC in unilateral PTC through a retrospective study conducted by our team and published articles online, respectively.

METHODS

We collected the patients' clinical data in our hospital, whose cancer was determined to be confined to the unilateral lobe by preoperative image examination (N = 204). These patients underwent initially total or near-total thyroidectomy and included their clinical data in the meta-analysis. We searched related literature in the PubMed, Embase, MEDLINE, Cochrane, and Web of Science databases until December 7, 2020, in order to perform a meta-analysis. The relevant articles were examined and the eligible studies were included to assess the association between clinicopathologic factors and contralateral occult PTC.

RESULTS

The meta-analysis included nine studies (involving 4347 patients). Of these, eight studies were from the databases, and one study was our retrospective data. The meta-analysis showed that the prevalence of contralateral occult PTC was 26.6% in all patients. A tumor size > 1 cm, ipsilateral multifocality, contralateral benign nodule, and central lymph node metastasis were significantly associated with contralateral occult PTC. In contrast, sex, age, ETE, capsular invasion, BRAF mutation, Hashimoto thyroiditis, and lateral lymph node metastasis were insignificantly associated with contralateral occult PTC.

CONCLUSION

The meta-analysis identified a tumor size > 1 cm, ipsilateral multifocality, contralateral benign nodule, and CLNM as being significant risk factors for contralateral occult PTC. These findings may guide the extent of surgery in unilateral PTC patients.

Impact of the 8th Edition of the AJCC-TNM Staging System on Estimated Cancer-Specific Survival in Patients Aged 45-54 Years at Diagnosis with Differentiated Thyroid Carcinoma: A Single Center Report

BACKGROUND

The 8^th edition of the American Joint Committee on Cancer (AJCC) staging system changed the age cutoff for risk stratification of differentiated thyroid carcinoma (DTC), downgrading patients between 45 and 54 years to stage I or II. The aim of our study was to assess cancer-specific survival (CSS) in patients aged 45-54 years, in order to document the prognostic capability of the last edition of the staging system.

METHODS

We retrospectively reviewed the medical records of 172 patients that from January 1^st, 2005, to May 31^st, 2017, were diagnosed at our institution with DTC when aged 45-54 years. We restaged patients according to the 8^th edition of the staging system and estimated CSS.

RESULTS

101 out of 172 patients (58.7%) were reallocated to a lower stage. Of the 101 downstaged patients, 88 (88.9%) showed a high or intermediate American Thyroid Association (ATA) risk of recurrence. We recorded no cancer-specific deaths.

CONCLUSIONS

Risk of cancer-specific mortality in patients aged 45-54 years with DTC is low, supporting the prognostic capability of the 8^th edition of the staging system. However, we recommend to consider carefully the significant proportion of patients at intermediate or high risk of recurrence in this group of patients.

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.

Outcomes for Minimally Invasive Follicular Thyroid Carcinoma in Relation to the Change in Age Stratification in the AJCC 8th Edition

BACKGROUND

Completion total thyroidectomy with radioactive iodine (RAI) therapy is not uniformly recommended for minimally invasive follicular thyroid carcinomas (MI-FTCs) without distant metastasis, but may be considered for cases with a risk factor of recurrence, such as age ≥ 45 years.

OBJECTIVE

The present study aimed to investigate the outcomes for patients with MI-FTC using a stratification age of 55 years.

METHODS

The records of 478 patients with MI-FTC confirmed by surgical specimens at Ito Hospital from January 2005 to December 2014 were retrospectively reviewed. Twenty patients had distant metastasis at diagnosis and were subsequently classified as M1.

RESULTS

Among the 478 patients with MI-FTC, univariate analysis identified that age ≥ 55 years (p = 0.002) and M1 (p < 0.001) were related to cause-specific survival. In 458 patients with M0 MI-FTC, male sex (p = 0.041), age ≥ 55 years (p = 0.001), and tumor size > 40 mm (p < 0.001) were related to poor disease-free survival (DFS) in univariate analysis. Multivariate analysis showed that age ≥ 55 years (p = 0.005) and tumor size > 40 mm (p = 0.005) were independent prognostic factors for DFS. The 10-year DFS rates of patients aged < 45 years, 45 years ≤ age < 55 years, and ≥ 55 years were 97.0%, 95.5%, and 86.4%, respectively.

CONCLUSIONS

The change in the recommended age for completion total thyroidectomy with RAI, from 45 to 55 years, seemed reasonable.

Novel analysis of prognosis of young patients with stage II differentiated thyroid cancer based on AJCC 8.0 and 6.0 criteria to implement the staging system

Background

The incidence of thyroid cancer among young adults is increasing; however, the clinical challenges specific to this population, such as diagnosis, reduced healthcare access, and inconsistent care, have received limited attention. Here, we conducted a subgroup analysis on a series of relatively young patients with differentiated thyroid carcinomas (DTCs), focusing on those with distant metastases at stage II, to obtain a deeper understanding of the factors influencing survival.

Methods

Information on <45- or <55-year-old patients at any T/N stage with distant metastasis (M1) was extracted from the SEER database according to the staging system in the 6^th and 8^th American Joint Committee on Cancer (AJCC) editions, respectively. Patient mortality was evaluated using Cox proportional hazards regression analyses and Kaplan-Meier analyses with log-rank tests.

Results

Both cancer-specific and all-cause mortality rates per 1,000 person-years for patients ≥35 years old significantly differed from those of patients <35 years old. DTC-specific survival curves also significantly differed between these age groups, according to both the AJCC 6.0 and 8.0-based analyses (P=0.0017 and P<0.001, respectively), as did patient survival curves (P=0.0003, P<0.001, respectively). The multivariate Cox regression model also revealed that poor OS was strongly predicted by race (P<0.001) in the analysis based on the criteria of 8^th AJCC staging system.

Conclusions

Age is a risk factor for disease-specific and overall survival (OS) in young patients with stage II DTC, and young male patients exhibited poorer survival than females. Race also emerged as a potential risk factor for young patients in stage II. These findings offer guidance for improving the older and newer versions of the AJCC staging system.

Management of the Neck in Well-Differentiated Thyroid Cancer

PURPOSE OF REVIEW

In this narrative review, we discuss the indications for elective and therapeutic neck dissections and the postoperative surveillance and treatment options for recurrent nodal disease in patients with well-differentiated thyroid cancer.

RECENT FINDINGS

Increased availability of advanced imaging modalities has led to an increased detection rate of previously occult nodal disease in thyroid cancer. Nodal metastases are more common in young patients, large primary tumors, specific genotypes, and certain histological types. While clinically evident nodal disease in the lateral neck compartments has a significant oncological impact, particularly in the older age group, microscopic metastases to the central or the lateral neck in well-differentiated thyroid cancer do not significantly affect outcome. As patients with clinically evident nodal disease are associated with worse outcomes, they should be treated surgically in order to reduce rates of regional recurrence and improve survival. The benefit of elective neck dissection remains unverified as the impact of microscopic disease on outcomes is not significant.

Impact of gross extrathyroidal extension into major neck structures on the prognosis of papillary thyroid carcinoma according to the American Joint Committee on Cancer eighth edition

This study investigated the impact of gross extrathyroidal extension into major neck structures on the prognosis of papillary thyroid carcinoma according to changes in the American Joint Committee on Cancer (AJCC)/Tumor-Node-Metastasis staging system. Overall, 183 patients with gross extrathyroidal extension into major neck structures were enrolled. The 10-year disease-specific survival (DSS) of patients in each stage showed appropriate correlation and stratification with the AJCC eighth edition. However, the 10-year DSS rate in stage III was better than the expected 10-year DSS rate, according to the AJCC eighth edition. Patients in stage III were subcategorized into three new groups: stage IIIA, patients with only recurrent laryngeal nerve invasion; stage IIIB, patients with superficial invasion of the aerodigestive tract; and stage IIIC, patients with intraluminal invasion of the aerodigestive tract. The prognostic differences among these three groups and stage IVA were examined. Although the DSS rate of patients in stage IIIA was excellent, that of patients with T4a disease was worse due to the progression of aerodigestive tract infiltration. Of the four groups, the time to locoregional recurrence was the shortest for patients in stage IVA. The distant recurrent-free survival for patients in stages IIIC and IVA tended to be worse than those for patients in stages IIIA and IIIB. These results indicate that the progression of aerodigestive tract infiltration has an impact on the incidence of distant recurrence, and the presence of T4b disease has an impact on the incidence of distant and locoregional recurrences.

How to better stratify the risk of differentiated thyroid carcinomas: the key role of radioactive iodine therapy, age, and gender

PURPOSE

The risk of relapse of differentiated thyroid carcinomas (DTC) and their indication for radioactive iodine therapy (RAI) are assessed according to ATA risk stratification system principally based on tumor-nodes-metastasis (TNM) staging. However, while establishing the indication for RAI may be a "dilemma," performing it can improve the risk stratification. We aimed to evaluate whether (1) the stratification of risk of recurrence differs when TNM is considered with or without peri-RAI findings and (2) the assessment of the risk of disease-specific mortality is improved by adding age and gender.

METHODS

From our database, all DTC patients treated with thyroidectomy and RAI from 1992 to 2017 were included. Subjects with a follow-up shorter than 1 year and positive thyroid antibodies were excluded. Patients were classified into (1) a three-category ATA model based on TNM (basic model) and (2) a five-category model based on TNM plus peri-RAI findings, i.e., thyroglobulin and ¹³¹I whole-body scan (advanced model). Relapse was proven by histology and/or imaging. Differences in disease-free survival (DFS) and overall survival (OS) were assessed.

RESULTS

We enrolled 907 patients; of these, 4.4% died and 21% suffered recurrence. According to the basic model, there were 11.8% high-risk, 32.9% intermediate-risk, and 55.3% low-risk patients. According to the advanced model, 29.9% of patients were re-classified in a higher risk category and the five categories of this model displayed significantly different risks of relapse and death. The estimate of DFS was significantly higher in the advanced model than in the basic one (Δ_C-index = + 6.8%, P < .001). By adding age and gender to the advanced model, the highest performance in predicting death was achieved (Δ_C-index = + 5.1%, P < .001).

CONCLUSIONS

The peri-RAI findings are essential in order to carefully stratify the risk of DTC recurrence. Integrating these data with age and gender enables those cases at highest risk of death to be identified.

Long-term all-cause mortality and its association with cardiovascular risk factors in thyroid cancer survivors: an Israeli population-based study

BACKGROUND

The global incidence of thyroid cancer (TC) has risen considerably during the last three decades, while prognosis is generally favorable. We assessed the long-term all-cause mortality in TC survivors compared to the general population, and its association with cardiovascular risk factors.

METHODS

Individuals diagnosed with TC during 2001-2014 (TC group) and age- and sex-matched individuals from the same Israeli healthcare system without thyroid disease or a cancer history (non-TC group) were compared. Cox regression hazard ratios (HRs) and 95% confidence intervals (95%CIs) for all-cause mortality were calculated by exposure status.

RESULTS

During a 15-year follow-up (median 8 years), 577 TC survivors out of 5677 (10.2%) TC patients and 1235 individuals out of 23,962 (5.2%) non-TC patients died. The TC survivors had an increased risk of all-cause mortality (HR = 1.89, 95%CI 1.71-2.10), after adjusting for cardiovascular risk factors already present at follow-up initiation. This increased risk was most pronounced in the 55- to 64-year-old age group (HR = 1.49, 95%CI 1.33-1.67). The TC survivors who died by study closure had more hypertension (14.6% vs. 10.3%, P = 0.002), more dyslipidemia (11.4% vs. 7.2%, P <  0.001), and more cardiovascular disease (33.6% vs. 22.3%, P = 0.05) compared to those who died in the non-TC group.

CONCLUSIONS

This large cohort study showed higher all-cause mortality with a higher prevalence of hypertension, dyslipidemia, and cardiovascular disease among TC survivors compared to matched non-TC individuals. Primary and secondary prevention of cardiovascular risk factors in TC survivors is mandatory.

High risk of malignancy in cases with atypia of undetermined significance on fine needle aspiration of thyroid nodules even after exclusion of NIFTP

BACKGROUND

Fine needle aspiration cytopathology (FNAC) is the most reliable tool for evaluating thyroid nodules. However, diagnosing Bethesda category III, atypia/follicular lesion of undetermined significance (AUS/FLUS), is a major limitation. The aim of this study was to evaluate the risk of malignancy (RoM) in AUS/FLUS nodules. A systematic review was also carried out analyzing the largest series.

METHODS

Totally 1750 cases (9%) diagnosed with AUS/FLUS were evaluated retrospectively out of 19 392 cases within last 13 years. All patients undergoing surgery for AUS/FLUS were included into the study. Histopathology results were correlated; the impact of noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) diagnosis on RoM is evaluated.

RESULTS

Of the 280 patients (16%) undergoing surgery, neoplasia were detected in 177 (RoN:63.2%) and malignancy in 119 (RoM:42.5%) of these neoplasia. Follicular variant of papillary thyroid carcinoma (FVPTC) was the commonest malignancy (55.5%). Additional 58 (20.7%) nodules were neoplastic, of which 26 (9.3%) were encapsulated follicular tumors with unknown malignancy potential (FT-UMP) and 32 (11.4%) were follicular adenomas. The remaining 103 patients (36.8%) had non-neoplastic nodules. After reevaluation of the encapsulated FVPTC cases, 20 of them were NIFTP and RoM dropped to 35.4% with a relative decrease of 16.7% and an absolute decrease of 7.1%.

CONCLUSION

In our series, 42.5% of nodules with AUS/FLUS were malignant; 63.2% of them were neoplastic. The RoM and RoN for AUS/FLUS nodules are still much higher than the revised expected RoM of international guidelines even after NIFTP cases excluded. Therefore, current recommendations should be reevaluated periodically in view of detailed clinicopathologic studies.

Is There a Difference Between Minimal and Gross Extension into the Strap Muscles for the Risk of Recurrence in Papillary Thyroid Carcinomas?

Background: The morbidity of papillary thyroid carcinoma (PTC) is primarily related to locoregional recurrences and distant metastases. The definition of minimal extrathyroidal extension (mETE) has been recently revised. The presence of mETE does not impact mortality and is generally not considered to be a predictor for the risk of recurrence. This study aimed at comparing the risk of recurrence and the response to therapy of PTC with mETE and gross extrathyroidal extension (ETE) into the strap muscles (gETE) with low- and intermediate-risk PTC without ETE (low risk w/o ETE and intermediate risk w/o ETE, respectively) to further characterize the impact of ETE on outcomes. Methods: A total of 596 PTCs were analyzed according to the degree of ETE as well as other predictors of recurrence. Four groups of patients were compared, low risk w/o ETE (n = 251), intermediate risk w/o ETE (n = 89), mETE (n = 191), and gETE (n = 65), to determine the risk of recurrence and the response to treatment. Cox proportional hazards models were used to investigate associations between groups and disease-free survival (DFS). Results: The risk of recurrence was 3% in low risk w/o ETE PTC, 14% in intermediate risk w/o ETE, 14% in mETE, and 25% in gETE. The recurrence risk was increased by the presence of ETE (odds ratio [OR] = 2.86, 95% confidence interval [CI] 1.36-5.85, p = 0.005) and lymph node metastases (OR = 2.44 [95% CI 1.25-4.76], p = 0.009). Patients with low-risk carcinomas w/o ETE experienced longer DFS than those with mETE (hazard ratio = 0.08 [95% CI 0.02-0.28], p < 0.001), but no significant difference was observed between intermediate risk w/o ETE, mETE, and gETE. In terms of the response to therapy, patients with gETE had higher rates of biochemical and/or structural incomplete responses within the first year of treatment (OR = 2.68 [95% CI 1.31-5.45], p = 0.007) and at the final follow-up evaluation (OR = 4.35 [95% CI 1.99-9.51], p < 0.001) compared with those with mETE. An analysis of the subgroups of microcarcinomas without lymph node metastases revealed no significant difference in DFS or the response to therapy between the low risk w/o ETE and mETE PTC groups. Conclusions: The results of this study suggest that both mETE and gETE are independent risk factors for the risk of recurrence in PTC. Although gETE has a more pronounced impact on the recurrence risk and is associated with a worse response to therapy, mETE may not be associated with a low risk of recurrence. This observation suggests that patients with PTC and mETE may, in part, have an intermediate risk of recurrence and need to be followed accordingly.

Development and Validation of a Risk Scoring System Derived from Meta-Analyses of Papillary Thyroid Cancer

BACKGROUND

The aim of this study was to develop a scoring system to stratify the risk of papillary thyroid cancer (PTC) and to select the proper management.

METHODS

We performed a systematic search of MEDLINE and Embase. Data regarding patients' prognoses were obtained from the included studies. Odds ratios (ORs) with statistical significance were extracted from the publications. To generate a risk scoring system (RSS), ORs were summed (RSS1), and summed after natural-logarithmic transformation (RSS2). RSS1 and RSS2 were compared to the eighth edition of the American Joint Committee on Cancer (AJCC) staging system and the 2015 American Thyroid Association (ATA) guidelines for thyroid nodules and differentiated thyroid carcinoma.

RESULTS

Five meta-analyses were eligible for inclusion in the study. Eight variables (sex, tumour size, extrathyroidal extension, BRAF mutation, TERT mutation, histologic subtype, lymph node metastasis, and distant metastasis) were included. RSS1 was the best of the analysed models.

CONCLUSION

We developed and validated a new RSS derived from previous meta-analyses for patients with PTC. This RSS seems to be superior to previously published systems.

Patient Age Is an Independent Risk Factor of Relapse of Differentiated Thyroid Carcinoma and Improves the Performance of the American Thyroid Association Stratification System

Background: The 2015 American Thyroid Association (ATA) guidelines proposed a three-category system for estimating the risk of recurrence of differentiated thyroid carcinoma (DTC). This system includes several perioperative features, but not age at diagnosis. However, age has traditionally been recognized as a critical factor in the survival of DTC patients, and the eighth edition of TNM stated that patients older than 55 years were at higher risk of death. In this study, we raised the question of whether age at DTC diagnosis impacts on its risk of recurrence. Specifically, the present study aimed to (i) evaluate the association between age at diagnosis and structural recurrence and (ii) investigate whether age at diagnosis could improve the performance of the ATA system. Methods: During the study period, four institutions selected DTC patients treated with both thyroidectomy and radioiodine and who had follow-up for at least one year. Patients with proven structural evidence of disease during follow-up were identified, and disease-free survival (DFS) was calculated accordingly. Results: The study involved 1603 DTC patients with a median age of 49 years and DFS of 44 months. Disease recurred in 8%. The shortest DFS was found in the oldest patients. The Kaplan-Meier curves were calculated for each decade of age, and there was a significant association with DFS (p = 0.0014). Patients older than 55 years had significantly higher risk (hazard ratio [HR] 1.78, 95% confidence interval [CI 1.23-2.56]). The Kaplan-Meier curves of DFS in high-, intermediate- and low-risk groups showed a significant association only in the high-risk group (p = 0.0058). Patients older than 55 years had significantly higher risk of relapse over time only in the high-risk group (HR 2.15 [CI 2.01-4.53]). Cox's proportional analysis showed that the age cutoff of 55 years and the ATA system were significant predictors of relapse. Adding age at diagnosis above 55 years to the ATA system identified a subgroup of patients at highest risk for relapse. Conclusions: The age threshold adopted in the eighth edition of TNM staging system for DTC patients' prognosis also identifies cases at higher risk of relapse. Applying age at diagnosis, with a cutoff of 55 years, to the ATA risk stratification system identifies cases at highest risk of relapse.

The impact of radioactive iodine treatment on survival among papillary thyroid cancer patients according to the 7th and 8th editions of the AJCC/TNM staging system: a SEER-based study

Papillary thyroid cancer is a very common endocrine malignancy. The 8th American Joint Committee on Cancer/Union for International Cancer Control (AJCC/UICC) staging system introduced major changes. We conducted this retrospective cohort analysis to assess the benefits of radioactive iodine (RAI) according to different stratification of patients. The source of the data was the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) database. From 2006 to 2015, patients with papillary thyroid cancer were included in our study. The interactions between different variables and RAI treatment were tested by multivariate Cox regression models to compare the survival differences according to RAI treatment between the patients assessed with the 7th and 8th edition of the AJCC/TNM staging system. The results of the interaction analysis and group comparisons indicated that the effects of RAI treatment on patients staged with the 7th and 8th editions were similar. Patients with early Stage, early T stage, N0 and subtotal or near total thyroidectomy benefited greatly from RAI treatment. Patients with Stage III according to the 8th edition benefited less from RAI than patients with Stage III according to the 7th edition. Patients with T1a benefited from RAI but benefited less than patients with other T stages. Patients with T3a benefited more from RAI than those with T3b. According to the 8th edition, Stage III/IV more accurately differentiates patients with advanced stage disease. These patients benefitted less from RAI treatment, which may be due to the relatively weaker iodine uptake by tumor cells. T1a patients benefitted less than patients with other T stages. The difference in RAI benefit between patients with T3a and T3b is a novel finding in our study.

Predictive factors for central lymph node metastases in papillary thyroid microcarcinoma

Papillary thyroid microcarcinoma (PTMC) measures 1 cm or less in its longest dimension. The incidence of PTMC is increasing worldwide. Surgery is the primary treatment; however, prophylactic central lymph node dissection is controversial, and discrepancies between different guidelines have been noted. Routine prophylactic central lymph node dissection may result in hypoparathyroidism and recurrent laryngeal nerve injury in some patients without lymph node metastasis, while simple thyroidectomy may leave metastatic lymph nodes in high-risk patients. To selectively perform prophylactic lymph node dissections in high-risk patients, it is important to identify predictive factors for lymph node metastases in patients with PTMC. Several studies have reported on this, but their conclusions are not entirely consistent. Several clinicopathologic characteristics have been identified as risk factors for central lymph node metastases, and the most commonly reported factors include age, gender, tumor size and location, multifocality, bilaterality, extrathyroidal extension, and abnormal lymph node found using ultrasound. Here, we provide an overview of previous studies along with a favorable opinion on or against these factors, with the aim of increasing the understanding of this topic among the medical community. In addition, current opinions about prophylactic central lymph node dissection are reviewed and discussed.

Comparison of Survival and Risk Factors of Differentiated Thyroid Cancer in the Geriatric Population

Purpose: The incidence rate of differentiated thyroid cancer (DTC), the most common type of thyroid cancer, has increased in the past two decades. The present study analyzed the clinical and pathological characteristics of DTC, and discussed the risk factors for survival in elderly age-risk DTC patients.

Methods: Elderly patients who were diagnosed with DTC, and subsequently underwent surgery for DTC, were identified from the SEER database (1988–2008). Based on histology, these patients were divided into C-PTC, FV-PTC, and FTC. The clinical characteristics, pathological features, and treatments undertaken were compared among these patients. Cox proportional hazards analysis was performed to evaluate the risk factors to disease-specific survival (DSS).

Results: In elderly DTC patients, FV-PTC shows intermediate tumor features compared to C-PTC and FTC, but presented a better outcome. Being male, African-American, tumors sized bigger than 4 cm, extrathyroidal extension, lymph node metastasis, and distant metastasis, were all strong risk factors for DSS in elderly DTC patients (all p < 0.05). No difference was found between lobectomy and total thyroidectomy with respect to DSS, and radiation therapy conferred no apparent advantage with respect to DSS (both p > 0.05).

Discussion: Patients with FV-PTC needed more specific histology cataloging and risk assessment, suggesting conservative therapy. Risk stratification should be paid attention to, and treatment should be individualized for elderly patients.

Comparison of long-term prognosis for differentiated thyroid cancer according to the 7th and 8th editions of the AJCC/UICC TNM staging system

BACKGROUND

The 8th edition of the American Joint Committee on Cancer/Union for International Cancer Control (AJCC/UICC) tumor-node-metastasis (TNM) staging system was released with major revisions. The purpose of this retrospective study was to investigate differences between the 7th and 8th editions of the AJCC/UICC TNM staging system and to compare the predictability of prognosis between the two staging systems with patients who underwent thyroidectomy for differentiated thyroid cancer (DTC) at a single institution.

METHODS

A total of 3238 patients underwent thyroid operation from January 2002 to December 2006 at Yonsei University Hospital (Seoul, Korea), of which 2294 with complete clinical data and sustained follow up were enrolled. Clinicopathologic features and TNM staging by applying the 7th and 8th editions of the AJCC/UICC were analyzed retrospectively by the complete review of medical charts and pathology reports of patients. Mean follow-up duration was 132.9 ± 27.9 months.

RESULTS

A significant number of T3 patients were downstaged to T1 (838, 36.5%) and T2 (122, 5.3%). After applying the 8th edition of the AJCC/UICC TNM staging system, the number of stage I patients increased significantly from 1434 (62.5%) to 2058 (89.7%), whereas numbers of stage III and IV patients decreased significantly from 644 (28.1%) to 33 (1.4%) and from 199 (8.7%) to 17 (0.7%), respectively. According to Kaplan-Meier survival analyses and values of the Harrell's c-index and integrated area under the curve (iAUC), the 8th edition has significantly better predictive performance for disease-free survival (DFS) and disease-specific survival (DSS) than the 7th edition.

CONCLUSIONS

A significant population was downstaged after applying the 8th edition of the AJCC/UICC TNM staging system, and the 8th edition provided significantly better accuracy in predicting DFS and DSS in patients with DTC.

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.

Prognosis of patients with differentiated thyroid carcinomas having a preoperative cytological report of indeterminate at low or high risk. A multicenter study

BACKGROUND

Italian cytology system for thyroid fine-needle aspiration (FNA) includes indeterminate lesions at low- (Tir 3A) and high-risk (Tir 3B). The present retrospective multicenter study was undertaken to compare the histological type of cancers and disease-free survival in these two groups.

METHODS

Eight institutions participated. Thyroid cancer patients diagnosed and followed-up after Tir 3A or Tir 3B were reviewed. Histological diagnosis was adopted as the gold standard. Patients were defined with cancer recurrence or no evidence of disease. Disease-free survival (DFS) was calculated. A non-parametric statistical analysis was used. DFS was estimated by Kaplan-Meier method and Hazard Ratio (HR) defined the slope of curves.

RESULTS

Two hundred and nine patients (median DFS 24 months) were enrolled and a 6.3% of these recurred. Tir 3B group had higher age (p = 0.014), larger cancer size (p = 0.0002), shorter DFS (p = 0.003), higher number of aggressive cancers (p = 0.006), and relapse frequency double than Tir 3A. At survival curves analysis, Tir 3B group had HR of 2.37 with respect to Tir 3A. At Cox's proportional hazard regression analysis histology was the only significant predictor of relapse.

CONCLUSIONS

While patients with thyroid FNA of Tir 3B should be addressed to surgery due to high likelihood of more aggressive cancer, a diagnostic surgery could be avoided in patients with Tir 3A if concurrent unsuspicious clinical features are found.

Stage II Differentiated Thyroid Cancer Is a High-Risk Disease in Patients <45/55 Years Old

PURPOSE

The mortality risk of stage II differentiated thyroid cancer (DTC) based on the American Joint Committee on Cancer (AJCC) staging system requires further investigation.

METHODS

Retrospective study of DTC in the US Surveillance, Epidemiology, and End Results program for disease-specific mortality risk in various AJCC stages, with patient age stratification of stage II disease.

RESULTS

Using AJCC staging system 6.0, hazard ratios (HRs) of mortality for stage II DTC in patients <45 yo and patients ≥45 yo and stages III, IVA, IVB, and IVC compared with stage I were 46.95, 4.95, 9.82, 57.37, 222.10, and 468.68, respectively, showing a robustly higher mortality risk in stage II disease in patients <45 yo than in older patients (P < 0.001), comparable with stage IVA (P = 0.482). Similar results were obtained with AJCC 7.0. With AJCC 8.0, HRs of mortality for stage II in patients <55 yo and patients ≥55 yo and stages III, IVA, and IVB compared with stage I were 75.16, 11.23, 69.45, 134.94, and 235.70, respectively, showing a robustly higher risk in stage II disease in patients <55 yo than in older patients (P < 0.001), comparable with stage III (P = 0.57). Kaplan-Meier survival curves displayed a sharp decline with stage II disease in patients <45/55 yo compared with older patients.

CONCLUSIONS

The mortality risk of stage II DTC was sharply differentiated at patient age 45/55 years, being robustly high in younger patients and comparable with stage III/IVA. This emphasizes the importance of considering age when managing stage II DTC and not treating it as a uniformly low-risk disease.

Preoperative Computed Tomography Changes Surgical Management for Clinically Low-Risk Well-Differentiated Thyroid Cancer

BACKGROUND

In the current guidelines for differentiated thyroid cancer (DTC), computed tomography (CT) of the neck has a limited role. The authors hypothesized that adding CT to the workup of clinically low-risk DTC size 4 cm or smaller changes the surgical management for a portion of patients due to detection of clinically significant lymph node metastases not located by ultrasound of the neck.

METHODS

A prospective cohort of DTC patients at an academic referral center between 2012 and 2016 was reviewed. All the patients with fine-needle aspiration cytopathology results suspicious for malignancy or malignant tumor (Bethesda category 5 or 6, respectively) underwent CT before surgery. Clinically low-risk DTC patients were selected if they had a tumor diameter of 4 cm or less and no evidence for local invasion or suspicious lymph nodes seen on ultrasound. Outcomes focused on alteration of the surgical plan based on CT and correlation with pathology.

RESULTS

The CT findings for 25 (22.5%) of 111 patients with clinically low-risk DTC led to a change in surgical management. Of these 25 patients, 16 (14.4% of the entire cohort) benefited due to the removal of clinically significant lymph node disease not seen on ultrasound. Categorization of the group that had a change in management showed that 6 (85.7%) of 7 lateral neck dissections and 10 (55.6%) of 18 central neck dissections (CND) harbored metastatic nodes larger than 2 mm.

CONCLUSIONS

In the group with clinically low-risk DTC, CT changed surgical management for a substantial number of the patients with clinically significant nodal disease not detected by ultrasound. This highlights the fact that in certain practice settings, adding CT to the preoperative staging may be favorable for the detection of nodal metastasis.

Mortality Risk of Nonoperative Papillary Thyroid Carcinoma: A Corollary for Active Surveillance

Background: Active surveillance is established as an alternative to surgery for papillary thyroid microcarcinomas, but inclusion criteria and mortality risk for pursuing a nonsurgical approach have not been clearly defined. To gauge the feasibility of expanding active surveillance thresholds, we investigated the effects of increasing size and age on disease-specific survival (DSS) in a large nonoperative thyroid cancer cohort, compared against a matched group of surgical patients. Methods: Papillary thyroid carcinoma patients staged T1-4N0M0 were identified in the Surveillance, Epidemiology, and End Results (SEER) database between 1975 and 2015, stratified by nonsurgical and surgical management. Propensity score matching was performed to adjust for imbalances in covariates. Multivariable models were constructed using restricted cubic splines to model nonlinear relationships of age and tumor size with DSS. Results: Overall, 1453 nonoperative patients and 54,718 surgical patients met the inclusion criteria. Collectively, increasing age and size after certain thresholds independently led to greater differences in DSS between nonsurgical and surgical patients. For younger ages (14-55 years), surgical approach compared with nonsurgical approach was not associated with any difference in the 10-year DSS among 0-4 cm cancers (99.8% vs. 100%, p = 0.470), 4.1-6 cm cancers (98.8% vs. 100%, p = 0.599), or >6 cm cancers (97.3% vs. 100%, p = 0.718). Older patients with larger tumors (>75 years, >6 cm) demonstrated the greatest difference in DSS (48.1% vs. 91.3%, p < 0.001). Similar results were found when applying propensity score matching. For age, restricted cubic spline plots showed minimal relative survival hazard in nonoperative cases beginning after age 60 years, with a change point illustrating acceleration in relative hazard beyond age 72 years. For size, relative survival hazard was observed after 2.0 cm and increased slowly with nodule growth up to an inflection point of 4.5 cm. Beyond this, mortality risk escalated with each additional year without plateau. Conclusions: Increasing age and size lead to progressively greater mortality risk without surgery, but only beyond certain thresholds. We define escalating gradients at which a nonsurgical approach may be deemed appropriate, and beyond which survival benefits from surgery become apparent. Such findings reconcile controversial observations regarding age and size in active surveillance and further reshape evolving treatment paradigms in thyroid cancer.

Genomic and Transcriptomic Characterization of Papillary Microcarcinomas With Lateral Neck Lymph Node Metastases

CONTEXT

Most papillary microcarcinomas (PMCs) are indolent and subclinical. However, as many as 10% can present with clinically significant nodal metastases.

OBJECTIVE AND DESIGN

Characterization of the genomic and transcriptomic landscape of PMCs presenting with or without clinically important lymph node metastases.

SUBJECTS AND SAMPLES

Formalin-fixed paraffin-embedded PMC samples from 40 patients with lateral neck nodal metastases (pN1b) and 71 patients with PMC with documented absence of nodal disease (pN0).

OUTCOME MEASURES

To interrogate DNA alterations in 410 genes commonly mutated in cancer and test for differential gene expression using a custom NanoString panel of 248 genes selected primarily based on their association with tumor size and nodal disease in the papillary thyroid cancer TCGA project.

RESULTS

The genomic landscapes of PMC with or without pN1b were similar. Mutations in TERT promoter (3%) and TP53 (1%) were exclusive to N1b cases. Transcriptomic analysis revealed differential expression of 43 genes in PMCs with pN1b compared with pN0. A random forest machine learning-based molecular classifier developed to predict regional lymph node metastasis demonstrated a negative predictive value of 0.98 and a positive predictive value of 0.72 at a prevalence of 10% pN1b disease.

CONCLUSIONS

The genomic landscape of tumors with pN1b and pN0 disease was similar, whereas 43 genes selected primarily by mining the TCGA RNAseq data were differentially expressed. This bioinformatics-driven approach to the development of a custom transcriptomic assay provides a basis for a molecular classifier for pN1b risk stratification in PMC.

Prognostic Parameters in Differentiated Thyroid Carcinomas

Differentiated thyroid carcinomas make up most thyroid malignancies. The AJCC staging system and the ATA risk prediction system are the best predictors of mortality and recurrence, respectively. Key factors to be identified and reported by pathologists are reviewed in this article and include: (1) aggressive histologic variants of papillary thyroid carcinoma (including tall cell, columnar cell, and hobnail variants); (2) presence of gross extrathyroidal extension (into skeletal muscle or adjacent organs); (3) angioinvasion (including number of foci); (4) number, anatomic level, and size of lymph node metastases; (4) extranodal extension; (5) genetics (especially BRAF V600E or TERT promoter mutation).

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.

Age, thyroglobulin levels and ATA risk stratification predict 10-year survival rate of differentiated thyroid cancer patients

INTRODUCTION

Differentiated thyroid cancer (DTC) is the most common of endocrine cancers. Many studies have focused on recurrence-free survival of DTC patients, however, few studies have addressed overall survival rates. Given its very good prognosis, estimating overall or long-term survival in patients with DTC seems rational. So far, neither the impact of pre- and post-ablation thyroglobulin, nor that of initial American Thyroid Association (ATA) risk stratification on long-term disease-specific survival, have been sufficiently studied.

OBJECTIVE

The aim of this study was to determine the factors that influence long-term disease-specific survival and thyroglobulin levels in patients with DTC who have been previously treated with thyroidectomy and radioactive iodine (RAI) remnant ablation.

PATIENTS AND METHODS

This observational retrospective study included 1093 patients who were treated for DTC between 1995 and 2010 and are still monitored in our tertiary center. Only patients who needed RAI ablation after thyroidectomy were included in this study. Patients who were treated with RAI following rhTSH stimulation, patients who presented positive anti-thyroglobulin antibodies, and patients who had micro-cancers were excluded. Pre-ablation stimulated thyroglobulin (Pre-ablation sTg) was measured after thyroid hormone withdrawal (THW), just before RAI.

RESULTS

According to ATA standards, 29 patients (2.7%) were classified as high-risk patients. Initial ATA high-recurrence risk rating (HR 21.9; 95% CI: 8.5-56.3), age>55 years (HR 23.8; 95%-CI: 7.5-75.3) and pre-ablation sTg≥30 μg/l (HR 8.4; 95% CI: 4.6-15.3) significantly impacted ten-year survival. Moreover, age over 45 years, ATA moderate-risk and follicular DTC were also significant. Ten-year survival was lower in ATA high-risk patients (51% vs 95% and 93% for the low and intermediate risk; p<10-7), patients older than 55 years (82% vs 98%; p<10-7), and in patients with pre-ablation sTg≥30 (78% vs 95%; p<10-7). Three rates of long-term survival were distinguished: excellent (survival rate of 99% in patients<55 years with pre-ablation sTg <30μg/l) representing 59% of the cohort, moderate (survival rate of 94.5% in patients <55 years with pre-ablation sTg ≥30μg/l or ≥55 years with pre-ablation sTg <30 μg/l) representing 38% of the cohort, and low (survival rate of 49% in patients ≥55 years with pre-ablation sTg ≥30μg/l) representing 3% of the cohort.

CONCLUSION

Initial ATA high-risk classification, age over 55 years old and pre-ablation sTg ≥30 μg/l are the main negative factors that influence the ten-year survival in DTC. We suggest three categories of overall survival rates. Patients older than 55 years with pre-ablation sTg ≥30 μg/l have the worst survival rate.

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.

The relationship of comorbidities to mortality and cause of death in patients with differentiated thyroid carcinoma

Understanding how comorbidities contribute to death in cancer patients is becoming an important topic. The present study assessed the role of comorbidities in overall mortality and causes of death in patients with differentiated thyroid carcinoma (DTC). This retrospective cohort study included 2070 patients who underwent thyroidectomy for DTC at a single institution between 2002 and 2005. Probabilities of overall, DTC-specific and other-cause death were examined according to the number of comorbidities, with consideration for competing events. The estimated 15-year cumulative incidences of overall, DTC-specific, and other-cause death were 7.3%, 1.6%, and 5.7%, respectively. Taking the group without comorbidities as a reference, we found that the group with 1-2 comorbidities and the group with ≥3 comorbidities had higher probabilities of other-cause death (subhazard ratios = 2.48 and 9.41, respectively; p < 0.01) and consequently shorter overall survival (hazard ratio = 1.95 and 5.33, respectively; p < 0.01), with adjustment for age, sex, and tumor-node-metastasis classification. In contrast, the probability of DTC-specific death was reduced in patients with ≥3 comorbidities (subhazard ratio = 6.81e-10, p < 0.01). For overall death, the relative proportion of death from DTC reduced when the number of comorbidities increased, and DTC-specific death was not observed in patients with ≥3 comorbidities. Our results show that death from DTC itself accounted for only a fraction of the overall deaths among patients who underwent surgery for DTC. Comorbidities increased overall mortality by increasing the probability of other-cause death. Patients with multiple comorbidities had a low probability of dying from DTC because they died earlier from comorbidities.

Clinical features and therapeutic outcomes of patients with papillary thyroid microcarcinomas and larger tumors

OBJECTIVE

The aim of this study was to identify clinical features and therapeutic outcomes of patients with papillary thyroid cancer (PTC) according to tumor diameter and evaluate the correlation of neck lymph node (LN) involvement of papillary thyroid microcarcinoma (PTMC) according to patients' age.

PATIENTS AND METHODS

We divided 467 patients into two groups according to tumor diameter: PTMC group (≤1 cm) and non-PTMC group (>1 cm). The clinical data were analyzed retrospectively. Thereafter, we divided the PTMC patients into three subgroups according to age: young subgroup (<45 years), middle subgroup (45-54 years), and old subgroup (≥55 years). A further study about clinical features, especially the neck LN involvement in three subgroups, was analyzed.

RESULTS

All patients received radioiodine ablation at least once. There were more patients with a single cancer lesion and cancer in the unilateral lobe, less number of neck LN involvement, fewer patients with neck lymph node metastasis (LNM), and more patients with Hashimoto's thyroiditis in PTMC group than in non-PTMC group. At the further evaluation, 58.03% patients maintained clinical remission, which was more in the PTMC group than in non-PTMC group. There was no significant difference in recurrence, but the disease-free survival rate of patients in the PTMC group was higher than in the non-PTMC group. In the PTMC group, the radioactive iodine curative ratio in younger patients is lower than that in the other two subgroups. Both the LNM and central LNM (CLNM) rates were significantly higher in young patients compared with older patients. In addition, the LNM-positive group had more male patients, larger tumor size, and higher thyroglobulin antibody level. Both LNM and the CLNM rates were significantly higher in the young subgroup than in the older subgroup. Young and middle age and extrathyroid extension were independent risk factors for neck LNM. Unlike LNM, young age, extrathyroid extension, and male sex were independent risk factors for CLNM.

CONCLUSION

Some PTMCs were less aggressive and the therapeutic outcomes of them were better than non-PTMC. Moreover, PTMCs in young patients were more aggressive, especially in LNM. Hence, clinicians should consider an individualized treatment according to tumor characteristics and age to achieve better therapeutic efficacy.

A review of head and neck cancer staging system in the TNM classification of malignant tumors (eighth edition)

A number of major modifications were made to the classification of head and neck carcinomas in the eighth edition of the American Joint Committee on Cancer, Cancer Staging Manual and Union for International Cancer Control TNM classification of Malignant Tumors. These modifications were aimed at improving the prognosis prediction accuracy of the system. In this article, we review the new edition of the TNM classification system. Among the several changes in the new system, a separate algorithm for p16-positive oropharyngeal carcinoma was included, as were new chapters on ‘Head and Neck Skin Carcinoma’ and ‘Unknown Primary Carcinoma—Cervical Nodes.’ Changes to Tumor (T) classification were made by introducing the depth of invasion of oral carcinoma, whereas changes to Node (N) classification were made by adding extra-nodal extension. It is believed that these changes will help improve the accuracy of the system in the prediction of prognosis. However, it is necessary to verify their validity through further clinical research.

In-Depth Proteomics Analysis to Identify Biomarkers of Papillary Thyroid Cancer Patients Older Than 45 Years with Different Degrees of Lymph Node Metastases

PURPOSE

Investigations of the molecular mechanisms underlying the metastatic phenotype of papillary thyroid cancer (PTC) and identification of novel candidate biomarkers to better predict PTC metastasis are urgently required.

EXPERIMENTAL DESIGN

Tandem mass tag-based quantitative proteomics approach is used to identify differentially expressed proteins (DEPs) in PTC tumorous tissues with different degrees of lymph node metastases (LNMs). Furthermore, DEPs and their clinical significance are analyzed in another independent Cancer Genome Atlas dataset.

RESULTS

The protein profiles among tumorous tissues with different degrees of LNMs are clearly distinguished, while the protein profiles in normal tissues are remarkably similar. DEPs in tumorous tissues are mostly enriched in the categories associated with pathological hallmarks of cancer, including extracellular matrix, metabolism, and cell growth. The expression patterns of six DEPs (LAMC2, LAMB3, ATP5A1, MYO1G, S100A4, and FAS) are confirmed by the Cancer Genome Atlas dataset. Additionally, the elevated expression of LAMC2 and MYO1G mRNA levels in tumorous tissues show a positive relationship with unfavorable variables, including larger tumor size, LNMs, high AJCC staging, BRAF^V600E mutation, and poor prognosis.

CONCLUSIONS AND CLINICAL RELEVANCE

LAMC2 and MYO1G are identified as potential candidate biomarkers for the prediction of PTC metastasis and prognosis.

Time-Varying Pattern of Mortality and Recurrence from Papillary Thyroid Cancer: Lessons from a Long-Term Follow-Up

Background: Little is known about annual hazard rates of cancer mortality and recurrence for papillary thyroid cancer (PTC). This study investigated the time-varying pattern of cancer death and recurrence from PTC and independent prognostic factors for cause-specific mortality (CSM) and recurrence of PTC. Methods: This retrospective chart review enrolled 466 patients diagnosed with PTC who underwent curative initial surgery between April 1981 and December 1991 with a median follow-up of 18.4 years. Clinical characteristics, cancer mortality (primary endpoint), and recurrence (secondary endpoint) were ascertained. The failure rates of either death or recurrence were estimated using the Kaplan-Meier methods, and annual death/recurrence hazard was depicted using hazard function. Results: In this Japanese cohort where only 1.5% of patients received radioactive iodine therapy, the 10-, 20-, and 30-year CSM rates were 2.7%, 6.2%, and 8.6%, respectively. Eleven (44.0%) cases of death occurred within the first 10 years, whereas 10 (40.0%) and 4 (16.0%) cases occurred within 10-20 and 20-30 years after surgery, respectively. The 10-, 20-, and 30-year recurrence rates were 11.3%, 21.8%, and 29.4%, respectively. Forty-six (54.8%) cases of recurrence occurred within the first 10 years, predominantly within the first five years (31 cases; 36.9%), whereas 29 (34.5%), 7 (8.3%), and 2 (2.4%) cases occurred within 10-20, 20-30, and ≥30 years after surgery, respectively. Age ≥55 years was the only independent prognostic factor for CSM. Age ≥55 years, male, tumor size > 4 cm, extranodal extension, and positive pathological lymph node metastasis were independent prognostic factors for recurrence. The annual hazard curve of cancer mortality presented a double-peaked distribution, with a first peak at the 10th year, and the second peak reaching the maximum at the 20th year after surgery for the entire population. The annual hazard curve of recurrence showed a triple-peaked pattern, with surges at about 12, 22, and 29 years after surgery. Conclusions: Patients with PTC harboring at least one of the prognostic characteristics may be at persistent risk of cancer mortality and recurrence even 10 or more years after initial treatment. Understanding the hazard rate of PTC is key to creating more tailored treatment and surveillance.

miR-222 expression is correlated with the ATA risk stratifications in papillary thyroid carcinomas

BACKGROUND

miR-222 is one of the most consistently overexpressed miRNAs in papillary thyroid carcinoma (PTC). Previous studies demonstrated that miR-222 overexpression conferred high-risk features in PTC patients, suggesting its value in risk-stratification. However, studies in term of miR-222's utility on stratifying PTCs are lacking.

METHODS

One hundred patients including 10 with multinodular goiter and 90 with PTC were enrolled. Formalin-fixed paraffin-embedded samples were exploited for miR-222 quantitative reverse transcriptase- polymerase chain reaction (RT-PCR) analysis. Correlations between miR-222 expression and different clinicopathological features, Tumor-node-metastasis (TNM) staging and ATA risk level were analyzed.

RESULTS

miR-222 expression of the PTC group was significantly higher than that of the goiter group (P < .001). Furthermore, miR-222 expression was significantly higher in PTCs with advanced features like larger tumor, capsular invasion, vascular invasion and lymph nodes metastasis. The majority of patients (61%) were in stage I group (similar to ATA low-risk) by TNM staging system. As to the ATA system, the majority (73%) were in intermediate-risk group (similar to TNM stage II and III roughly). Contrary to previous report, here we found that miR-222 expression was correlated with the ATA risk level (P < .001), but not with the TNM staging (P = .122).

CONCLUSION

In the present study, we demonstrated that miR-222 overexpression was correlated with advanced features like capsular invasion, vascular invasion, larger tumor size and lymph node metastasis in PTCs. Most importantly, miR-222 expression was correlated with ATA risk levels, suggesting its potential value in PTC risk-stratification.

Changes in the 8th Edition of the American Joint Committee on Cancer (AJCC) Staging of Head and Neck Cancer: Rationale and Implications

PURPOSE OF REVIEW

The objectives of this article are to review the major changes in the staging of head and neck cancers and the rationale for the modifications.

RECENT FINDINGS

Information gathered from various institutional reports lead to a better understanding of the clinical and biological behavior of head and neck tumors, resulting in distinct outcomes, which were used to update the staging system. This article reviews the changes in the staging of head and neck cancers published in the 8th edition of the AJCC/UICC TNM staging system.

The optimal surgical approach for papillary thyroid carcinoma with pathological n1 metastases: An analysis from the SEER database

OBJECTIVES/HYPOTHESIS

The definition of large-volume pathologic N1 metastases has been changed in the 2017 version 2 of the National Comprehensive Cancer Network guidelines, leading to a controversy over the optimal surgical approach selection for patients with biopsy-proven papillary thyroid carcinoma (PTC). The aim of this study was to investigate the therapeutic efficacy of total thyroidectomy (TT) and thyroid lobectomy (TL) for these patients.

STUDY DESIGN

Retrospective population-based database analysis.

METHODS

A total of 906 consecutive PTC patients with pathologic N1 metastases (>5 involved nodes with metastases ≤5 mm in the largest dimension) were retrieved from the Surveillance, Epidemiology, and End Results database, and divided into two groups (≤2 mm, >2-5 mm) based on the size of the extent of disease. Overall survival (OS) was then compared between patients treated with TT and TL, followed by Cox proportional hazards regression analysis to explore multiple prognostic factors.

RESULTS

OS favored TT compared with TL in patients with more than five involved nodes and metastases >2 to 5 mm in the largest dimension (P < .05). Cox analysis showed that the TL was not an independent factor associated with poorer OS than TT in these patients (P > .05).

CONCLUSIONS

TT showed better survival than TL for patients with more than five involved nodes and metastases >2 to 5 mm in the largest dimension. For patients with more than five involved nodes and metastases ≤2 mm in the largest dimension, either TT or TL can be recommended because there was no difference in survival.

LEVEL OF EVIDENCE

NA Laryngoscope, 130:269-273, 2020.

Treatment outcomes of differentiated thyroid cancer with distant metastasis improve by tyrosine kinase inhibitors

In patients with distant metastasis, treatment for differentiated thyroid cancer (DTC) includes complete total thyroidectomy, followed by radioactive iodine (RAI) therapy for metastatic lesions. Tyrosine kinase inhibitor (TKI) treatment is the final treatment option for metastatic lesions, which is incurable with surgery/RAI therapy. The present study examined whether treatment outcomes for DTC in patients with distant metastasis improved following TKI treatment. This study included 147 patients (median age, 71; range, 33-91 years) who underwent surgery in our hospitals and were diagnosed with distant metastasis. Disease progression was observed in 70 patients, of whom 56 were treated with TKI (TKI group); 14 refused TKI treatment or showed no treatment indication [untreated (UT) group]. Disease progression and treatment outcomes were assessed using imaging evaluations. The present study investigated thyroglobulin doubling time (Tg-DT) and Tg antibody presence/absence and their relation to disease progression. Overall survival following disease progression between the two groups was compared. The study included 22 cases of sorafenib, 49 of lenvatinib, and 15 involving TKIs. The mean dosing period for sorafenib was 153 days and for lenvatinib was 462 days. In the TKI group, 16, 26, and 9 patients exhibited partial responses (PRs), stable disease (SD), and progressive disease (PD), respectively, whereas 5 patients were not evaluable. The disease control rate (DCR) (PR+SD) was 75.0%. A total of 16 patients died in the TKI group, whereas 10/14 patients in the UT group died. Survival curves for the groups were significantly different. TKI treatment improved the prognosis of patients with distant metastasis and PD.

Impact of the updated TNM staging criteria on prediction of persistent disease in a differentiated thyroid carcinoma cohort

OBJECTIVE

The 8th TNM system edition (TNM-8) released in 2018 presents significant changes when compared to the 7th edition (TNM-7). The aim of this study was to assess the impact of changing the TNM staging criteria on the outcomes in a Brazilian cohort of differentiated thyroid carcinoma (DTC).

SUBJECTS AND METHODS

DTC patients, attending a tertiary, University-based hospital, were classified by TNM-7 and TNM-8. Prediction of disease outcomes status of the two systems was compared in a retrospective cohort study design.

RESULTS

Four hundred and nineteen DTC patients were evaluated, comprised by 82% (345/419) women, with mean age at diagnosis of 46.4 ± 15.6 years, 89% (372/419) papillary thyroid carcinoma, with a median tumor size of 2.3 cm (P25-P75, 1.3-3.5). One hundred and sixty patients (38%) had lymph node metastases and 47 (11%) distant metastases at diagnosis. Using the TNM-7 criteria, 236 (56%) patients were classified as Stage I, 50 (12%) as Stage II, 75 (18%) as Stage III and 58 (14%) as Stage IV. When evaluated by the TNM-8, 339 (81%) patients were classified as Stage I, 64 (15%) as Stage II, 2 (0.5%) as Stage III and 14(3%) as Stage IV. After a median follow-up of 4.4years (P25-P75 2.6-6.6), the rate of incomplete biochemical and/or structural response was 54% vs. 92% (P = 0.004) and incomplete structural response was 42% vs. 86% (P = 0.009) for patients classified as stage IV by TNM-7 vs TNM-8, respectively. Only 4 (1%) disease-related deaths were recorded.

CONCLUSIONS

In our cohort, 37% of DTC patients were down staged with the application of TNM-8 (vs. TNM-7). Additionally, TNM-8 seems to better stratify the risk of structural incomplete response at follow-up.

Evaluating the predicted impact of changes to the AJCC/TMN staging system for differentiated thyroid cancer (DTC): A prospective observational study of patients in South East Scotland

OBJECTIVES

To assess the impact of the eighth edition AJCC/TMN staging system on patients with new diagnoses of differentiated thyroid cancers presenting to our regional multidisciplinary team meetings.

DESIGN

We analysed Endocrine Cancer MDT meeting records from 2009 to 2015 to identify all patients in the region presenting with a new diagnosis of differentiated thyroid cancer. We re-staged patients according to the eighth edition AJCC/TNM staging classification and analysed the survival outcomes of patients in each stage under the seventh and eighth systems.

SETTING

Tertiary referral centre in South East Scotland (NHS Lothian).

PARTICIPANTS

Three hundred and sixty-one patients were newly diagnosed with DTC within South East Scotland during the study period and met our inclusion criteria.

MAIN OUTCOME MEASURES

Disease-specific mortality at any time during follow-up.

RESULTS

In total, 119 of 361 (33%) patients were re-staged when the eighth edition AJCC/TMN system was applied. The number of patients classified as having advanced stage (III/IV) disease fell from 76 (21%) to 8 (2%). The most common reason for down-staging was re-classification of tumour size, a factor in 96 (80.7%) down-staged patients. The five-year disease-specific survival of the cohort overall was 98%. Overall, 7 (1.9%) thyroid cancer-related deaths occurred during follow-up, three of whom were down-staged.

CONCLUSIONS

On implementation of the eighth edition of the AJCC/TMN staging system, we expect many patients who would previously have been considered to have advanced thyroid cancer will now be classified as early stage. This will accurately reflect their excellent survival outcomes.

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.

Poorly Differentiated Carcinoma of the Thyroid Gland: Current Status and Future Prospects

BACKGROUND

Poorly differentiated thyroid cancer (PDTC) is a rare but clinically highly significant entity because it accounts for most fatalities from non-anaplastic follicular cell-derived thyroid cancer. Due to the relative rarity of the disease and heterogeneous diagnostic criteria, studies on PDTC have been limited. In light of the evolution of ultra-deep next-generation sequencing technologies and through correlation of clinicopathologic and genomic characteristics of PDTC, an improved understanding of the biology of PDTC has been facilitated. Here, the diagnostic criteria, clinicopathologic characteristics, management, and outcomes in PDTC, as well as genomic drivers in PDTC reported in recent next-generation sequencing studies, are reviewed. In addition, future prospects in improving the outcomes in PDTC patients are reviewed.

SUMMARY

PDTC patients tend to present with adverse clinicopathologic characteristics: older age, male predominance, advanced locoregional disease, and distant metastases. Surgery with clearance of all gross disease can achieve satisfactory locoregional control. However, the majority of PDTC patients die of distant disease. Five-year disease-specific survival for PDTC patients has been reported at 66%. On multivariate analysis, reported predictors of poor survival in PDTC patients have been older age (>45 years), T4a pathological stage, extrathyroidal extension, high mitotic rate, tumor necrosis, and distant metastasis at presentation. BRAF^V600E or RAS mutations (27% and 24% of cases, respectively) remain mutually exclusive main drivers in PDTC. TERT promoter mutations represent the most common alteration in PDTC (40%). Mutation in translation initiation factor EIF1AX (11%) and tumor suppressor TP53 (16%) have also been reported in PDTC. High rates of novel mutations (MED12 and RBM10) have been reported in fatal PDTC (15% and 12%, respectively). Chromosome 1q gains represent the most common arm-level alterations in PDTC, and those patients show worse survival rates. Chromosome 22q losses are also found in PDTC and show strong association with RAS mutation.

CONCLUSIONS

These new insights into the clinicopathologic and molecular characteristics of PDTC, together with further advancement in ultra-deep sequencing technologies, will be conducive in narrowing the focus in order to develop novel targeted therapies and improve the outcomes in PDTC patients.