Dissecting Anaplastic Thyroid Carcinoma: A Comprehensive Clinical, Histologic, Immunophenotypic, and Molecular Study of 360 Cases

Background: Anaplastic thyroid carcinoma (ATC) is nearly always fatal. Large studies on ATC are exceedingly rare. We aimed to study the clinical, genotypic, and histologic characteristics of ATC in the largest retrospective cohort of ATC to date. Methods: Three hundred sixty patients with ATC from two tertiary centers were studied. Molecular testing was performed in 126 cases including 107 using next-generation sequencing. Results: The median patients' age was 68 years. Differentiated thyroid carcinoma (DTC) was present in 208 cases (58%), the most common being papillary carcinoma (n = 150). The 1-, 2-, 3-, and 5-year overall survival (OS) was 36%, 17%, 13%, and 11%, respectively. On univariate analysis, age, resectability, chemotherapy, radiotherapy, margin status, encapsulation, gross residual disease, gross extrathyroidal extension, percentage, and size of ATC in the primary tumor predicted OS (p < 0.05). Age, resectability, chemotherapy, and gross residual disease were independent prognostic factors in the entire cohort, while gross residual disease was the only independent predictor of OS in patients who had resection of their tumor. BRAF, RAS, TERT promoter, TP53, PIK3CA, E1F1AX, and PTEN mutations were detected in 45%, 24%, 75%, 63%, 18%, 14%, and 14% of ATC, respectively. Concomitant BRAF/RAS and TERT mutations were associated with worse outcome than mutation in only one of the genes. BRAF-mutated and RAS-mutated ATCs had similar frequency of nodal and distant metastasis. Twelve cases were pure squamous cell carcinoma, 60% of which carried BRAF^V600E mutation and showed a similar OS to other ATCs. Conclusions: (i) Gross residual disease remains the most crucial indicator of outcome in ATC. (ii) Encapsulation, margin status, percentage, and size of ATC in the primary were prognostically relevant. (iii) Pure thyroid squamous cell carcinoma may be considered as ATC given a BRAF^V600E genotype and similar outcome. (iv) In contrast to DTC, BRAF-mutated and RAS-mutated ATCs have similar metastatic spread. (v) Concomitant mutations of BRAF or RAS with TERT confer a worse prognosis.

Data set for reporting carcinoma of the thyroid: recommendations from the International Collaboration on Cancer Reporting

Thyroid cancer therapy is increasingly tailored to patients' risk of recurrence and death, placing renewed importance on pathologic parameters. The International Collaboration on Cancer Reporting (ICCR), an organization promoting evidence-based, internationally agreed-upon standardized pathology data sets, is the ideal conduit for the development of a pathology reporting protocol aimed at improving the care of patients with thyroid carcinomas. An international expert panel reviewed each element of thyroid pathology reporting. Recommendations were made based on the most recent literature and expert opinion.The data set uses the most recent World Health Organization (WHO) classification for the purpose of a more clinically and prognostically relevant nomenclature. One example is the restriction of the term minimally invasive follicular carcinoma to tumors with capsular invasion only. It reinforces the already established criteria for blood vessel invasion adopted by the most recent WHO classification and Armed Forces Institute of Pathology fascicle. It emphasizes the importance of the extent of blood vessel invasion and extrathyroid extension to better stratify patients for appropriate therapy. It is the first data set that requires pathologists to use the more recently recognized prognostically powerful parameters of mitotic activity and tumor necrosis. It highlights the importance of assessing nodal disease volume in predicting the risk of recurrence.The ICCR thyroid data set provides the tools to generate a report that will guide patient treatment in a more rational manner aiming to prevent the undertreatment of threatening malignancies and spare patients with indolent tumors the morbidity of unnecessary therapy. We recommend its routine use internationally for reporting thyroid carcinoma histology.

Grading of medullary thyroid carcinoma on the basis of tumor necrosis and high mitotic rate is an independent predictor of poor outcome

Medullary thyroid carcinoma (MTC) is a rare nonfollicular cell-derived tumor. A robust grading system may help better stratify patients at risk for recurrence and death from disease. In total, 144 MTC between 1988 and 2018 were subjected to a detailed histopathologic evaluation. Clinical and pathologic data were correlated with disease specific survival (DSS), local recurrence free survival (LRFS)  and distant metastasis free survival (DMFS). Median age was 53 years (range: 3-88). Median tumor size was 1.8 cm (range: 0.2-11). Lymph node metastases were present in 84 (58%) cases while distant metastases at presentation were found in 9 (6%) patients. Seven (5%) had ≥5 mitoses/10 HPFs. Tumor necrosis was present in 30 cases (20%) while lymphovascular invasion occurred in 41 (28%) of tumors. Extra-thyroidal extension was found in 44 (31%) and positive margins were seen in 19 (14%). There was a strong correlation between increasing tumor size and tumor necrosis (p < 0.001). Median follow up was 39 months. In univariate analysis, male gender, higher American Joint Committee on Cancer (AJCC) stage group, larger tumor size, tumor necrosis, high mitotic index (≥5/10 HPF), nodal status, size of largest nodal metastasis, and elevated postoperative serum calcitonin predicted worse DSS, LRFS, and DMFS (p < 0.05). Extra-thyroidal extension correlated with DSS and DMFS while positive margins and distant metastasis at presentation imparted worse DSS (p < 0.05). In multivariate analysis, tumor necrosis and mitotic activity (5 mitosis/10 HPFs as the cutoff) were the only independent predictors for DSS (p = 0.008 and 0.026, respectively). Tumor necrosis was the sole independent prognostic factor for LRFS and DMFS (p = 0.001 and 0.003, respectively). The presence of tumor necrosis and high mitotic rate are powerful independent prognostic factors in MTC and outperform serum calcitonin and stage. We propose a grading system based on tumor necrosis and mitotic activity to better stratify MTC patients for counseling, post-resection surveillance, and therapy.

Structural Doubling Time Predicts Overall Survival in Patients with Medullary Thyroid Cancer in Patients with Rapidly Progressive Metastatic Medullary Thyroid Cancer Treated with Molecular Targeted Therapies

Purpose: To evaluate the impact of structural disease progression of metastatic lesions after initial surgery on overall survival (OS) of patients presenting with metastatic medullary thyroid cancer (MTC). We used tumor volume doubling time (TVDT) as a marker of structural disease progression and aimed to correlate the average structural tumor volume doubling time (midDT) with OS in MTC patients after initial surgery. Methods: In this retrospective study, we examined the clinical characteristics; average tumor volume doubling times of neck, lung, and liver metastasis; and disease-specific survival of patients with metastatic MTC. Results: Tumor growth is constant in MTC metastasis, irrespective of location of the metastasis. The median correlation coefficient (r) and the coefficient of determination (r²) were similar in lung metastasis (r = 0.91, r² = 0.95) and liver metastasis (r = 0.88, r² = 0.94), and comparable in neck metastasis (r = 0.73, r² = 0.85). Patients with metastatic MTC with a midDT ≤1 year have a worse prognosis than those with higher midDT (p = 0.002). Those with midDT ≤1 year had a median OS of 11.1 years [confidence interval (CI) 7.4-14.8 years]. In contrast, patients with midDT 1-3 years had a median OS of 16.5 years [CI 10.3-22.6 years]. All patients with midDT ≥3 survived by the end of the follow-up period. Preliminary results suggest that measurement of midDT can predict response to molecular targeted therapies. Conclusions: In conclusion, TVDT is a strong predictor of OS in patients with recurrent or metastatic MTC, can be used as a marker of progression, and potentially can help select patients who may benefit from molecular targeted therapy.

Is a Prophylactic Central Compartment Neck Dissection Required in Papillary Thyroid Carcinoma Patients with Clinically Involved Lateral Compartment Lymph Nodes?

BACKGROUND

The 2015 American Thyroid Association guidelines state that a prophylactic central compartment neck dissection (PCND) should be considered for patients with papillary thyroid carcinoma (PTC) and clinically involved lateral neck lymph nodes (cN1b). The purpose of our study was to determine the rate of central neck recurrence in select cN1b patients, with no evidence of clinically involved central compartment lymph nodes, treated without a PCND.

METHODS

After institutional review board approval, adult PTC patients with cN1b disease who were treated with a total thyroidectomy and lateral neck dissection were identified from an institutional database of 6259 patients who underwent initial surgery for well-differentiated thyroid carcinoma from 1986 to 2015. Patients with gross extrathyroidal extension, distant metastases, or no preoperative imaging were excluded. Patients with evidence of clinically involved central compartment lymph nodes, on preoperative imaging or intraoperative evaluation, also were excluded. A total of 152 cN1b patients were included and categorized into non-PCND and PCND groups. Central neck recurrence-free probability (CNRFP) was calculated using the Kaplan-Meier method and log-rank tests.

RESULTS

One hundred three patients (67.8%) did not have a PCND. With a median follow-up of 65 months, the 5- and 10-year CNRFP was 98.4% in the non-PCND group and 93.6% in the PCND group (p = 0.133).

CONCLUSIONS

Select PTC patients with cN1b disease but no evidence of clinically involved central compartment lymph nodes, on preoperative imaging and intraoperative evaluation, appear to have a low rate of central neck recurrence. These patients may not require or benefit from a PCND.

Radioiodine (RAI) in combination with durvalumab for recurrent/metastatic thyroid cancers

6587

Background: Immune checkpoint blockade (ICB) has limited efficacy for radioiodine-refractory thyroid cancer. The high incidence of autoimmune thyroid disease and ICB-induced hypothyroidism suggests that loss of T cell tolerance to thyroid protein epitopes is common and can be activated by ICB to induce immune responses. We hypothesize that RAI can enhance presentation of thyroid protein immunogens and putative neoantigens in thyroid cancers to amplify the effectiveness of ICB. We studied the safety and efficacy of RAI plus the anti-PD-L1 agent durvalumab (durva) in recurrent/metastatic (R/M) patients (pts). Methods: Pts. had at least one RAI-avid tumor on the most recent RAI scan or one tumor on FDG PET with an SUVmax < 10. RECIST measurable disease was required. Any number of prior therapies was allowed. Pts were treated with durva 1500 mg IV every 4 weeks with recombinant human TSH (rhTSH)-stimulated RAI (100 mCi) administered in Cycle 1. Treatment beyond progression was allowed. The primary objective was to assess safety. Durva related dose limiting toxicities (DLTs) were monitored for 6 weeks after the first dose. Since no durva DLTs were observed in the first 6 pts, per protocol rules the trial accrued 11 pts total. Secondary objectives were assessing best overall response (BOR) per RECIST and progression-free survival (PFS). Results: 11 pts (7 female) were enrolled. Eight had prior drug therapy. No DLTs or > Grade 3 durva related adverse events (AEs) were observed. The most common non-laboratory AEs (regardless of attribution) were cough (7), hypertension (7), pain (6), edema (5), and fatigue/nausea/diarrhea/arthralgia/dry skin/dyspnea/edema (4 each). As of 2/6/20, 2 had partial response, 7 stable disease, and 2 progression of disease as BOR. Six pts had tumor regression. Four pts received treatment for > 6 months. Six are still on treatment. Analyses of research biopsies (bxs) (8 had pre-treatment bxs, 6 had an additional on-treatment bx) will be presented. Conclusions: Durva plus RAI is safe and well tolerated. The preliminary efficacy signal in this small cohort is promising. Understanding how RAI plus PD-L1 targeting impacts the tumor immune microenvironment may guide how RAI should be evaluated in future ICB trials. Clinical trial information: NCT03215095 .

MON-520 How Does the American Joint Committee on Cancer 8thEdition Tumor, Node, Metastasis Staging System Perform in Patients Evaluated at a Major Middle Eastern Medical Center?

The American Joint Committee on Cancer (AJCC) Tumor Node Metastasis (TNM) Classification of Cancer 8^th edition (AJCC8) was officially introduced in January 2018 as a replacement for the previous version (AJCC7). Validation studies using data obtained from large cancer registries in North America demonstrated the superiority of AJCC8 over AJCC7 for prediction of survival. Subsequent studies from Europe and East Asia have mostly shown similar findings. However, these data may not be generalizable to other parts of the world. In this first study from the Middle East (Saudi Arabia), we compared these two versions of AJCC staging for their concordance and prediction of outcome in a large unselected sample of patients (pts) with DTC managed at a major referral medical center. We also compared the AJCC staging systems with the American Thyroid Association (ATA) Risk Classification.

Of 814 consecutive pts seen during this period, 94 were excluded either due to their diagnosis being medullary or anaplastic thyroid cancer (37) or because of deficient data. The remaining 720 pts (149 males (20.7%), 571 females (79.3%) were included. The median age at the diagnosis was 37 yrs (range, 6-83). Total thyroidectomy was performed in 693 pts (96.3%) and central and/or lateral lymph node dissections in 487 pts (67.6%). I-131 was administered to 626 pts (87%). The tumors were classic PTC in 519 pts (72%), follicular variant PTC in 100 (13.9%), Tall cell PTC in 22 (3.1%), diffuse sclerosing PTC in 10 (1.4%), follicular thyroid cancer in 21 (2.9%) and other rare subtypes in 48 pts (6.8%).

The number (%) of pts within each stage group by AJCC7 and AJCC8 respectively are as follows: Stage 1: 514 (71.4%) vs. 597 (82.9%), Stage 2: 46 (6.4%) vs. 75 (10.4%), Stage 3: 63 (8.8%) vs. 11 (1.5%), Stage 4: 97 (13.5%) vs. 37 (5.1%).

Comparing AJCC8 with the ATA risk stratification system in 709 pts in which data were available, we found a high correlation with 96.8% of ATA low risk group being stage 1 in AJCC8, 2.9% stage 2 and 0.3% stage 3 and none in stage 4. The ATA intermediate risk group was 87.4% AJCC8 stage 1, 12.3% stage 2, 0.4% stage 3 and none in stage 4. The ATA high risk group was 19.1% in AJCC8 stage 1, 33% in stage 2, 9.6% in stage 3 and 38.3% in stage 4.

In addition, AJCC8 was more predictive of the outcome with 80% of pts with evidence of disease (biochemically and structurally incomplete) being in AJCC8 stage 3 or 4 compared with 60% in AJCC7. For ATA staging, 8.6%, 22.4% and 67.7% of low, intermediate and high risk groups had evidence of disease at the last follow up, respectively.

Conclusion: In this Middle Eastern population, AJCC8 downstaged a significant percentage of pts with DTC from higher stages in AJCC7. It also correlated better with the outcome and with the ATA risk classification system.

Management of Retropharyngeal Lymph Node Metastases in Differentiated Thyroid Carcinoma

Background: Retropharyngeal lymph node metastases (RPMs) from differentiated thyroid carcinoma (DTC) are rare. Treatment includes surgical resection, radioactive iodine (RAI) therapy, or external beam radiation therapy (EBRT). The objective of this study was to describe our experience in the management of DTC-associated RPMs. Methods: Patients diagnosed with a DTC-associated RPM from 1999 to 2018 were identified at our institution, using key search terms in imaging and histology reports. Patient and tumor characteristics were recorded, and patients were grouped according to RPM management: observation, nonsurgical treatment, or surgical resection. The estimated rates of local RPM control, disease-specific survival (DSS), and distant metastasis-free probability (DMFP) were calculated by using the Kaplan-Meier method. Results: Of the 65 patients identified, 53 (82%) had an RPM as a manifestation of recurrent disease. Twenty-five patients (38%) underwent observation, 13 (20%) received nonsurgical treatment (RAI, EBRT, and/or systemic therapy), and 27 (42%) underwent surgical resection. In the observation cohort, all patients had a stable RPM, which in the majority (80%) of cases remained <1.5 cm during the period of observation (median 28 months). Of the 13 patients in the nonsurgical treatment cohort, 3 received RAI therapy, 7 received EBRT, and 3 received systemic therapy only. In the surgical cohort, the median RPM maximum diameter was 2.0 cm (range 0.8-4.2 cm). The size of the RPM was predictive of surgical resection versus observation (p < 0.001). A transcervical approach was employed in 19 patients, and a transoral approach was used in 8 patients. The 5-year rate of local RPM control was 92%. For the whole cohort, the 5- and 10-year DMFP were 72% and 62%, respectively; the 5- and 10-year DSS were 93% and 81%, respectively. Conclusions: DTC-associated RPMs manifest as recurrent disease in the majority of patients. Select patients with a small-volume and nonprogressive RPM may be suitable for observation, whereas surgery is likely warranted in large or progressing RPMs. In general, the presence of an RPM from DTC appears to be associated with aggressive disease.

Active Surveillance in Papillary Thyroid Microcarcinomas is Feasible and Safe: Experience at a Single Italian Center

CONTEXT

The dramatic rise in the incidence of thyroid cancer over the last 30 years is largely attributable to the increasing diagnosis of papillary microcarcinomas (mPTCs). Current guidelines endorse an observational management approach in properly selected cases.

OBJECTIVE

To evaluate the feasibility of active surveillance in mPTC in Italy, its impact on real life, and to identify risk factors of progression.

DESIGN AND SETTING

In 2014 we started a prospective-observational study of active surveillance in mPTC patients.

PATIENTS

Included patients demonstrated a single Thy4 or Thy5 thyroid nodule, with largest diameter ≤1.3 cm, and no suspicious laterocervical lymph nodes by neck ultrasonography. Of 185 eligible subjects, 50.3% (93/185) enrolled in the observational management protocol while the others opted for surgery and were excluded from this analysis.

INTERVENTION

Enrolled patients were followed with neck ultrasound at 6- to 12-month intervals. Disease progression was defined as the appearance of abnormal lymph nodes or nodule enlargement during follow-up. In these cases, patients were directed to surgery.

RESULTS

Three patients (3/93, 3%) showed clinical progression and required surgery. Another 19 patients (19/93, 20%) decided to transition to surgical intervention even though there was no evidence of disease progression. All operated patients had excellent response to initial treatment despite the delayed surgery.

CONCLUSIONS

Within an Italian medical context, active surveillance appears to be a feasible and safe alternative to immediate surgery in healthy mPTC patients. Only 3% of mPTC demonstrated disease progression during a median follow-up of 19 months (range 6-54) and importantly demonstrated excellent outcomes after surgical intervention in a short-term follow-up.

Repeatability of Quantitative Diffusion-Weighted Imaging Metrics in Phantoms, Head-and-Neck and Thyroid Cancers: Preliminary Findings

The aim of this study was to establish the repeatability measures of quantitative Gaussian and non-Gaussian diffusion metrics using diffusion-weighted imaging (DWI) data from phantoms and patients with head-and-neck and papillary thyroid cancers. The Quantitative Imaging Biomarker Alliance (QIBA) DWI phantom and a novel isotropic diffusion kurtosis imaging phantom were scanned at 3 different sites, on 1.5T and 3T magnetic resonance imaging systems, using standardized multiple b-value DWI acquisition protocol. In the clinical component of this study, a total of 60 multiple b-value DWI data sets were analyzed for test–retest, obtained from 14 patients (9 head-and-neck squamous cell carcinoma and 5 papillary thyroid cancers). Repeatability of quantitative DWI measurements was assessed by within-subject coefficient of variation (wCV%) and Bland–Altman analysis. In isotropic diffusion kurtosis imaging phantom vial with 2% ceteryl alcohol and behentrimonium chloride solution, the mean apparent diffusion (D_app × 10⁻³ mm²/s) and kurtosis (K_app, unitless) coefficient values were 1.02 and 1.68 respectively, capturing in vivo tumor cellularity and tissue microstructure. For the same vial, D_app and K_app mean wCVs (%) were ≤1.41% and ≤0.43% for 1.5T and 3T across 3 sites. For pretreatment head-and-neck squamous cell carcinoma, apparent diffusion coefficient, D, D*, K, and f mean wCVs (%) were 2.38%, 3.55%, 3.88%, 8.0%, and 9.92%, respectively; wCVs exhibited a higher trend for papillary thyroid cancers. Knowledge of technical precision and bias of quantitative imaging metrics enables investigators to properly design and power clinical trials and better discern between measurement variability versus biological change.

Quantitative Non-Gaussian Intravoxel Incoherent Motion Diffusion-Weighted Imaging Metrics and Surgical Pathology for Stratifying Tumor Aggressiveness in Papillary Thyroid Carcinomas

We assessed a priori aggressive features using quantitative diffusion-weighted imaging metrics to preclude an active surveillance management approach in patients with papillary thyroid cancer (PTC) with tumor size 1-2 cm. This prospective study enrolled 24 patients with PTC who underwent pretreatment multi-b-value diffusion-weighted imaging on a GE 3 T magnetic resonance imaging scanner. The apparent diffusion coefficient (ADC) metric was calculated from monoexponential model, and the perfusion fraction (f), diffusion coefficient (D), pseudo-diffusion coefficient (D*), and diffusion kurtosis coefficient (K) metrics were estimated using the non-Gaussian intravoxel incoherent motion model. Neck ultrasonography examination data were used to calculate tumor size. The receiver operating characteristic curve assessed the discriminative specificity, sensitivity, and accuracy between PTCs with and without features of tumor aggressiveness. Multivariate logistic regression analysis was performed on metrics using a leave-1-out cross-validation method. Tumor aggressiveness was defined by surgical histopathology. Tumors with aggressive features had significantly lower ADC and D values than tumors without tumor-aggressive features (P < .05). The absolute relative change was 46% in K metric value between the 2 tumor types. In total, 14 patients were in the critical size range (1-2 cm) measured by ultrasonography, and the ADC and D were significantly different and able to differentiate between the 2 tumor types (P < .05). ADC and D can distinguish tumors with aggressive histological features to preclude an active surveillance management approach in patients with PTC with tumors measuring 1-2 cm.

Active surveillance for patients with very low-risk thyroid cancer

Over the past 30 years in the United States, increasing identification of small thyroid nodules has led to a dramatic rise in the detection of small thyroid cancers, many of which are unlikely to progress to overt clinical disease. Because autopsy studies reveal that up to 30% of people harbor clinically occult thyroid cancers, the growing use of diagnostic technologies has identified an increasing number of small, clinically low risk papillary thyroid cancers (PTCs). In recent years, clinical practice has evolved to de-intensify the treatment for PTCs, with fewer total thyroidectomy and nodal dissection procedures being performed, in favor of more limited operations. In addition, vigilant observation of selected low risk cancers has demonstrated outcomes comparable to those patients who undergo immediate surgical intervention. Active surveillance has emerged as a new option within the treatment algorithm of PTCs. There is now robust data from cancer centers in Japan and Korea which have reported excellent oncologic outcomes among patients undergoing active surveillance for PTC, as well as more recent, similar data from the United States. American Thyroid Association guidelines now include the option of active surveillance for appropriately selected patients with low-risk PTC. With active surveillance now one option within the standard of care for patients with certain thyroid cancers, surgeons have become critical to facilitating shared decision-making for patients facing this diagnosis.

Dynamic contrast-enhanced MRI model selection for predicting tumor aggressiveness in papillary thyroid cancers

The purpose of this study was to identify the optimal tracer kinetic model from T1 -weighted dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) data and evaluate whether parameters estimated from the optimal model predict tumor aggressiveness determined from histopathology in patients with papillary thyroid carcinoma (PTC) prior to surgery. In this prospective study, 18 PTC patients underwent pretreatment DCE-MRI on a 3 T MR scanner prior to thyroidectomy. This study was approved by the institutional review board and informed consent was obtained from all patients. The two-compartment exchange model, compartmental tissue uptake model, extended Tofts model (ETM) and standard Tofts model were compared on a voxel-wise basis to determine the optimal model using the corrected Akaike information criterion (AICc) for PTC. The optimal model is the one with the lowest AICc. Statistical analysis included paired and unpaired t-tests and a one-way analysis of variance. Bonferroni correction was applied for multiple comparisons. Receiver operating characteristic (ROC) curves were generated from the optimal model parameters to differentiate PTC with and without aggressive features, and AUCs were compared. ETM performed best with the lowest AICc and the highest Akaike weight (0.44) among the four models. ETM was preferred in 44% of all 3419 voxels. The ETM estimates of Ktrans in PTCs with the aggressive feature extrathyroidal extension (ETE) were significantly higher than those without ETE (0.78 ± 0.29 vs. 0.34 ± 0.18 min-1 , P = 0.005). From ROC analysis, cut-off values of Ktrans , ve and vp , which discriminated between PTCs with and without ETE, were determined at 0.45 min-1 , 0.28 and 0.014 respectively. The sensitivities and specificities were 86 and 82% (Ktrans ), 71 and 82% (ve ), and 86 and 55% (vp ), respectively. Their respective AUCs were 0.90, 0.71 and 0.71. We conclude that ETM Ktrans has shown potential to classify tumors with and without aggressive ETE in patients with PTC.

How Many Papillae in Conventional Papillary Carcinoma? A Clinical Evidence-Based Pathology Study of 235 Unifocal Encapsulated Papillary Thyroid Carcinomas, with Emphasis on the Diagnosis of Noninvasive Follicular Thyroid Neoplasm with Papillary-Like Nuclear Features

Background: The percentage of papillae is a crucial criterion in differentiating noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) from papillary thyroid carcinomas (PTCs) and in subclassifying PTC into classic and follicular variant. Since the description of NIFTP, three studies have shown that the presence of any papillae may be associated with nodal metastasis, which led to modification of the NIFTP criterion from <1% papillae to no true papillae allowed. We aim at providing clinical evidence-based data on the impact that papillary growth has on nodal spread and tumor genotype in tumors previously diagnosed as encapsulated unifocal PTC. Methods: A meticulous histopathologic examination was performed on 235 cases previously diagnosed as unifocal encapsulated PTC (U-EPTC). One hundred of these cases were subjected to BRAF^V600E and NRAS^Q61R immunohistochemistry. Results: In our cohort, 27 patients (12%) had lymph node metastasis (N1) at the time of initial resection. Overall, 89% of the tumors in the N1 group contained ≥50% papillae, compared with 13% in the N0/Nx group. Nodal metastases were only present in tumors with ≥1% papillae. In noninvasive U-EPTC (n = 161), N1 disease was seen only in tumors with ≥10% papillae. A higher percentage of papillae within the tumor also correlated with an increased frequency of BRAF^V600E and decreased rate of NRAS^Q61R. None of the 26 NRAS-positive cases had nodal disease, including the invasive tumors. Among 216 patients with follow-up (median: 5.2 years), 3 patients (1.5%) had distant metastases, all detected at the initial presentation. All three tumors displayed 100% follicular growth, and capsular or vascular invasion. There was no locoregional recurrence in the entire cohort. Conclusion: In U-EPTC, there is a strong correlation between high percentage of papillary growth, presence of nodal metastasis, and BRAF+/RAS- genotype regardless of invasive status. Nodal metastases were not seen in tumors with <1% papillae irrespective of invasive status. These findings indicate that the initial criterion of <1% papillae is still valid for the diagnosis of NIFTP. Reinstituting this criterion will spare a carcinoma diagnosis and unnecessary therapy with its side effects on patients who have negligible clinical risk.

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.

Long-Term Oncologic Outcomes After Curative Resection of Familial Medullary Thyroid Carcinoma

INTRODUCTION

Long-term outcomes after curative resection in patients with germline RET mutations and medullary thyroid cancer (MTC) are highly variable and mutation-specific oncologic outcomes are not well-described.

METHODS

Sixty-six patients identified from 1986 to 2017 from a single-institution cancer database were assessed for recurrence and survival using Kaplan-Meier estimates, and correlated with clinicopathologic features using log-rank or Cox proportional hazards.

RESULTS

Median follow-up was 9.3 years (range 0.3-31.5), median tumor diameter was 1.5 cm (range 0.1-7.5), and preoperative calcitonin was known in 41 patients [median 636 (range 0-9600)]. Overall survival (OS) of the cohort was 94% at 10 years, the cumulative incidence of locoregional recurrence was 38% at 10 years, and 19/24 (79%) patients underwent repeat neck operation. The cumulative incidence of distant recurrence was 27% at 10 years. Predictors of distant recurrence were tumor size, positive lymph nodes, and pre- and postoperative carcinoembryonic antigen, but not calcitonin. M918T mutation-bearing patients had 10-year distant recurrence-free survival of 0%, compared with 83% in all other patients (p < 0.001), and equivalent 10-year OS (100% vs. 92%; p = 0.49).

CONCLUSIONS

Structural and metastatic recurrence is common in patients with germline RET mutations, and MTC and can occur 20 years after initial treatment, however survival remains high. Management should focus on optimal surveillance strategies and long-term control of structural disease.

Should multifocality be an indication for completion thyroidectomy in papillary thyroid carcinoma?

BACKGROUND

Multifocality in papillary thyroid carcinoma is common. The aim of this study is to determine whether patients with multifocal disease, treated with lobectomy alone, have an increased risk of contralateral lobe papillary thyroid carcinoma, regional recurrence, and poorer survival.

METHODS

After institutional review board approval, papillary thyroid carcinoma patients managed from 1986 to 2015 with lobectomy alone were identified from an institutional database. Papillary thyroid carcinoma patients with pT3 to T4 classification, nodal disease, or distant metastases were excluded. After excluding 40 patients who underwent an immediate completion thyroidectomy, 849 were included in the analysis; 619 (72.9%) had unifocal disease and 230 (27.1%) had multifocal disease. Contralateral lobe papillary thyroid carcinoma-free probability, regional recurrence-free probability, disease-specific survival, and overall survival were calculated using the Kaplan-Meier method.

RESULTS

With a median follow-up of 58 months, unifocal disease and multifocal disease patients had similar rates of contralateral lobe papillary thyroid carcinoma, regional recurrence, and overall survival (10-year contralateral lobe papillary thyroid carcinoma-free probability 98.6% vs 97.8%; regional recurrence-free probability 99.5% vs 99.4%; overall survival 91.6% vs 93.1%, respectively). There were no disease-related deaths.

CONCLUSION

Select multifocal disease patients, managed with lobectomy alone, have rates of contralateral lobe papillary thyroid carcinoma, regional recurrence, and overall survival comparable to unifocal disease patients. Multifocal disease should not be an indication for completion thyroidectomy.

Vemurafenib Redifferentiation of BRAF Mutant, RAI-Refractory Thyroid Cancers

CONTEXT

BRAFV600E mutant thyroid cancers are often refractory to radioiodine (RAI).

OBJECTIVES

To investigate the utility and molecular underpinnings of enhancing lesional iodide uptake with the BRAF inhibitor vemurafenib in patients with RAI-refractory (RAIR).

DESIGN

This was a pilot trial that enrolled from June 2014 to January 2016.

SETTING

Academic cancer center.

PATIENTS

Patients with RAIR, BRAF mutant thyroid cancer.

INTERVENTION

Patients underwent thyrotropin-stimulated iodine-124 (124I) positron emission tomography scans before and after ~4 weeks of vemurafenib. Those with increased RAI concentration exceeding a predefined lesional dosimetry threshold (124I responders) were treated with iodine-131 (131I). Response was evaluated with imaging and serum thyroglobulin. Three patients underwent research biopsies to evaluate the impact of vemurafenib on mitogen-activated protein kinase (MAPK) signaling and thyroid differentiation.

MAIN OUTCOME MEASURE

The proportion of patients in whom vemurafenib increased RAI incorporation to warrant 131I.

RESULTS

Twelve BRAF mutant patients were enrolled; 10 were evaluable. Four patients were 124I responders on vemurafenib and treated with 131I, resulting in tumor regressions at 6 months. Analysis of research tumor biopsies demonstrated that vemurafenib inhibition of the MAPK pathway was associated with increased thyroid gene expression and RAI uptake. The mean pretreatment serum thyroglobulin value was higher among 124I responders than among nonresponders (30.6 vs 1.0 ng/mL; P = 0.0048).

CONCLUSIONS

Vemurafenib restores RAI uptake and efficacy in a subset of BRAF mutant RAIR patients, probably by upregulating thyroid-specific gene expression via MAPK pathway inhibition. Higher baseline thyroglobulin values among responders suggest that tumor differentiation status may be a predictor of vemurafenib benefit.

Outcome and molecular characteristics of non-invasive encapsulated follicular variant of papillary thyroid carcinoma with oncocytic features

PURPOSE

In 2016, non-invasive encapsulated follicular variant of papillary thyroid carcinoma (NI-EFVPTC) was renamed as noninvasive thyroid follicular neoplasm with papillary-like nuclear features (NIFTP). However, as the study cohort did not mention tumors with oncocytic features, such lesions are still labeled by some as FVPTC. It is therefore crucial to evaluate the outcome and molecular profile of oncocytic NI-EFVPTC.

METHODS

A multi-institutional clinico-pathologic review was conducted to select 61 patients having oncocytic NI-EFVPTC. A detailed molecular profile was carried out in 15 patients.

RESULTS

Oncocytic NI-EFVPTCs predominantly affected women in their 50s. There was no distant metastasis, lymph node metastases, or structural recurrence in the entire cohort. Among patients with ≥5 years of FU, all 33 individuals did not recur with a median FU of 10.2 years. Oncocytic NI-EFVPTC commonly had RAS (33%) mutations, a high frequency of mitochondrial DNA mutations (67%) and multiple chromosomal gains/losses (53%). No fusion genes were detected.

CONCLUSIONS

Oncocytic NI-EFVPTC, when stringently selected for, lacks metastasis at presentation and follows an extremely indolent clinical course, even when treated conservatively with lobectomy alone without RAI therapy. These tumors share a similar mutational profile as NIFTP, FVPTC, and follicular neoplasm and are predominantly RAS-related. Like Hurthle cell neoplasms, they harbor a high frequency of mitochondrial DNA mutations, which contribute to the oncocytic cytomorphology. However, they lack the widespread chromosomal alterations observed in Hurthle cell carcinoma. Consideration should be given to include oncocytic NI-EFVPTCs as NIFTP in order to avoid overtreatment of these highly indolent tumors.

Prolongation of tumour volume doubling time (midDT) is associated with improvement in disease-specific survival in patients with rapidly progressive radioactive iodine refractory differentiated thyroid cancer selected for molecular targeted therapy

PURPOSE

To assess molecular targeted therapy (MTT)'s ability to affect tumour volume doubling time (TVDT) and disease-specific survival (DSS) in patients presenting with lung metastasis from radioactive iodine refractory progressive thyroid cancer.

METHODS

In this retrospective study, we examined the clinical characteristics, average tumour volume doubling times of lung metastasis and disease-specific survival of patients with lung metastasis from differentiated thyroid cancer who were treated with MTT.

RESULTS

The 5-year DSS from the distant metastasis (DM) diagnosis was 72% with median survival of 8 years (95% CI: 6.6-9.5). The median survival was 2.9 years after MTT start (95% CI: 2.1-3.6). On MTT, lung average tumour volume doubling time (midDT) was prolonged to midDT ≥3 years in 75% of patients with baseline midDT ≤1 year and 100% of patients with midDT 1-3 years. In patients with rapidly progressive thyroid cancer (midDT ≤1 year at baseline), the median survival was 4.5 years in those with MTT-achieved midDT ≥3 years (95% CI: 2.9-6.2), as opposed to 2.3 years (95% CI: 0.3-4.3) and 0.7 years (95% CI: 0.2-1.3) in those with MTT-achieved midDT of 1-3 years and MTT-achieved midDT ≤1 year, respectively (log rank P < 0.001).

CONCLUSION

Lung midDT is a useful and important clinical marker of disease-specific survival for patients with progressive radioactive iodine refractory (RAIR) metastatic thyroid cancer. In patients with rapidly progressive metastatic RAIR thyroid cancer, molecular targeted therapy prolongs lung tumour volume doubling time and is associated with improved disease-specific survival.

Controversies, Consensus, and Collaboration in the Use of 131I Therapy in Differentiated Thyroid Cancer: A Joint Statement from the American Thyroid Association, the European Association of Nuclear Medicine, the Society of Nuclear Medicine and Molecular Imaging, and the European Thyroid Association

BACKGROUND

Publication of the 2015 American Thyroid Association (ATA) management guidelines for adult patients with thyroid nodules and differentiated thyroid cancer was met with disagreement by the extended nuclear medicine community with regard to some of the recommendations related to the diagnostic and therapeutic use of radioiodine (¹³¹I). Because of these concerns, the European Association of Nuclear Medicine and the Society of Nuclear Medicine and Molecular Imaging declined to endorse the ATA guidelines. As a result of these differences in opinion, patients and clinicians risk receiving conflicting advice with regard to several key thyroid cancer management issues.

SUMMARY

To address some of the differences in opinion and controversies associated with the therapeutic uses of ¹³¹I in differentiated thyroid cancer constructively, the ATA, the European Association of Nuclear Medicine, the Society of Nuclear Medicine and Molecular Imaging, and the European Thyroid Association each sent senior leadership and subject-matter experts to a two-day interactive meeting. The goals of this first meeting were to (i) formalize the dialogue and activities between the four societies; (ii) discuss indications for ¹³¹I adjuvant treatment; (iii) define the optimal prescribed activity of ¹³¹I for adjuvant treatment; and (iv) clarify the definition and classification of ¹³¹I-refractory thyroid cancer.

CONCLUSION

By fostering an open, productive, and evidence-based discussion, the Martinique meeting restored trust, confidence, and a sense of collegiality between individuals and organizations that are committed to optimal thyroid disease management. The result of this first meeting is a set of nine principles (The Martinique Principles) that (i) describe a commitment to proactive, purposeful, and inclusive interdisciplinary cooperation; (ii) define the goals of ¹³¹I therapy as remnant ablation, adjuvant treatment, or treatment of known disease; (iii) describe the importance of evaluating postoperative disease status and multiple other factors beyond clinicopathologic staging in ¹³¹I therapy decision making; (iv) recognize that the optimal administered activity of ¹³¹I adjuvant treatment cannot be definitely determined from the published literature; and (v) acknowledge that current definitions of ¹³¹I-refractory disease are suboptimal and do not represent definitive criteria to mandate whether ¹³¹I therapy should be recommended.

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

CONTEXT

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

EVIDENCE ACQUISITION

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.

EVIDENCE SYNTHESIS

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.

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.

European Perspective on 2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer: Proceedings of an Interactive International Symposium

BACKGROUND

The American Thyroid Association (ATA) management guidelines for patients with thyroid nodules and differentiated thyroid cancer (DTC) are highly influential practice recommendations. The latest revision appeared in 2015 ("ATA 2015"). These guidelines were developed predominantly by North American experts. European experts frequently have different perspectives, given epidemiological, technological/methodological, practice organization, and medicolegal differences between the respective regions.

SUMMARY

Divergent viewpoints were the focus of an invited symposium organized by the European Association of Nuclear Medicine involving 17 European thyroidologists, four ATA Guidelines Taskforce members, and an audience of 200 international experts. The group discussed the preoperative assessment of thyroid nodules, surgery and the role of pathology, radioiodine (RAI) therapy (RAIT), the assessment of initial therapy and dynamic risk stratification, and the treatment of persistent disease, recurrences, and advanced thyroid cancer. The dialogue resulted in this position paper contrasting European and ATA 2015 perspectives on key issues. One difference pertains to the permissiveness of ATA 2015 regarding lobectomy for primary tumors ≤4 cm. European panelists cited preclusion of RAIT, potential need for completion thyroidectomy, frequent inability to avoid chronic thyroid hormone replacement, and limitations of supportive evidence as arguments against widely applying lobectomy. Significant divergence involved ATA 2015's guidance regarding RAIT. European panelists favored wider use of postoperative RAIT than does ATA 2015. Rationales included the modality's association with favorable patient outcomes and generally limited toxicity, and lack of high-quality evidence supporting withholding RAIT. Additionally, European panelists favored recombinant human thyrotropin (rhTSH) in more settings than does ATA 2015, citing avoidance of hypothyroid morbidity and quality-of-life impairment, without apparent sacrifice in oncologic outcomes. Based on clinical evidence plus theoretical advantages, European experts advocated dosimetric versus fixed-activity RAIT approaches for advanced DTC. European panelists noted that the ATA 2015 risk-stratification system requires information sometimes unavailable in everyday practice. ATA 2015 recommendations regarding RAI-refractory DTC should consider potential palliative benefits of RAIT in patients who also have RAI-susceptible lesions.

CONCLUSIONS

European panelists suggested modifications to approximately one-third of ATA 2015 recommendations. Varying European and ATA 2015 perspectives can stimulate analysis and discussion of the literature and performance of primary research to resolve discrepant recommendations and potentially improve patient outcomes.

American Head and Neck Society Endocrine Section clinical consensus statement: North American quality statements and evidence-based multidisciplinary workflow algorithms for the evaluation and management of thyroid nodules

BACKGROUND

Care for patients with thyroid nodules is complex and multidisciplinary, and research demonstrates variation in care. The objective was to develop clinical guidelines and quality metrics to reduce unwarranted variation and improve quality.

METHODS

Multidisciplinary expert consensus and modified Delphi approach. Source documents were workflow algorithms from Kaiser Permanente Northern California and Cancer Care of Ontario based on the 2015 American Thyroid Association management guidelines for adult patients with thyroid nodules and differentiated thyroid cancer.

RESULTS

A consensus-based, unified preoperative, perioperative, and postoperative workflow was developed for North American use. Twenty-one panelists achieved consensus on 16 statements about workflow-embedded process and outcomes metrics addressing safety, access, appropriateness, efficiency, effectiveness, and patient centeredness of care.

CONCLUSION

A panel of Canadian and United States experts achieved consensus on workflows and quality metric statements to help reduce unwarranted variation in care, improving overall quality of care for patients diagnosed with thyroid nodules.

Implementing Key Changes in the American Thyroid Association 2015 Thyroid Nodules/Differentiated Thyroid Cancer Guidelines Across Practice Types

OBJECTIVE

This article provides suggestions to help clinicians implement important changes in the 2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Carcinoma ("ATA 2015") across diverse settings.

METHODS

Key ATA 2015 changes are summarized regarding: ( 1) thyroid nodule management; ( 2) lobectomy versus thyroidectomy for differentiated thyroid carcinoma (DTC); and ( 3) surveillance following primary treatment of DTC. Advice to facilitate implementation is based on clinical experience and selected literature.

RESULTS

Strategies are described to enhance acquisition of high-quality information that helps identify patients who may possibly avoid fine-needle aspiration (FNA) of thyroid nodules or total thyroidectomy for DTC, or undergo less intense postoperative surveillance. Sonographic imaging of nodules may improve if sonograms are obtained by clinicians ordering or performing FNA or trusted high-volume sonographers. Cytopathologic assessment and reporting can be improved by working with regional or national experts. Pre-operative evaluation by endocrinologists is important so that patients are referred to experienced, proficient surgeons and assisted with well-informed decision-making regarding surgical radicality. Endocrinologists and surgeons should ensure performance of pre-operative neck ultrasonography, voice/laryngeal evaluation, and contrast-enhanced cross-sectional imaging when appropriate. Findings should be disseminated to all healthcare team members, ideally through a comprehensive medical record accessible to the entire team.

CONCLUSION

Optimization of the sequence of specialist visits and assembly of interactive multidisciplinary teams coupled with intensified interdisciplinary and patient communication may enable clinicians to more effectively implement ATA 2015, which calls for more individualized, and often, less "invasive" management of thyroid nodules and DTC.

ABBREVIATIONS

ATA 2009 = 2009 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Carcinoma; ATA 2015 = 2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Carcinoma; DTC = differentiated thyroid carcinoma; FNA = fine-needle aspiration; PET/CT = positron emission tomography/computed tomography.

Stage migration with the new American Joint Committee on Cancer (AJCC) staging system (8th edition) for differentiated thyroid cancer

BACKGROUND

Tumor, node, and metastasis staging in thyroid carcinoma is important for assessing prognosis. However, patients with stage III or IV disease have an overall survival rate of 90%. The change to 55 years of age as the cutoff will create stage migration and many patients will be downstaged.

METHODS

We reviewed our database of 3,650 patients to analyze the impact of the new American Joint Committee on Cancer staging system. There were 994 men (27%) and 2,656 women (73%). The median age was 46 years. Patients were staged using both 7th and 8th editions, with a cutoff of 55 years of age and new definitions of T3 and T4, and nodal staging.

RESULTS

Of 3,650 patients, 1,057 (29%) were downstaged. There were 104 (10%) who went from stage IV to I, 109 (10%) who went from stage IV to stage II, and 68 (6%) who went to stage III. There were 218 (21%) who went from stage III to I, 347 (33%) who went from stage III to stage II, and 211 (20%) who went from stage II to I. The overall disease-specific and relapse-free survival was analyzed and showed better stratification with the new staging system.

CONCLUSION

The new staging system reflects more appropriately the biology of thyroid cancer and will have significant impact on the management of thyroid cancer.

Using the American Thyroid Association Risk-Stratification System to Refine and Individualize the American Joint Committee on Cancer Eighth Edition Disease-Specific Survival Estimates in Differentiated Thyroid Cancer

BACKGROUND

The eighth edition of the American Joint Committee on Cancer (AJCC) staging system has reclassified up to one third of differentiated thyroid cancer patients into one of the younger prognostic stage groups (<55 years of age at diagnosis, stage I or stage II). This reclassification widens the spectrum of disease in these lower stages without significantly impacting overall disease-specific survival (DSS) for the entire stage group. However, the optimistic DSS estimates in the <55-year-old stage groups may not accurately reflect the prognosis of individual patients with American Thyroid Association (ATA) high-risk features. Therefore, the aim of this study was to integrate the ATA risk classification system into the eighth edition AJCC staging system to refine and individualize DSS estimates for differentiated thyroid cancer patients aged <55 years at diagnosis.

METHODS

Using the Memorial Sloan Kettering Cancer Center tumor registry, 4881 adult DTC patients aged <55 years at diagnosis receiving initial therapy between 1980 and 2016 were retrospectively analyzed. Using Memorial Sloan Kettering Cancer Center registry coded data, all patients were assigned an eighth edition AJCC stage (I or II), ATA risk of recurrence (low, intermediate, or high), and age group at diagnosis (younger patients defined as ≤45 years old, older patients defined as 45-55 years old). The primary outcome was 10-year DSS.

RESULTS

A total of 122 (2.5%) disease-related deaths were observed in the cohort of 4881 patients during a median follow-up of 6.6 years. Integration of the AJCC stage, ATA risk, and age groups identified six subgroups with differing outcomes: (i) stage I/ATA low risk, younger and older, 100% DSS; (ii) stage I/ATA intermediate risk, younger and older, 98% DSS; (iii) stage I/ATA high risk, younger, 95% DSS; (iv) stage I/ATA high risk, older, 89% DSS; (v) stage II/ATA high risk, younger, 78% DSS; and (vi) stage II/ATA high risk, older, 61% DSS.

CONCLUSIONS

Integration of AJCC stage, ATA risk, and age group (i) identifies six subgroups of patients with progressively worse DSS as AJCC stage, ATA risk, and age increases, and (ii) provides a more individualized estimate of DSS, especially in ATA high-risk patients.

Thyroid Cancer Treatment Choice: A Pilot Study of a Tool to Facilitate Conversations with Patients with Papillary Microcarcinomas Considering Treatment Options

BACKGROUND

The 2015 American Thyroid Association guidelines recognize active surveillance as an alternative to immediate surgery in patients with papillary microcarcinomas (PMCs). As a way to incorporate active surveillance as one of the management options for patients with PMCs, we developed and tested a tool to support conversations between clinicians and patients with PMCs considering treatment options.

METHODS

Thyroid Cancer Treatment Choice was developed using an iterative process based on the principles of interaction, design, and participatory action research. To evaluate the impact of the tool on treatment choice, a prospective study was conducted in two thyroid cancer clinics in Seongnam-si and Seoul, South Korea. Both clinics had the expertise to offer active surveillance as well as immediate surgery. One clinic was trained in the use of the conversation aid, while the other clinic continued to care for patients without access to the conversation aid.

RESULTS

Between May 2016 and April 2017, 278 patients, mostly women (n = 220, 79%), were included in the study; 152 (53%) received care at the clinic using the conversation aid. Age, sex, and mean (±SD) tumor size (6.6 ± 1.6 mm and 6.5 ± 1.9 mm) distributions were similar across clinics. Overall, 233 (84%) patients opted for active surveillance and 53 (16%) for thyroid surgery. Patients in the conversation aid group were more likely to choose active surveillance than the patients seen in the usual care clinic (relative risk = 1.16 [confidence interval 1.04-1.29]). Of all patients opting for active surveillance, more patients in the conversation aid group had thyroid cancer nodules >5 mm than in the usual care group (81% vs. 67%; p = 0.013).

CONCLUSIONS

Thyroid Cancer Treatment Choice is an evidence-based tool that supports the presentation of treatment options for PMCs. Pilot testing suggests that this conversation tool increases acceptance of active surveillance, suggesting that this option is an acceptable and preferable alternative for informed patients. Further studies are warranted to confirm this finding.

Enhanced interdisciplinary communication: development of an interactive thyroid nodule/cancer disease map

OBJECTIVES

Deficits related to inadequate clinical communication can result in incorrect diagnoses, inappropriate surgery, incorrect disease stratification, pathologic reporting, and/or interpretation. There are currently no validated or defined solutions to disease-specific communication with regard to thyroid care.

METHODS

We propose a solution that could ameliorate problems arising from inadequate disease-specific communications between physicians through the development of a thyroid disease-specific database, the Thyroid Care Collaborative.

RESULTS

To improve the quality of thyroid nodule and cancer care, we have developed an imaging module for enhanced reporting of ultrasound, cytologic, surgical, and pathologic details that are obtained during the workup and treatment of a patient.

CONCLUSION

The main advantages of this disease-specific, dynamic, three-dimensional, anatomic disease map are: 1) portability across institutions and disciplines, 2) disease specificity to thyroid nodule and cancer care, and 3) ability to trigger more detailed evaluation or reconciliation of any change in a patient's status regarding the nature or the extent of a patient's disease. The first and second advantages above have been identified as areas representing opportunities for quality improvement in health informatics research. Laryngoscope, 129:269-274, 2019.

Intensity-Modulated Radiation Therapy With or Without Concurrent Chemotherapy in Nonanaplastic Thyroid Cancer with Unresectable or Gross Residual Disease

BACKGROUND

Differentiated thyroid cancer typically has an indolent clinical course but can cause significant morbidity by local progression. Oncologic surgical resection can be technically difficult due to the proximity to critical normal structures in the neck. Our objective was to review the safety, feasibility, and outcomes of definitive-intent intensity-modulated radiation therapy (IMRT) and to analyze whether patients receiving concurrent chemotherapy (CC-IMRT) had higher rates of disease control and survival over IMRT alone in patients with unresectable or gross residual disease (GRD).

METHODS

Eighty-eight patients with GRD or unresectable nonanaplastic, nonmedullary thyroid cancer treated with definitive-intent IMRT between 2000 and 2015 were identified. Local progression-free survival (LPFS), distant metastasis-free survival (DMFS), and overall survival (OS) were evaluated using the Kaplan-Meier method. Univariate and multivariate analyses using cox regression were used to determine the impact of clinical conditions and treatment on LPFS, DMFS, and OS.

RESULTS

Of the 88 patients identified, 45 (51.1%) were treated CC-IMRT and 43 (48.9%) were treated with IMRT alone. All patients treated with CC-IMRT received weekly doxorubicin (10 mg/m²). The median follow-up among surviving patients was 40.3 months and 29.2 months for all patients. The LPFS at 4 years was 77.3%. Patients receiving CC-IMRT had higher LPFS compared with IMRT alone (CC-IMRT 85.8% vs. IMRT 68.8%, p = 0.036). The 4-year OS was 56.3% for all patients. Patients treated with CC-IMRT had higher OS compared to patients treated with IMRT alone (CC-IMRT 68.0% vs. IMRT 47.0%, p = 0.043). On multivariate analysis, receipt of concurrent chemotherapy was associated with a lower risk of death (HR 0.395, p = 0.019) and lower risk of local failure (HR 0.306, p = 0.042). Grade 3+ acute toxicities occurred in 23.9% of patients, the most frequent being dermatitis (18.2%) and mucositis (9.1%). 17.1% of patients required a percutaneous endoscopic gastrostomy (PEG) tube during or shortly after completion of RT, with 10.1% of patients needing a PEG more than 12 months after therapy. The rates of acute and late toxicities were not statistically higher in the CC-IMRT cohort, although trends towards higher toxicity in the CC-IMRT were present for dermatitis and PEG requirement.

CONCLUSIONS

IMRT is a safe and effective means to achieve local control in patients with unresectable or incompletely resected nonanaplastic, nonmedullary thyroid cancer. Concurrent doxorubicin was not associated with worse toxicity and should be considered in these patients given its potential to improve local control and overall survival.

Controversial Issues in Thyroid Cancer Management

The lack of prospective randomized clinical trials for most management topics in differentiated thyroid cancer forces us to make management recommendations based on retrospective observational data, which are often incomplete, subject to selection bias, and conflicting. Therefore, it is not surprising that many aspects of thyroid cancer management remain controversial and not well defined. This review will examine the controversies surrounding 3 important topics in thyroid cancer management: the option of thyroid lobectomy as initial therapy, the use of preoperative neck imaging to optimize the completeness of the initial surgery, and the selective use of radioactive iodine for remnant ablation, adjuvant treatment, or treatment for known persistent or recurrent disease. As thyroid cancer management moves toward a much more risk-adapted approach to personalized recommendations, clinicians and patients must balance the risks and benefits of the potential options to arrive at a plan that is optimized regarding both patient preferences/values and the philosophy/experience of the local disease management team.

No Evidence of Increase in Calcitonin Concentrations or Development of C-Cell Malignancy in Response to Liraglutide for Up to 5 Years in the LEADER Trial

OBJECTIVE

To describe the changes in serum levels of calcitonin in liraglutide- and placebo-treated patients in the Liraglutide Effect and Action in Diabetes: Evaluation of Cardiovascular Outcome Results-A Long Term Evaluation (LEADER) trial over a 3.5-5-year period.

RESEARCH DESIGN AND METHODS

Patients (n = 9,340) with type 2 diabetes and high risk for cardiovascular events were randomized 1:1 to liraglutide or placebo. We analyzed calcitonin levels, thyroid and C-cell adverse events, and neoplasms.

RESULTS

At 36 months, patients randomized to liraglutide versus placebo showed no evidence of increase in calcitonin concentrations in male (estimated treatment ratio [ETR] 1.03 [95% CI 1.00, 1.06]; P = 0.068) and female (ETR 1.00 [95% CI 0.97, 1.02]; P = 0.671) subgroups. There were no episodes of C-cell hyperplasia or medullary thyroid carcinoma in liraglutide-treated patients.

CONCLUSIONS

There was no evidence of a difference in calcitonin concentrations between the liraglutide and placebo groups, and no C-cell malignancies occurred in the liraglutide group.

A clinical framework to facilitate selection of patients with differentiated thyroid cancer for active surveillance or less aggressive initial surgical management

INTRODUCTION

In the past, total thyroidectomy was usually recommended as the initial therapeutic approach in all but the lowest risk differentiated thyroid cancers. Today, many patients with low risk papillary thyroid cancers may be candidates for either an observational management approach (active surveillance/deferred surgical intervention) or a minimalist surgical approach (thyroid lobectomy/isthmusectomy).

AREAS COVERED

After a comprehensive review of the PubMed database and based on our clinical experience, we describe a clinical framework that integrates important factors in three major inter-related domains (pre-operative imaging/clinical findings, medical team characteristics, and patient characteristics) to classify a patient as either ideal, appropriate or inappropriate for conservative treatment options. As part of this clinical framework, we examine how the medical decision making construct (minimalist versus maximalist) of the patient and clinician can impact selection of initial therapy.

EXPERT COMMENTARY

The dramatic rise in the incidence of very low risk differentiated thyroid cancer demands a re-evaluation of the appropriate use of more minimalistic treatment options. The selection of appropriate patients for less aggressive initial treatment options requires thoughtful, open discussions that can be aided by clinical decision making frameworks that recognize and value the medical decision making process of clinicians and patients.

Surgical management of the recurrent laryngeal nerve in thyroidectomy: American Head and Neck Society Consensus Statement

"I have noticed in operations of this kind, which I have seen performed by others upon the living, and in a number of excisions, which I have myself performed on the dead body, that most of the difficulty in the separation of the tumor has occurred in the region of these ligaments…. This difficulty, I believe, to be a very frequent source of that accident, which so commonly occurs in removal of goiter, I mean division of the recurrent laryngeal nerve." Sir James Berry (1887).