The genomic and evolutionary landscapes of anaplastic thyroid carcinoma

Anaplastic thyroid carcinoma is arguably the most lethal human malignancy. It often co-occurs with differentiated thyroid cancers, yet the molecular origins of its aggressivity are unknown. We sequenced tumor DNA from 329 regions of thyroid cancer, including 213 from patients with primary anaplastic thyroid carcinomas. We also whole genome sequenced 9 patients using multi-region sequencing of both differentiated and anaplastic thyroid cancer components. Using these data, we demonstrate thatanaplastic thyroid carcinomas have a higher burden of mutations than other thyroid cancers, with distinct mutational signatures and molecular subtypes. Further, different cancer driver genes are mutated in anaplastic and differentiated thyroid carcinomas, even those arising in a single patient. Finally, we unambiguously demonstrate that anaplastic thyroid carcinomas share a genomic origin with co-occurring differentiated carcinomas and emerge from a common malignant field through acquisition of characteristic clonal driver mutations.

The Clinical Utility of Gallium-68-DOTATATE Positron Emission Tomography Scanning in Medullary Thyroid Cancer

OBJECTIVE

Somatostatin receptor (SST) functional imaging with positron emission tomography (PET)/computed tomography (CT) has broadened the diagnostic and staging capabilities for medullary thyroid cancer (MTC). Gallium-68 (68Ga)-DOTA-conjugated peptide (Tyr3)-octreotate (DOTATATE) is a radiotracer with a high affinity for type 2 SSTs expressed in several, but not all, MTCs. The utility of 68Ga-DOTATATE PET/CT and 18fluorine-labeled fluoro-2-deoxy-D-glucose (18F-FDG)-PET/CT imaging in predicting MTC prognosis is also unknown.

METHODS

In this single-center retrospective study, 103 of patients with MTC underwent assessment of SST2 and SST5 immunohistochemistry (IHC). A subgroup of 37 patients received 68Ga-DOTATATE PET/CT imaging, and 13 received contemporaneous 18F-FDG-PET/CT imaging. The maximum standardized uptake value (SUV), mean SUV, metabolic tumor volume, and total lesion activity (TLA) were assessed.

RESULTS

Forty-two patients (41%) demonstrated positive expression of SST2, and 45 (44%) had a positive SST5 IHC result. Seventeen patients (17%) expressed both SST2 and SST5. No survival advantage was identified with SST2 or SST5 IHC positivity. No correlation was noted between the maximum SUV, mean SUV, metabolic tumor volume, or TLA and SST2 and/or SST5 expression by IHC. Shorter survival was associated with a TLA of >20 (P = .04). A RET-negative status also appeared to have shorter survival, although this may be because the small numbers did not reach statistical significance (P = .12).

CONCLUSION

Assessment of TLA from 68Ga-DOTATATE PET/CT may predict survival. SST2 IHC was not correlated with 68Ga-DOTATATE avidity. Metastatic disease may be optimally assessed by concurrent 18F-FDG and 68Ga-DOTATATE imaging.

Association of the Genomic Profile of Medullary Thyroid Carcinoma with Tumor Characteristics and Clinical Outcomes in an International Multicenter Study

Purpose: The prognostic importance of RET and RAS mutations and their relationship to clinicopathologic parameters and outcomes in medullary thyroid carcinoma (MTC) need to be clarified. Experimental Design: A multicenter retrospective cohort study was performed utilizing data from 290 patients with MTC. The molecular profile was determined and associations were examined with clinicopathologic data and outcomes. Results: RET germ line mutations were detected in 40 patients (16.3%). Somatic RET and RAS mutations occurred in 135 (46.9%) and 57 (19.8%) patients, respectively. RETM918T was the most common somatic RET mutation (n = 75). RET somatic mutations were associated with male sex, larger tumor size, advanced American Joint Committee Cancer (AJCC) stage, vascular invasion, and high International Medullary Thyroid Carcinoma Grading System (IMTCGS) grade. When compared with other RET somatic mutations, RETM918T was associated with younger age, AJCC (eighth edition) IV, vascular invasion, extrathyroidal extension, and positive margins. RET somatic or germ line mutations were significantly associated with reduced distant metastasis-free survival on univariate analysis, but there were no significant independent associations on multivariable analysis, after adjusting for tumor grade and stage. There were no significant differences in outcomes between RET somatic and RET germ line mutations, or between RETM918T and other RET mutations. Other recurrent molecular alterations included TP53 (4.2%), ARID2 (2.9%), SETD2 (2.9%), KMT2A (2.9%), and KMT2C (2.9%). Among them, TP53 mutations were associated with decreased overall survival (OS) and disease-specific survival (DSS), independently of tumor grade and AJCC stage. Conclusions: RET somatic mutations were associated with high-grade, aggressive primary tumor characteristics, and decreased distant metastatic-free survival but this relationship was not significant after accounting for tumor grade and disease stage. RETM918T was associated with aggressive primary tumors but was not independently associated with clinical outcomes. TP53 mutation may represent an adverse molecular event associated with decreased OS and DSS in MTC, but its prognostic value needs to be confirmed in future studies.

Management of Medullary Thyroid Cancer: Patterns of Recurrence and Outcomes of Reoperative Surgery

BACKGROUND

There remains uncertainty regarding the optimal extent of initial surgery and management of recurrent disease in medullary thyroid cancer (MTC). We aim to describe the patterns of disease recurrence and outcomes of the reoperative surgery in a cohort of consecutively treated patients at a specialized tertiary referral center.

PATIENTS AND METHODS

A retrospective cohort study of 235 surgically treated patients with MTC at a tertiary referral center was performed using prospectively collected data.

RESULTS

In the study period 1986-2022, 235 patients underwent surgery for MTC. Of these, 45 (19%) patients had reoperative surgery for cervical nodal recurrence at a median (range) 2.1 (0.3-16) years following the index procedure. After a median follow-up of 4 years, 38 (84%) patients remain free of structural cervical recurrence, although 15 (33%) underwent 2 or more reoperative procedures. No long-term complications occurred after reoperative surgery. Local cervical recurrence was independently predicted by pathologically involved nodal status (OR 5.10, P = .01) and failure to achieve biochemical cure (OR 5.0, P = .009). Local recurrence did not adversely affect overall survival and was not associated with distant recurrence (HR 0.93, P = .83). Overall survival was independently predicted by high pathological grade (HR 10.0, P = .002) and the presence of metastatic disease at presentation (HR 8.27, P = 0018).

CONCLUSION

Loco-regional recurrence in MTC does not impact overall survival, or the development of metastatic disease, demonstrating the safety of the staged approach to the clinically node-negative lateral neck. When recurrent disease is technically resectable, reoperative surgery can be undertaken with minimal morbidity in a specialized center and facilitates structural disease control.

A Detailed Histologic and Molecular Assessment of the Diffuse Sclerosing Variant of Papillary Thyroid Carcinoma

Diffuse sclerosing variant papillary thyroid carcinoma (DS-PTC) is characterized clinically by a predilection for children and young adults, bulky neck nodes, and pulmonary metastases. Previous studies have suggested infrequent BRAFV600E mutation but common RET gene rearrangements. Using strict criteria, we studied 43 DS-PTCs (1.9% of unselected PTCs in our unit). Seventy-nine percent harbored pathogenic gene rearrangements involving RET, NTRK3, NTRK1, ALK, or BRAF; with the remainder driven by BRAFV600E mutations. All 10 pediatric cases were all gene rearranged (P = .02). Compared with BRAFV600E-mutated tumors, gene rearrangement was characterized by psammoma bodies involving the entire lobe (P = .038), follicular predominant or mixed follicular architecture (P = .003), pulmonary metastases (24% vs none, P = .04), and absent classical, so-called "BRAF-like" atypia (P = .014). There was no correlation between the presence of gene rearrangement and recurrence-free survival. Features associated with persistent/recurrent disease included pediatric population (P = .030), gene-rearranged tumors (P = .020), microscopic extrathyroidal extension (P = .009), metastases at presentation (P = .007), and stage II disease (P = .015). We conclude that DS-PTC represents 1.9% of papillary thyroid carcinomas and that actionable gene rearrangements are extremely common in DS-PTC. DS-PTC can be divided into 2 distinct molecular subtypes and all BRAFV600E-negative tumors (1.5% of papillary thyroid carcinomas) are driven by potentially actionable oncogenic fusions.

A Critical Assessment of Diagnostic Criteria for the Tall Cell Subtype of Papillary Thyroid Carcinoma-How Much? How Tall? And When Is It Relevant?

Tall cell papillary thyroid carcinoma (TC-PTC) is considered adverse histology. However, previous studies are confounded by inconsistent criteria and strong associations with other adverse features. It is therefore still unclear if TC-PTC represents an independent prognostic factor in multivariate analysis and, if it does, what criteria should be employed for the diagnosis. We retrospectively reviewed 487 PTCs from our institution (where we have historically avoided the prospective diagnosis of TC-PTC) for both the height of tall cells (that is if the cells were two, or three, times as tall as wide) and the percentage of tall cells. On univariate analysis, there was significantly better disease free survival (DFS) in PTCs with no significant tall cell component (< 30%) compared to PTCs with cells two times tall as wide (p = 0.005). The proportion of tall cells (30-50% and > 50%) was significantly associated with DFS (p = 0.012). In a multivariate model including age, size, vascular space invasion, and lymph node metastasis, the current WHO tall cell criteria, met by 7.8% of PTCs, lacked statistical significance for DFS (p = 0.519). However, in the subset of tumours otherwise similar to the American Thyroid Association (ATA) guidelines low-risk category, WHO TC-PTC demonstrated a highly significant reduction in DFS (p = 0.004). In contrast, in intermediate to high-risk tumours, TC-PTC by WHO criteria lacked statistical significance (p = 0.384). We conclude that it may be simplistic to think of tall cell features as being present or absent, as both the height of the cells (two times versus three times) and the percentage of cells that are tall have different clinical significances in different contexts. Most importantly, the primary clinical significance of TC-PTC is restricted to PTCs that are otherwise low risk by ATA guidelines.

Natural History and Predictive Factors of Outcome in Medullary Thyroid Microcarcinoma

CONTEXT

Management of sporadic medullary thyroid microcarcinoma smaller than 1 cm (micro-MTC) is controversial because of conflicting reports of prognosis. As these cancers are often diagnosed incidentally, they pose a management challenge when deciding on further treatment and follow-up.

OBJECTIVE

We report the outcomes of surgically managed sporadic micro-MTC in a specialist endocrine surgery and endocrinology unit and identify associations for recurrence and disease-specific survival in this population.

METHODS

Micro-MTCs were identified from a prospectively maintained surgery database, and slides were reviewed to determine pathological grade. The primary end points were recurrence, time to recurrence and disease-specific survival. Prognostic factors assessed included size, grade, lymph node metastasis (LNM), and postoperative calcitonin.

RESULTS

From 1995 to 2022, 64 patients were diagnosed with micro-MTC with 22 excluded because of hereditary disease. The included patients had a median age of 60 years, tumor size of 4 mm, and 28 (67%) were female. The diagnosis was incidental in 36 (86%) with 4 (10%) being high grade, 5 (12%) having LNM and 9 (21%) having elevated postoperative calcitonin. Over a 6.6-year median follow-up, 5 (12%) developed recurrence and 3 (7%) died of MTC. High grade and LNM were associated with 10-year survival estimates of 75% vs 100% for low grade and no LNM (hazard ratio = 831; P < .01). High grade, LNM, and increased calcitonin were associated with recurrence (P < .01). Tumor size and type of surgery were not statistically significantly associated with recurrence or survival. No patients with low grade micro-MTC and normal postoperative calcitonin developed recurrence.

CONCLUSION

Most sporadic micro-MTCs are detected incidentally and are generally associated with good outcomes. Size is not significantly associated with outcomes. Using grade, LNM, and postoperative calcitonin allows for the identification of patients at risk of recurrence to personalize management.

Minimally invasive adrenalectomy: a cohort study of surgical approach and outcomes

BACKGROUND

In the context of minimally invasive adrenal surgery, there remains debate about whether the transperitoneal adrenalectomy (TPA) and posterior retroperitoneoscopic adrenalectomy (PRA) approach have equivalent indications. This study aims to examine complication and conversion rates associated with three surgical approaches for adrenal tumours over the last 17 years in a specialized endocrine surgical unit.

METHODS

All adrenalectomy cases performed in the period 2005-2021 were identified within a prospectively maintained surgical database. A retrospective cohort study was undertaken with patients divided into two cohorts (2005-2013 and 2014-2021). Surgical approach (open adrenalectomy (OA), TPA, PRA), tumour size, histopathology, complication and conversion rates were compared.

RESULTS

During the study period, 596 patients underwent adrenalectomy with 31 and 40 cases each year per cohort. The dominant surgical approach per cohort significantly changed from TPA (79% versus 17%) to PRA (8% versus 69%, P < 0.001), whilst the frequency of OA remained stable (13% versus 15%). TPA removed larger tumours (3.0 ± 2.9 cm) than PRA (2.8 ± 2.2 cm, P = 0.02), with the median size increasing from 3.0 ± 2.5 to 4.5 ± 3.5 cm per cohort (P < 0.001). The maximum tumour sizes treated by TPA and PRA were 15 and 12 cm, respectively. Adrenocortical adenoma was the commonest pathology treated by either laparoscopic technique. Complication rates were greatest for OA (30.1%) with no significant difference between minimally invasive approaches (TPA 7.3%, PRA 8.3%, P = 0.7). Both laparoscopic techniques had equivalent conversion rates (3.6%). PRA was preferably converted to TPA (2.8%) over OA (0.8%).

CONCLUSION

This study demonstrates the transition from TPA to PRA, offering similarly low complication and conversion rates.

A Prospective Study of Electromyographic Amplitude Changes During Intraoperative Neural Monitoring for Open Thyroidectomy

BACKGROUND

Intraoperative nerve monitoring (IONM) of the vagus and recurrent laryngeal nerve (RLN) enables prediction of postoperative nerve function. The underlying mechanism for loss of signal (LOS) in a visually intact nerve is poorly understood. The correlation of intraoperative electromyographic amplitude changes (EMG) with surgical manoeuvres could help identify mechanisms of LOS during conventional thyroidectomy.

METHODS

A prospective study of consecutive patients undergoing thyroidectomy was performed with intermittent IONM using the NIM Vital nerve monitoring system. The ipsilateral vagus and RLN was stimulated, and vagus nerve signal amplitude recorded at five time points during thyroidectomy (baseline, after mobilisation of superior pole, medialisation of the thyroid lobe, before release at Ligament of Berry, end of case). RLN signal amplitude was recorded at two time points; after medialisation of the thyroid lobe (R1), and end of case (R2).

RESULTS

A total of 100 consecutive patients undergoing thyroidectomy were studied with 126 RLN at risk. The overall rate of LOS was 4.0%. Cases without LOS demonstrated a highly significant vagus nerve median percentage amplitude drop at medialisation of the thyroid lobe (- 17.9 ± 53.1%, P < 0.001), and end of case (- 16.0 ± 47.2%, P < 0.001) compared to baseline. RLN had no significant amplitude drop at R2 compared to R1 (P = 0.207).

CONCLUSIONS

A significant reduction in vagus nerve EMG amplitude at medialisation of the thyroid and the end of case compared to baseline indicates that stretch injury or traction forces during thyroid mobilisation are the most likely mechanism of RLN impairment during conventional thyroidectomy.

The Presence of Typical "BRAFV600E-Like" Atypia in Papillary Thyroid Carcinoma is Highly Specific for the Presence of the BRAFV600E Mutation

Papillary thyroid carcinomas (PTCs) are driven by a variety of molecular abnormalities including BRAF, RAS, ALK, RET, and NTRK alterations. PTCs driven by the BRAFV600E mutation, or tumours which demonstrate a similar gene expression profile to PTCs driven by this mutation, have been reported to demonstrate specific morphological features sometimes termed "BRAFV600E-like" atypia. BRAFV600E-like atypia is characterised by a well-developed papillary architecture, infiltrative growth, marked nuclear clearing, prominent intranuclear pseudoinclusions, abundant eosinophilic cytoplasm, and scattered psammoma bodies. We sought to investigate the sensitivity and specificity of these morphological features for the presence of BRAFV600E mutation in PTCs as determined by mutation specific immunohistochemistry. An unselected cohort of 495 PTCs was reviewed by a single pathologist and categorised into three groups: typical BRAFV600E-like atypia (145 cases, 29%), possible BRAFV600E-like atypia (166 cases, 33%) and little/no BRAFV600E-like atypia (184 cases, 37%). The specificity and sensitivity of typical BRAFV600E-like atypia for the BRAFV600E mutation was 97.2% and 44.3%, respectively. When typical and possible BRAFV600E-like atypia were analysed together, the specificity was 70.6% and the sensitivity was 81.7%. In the morphologically little/no BRAFV600E-like atypia group, 58 cases (31.5%) had a BRAFV600E mutation. We conclude that typical BRAFV600E-like atypia is highly specific for the presence of the BRAFV600E mutation; however, the absence of BRAFV600E-like atypia does not exclude this mutation.

The Prognostic Impact of Extent of Vascular Invasion in Follicular Thyroid Carcinoma

BACKGROUND

Encapsulated angioinvasive follicular thyroid carcinoma (EAFTC) is associated with an increased risk of distant metastasis and reduced survival compared to minimally invasive follicular thyroid carcinoma (MIFTC). There is controversy regarding the extent of surgery and adjuvant radioactive iodine therapy for angioinvasive follicular thyroid carcinoma when stratified by number of foci of angioinvasion.

METHODS

All follicular thyroid carcinoma cases from 1990-2018 were identified from a thyroid cancer database. Primary outcomes were distant metastasis-free survival (DMFS) and disease-specific survival (DSS) with factors of interest being age, gender, tumour size, treatment, foci of angioinvasion and histological subtype.

RESULTS

A total of 292 cases were identified; 139 MIFTC, 141 EAFTC and 12 widely invasive follicular thyroid carcinoma (WIFTC). Over a follow-up period of 6.25 years, DMFS was significantly reduced (p < 0.001) with 14.2% (EAFTC) and 50% of WIFTC developing metastasis. The risk of metastasis in EAFTC with ≥ 4 foci of angioinvasion was 31.7% (HR = 5.89, p = 0.004), 6.3% for EAFTC with < 4 foci of angioinvasion (HR = 1.74, p = 0.47), compared to 3.6% MIFTC. Age ≥ 50 years (HR = 4.24, p = 0.005) and tumour size (HR = 1.27, p = 0.014) were significantly associated with increased risk of distant metastasis. DSS was reduced significantly (p < 0.001), with 7.8% EAFTC patients dying of disease. For EAFTC patients, DSS was 96.8% for < 4 foci and 82.6% for ≥ 4 foci of angioinvasion (p = 0.003).

CONCLUSION

EAFTC is at increased risk of distant metastasis related to the extent of angioinvasion. Tumours with < 4 foci of angioinvasion should be considered for a total thyroidectomy, particularly in older patients.

Surgical Aspects of Primary Hyperparathyroidism

Parathyroidectomy (PTX) is the treatment of choice for symptomatic primary hyperparathyroidism (PHPT). It is also the treatment of choice in asymptomatic PHPT with evidence for target organ involvement. This review updates surgical aspects of PHPT and proposes the following definitions based on international expert consensus: selective PTX (and reasons for conversion to an extended procedure), bilateral neck exploration for non-localized or multigland disease, subtotal PTX, total PTX with immediate or delayed autotransplantation, and transcervical thymectomy and extended en bloc PTX for parathyroid carcinoma. The systematic literature reviews discussed covered (i) the use of intraoperative PTH (ioPTH) for localized single-gland disease and (ii) the management of low BMD after PTX. Updates based on prospective observational studies are presented concerning PTX for multigland disease and hereditary PHPT syndromes, histopathology, intraoperative adjuncts, localization techniques, perioperative management, "reoperative" surgery and volume/outcome data. Postoperative complications are few and uncommon (<3%) in centers performing over 40 PTXs per year. This review is the first global consensus about surgery in PHPT and reflects the current practice in leading endocrine surgery units worldwide. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

A Retrospective Cohort Study with Validation of Predictors of Differentiated Thyroid Cancer Outcomes

Background: The goal of radioactive iodine (RAI) in differentiated thyroid cancer (DTC) is to treat metastasis and reduce recurrence risk. International guidelines provide broad risk stratification to aid treatment decisions, but a more nuanced approach to individualize care is warranted. We developed a predictive risk model for DTC. Methods: We performed a retrospective multivariable analysis of 899 patients who received RAI after thyroidectomy at a quaternary center in Australia between 2008 and 2016. Collected data included age, gender, histology, stimulated thyroglobulin (sTg), and 8th American Joint Committee Cancer (AJCC) staging. The ATA Modified Initial Risk (ATA) was calculated retrospectively. Recurrence was defined as clinically significant progression requiring either surgical intervention or administration of a second activity of RAI. Synchronous metastasis was defined as distant metastasis (i.e., outside of the neck) that was present at the time of diagnosis on structural imaging or initial post-iodine treatment scan. The features significantly associated with synchronous metastasis or recurrence were employed in the generation of a predictive risk model. A separate cohort of 393 patients who received RAI in 2017-2021 was used for validation. Results: On multivariate analysis, sTg ≥10 μg/L, extrathyroidal extension (ETE) and lymph node involvement predicted recurrence. Independent of ATA, patients with sTg ≥10 μg/L had a shorter disease-free survival (DFS) than those with sTg <10 μg/L (p < 0.001). The ETE stratified by four histological categories was significantly associated with worse DFS (p < 0.001). In a subset of patients, the presence of thyroglobulin antibody (TgAb) did not influence recurrence in patients with sTg <10 μg/L. On multivariate analysis, widespread ETE, sTg ≥10 μg/L, multifocal papillary thyroid cancer and follicular thyroid cancer were positively associated with synchronous metastasis. A predictive risk model was developed to estimate synchronous metastasis/recurrence risk and validated successfully in the second cohort. Conclusions: Our novel predictive risk model modifies and extends ATA stratification by including sTg and ETE, which we found to be independent predictors of both recurrence and synchronous metastasis in DTC.

Outcomes of Papillary Thyroid Microcarcinoma Presenting with Palpable Lateral Lymphadenopathy

Purpose: Papillary thyroid microcarcinoma (PTMC) is typically indolent in nature, allowing management with active surveillance protocols. Occasionally, a more aggressive phenotype can present and may lead to poor outcomes such as patients presenting with clinically significant lateral lymphadenopathy (cN1b). Prior analysis of the outcomes of this cohort is largely from papillary thyroid cancer (PTC) (>1 cm) or from institutions where use of radioactive iodine (RAI) is limited. Hence, we aim to describe the outcomes of patients with PTMC who presented with palpable cN1b disease, treated with total thyroidectomy and RAI. Methodology: We performed a retrospective cohort study. Outcomes of patients with PTMC who presented with palpable lateral lymph node (LN) metastases (microPTC cN1b) treated between 1997 and 2020 at Royal North Shore Hospital were compared with two control groups' outcomes: patients with clinically detected PTMC without evidence of involved LNs (microPTC cN0) and with larger PTC (>10 mm) who presented with palpable lateral lymphadenopathy (larger PTC cN1b). We assessed clinicopathological variables, postoperative risk stratification, rates of disease recurrence, reoperative surgery, and structural disease-free survival (DFS). Results: In total, 1534 PTMCs were diagnosed following thyroid surgery in the study period; of these, 157 (10%) were clinically detected microPTC cN0 and 26 microPTC cN1b (1.7%). There were 138 patients in the larger PTC cN1b control group. All cN1b patients were treated with total thyroidectomy and adjuvant RAI. Mean size of the largest LN deposit was similar between the microPTC cN1b and larger PTC cN1b groups (23 vs. 27 mm, p = 0.11). Patients with microPTC cN1b were more likely to have biochemical or structural persistence or recurrence compared with microPTC cN0 (19%, 5/26 vs. 3.8%, 6/157, p = 0.002) but less likely than larger PTC cN1b patients (19%, 5/26 vs. 42%, 58/138, p = 0.04). All patients in the microPTC cN1b group who had an excellent response to initial therapy (85%, 22/26) were disease free at last follow-up. The rate of reoperation was similar for the microPTC cN1b and microPTC cN0 groups (4%, 1/26 vs. 2%, 3/157, p = 0.461) and significantly lower than the larger PTC cN1b group (4%, 1/26 vs. 26%, 36/138, p = 0.002). Five-year DFS estimates were significantly better for microPTC cN1b patients than for larger PTC cN1b patients (94% vs. 59%, p = 0.001). Conclusions: MicroPTC cN1b patients treated with thyroidectomy and adjuvant RAI have inferior clinical outcomes compared with microPTC cN0 patients but have better outcomes than their larger PTC cN1b counterparts with respect to disease persistence and recurrence. Response to initial therapy provides valuable prognostication in microPTC cN1b patients: if these patients had an excellent response to initial treatment, they achieved long-term DFS in this series.

Thyroidectomy in Australia 2022: lessons from 21,000 consecutive cases

In this article, we aim to describe our modern-day approach to total thyroidectomy, detailing the subtle refinements of our technique, as it has evolved over three decades and 21 000 cases. Since Delbridge's seminal paper in 2003, the major changes to our approach include a retrograde approach to the recurrent laryngeal nerve that allows dissection of the distal RLN from fascial bands within the ligament of Berry before medialisation of the thyroid lobe. Routine use of intraoperative nerve monitoring systems has increased our awareness of temporary neuropraxia, facilitated a reduction in the risk of bilateral RLN palsy and improved our identification and preservation of the external branch of the superior laryngeal nerve. The increasing use of advanced energy devices has been associated with a reduction in post-operative haematoma rates. We adopt a low threshold to parathyroid auto-transplantation, unless all glands are assessed to be clearly not at risk, and routinely supplement patients with Caltrate in the immediate post-operative period to minimize the risk of symptomatic hypocalcaemia. Ultimately, when we reflect on the subtle refinements that have contributed to improved outcomes, the fundamental principles of exposure and dissection that have evolved over decades remain the basis of our surgical approach and must continue to do so.

Tumour volume is a predictor of lymphovascular invasion in differentiated small thyroid cancer

Objectives

For small thyroid cancers (≤2 cm), tumour volume may better predict aggressive disease, defined by lymphovascular invasion (LVI) than a traditional single measurement of diameter. We aimed to investigate the relationship between tumour diameter, volume and associated LVI.

Methods

Differentiated thyroid cancers (DTC) ≤ 2 cm surgically resected between 2007 and 2016 were analysed. Volume was calculated using the formula for an ellipsoid shape from pathological dimensions. A 'larger volume' cut-off was established by receiver operating characteristic (ROC) analysis using the presence of lateral cervical lymph node metastasis (N1b). Logistic regression was performed to compare the 'larger volume' cut-off to traditional measurements of diameter in the prediction.

Results

During the study period, 2405 DTCs were surgically treated and 523 met the inclusion criteria. The variance of tumour volume relative to diameter increased exponentially with increasing tumour size; the interquartile ranges for the volumes of 10, 15 and 20 mm diameter tumours were 126, 491 and 1225 mm^3, respectively. ROC analysis using volume to predict N1b disease established an optimal volume cut-off of 350 mm³ (area under curve = 0.59, P = 0.02) as 'larger volume'. 'Larger volume' DTC was an independent predictor for LVI in multivariate analysis (odds ratio (OR) = 1.7, P = 0.02), whereas tumour diameter > 1 cm was not (OR = 1.5, P = 0.13). Both the volume > 350 mm³ and dimension > 1 cm were associated with greater than five lymph node metastasis and extrathyroidal extension.

Conclusion

In this study for small DTCs ≤ 2 cm, the volume of >350 mm³ was a better predictor of LVI than greatest dimension > 1 cm.

Change in Practice of Radioactive Iodine Administration in Differentiated Thyroid Cancer: A Single-Centre Experience

OBJECTIVE

Our study aimed to analyse temporal trends in radioactive iodine (RAI) treatment for thyroid cancer over the past decade; to analyse key factors associated with clinical decisions in RAI dosing; and to confirm lower activities of RAI for low-risk patients were not associated with an increased risk of recurrence.

METHODS

Retrospective analysis of 1,323 patients who received RAI at a quaternary centre in Australia between 2008 and 2018 was performed. Prospectively collected data included age, gender, histology, and American Joint Committee on Cancer stage (7th ed). American Thyroid Association risk was calculated retrospectively.

RESULTS

The median activities of RAI administered to low-risk patients decreased from 3.85 GBq (104 mCi) in 2008-2016 to 2.0 GBq (54 mCi) in 2017-2018. The principal driver of this change was an increased use of 1 GBq (27 mCi) from 1.3% of prescriptions in 2008-2011 to 18.5% in 2017-2018. In patients assigned as low risk per ATA stratification, lower activities of 1 GBq or 2 GBq (27 mCi or 54 mCi) were not associated with an increased risk of recurrence. In patients assigned to intermediate- or high-risk categories who received RAI as adjuvant therapy, there was no difference in risk of recurrence between 4 GBq (108 mCi) and 6 GBq (162 mCi).

CONCLUSIONS

Our data demonstrate an evolution of RAI activities consistent with translation of ATA guidelines into clinical practice. Use of lower RAI activities was not associated with an increase in recurrence in low-risk thyroid cancer patients. Our data also suggest lower RAI activities may be as efficacious for adjuvant therapy in intermediate- and high-risk patients.

Focused parathyroidectomy without intraoperative parathyroid hormone measurement in primary hyperparathyroidism: Still a valid approach?

BACKGROUND

Concern regarding suboptimal cure rates has led to some endocrine surgery units abandoning focused parathyroidectomy for primary hyperparathyroidism in favor of open bilateral neck exploration or making intraoperative parathyroid hormone estimation mandatory in focused parathyroidectomy. This study explores whether focused parathyroidectomy for radiologically localized primary hyperparathyroidism without intraoperative parathyroid hormone is still a valid approach.

METHODS

Retrospective review of a tertiary referral endocrine surgery unit database. All parathyroidectomies for primary hyperparathyroidism over 6 years (2013-2019) were included. Lithium-induced hyperparathyroidism, reoperations, familial disease, and concurrent thyroid surgery were excluded. Characteristics and outcomes for focused parathyroidectomy and open bilateral neck exploration were compared by intention-to-treat and treatment delivered. Persistence and recurrence, conversions and complications were analyzed as endpoints.

RESULTS

A total of 2,828 parathyroidectomies were performed and 2,421 analyzed. By intention to treat there were 1,409 focused parathyroidectomies and 1,012 open bilateral neck explorations. Focused parathyroidectomy patients were younger: 63 vs 66 years (P < .01); however, gender (77%, 79% female), preoperative peak serum calcium (2.72, 2.70 mmol/L [P = .23]), and serum parathyroid hormone (11.5, 11.0 pmol/L [P = .52]) did not differ. In total, 229 (16.3%) focused parathyroidectomies were converted to open bilateral neck exploration. Multiple gland disease was confirmed in 54.5% of converted patients. Median follow-up was 41 months (3-60 months). Persistence or recurrence requiring reoperation totaled 2.2% and did not differ between focused parathyroidectomy and open bilateral neck exploration in either intention to treat or final treatment analyses. Complications occurred in 1.2% of focused parathyroidectomy and 3.2% open bilateral neck exploration (P < .01).

CONCLUSIONS

In experienced hands and with a ready-selective approach to conversion, focused parathyroidectomy based on concordant imaging and without intraoperative parathyroid hormone may deliver equivalent cure rates to open bilateral neck exploration with significantly fewer complications. Focused parathyroidectomy without intraoperative parathyroid hormone should therefore be maintained in the endocrine surgeon's armamentarium.

Multimodality Treatment Improves Locoregional Control, Progression-Free and Overall Survival in Patients with Anaplastic Thyroid Cancer: A Retrospective Cohort Study Comparing Oncological Outcomes and Morbidity between Multimodality Treatment and Limited Treatment

BACKGROUND

Patients with anaplastic thyroid cancer (ATC) have poor overall survival, and the optimal management approach remains unclear. The aim of this study is to evaluate our experience with multimodality (MMT) versus limited treatment (LT) for ATC.

PATIENTS AND METHODS

A cohort study of patients with ATC managed in a tertiary referral center was undertaken. The outcomes of MMT were compared with those of LT. The primary outcome measures were locoregional control and progression-free and overall survival. Secondary outcome measures were treatment-related complications and factors associated with improved survival.

RESULTS

In total, 59 patients (35 females) with a median age of 73 years (range 39-99 years) and ATC stage IVA (n = 2), IVB (n = 28), or IVC (n = 29) were included. LT was utilized in 25 patients (42%), and 34 cases had MMT. MMT patients had a longer time of locoregional control (18.5 versus 1.9 months; p < 0.001), progression-free survival (3.5 versus 1.2 months; p < 0.001), and overall survival (6.9 versus 2.0 months; p < 0.001) when compared with LT. For patients with stage IVC ATC, locoregional control (p = 0.03), progression-free survival (p < 0.001), and overall survival (p < 0.001) were superior in the MMT cohort compared with LT. MMT had more treatment-related complications than LT (p < 0.001). An Eastern Cooperative Oncology Group performance status < 2 (HR 0.30; p = 0.001) and MMT (HR 0.35; p = 0.008) were associated with improved overall survival.

CONCLUSION

MMT is likely to improve locoregional control, progression-free survival, and overall survival in selected ATC patients including stage IVC tumors but comes with a greater complication risk.

Predicting distant metastatic disease in differentiated thyroid cancer: a matched case-control study

BACKGROUND

The occurrence of distant metastasis (DM) is the most important prognostic factor influencing survival outcomes in differentiated thyroid cancer (DTC). Identifying patients who are likely to develop DM and offering these cases more aggressive surgical approaches and I-131 therapy, is paramount to achieving the best possible outcomes. DM on presentation in DTC are uncommon, with an incidence of 1-9%. However, the incidence of DTC is rising and the disease affects a relatively young cohort of patients. The aims of this study were to investigate predictive factors in the development of DM by comparing a homogenous group of DTC patients with and without DM, and to illustrate the overall and disease-specific survival (DSS) rates of DTC patients presenting with DM.

METHODS

A matched case-control study of patients with DTC and DM was undertaken. The study group comprised a consecutive series of cases with DM treated in the period 1968-2014. Patients with DM at initial presentation were identified (DTC-DM group). A control group of patients without DM were matched based on age, gender, tumour size and histological subtype. The primary outcome measures were overall and disease-free survival. Secondary outcome measures were lymph node involvement (LNI), extra-thyroidal extension (ETE) of tumour and presence of BRAFV600E mutation identified on immunohistochemistry.

RESULTS

A total of 2547 patients with DTC were reviewed and of these 83 (3.26%) had DM at initial presentation. At 5 and 10 years, the overall survival rates for DTC-DM patients were 89.6% and 64%, respectively. The 5 and 10 year DSS rates for DTC-DM cases were 90.2% and 67.3%, respectively. When compared to the DTC group, the DTC-DM group had significantly higher rates of ETE (63% vs. 29.5%, P < 0.0001) and LNI (32.5% vs. 18.8%, P = 0.044). Among patients with papillary thyroid cancer (PTC), the presence of BRAFV600E mutation was significantly associated with DM (62.2% vs. 36.8%, P = 0.028).

CONCLUSION

ETE, LNI and BRAFV600E mutation in PTC are significant predictors for the development of distant metastatic disease.

The Significance of Histologically "Large Normal" Parathyroid Glands in Primary Hyperparathyroidism

INTRODUCTION

We investigated outcomes in a cohort of patients with a biochemical diagnosis of primary hyperparathyroidism (pHPT) undergoing surgery for asymptomatic disease or target organ damage, where a focussed or four-gland operation was undertaken and the histopathology only reported a "large normal" parathyroid gland (LNP).

METHODS AND MATERIALS

Patients subjected to a parathyroidectomy for pHPT between 2012 and 2018 with a pathology of LNP were included. Patients with fat depletion or additional histological features of adenoma or hyperplasia in any of the resected glands were excluded. A control group was formed from 50 consecutive patients with the histological finding of adenoma or hyperplasia during the same study period. The primary outcome was biochemical normalisation of pHPT at 1-2 weeks and after 6 months post-operatively.

RESULTS

Forty-eight LNP patients (2% of all parathyroidectomies) were included in the study group with 50 matched controls. LNP patients had a lower biochemical cure rate (81% vs. 98% P < 0.05) and a higher risk of recurrence (10% vs. 0%, P = 0.06). LNP patients had a milder form of pHPT (Ca²⁺ 2.63 vs. 2.68 P < 0.05) with a smaller PTH and Ca²⁺ drop post-operatively. For LNP patients with failure, a definite additional cause of pHPT was found in only two patients.

CONCLUSION

This study highlights a controversial area in pHPT and reports LNP as a cause of pHPT. The biochemical analysis of this LNP group supports a benefit in resection in the setting of pHPT, although the risk of failure (persistence/recurrence) is higher than those with adenoma or hyperplasia. Stricter post-operative follow-up of LNP patients should be considered.

Biochemistry may be misleading in metachronous MEN2A-associated phaeochromocytoma following unilateral total adrenalectomy

A 63-year-old woman with multiple endocrine neoplasia type 2A (MEN2A) presented with recurrent spells of headaches, sweats and palpitations decades after right adrenalectomy for phaeochromocytoma, and total thyroidectomy for medullary thyroid cancer. She was hypertensive and in sinus rhythm. DOTA-TATE positron-emission tomography (PET) demonstrated a 12mm enhancing left adrenal incidentaloma. 24 hours urine catecholamines, and multiple plasma metanephrine and normetanephrine measurements were all within normal reference ranges. Based on her symptoms and imaging findings, left adrenalectomy was performed and found a 40 mm phaeochromocytoma. Her symptoms have since completely resolved and plasma metanephrine is now undetectable MEN2-associated phaeochromocytomas are often bilateral and may be metachronous. Patients at high risk of phaeochromocytoma who develop symptoms of catecholamine excess should be carefully evaluated even if plasma or urinary metanephrines are within the normal reference range. Biochemical reference ranges for metanephrines need to be adjusted accordingly in patients who have had prior unilateral total adrenalectomy.

Clinical Outcomes After Unilateral Adrenalectomy for Primary Aldosteronism

Importance

In addition to biochemical cure, clinical benefits after surgery for primary aldosteronism depend on the magnitude of decrease in blood pressure (BP) and use of antihypertensive medications with a subsequent decreased risk of cardiovascular and/or cerebrovascular morbidity and drug-induced adverse effects.

Objective

To evaluate the change in BP and use of antihypertensive medications within an international cohort of patients who recently underwent surgery for primary aldosteronism.

Design, Setting, and Participants

A cohort study was conducted across 16 referral medical centers in Europe, the United States, Canada, and Australia. Patients who underwent unilateral adrenalectomy for primary aldosteronism between January 2010 and December 2016 were included. Data analysis was performed from August 2017 to June 2018. Unilateral disease was confirmed using computed tomography, magnetic resonance imaging, and/or adrenal venous sampling. Patients with missing or incomplete preoperative or follow-up data regarding BP or corresponding number of antihypertensive medications were excluded.

Main Outcomes and Measures

Clinical success was defined based on postoperative BP and number of antihypertensive medications. Cure was defined as normotension without antihypertensive medications, and clear improvement as normotension with lower or equal use of antihypertensive medications. In patients with preoperative normotensivity, improvement was defined as postoperative normotension with lower antihypertensive use. All other patients were stratified as no clear success because the benefits of surgery were less obvious, mainly owing to postoperative, persistent hypertension. Clinical outcomes were assessed at follow-up closest to 6 months after surgery.

Results

On the basis of inclusion and exclusion criteria, a total of 435 patients (84.6%) from a cohort of 514 patients who underwent unilateral adrenalectomy were eligible. Of these patients, 186 (42.3%) were women; mean (SD) age at the time of surgery was 50.7 (11.4) years. Cure was achieved in 118 patients (27.1%), clear improvement in 135 (31.0%), and no clear success in 182 (41.8%). In the subgroup classified as no clear success, 166 patients (91.2%) had postoperative hypertension. However, within this subgroup, the mean (SD) systolic and diastolic BP decreased significantly by 9 (22) mm Hg (P < .001) and 3 (15) mm Hg (P = .04), respectively. Also, the number of antihypertensive medications used decreased from 3 (range, 0-7) to 2 (range, 0-6) (P < .001). Moreover, in 75 of 182 patients (41.2%) within this subgroup, the decrease in systolic BP was 10 mm Hg or greater.

Conclusions and Relevance

In this study, for most patients, adrenalectomy was associated with a postoperative normotensive state and reduction of antihypertensive medications. Furthermore, a significant proportion of patients with postoperative, persistent hypertension may benefit from adrenalectomy given the observed clinically relevant and significant reduction of BP and antihypertensive medications.

Treatment and management of adrenal cancer in a specialized Australian endocrine surgical unit: approaches, outcomes and lessons learnt

BACKGROUND

Adrenocortical carcinoma is a rare and heterogeneous malignancy with poor outcomes. Recent research has suggested that outcomes may be improved by centralization of care in specialist centres. We review our evolving 21-year experience in managing adrenocortical carcinoma with a view towards outcomes and lessons learnt.

METHODS

A retrospective study of patients treated in our specialist endocrine surgical unit over 21 years was undertaken.

RESULTS

Thirty-five patients were treated from diagnosis, 29 forming a primary study cohort. Additionally, seven patients were referred to us for quaternary care, forming a secondary study cohort. The European Network for the Study of Adrenal Tumours (ENSAT) stage and immunohistochemical marker Ki-67 index were strong prognostic indicators for survival.

CONCLUSIONS

Early stage, complete resection and Ki-67 <10% are the best prognosticators for survival. Aggressive surgical resection at index operation and of recurrent oligometastatic disease along with multimodal adjuvant treatment has led to long-term survivors of patients with Stage 4 disease in our aggregate cohort.

Sonographic Volumetric Assessment Is a More Accurate Measure Than Maximum Diameter Alone in Papillary Thyroid Cancer

Background

Tumor size is an important prognostic factor in papillary thyroid cancer (PTC). Management guidelines, staging systems, and pathological definitions use maximum diameter (Dmax) as a surrogate marker of tumor size. However, PTC nodules are three-dimensional (3D) structures, with behavior reflective of tumor cell count, which is directly proportional to volume. We explored the relationship between sonographically determined Dmax, volume, and lymph node status (LNS) in a cohort of patients with PTC.

Methods

All patients treated for PTC between 2003 and 2015 in our institution who had sonographic 3D nodule measurements available were evaluated. We examined the relationship between diameter, volume, and LNS.

Results

A total of 159 nodules in 153 patients met the inclusion criteria. Mean nodule dimensions were 2.4 × 1.9 × 1.5 cm, giving “ideal” nodule dimensions of y × 0.78y × 0.62y, where y is the Dmax. Observed volumes differed from predicted nodule volumes by an average of 26.2%. For PTC ≤2 cm, the coefficient of variation was 26.7%. Dmax did not correlate with the presence of lymph node metastases (Pearson coefficient 0.08), whereas volume very weakly correlated with LNS (Pearson coefficient 0.22). However, both Dmax and volume correlated very strongly with the number of nodal metastases (Pearson coefficients 0.93 and 0.89, respectively).

Conclusions

PTC nodules demonstrated significant volume heterogeneity, rendering Dmax an inaccurate marker of true tumor size. Although there was little difference between Dmax and volume in predicting nodal status or nodal disease burden, we propose that a prospective, randomized trial might demonstrate a clear clinical advantage of 3D sonographic nodule measurement over Dmax alone.

Role of DOTATATE-PET/CT in preoperative assessment of phaeochromocytoma and paragangliomas

CONTEXT

Diagnosis of paragangliomas (PGL) and phaeochromocytomas (PC) can be challenging particularly if the tumour is small. Detection of metastatic disease is important for comprehensive management of malignant PC/PGL. Somatostatin receptor imaging (SRI) agents have high sensitivity for these tumours, particularly the DOTA family of radiopharmaceuticals labelled with ⁶⁸ Gallium.

OBJECTIVE

To describe the utility of SRI in primary assessment (ie before surgery) for PC/PGL and whether measures of maximum standardized uptake (SUVmax) could be used to distinguish between adrenal adenomas and PCs.

DESIGN

Retrospective analysis of patients with PC and PGL between 2012 and 2017.

PATIENTS

Somatostatin receptor imaging (SRI) was performed for suspected PC (n = 46) or PGL (n = 27) of which 36 were during primary assessment and 37 during secondary assessment (follow-up after surgery). For comparison of adrenal SUVmax, scans from 30 patients without suspected PC/PGL (20 with normal adrenals; 10 with incidental adenomas) were evaluated.

MEASUREMENTS

Baseline description, sensitivity, specificity, Youden's index.

RESULTS

Sensitivity of DOTATATE-PET was 88% for PC and 100% for PGL. False-negative scans were seen in 2/10 PCs < 28 mm and in 1/14 PCs > 28 mm which had features of cystic degeneration. SUVmax of PCs and PGLs was more than double compared to adrenal adenomas (P > .001).

CONCLUSION

Somatostatin receptor imaging (SRI) has high sensitivity in primary assessment for PC and PGL. We recommend that SRI should be performed as part of primary assessment in all suspected PGLs (due to higher risk of multifocal lesions) and in PCs suspected to be associated with hereditary syndromes or metastases.

Randomized trial of low versus high carbon dioxide insufflation pressures in posterior retroperitoneoscopic adrenalectomy

BACKGROUND

Posterior retroperitoneoscopic adrenalectomy has gained widespread acceptance for the removal of benign adrenal tumors. Higher insufflation pressures using carbon dioxide (CO₂) are required, although the ideal starting pressure is unclear. This prospective, randomized, single-blinded, study aims to compare physiologic differences with 2 different CO₂ insufflation pressures during posterior retroperitoneoscopic adrenalectomy.

METHODS

Participants were randomly assigned to a starting insufflation pressure of 20 mm Hg (low pressure) or 25 mm Hg (high pressure). The primary outcome measure was partial pressure of arterial CO₂ at 60 minutes. Secondary outcomes included end-tidal CO₂, arterial pH, blood pressure, and peak airway pressure. Breaches of protocol to change insufflation pressure were permitted if required and were recorded.

RESULTS

A prospective randomized trial including 31 patients (low pressure: n = 16; high pressure: n = 15) was undertaken. At 60 minutes, the high pressure group had greater mean partial pressure of arterial CO₂ (64 vs 50 mm Hg, P = .003) and end-tidal CO₂ (54 vs 45 mm Hg, P = .008) and a lesser pH (7.21 vs 7.29, P = .0005). There were no significant differences in base excess, peak airway pressure, operative time, or duration of hospital stay. Clinically indicated protocol breaches were more common in the low pressure than the high pressure group (8 vs 3, P = .03).

CONCLUSION

In posterior retroperitoneoscopic adrenalectomy, greater insufflation pressures are associated with greater partial pressure of arterial CO₂ and end-tidal CO₂ and lesser pH at 60 minutes, be significant. Commencing with lesser CO₂ insufflation pressures decreases intraoperative acidosis.

Short and long-term impact of parathyroid autotransplantation on parathyroid function after total thyroidectomy

The most common complication of total thyroidectomy is parathyroid insufficiency. Acute, transient, post-operative hypoparathyroidism increases length of hospitalization, morbidity and cost associated with total thyroidectomy. While permanent hypoparathyroidism poses a significant medical burden with lifetime medication, regular follow up and considerable disease burden related to chronic renal failure and other sequelae. Parathyroid autotransplantation has been demonstrated to result in biochemically functional grafts, leading to the procedures' common use during total thyroidectomy. The clearest indications for parathyroid auto transplantation are inadvertently removed or devascularized parathyroid glands. Some centers utilize routine autotransplantation to reduce the risk of permanent hypoparathyroidism. Novel fluorescence techniques to aid in parathyroid detection during thyroid surgery are under evaluation. This review aims to define the role and impact of parathyroid autotransplantation undertaken during total thyroidectomy.

Disease Progression in Papillary Thyroid Cancer with Biochemical Incomplete Response to Initial Therapy

BACKGROUND

Dynamic risk stratification is utilized in the follow-up of patients with papillary thyroid carcinoma (PTC). Analysis of outcomes after biochemical incomplete response (BIR) to initial therapy will allow better individualization of care.

METHODS

A total of 494 patients with PTC were followed prospectively. Immunohistochemistry (IHC) for BRAF^V600E mutation was completed on all surgical specimens. After exclusion of patients with inadequate data, 353 patients were stratified into four categories of response to initial therapy: excellent, biochemical incomplete, structural incomplete, or indeterminate. Patients with BIR, defined as elevated stimulated thyroglobulin >2 µg/L with negative imaging, were analysed for progression of disease. The primary outcome measure was development of structural recurrence.

RESULTS

Forty-nine of 353 (13.9%) patients had BIR. BRAF^V600E mutation was present in 32 of 49 (65.3%) with BIR. Progression to structural recurrence occurred in 8 of 49 (16.3%) with BIR, all of whom were positive for the BRAF^V600E mutation (p = 0.02). Nine patients (18%) with BIR remitted during follow-up to no evidence of disease (6 had additional RAI therapy). After mean follow-up of 35 months, 12 patients with BIR (24%) remained biochemically abnormal with no structural evidence of disease.

CONCLUSIONS

Patients with BIR following initial treatment for PTC have generally favorable outcomes. Positive IHC for BRAF^V600E identifies patients at risk of structural disease recurrence.

TERT promoter mutations are a major indicator of recurrence and death due to papillary thyroid carcinomas

CONTEXT

TERT promoter mutations have been associated with adverse prognosis in papillary thyroid carcinomas (PTCs).

OBJECTIVE

We investigated the association between TERT promoter mutations and survival from PTC.

DESIGN

Retrospective observational cohort study.

PATIENTS

Eighty consecutive patients with PTC who underwent surgery between 1990 and 2003.

MEASUREMENTS

TERT promoter was genotyped in DNA from 80 archival PTCs by Sanger sequencing. Median follow-up was 106 months (range 1-270). Outcomes analysis was stratified according to disease and overall survival status. For each parameter, relative risk (RR) adjusted for age at first surgery and gender was estimated. Both univariate and multivariate analyses were performed using logistic regression, Kaplan-Meier survival analysis and Cox regression models.

RESULTS

PTCs from 11 patients (14%) contained either C228T or C250T TERT promoter mutation. TERT mutations were significantly associated with adverse prognostic features such as older age (P = 0·002), male gender (P = 0·01) and Stage IV disease (P = 0·03). Four patients died from PTC during follow-up: 3 patients with TERT mutations (27%) and one without (1·5%). Disease-related mortality rate with or without TERT mutations was 33·7 vs 1·6 per 1000 patient-years respectively, that is 10 (95% CI = 1·0-104·1, P = 0·05) fold higher, after adjustment for age at first surgery and gender. The combination of TERT promoter mutation and BRAF(V) (600E) significantly increased disease-related death risk (P = 0·002). TERT mutations increased expression of a reporter gene in thyroid cells containing BRAF(V) (600E) .

CONCLUSIONS

TERT promoter mutations are a major indicator of death due to PTCs. Conversely, absence of TERT mutations portends better survival.

Incidence and Risk Factors for Occult Level 3 Lymph Node Metastases in Papillary Thyroid Cancer

BACKGROUND

Papillary thyroid cancer (PTC) frequently disseminates into cervical lymph nodes. Lateral node involvement is described in up to 50 % patients undergoing prophylactic lateral neck dissection. This study aimed to assess this finding and identify which factors predict for occult lateral node disease.

METHODS

Patients with fine needle aspiration-confirmed PTC (Bethesda V or VI), without evidence of cervical lymph node metastases, underwent a total thyroidectomy with prophylactic ipsilateral central and level 3 dissection. Level 3 nodes were removed by compartmental dissection or by sampling the sentinel nodes overlying the jugular vein, according to surgeon preference. Data were collected prospectively from January 2011 to August 2014. Statistical analysis was performed by SPSS software.

RESULTS

A total of 137 patients underwent total thyroidectomy with prophylactic ipsilateral central and level 3 dissection for PTC. The incidence of occult level 3 disease was 30 % (41/137 patients). A total of 48 % of patients (66/137) harbored occult central neck disease. A total of 80.5 % of patients with pN1b disease had macrometastases (≥2 mm), and 15 % exhibited skip metastases with central compartment sparing. In patients with pN1b disease, a median of 6 level 3 nodes were retrieved, with an average involved nodal ratio of 0.29. Multivariate regression demonstrated risk factors for occult lateral neck metastasis include tumor size (odds ratio 1.1), upper pole tumors (odds ratio 6.6), and vascular invasion (odds ratio 3.2) (p < 0.05).

CONCLUSIONS

PTC is associated with a significant incidence of occult central and lateral nodal metastases. In patients undergoing prophylactic central neck dissection, inclusion of level 3 dissection should be considered in patients with large upper lobe cancers.

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

BACKGROUND

Age is a critical factor in outcome for patients with well-differentiated thyroid cancer. Currently, age 45 years is used as a cutoff in staging, although there is increasing evidence to suggest this may be too low. The aim of this study was to assess the potential for changing the cut point for the American Joint Committee on Cancer/Union for International Cancer Control (AJCC/UICC) staging system from 45 years to 55 years based on a combined international patient cohort supplied by individual institutions.

METHODS

A total of 9484 patients were included from 10 institutions. Tumor (T), nodes (N), and metastasis (M) data and age were provided for each patient. The group was stratified by AJCC/UICC stage using age 45 years and age 55 years as cutoffs. The Kaplan-Meier method was used to calculate outcomes for disease-specific survival (DSS). Concordance probability estimates (CPE) were calculated to compare the degree of concordance for each model.

RESULTS

Using age 45 years as a cutoff, 10-year DSS rates for stage I-IV were 99.7%, 97.3%, 96.6%, and 76.3%, respectively. Using age 55 years as a cutoff, 10-year DSS rates for stage I-IV were 99.5%, 94.7%, 94.1%, and 67.6%, respectively. The change resulted in 12% of patients being downstaged, and the downstaged group had a 10-year DSS of 97.6%. The change resulted in an increase in CPE from 0.90 to 0.92.

CONCLUSIONS

A change in the cutoff age in the current AJCC/UICC staging system from 45 years to 55 years would lead to a downstaging of 12% of patients, and would improve the statistical validity of the model. Such a change would be clinically relevant for thousands of patients worldwide by preventing overstaging of patients with low-risk disease while providing a more realistic estimate of prognosis for those who remain high risk.

Is there a role for an ultrasensitive thyroglobulin assay in patients with serum antithyroglobulin antibodies? A large (Australian) cohort study in differentiated thyroid cancer

OBJECTIVE

Serum thyroglobulin (Tg) is a marker of residual differentiated thyroid cancer (DTC) after total thyroidectomy; however, circulating antithyroglobulin antibodies (TgAb) may interfere with the immunoassay for Tg. Ultrasensitive assays may have a more significant role in detecting circulating Tg in the context of samples containing TgAb. The aim of this study was to evaluate the utility of ultrasensitive thyroglobulin (US-Tg) measurement compared to standard Tg measurement and to assess the influence of serum TgAb positivity on Tg detection in a large tertiary referral centre cohort in Australia.

DESIGN

All patients with DTC who had undergone total thyroidectomy were included in this retrospective, observational cohort study.

PATIENTS

Patients providing samples for the period of June 2006 until January 2014 were analysed. Three thousand two hundred and eight samples were measured at the same points in time, enabling serum Tg assays to be compared for the same TSH status (stimulated or suppressed).

MEASUREMENTS

The standard assay, the Siemens Immulite 2000 Tg assay, was compared to the serum ultrasensitive ELISA RSR^™ Tg. TgAb were simultaneously measured using Abbott Architect or Immulite 2000.

RESULTS

There were 3019 samples included in the final analysis for comparison of the standard and ultrasensitive assays along with TgAb status. The majority of samples were TgAb negative (87%), with 48% of TgAb-negative samples associated with an undetectable serum Tg, suggestive of disease-free status at the time of sampling. Of note, 26% (n = 104) of the TgAb-positive samples were positive for Tg on the ultrasensitive Tg assay, but negative on the immulite Tg assay, and 62·5% (n = 65) of these samples corresponded to DTC recurrence.

CONCLUSION

The US-Tg assay has greater clinical utility than the standard immulite Tg assay specifically in the scenario of antibody positivity, with a significant number of samples corresponding to clinically relevant recurrent or metastatic disease.

Survival from Differentiated Thyroid Cancer: What Has Age Got to Do with It?

BACKGROUND

In most staging systems, 45 years of age is used to differentiate low risk thyroid cancer from high risk thyroid cancer. However, recent studies have questioned both the precise 45 year age point and the concept of using a binary cut off as accurate predictors of disease specific mortality.

METHODS

A cohort of 3664 thyroid cancer patients that received surgery and adjuvant treatment at Memorial Sloan Kettering Cancer Center (MSKCC) from the years 1985 to 2010 were analyzed to determine the significance of age at diagnosis as a categorical variable at a variety of age cutoffs (5 year intervals between 30 and 70 years of age). The unadjusted and adjusted hazard ratio for the association between disease-specific survival and age was determined using a Cox proportional hazards model adjusted for other predictive variables sex, histology, and pathological T, N, and M status. Furthermore, predictive nomograms of disease-specific mortality were created and validated on an external dataset of 4551 patients to evaluate the impact of age at diagnosis as both a categorical and continuous variable.

RESULTS

In the MSKCC cohort, with a median follow-up time of 54 months (range 1-332), there were 59 deaths from thyroid cancer with a 10 year disease-specific survival of 96%. Adjusted hazard ratios for all age cutoffs from age 30 to age 70 years were significant. There was no specific cutoff age which risk stratifies patients with differentiated thyroid cancer (DTC). Categorizing age into five strata (<40, 40-49, 50-59, 60-69 and >70 years) showed a 37-fold increase in hazard ratio from age <40 years to age >70 years. A predictive nomogram using age as a continuous variable with other predictive variables had a high concordance index of 96%. Validation on the external cohort had a concordance index of 73%.

CONCLUSIONS

Mortality from DTC increases progressively with advancing age. There is no specific cutoff age which risk stratifies patients with DTC. A predictive nomogram using age as a continuous variable may be a more appropriate tool for stratifying patients with DTC and for predicting outcome.

A new association - multiple endocrine neoplasia type 1 and malignant peripheral nerve sheath tumor

We report a patient with multiple endocrine neoplasia type 1 (MEN-1) and an aggressive malignant peripheral nerve sheath tumor (MPNST) arising from a ganglioneuroma of the adrenal gland. Patients with MEN-1 require careful consideration of other tumor associations, including MPNST, as it can portend a poor prognosis. MEN-1 and MPNST have not been reported.

We report a patient with multiple endocrine neoplasia type 1 (MEN-1) and an aggressive malignant peripheral nerve sheath tumor (MPNST) arising from a ganglioneuroma of the adrenal gland. Patients with MEN-1 require careful consideration of other tumor associations, including MPNST, as it can portend a poor prognosis. MEN-1 and MPNST have not been reported.