Novel prognostic nomogram for predicting recurrence-free survival in medullary thyroid carcinoma

AIMS

Recently, there have been attempts to improve prognostication and therefore better guide treatment for patients with medullary thyroid carcinoma (MTC). In 2022, the International MTC Grading System (IMTCGS) was developed and validated using a multi-institutional cohort of 327 patients. The aim of the current study was to build upon the findings of the IMTCGS to develop and validate a prognostic nomogram to predict recurrence-free survival (RFS) in MTC.

METHODS AND RESULTS

Data from 300 patients with MTC from five centres across the USA, Europe, and Australia were used to develop a prognostic nomogram that included the following variables: age, sex, AJCC stage, tumour size, mitotic count, necrosis, Ki67 index, lymphovascular invasion, microscopic extrathyroidal extension, and margin status. A process of 10-fold cross-validation was used to optimize the model's performance. To assess discrimination and calibration, the area-under-the-curve (AUC) of a receiver operating characteristic (ROC) curve, concordance-index (C-index), and dissimilarity index (D-index) were calculated. Finally, the model was externally validated using a separate cohort of 87 MTC patients. The model demonstrated very strong performance, with an AUC of 0.94, a C-index of 0.876, and a D-index of 19.06. When applied to the external validation cohort, the model had an AUC of 0.9.

CONCLUSIONS

Using well-established clinicopathological prognostic variables, we developed and externally validated a robust multivariate prediction model for RFS in patients with resected MTC. The model demonstrates excellent predictive capability and may help guide decisions on patient management. The nomogram is freely available online at https://nomograms.shinyapps.io/MTC_ML_DFS/.

MET-receptor targeted fluorescent imaging and spectroscopy to detect multifocal papillary thyroid cancer

PURPOSE

Multifocal disease in PTC is associated with an increased recurrence rate. Multifocal disease (MD) is underdiagnosed with the current gold standard of pre-operative ultrasound staging. Here, we evaluate the use of EMI-137 targeted molecular fluorescence-guided imaging (MFGI) and spectroscopy as a tool for the intra-operative detection of uni- and multifocal papillary thyroid cancer (PTC) aiming to improve disease staging and treatment selection.

METHODS

A phase-1 study (NCT03470259) with EMI-137 was conducted to evaluate the possibility of detecting PTC using MFGI and quantitative fiber-optic spectroscopy.

RESULTS

Fourteen patients underwent hemi- or total thyroidectomy (TTX) after administration of 0.09 mg/kg (n = 1), 0.13 mg/kg (n = 8), or 0.18 mg/kg (n = 5) EMI-137. Both MFGI and spectroscopy could differentiate PTC from healthy thyroid tissue after administration of EMI-137, which binds selectively to MET in PTC. 0.13 mg/kg was the lowest dosage EMI-137 that allowed for differentiation between PTC and healthy thyroid tissue. The smallest PTC focus detected by MFGI was 1.4 mm. MFGI restaged 80% of patients from unifocal to multifocal PTC compared to ultrasound.

CONCLUSION

EMI-137-guided MFGI and spectroscopy can be used to detect multifocal PTC. This may improve disease staging and treatment selection between hemi- and total thyroidectomy by better differentiation between unifocal and multifocal disease.

TRIAL REGISTRATION

NCT03470259.

A Nod to the Nodes: An Overview of the Role of Central Neck Dissection in the Management of Papillary Thyroid Carcinoma

Lymph node metastasis in thyroid cancer is common and associated with an increased risk of locoregional recurrence (LRR). Although therapeutic central neck dissection is well established, prophylactic central node dissection (pCND) for microscopic occult nodal involvement is controversial and recommendations are based on low-level evidence. The potential benefits of pCND such as reducing LRR and re-operation, refining staging, and improving surveillance are enthusiastically debated and the decision to perform pCND must be weighed up against the increased risks of complications.

Lobectomy and completion thyroidectomy rates increase after the 2015 American Thyroid Association Differentiated Thyroid Cancer Guidelines update

Background

The 2015 American Thyroid Association (ATA) Guidelines permit thyroid lobectomy (TL) or total thyroidectomy in the management of low-risk papillary thyroid cancer (PTC). As definitive risk-stratification is only possible post-operatively, some patients may require completion thyroidectomy (CT) after final histopathological analysis.

Methods

A retrospective cohort study of patients undergoing surgery for low-risk PTC in a tertiary referral centre was undertaken. Consecutive adult patients treated from January 2013 to March 2021 were divided into two groups (pre- and post-publication of ATA Guidelines on 01/01/2016). Only those eligible for lobectomy under rule 35(B) of the ATA Guidelines were included: Bethesda V/VI cytology, 1-4 cm post-operative size and without pre-operative evidence of extrathyroidal extension or nodal metastases. We examined rates of TL, CT, local recurrence and surgical complications.

Results

There were 1488 primary surgical procedures performed for PTC on consecutive adult patients during the study period, of which 461 were eligible for TL. Mean tumour size (P = 0.20) and mean age (P = 0.78) were similar between time periods. The TL rate increased significantly from 4.5 to 18% in the post-publication period (P < 0.001). The proportion of TL patients requiring CT (43 vs 38%) was similar between groups (P = 1.0). There was no significant change in complications (P = 0.55) or local recurrence rates (P = 0.24).

Conclusion

The introduction of the 2015 ATA Guidelines resulted in a modest but significant increase in the rate of lobectomy for eligible PTC patients. In the post-publication period, 38% of patients who underwent TL ultimately required CT after complete pathological analysis.

Unexpected deaths after endocrine surgery: learning from rare events using a national audit of surgical mortality

BACKGROUND

The mortality rate is low in endocrine surgery, making it a difficult outcome to use for quality improvement in individual units. Lessons from population data sets are of value in improving outcomes. Data from the Australian and New Zealand Audit of Surgical Mortality (ANZASM) were used here to understand and elucidate potential systems issues that may contribute to preventable deaths.

METHODS

ANZASM data relating to 30-day mortality after thyroidectomy, parathyroidectomy, and adrenalectomy from 2009 to 2020 were reviewed. Mortality rates were calculated using billing data. Thematic analysis of independent assessor reports was conducted to produce a coding framework.

RESULTS

A total of 67 deaths were reported, with an estimated mortality rate of 0.03-0.07 per cent (38 for thyroidectomy (0.03-0.06 per cent), 16 for parathyroidectomy (0.03-0.06 per cent), 13 for adrenalectomy (0.15-0.33 per cent)). Twenty-seven deaths (40 per cent) were precipitated by clinically significant adverse events, and 18 (27 per cent) were judged to be preventable by independent ANZASM assessors. Recurrent themes included inadequate preoperative assessment, lack of anticipation of intraoperative pitfalls, and failure to recognize and effectively address postoperative complications. Several novel themes were reiterated, such as occult ischaemic heart disease associated with death after parathyroid surgery, unexpected intraoperative difficulties from adrenal metastasis, and complications due to anticoagulation therapy after thyroid surgery.

CONCLUSION

This study represents a large-scale national report of deaths after endocrine surgery and provides insights into these rare events. Although the overall mortality rate is low, 27 per cent of deaths involved systems issues that were preventable following independent peer review.

Outcomes of Advanced Medullary Thyroid Carcinoma in the Era of Targeted Therapy

BACKGROUND

Medullary thyroid carcinoma (MTC) can be targeted with tyrosine kinase inhibitors (TKIs). We aimed to report the outcomes of surgically managed MTC and to evaluate the impact of TKI use on patient survival.

METHODS

Consecutive patients treated surgically for MTC from 1986 to 2020 were identified from a prospectively collected database and were compared on the basis of stage at operation and TKI use. The primary outcome was overall survival (OS).

RESULTS

Among 154 patients with a median age of 52 years, 40% presented with stage I/II disease and 60% presented with advanced (stage III or IV) disease. During a median follow-up of 7.5 years, 21% received TKIs for systemic disease. Those presenting with advanced disease were more likely to receive a TKI (31% vs. 7%), present with tumor invasion of the recurrent laryngeal nerve (RLN; 12% vs. 0%) and undergo reoperation (42% vs. 23%) compared with stage I-II patients. For the 11 patients found to have invasion of the RLN, five had preoperative functional vocal cords. Five-year OS was 84% for advanced disease, and stage IV patients who received TKIs had a median survival of 21 years, versus 15 years for those who did not (p = 0.3).

CONCLUSIONS

Surgery achieves long-term survival for patients with advanced disease, however these patients are at greater risk of requiring RLN resection due to invasion. A significant OS benefit was not seen for TKI use. For patients with local invasion, neoadjuvant TKI therapy may have a role in reducing local morbidity if confirmed to be of benefit in clinical trials.

BRAF V600E Status Sharply Differentiates Lymph Node Metastasis-associated Mortality Risk in Papillary Thyroid Cancer

CONTEXT

How lymph node metastasis (LNM)-associated mortality risk is affected by BRAF V600E in papillary thyroid cancer (PTC) remains undefined.

OBJECTIVE

To study whether BRAF V600E affected LNM-associated mortality in PTC.

DESIGN, SETTING, AND PARTICIPANTS

We retrospectively analyzed the effect of LNM on PTC-specific mortality with respect to BRAF status in 2638 patients (2015 females and 623 males) from 11 centers in 6 countries, with median age of 46 [interquartile range (IQR) 35-58] years and median follow-up time of 58 (IQR 26-107) months.

RESULTS

Overall, LNM showed a modest mortality risk in wild-type BRAF patients but a strong one in BRAF V600E patients. In conventional PTC (CPTC), LNM showed no increased mortality risk in wild-type BRAF patients but a robustly increased one in BRAF V600E patients; mortality rates were 2/659 (0.3%) vs 4/321 (1.2%) in non-LNM vs LNM patients (P = 0.094) with wild-type BRAF, corresponding to a hazard ratio (HR) (95% CI) of 4.37 (0.80-23.89), which remained insignificant at 3.32 (0.52-21.14) after multivariate adjustment. In BRAF V600E CPTC, morality rates were 7/515 (1.4%) vs 28/363 (7.7%) in non-LNM vs LNM patients (P < 0.001), corresponding to an HR of 4.90 (2.12-11.29) or, after multivariate adjustment, 5.76 (2.19-15.11). Adjusted mortality HR of coexisting LNM and BRAF V600E vs absence of both was 27.39 (5.15-145.80), with Kaplan-Meier analyses showing a similar synergism.

CONCLUSIONS

LNM-associated mortality risk is sharply differentiated by the BRAF status in PTC; in CPTC, LNM showed no increased mortality risk with wild-type BRAF but a robust one with BRAF mutation. These results have strong clinical relevance.

Pros and cons of hemi-thyroidectomy for low-risk differentiated thyroid cancer

The debate regarding the surgical management of low-risk differentiated thyroid cancer (DTC) is ongoing. The recommended extent of surgery in DTC is based on an assessment of the predicted risk of recurrence and recent guidelines reflect an evolving philosophy of de-escalation of surgical management, informed by a growing understanding of the determinants of tumour biology and important prognostic factors. However, our current clinical and pathological risk stratification processes are imperfect and hence there is significant variation in clinical practice. Surgeons face the challenge of finding the balance between avoiding overtreatment, minimizing complications and providing adequate oncological management. This article discusses the nuances of the current management guidelines as well as the important considerations in preoperative decision making.

Bi-national Review of Phaeochromocytoma Care: Is ICU Admission Always Necessary?

BACKGROUND

Post-operative management after phaeochromocytoma resection includes monitoring of blood pressure and blood sugar, and vigilance for haemorrhage. Guidelines recommend 24 h of continuous blood pressure monitoring, usually necessitating HDU/ICU admission. We hypothesised that most patients undergoing phaeochromocytoma resection do not require post-operative HDU/ICU admission. We aim to describe current Australian and New Zealand perioperative management of phaeochromocytoma and determine whether it is safe to omit HDU/ICU care for most patients.

METHODS

We collected retrospective data on patients undergoing excision of phaeochromocytoma in 12 centres around Australia and New Zealand between 2007 and 2019. Data collected included preoperative medical management, anaesthetic management, vasopressor support, HDU/ICU admission and complications.

RESULTS

A total of 223 patients were included in the study, 173 (77%) of whom were admitted to HDU/ICU post-operatively. The group of patients treated in ICU was similar to the group of patients treated on the ward in terms of demographic and tumour characteristics, and there were significant differences in the proportion of patients admitted to HDU/ICU between centres. Of patients admitted to ICU, 71 (41%) received vasopressor support. This was weaned within 24 h in 55 (77%) patients. Patients with larger tumours (> 6 cm) and a transfusion requirement are more likely to require prolonged inotropic support. Among patients admitted to the ward, there were no complications that required escalation of care.

CONCLUSIONS

Although not widespread practice in Australia and New Zealand, it appears safe for the majority of patients undergoing minimally invasive resection of phaeochromocytoma to be admitted to the ward post-operatively.

Parathyroidectomy for patients with secondary hyperparathyroidism in a changing landscape for the management of end-stage renal disease

BACKGROUND

The landscape of patients with end-stage renal disease is changing with the increasing availability of kidney transplantation. In the near future, a less aggressive approach to treat secondary hyperparathyroidism might be beneficial. We report outcomes of parathyroidectomy for end-stage renal disease-related hyperparathyroidism comparing the outcomes of limited, subtotal, and total parathyroidectomy.

METHODS

We performed a retrospective analysis of prospectively collected data. Patients were divided into 3 parathyroidectomy subgroups: limited (<3 glands removed), subtotal (3-3.5 glands), and total (4 glands) parathyroidectomy. Primary outcome was serum levels of parathyroid hormone. Secondary endpoints were serum levels of calcium, phosphate, and alkaline phosphatase, postoperative complications, and persistent or recurrent disease rates.

RESULTS

In total, 195 patients were included for analysis of whom 13.8% underwent limited parathyroidectomy, 46.7% subtotal parathyroidectomy, and 39.5% total parathyroidectomy. Preoperative parathyroid hormone levels (pg/mL) were 471 (210-868), 1,087 (627-1,795), and 1,070 (475-1,632) for the limited, subtotal, and total parathyroidectomy groups, respectively (P < .001). A decrease in serum parathyroid hormone was seen in all groups; however, postoperative levels remained greater in the limited parathyroidectomy group compared to the subtotal and total parathyroidectomy groups (P < .001). Serum calcium, phosphate, and alkaline phosphatase levels decreased in all groups to within the reference range. In the limited parathyroidectomy group, persistent disease and recurrence occurred more frequently (P = .02 and P = .07, respectively).

CONCLUSION

Subtotal parathyroidectomy is the optimal strategy in an era with an increasing availability of kidney transplantation and improved regimens of dialysis. In this changing practice, the approach to parathyroid surgery, however, might shift to a less aggressive and patient-tailored approach.

Prophylactic central lymph node dissection informs the decision of radioactive iodine ablation in papillary thyroid cancer

BACKGROUND

Prophylactic central lymph node dissection (CLND) in papillary thyroid cancer (PTC) is controversial. We aimed to investigate if prophylactic CLND aids risk stratification and contributes to the decision for postoperative RAI ablation.

METHODS

Patients undergoing thyroidectomy for PTC and prophylactic CLND were identified from an endocrine surgical unit database. Pathology reports where reviewed for number and size of lymph nodes and patients stratified by risk according to the ATA guidelines.

RESULTS

426 patients were identified with PTC ≤4 cm and prophylactic CLND. 96 patients (23%) had central lymph node metastasis (CLNM) that qualified them for the intermediate risk group. In 17 patients (4%), the CLNM data led to upgrading independently of other histopathological characteristics. Correcting for multiple variables, CLNM was an independent factor contributing to RAI treatment.

CONCLUSION

Prophylactic CLND provides information to aid the selection of RAI ablation independent of primary cancer histology for risk stratification in 4% of patients. This benefit should be carefully balanced with the risk of CLND and patient treatment choice when deciding on management of PTC ≤4 cm.

Molecular Markers Guiding Thyroid Cancer Management

The incidence of thyroid cancer is rapidly increasing, mostly due to the overdiagnosis and overtreatment of differentiated thyroid cancer (TC). The increasing use of potent preclinical models, high throughput molecular technologies, and gene expression microarrays have provided a deeper understanding of molecular characteristics in cancer. Hence, molecular markers have become a potent tool also in TC management to distinguish benign from malignant lesions, predict aggressive biology, prognosis, recurrence, as well as for identification of novel therapeutic targets. In differentiated TC, molecular markers are mainly used as an adjunct to guide management of indeterminate nodules on fine needle aspiration biopsies. In contrast, in advanced thyroid cancer, molecular markers enable targeted treatments of affected signalling pathways. Identification of the driver mutation of targetable kinases in advanced TC can select treatment with mutation targeted tyrosine kinase inhibitors (TKI) to slow growth and reverse adverse effects of the mutations, when traditional treatments fail. This review will outline the molecular landscape and discuss the impact of molecular markers on diagnosis, surveillance and treatment of differentiated, poorly differentiated and anaplastic follicular TC.

BRAF V600E status may facilitate decision-making on active surveillance of low-risk papillary thyroid microcarcinoma

INTRODUCTION

Conservative active surveillance has been proposed for low-risk papillary thyroid microcarcinoma (PTMC), defined as ≤1.0 cm and lacking clinical aggressive features, but controversy exists with accepting it as not all such PTMCs are uniformly destined for benign prognosis. This study investigated whether BRAF V600E status could further risk stratify PTMC, particularly low-risk PTMC, and can thus help with more accurate case selection for conservative management.

METHODS

This international multicenter study included 743 patients treated with total thyroidectomy for PTMC (584 women and 159 men), with a median age of 49 years (interquartile range [IQR], 39-59 years) and a median follow-up time of 53 months (IQR, 25-93 months).

RESULTS

On overall analyses of all PTMCs, tumour recurrences were 6.4% (32/502) versus 10.8% (26/241) in BRAF mutation-negative versus BRAF mutation-positive patients (P = 0.041), with a hazard ratio (HR) of 2.44 (95% CI (confidence interval), 1.15-5.20) after multivariate adjustment for confounding clinical factors. On the analyses of low-risk PTMC, recurrences were 1.3% (5/383) versus 4.3% (6/139) in BRAF mutation-negative versus BRAF mutation-positive patients, with an HR of 6.65 (95% CI, 1.80-24.65) after adjustment for confounding clinical factors. BRAF mutation was associated with a significant decline in the Kaplan-Meier recurrence-free survival curve in low-risk PTMC.

CONCLUSIONS

BRAF V600E differentiates the recurrence risk of PTMC, particularly low-risk PTMC. Given the robust negative predictive value, conservative active surveillance of BRAF mutation-negative low-risk PTMC is reasonable whereas the increased recurrence risk and other well-known adverse effects of BRAF V600E make the feasibility of long-term conservative surveillance uncertain for BRAF mutation-positive PTMC.

Risk of needing completion thyroidectomy for low-risk papillary thyroid cancers treated by lobectomy

Background

Low-risk differentiated thyroid cancers may, according to the American Thyroid Association (ATA) 2015 guidelines, be managed initially with lobectomy. However, definitive risk categorization requires pathological assessment of the specimen, resulting in completion thyroidectomy being recommended when discordance between preoperative and postoperative staging occurs. This study sought to establish the expected rate of completion thyroidectomy in patients with papillary thyroid cancer (PTC) treated by lobectomy.

Methods

Patients with PTC treated over 5 years (2013-2017 inclusive) and meeting the ATA criteria for lobectomy were identified from the prospectively developed database of a high-volume, university department of endocrine surgery. Concordance between the ATA initial and final recommendation, and the putative rate of completion thyroidectomy were calculated. Multivariable analysis was used to assess preoperative factors as predictors of the need for total thyroidectomy.

Results

Of 275 patients with PTC who met ATA preoperative criteria for lobectomy there was concordance between this and the final recommendation in 158 (57·5 per cent) and discordance in 117 (43·5 per cent). Most common reasons for discordance were: angioinvasion (30·8 per cent), local invasion (23·9 per cent) or both (20·5 per cent). Four patients (1·5 per cent) had permanent hypoparathyroidism. On multivariable analysis, age, sex, tumour size and family history did not independently predict the final treatment required.

Conclusion

Although many patients may be treated adequately with lobectomy, just under half would require completion thyroidectomy. Further work is needed on preoperative risk stratification but, before this, total thyroidectomy remains the treatment of choice for low-risk 1-4-cm PTC in the hands of high-volume thyroid surgeons who can demonstrate low complication rates.

Treatment strategy of end stage renal disease-related hyperparathyroidism before, during, and after the era of calcimimetics

BACKGROUND

Since 2004, end-stage renal disease related hyperparathyroidism patients are treated mainly with cinacalcet, which ceased to be subsidized through the Australian Pharmaceutical Benefits Scheme in 2015. We aimed to investigate the impact of these changes on the treatment strategy in the Australian end-stage renal disease population.

METHODS

The following groups were formed according to the date of parathyroidectomy: A, before calcimimetics; B, during the era of calcimimetics; and C, after cinacalcet removal by the Australian Pharmaceutical Benefits Scheme. The primary outcome was time from start of dialysis to parathyroidectomy. Regression analysis was used to examine trends in parathyroidectomy rates.

RESULTS

Between 1998 and 2016, 195 parathyroidectomies were performed. Median time to referral was 69 (33-123), 67 (31-110) and 44 (23-102) months for groups A, B, and C, respectively (P = .55). Parathyroidectomy rates increased throughout the years (CI 0.09-1.13, R²=0.27, P = .02). A trend toward a dip in parathyroidectomy rates was seen during the era of cinacalcet (P = .08). Median preoperative parathyroid hormone levels increased significantly (842 [418-1,553] versus 1,040 [564-1,810] versus 1,350 [1,037-1,923] pg/mL, for groups A, B, and C, respectively [P < .01]).

CONCLUSION

Parathyroidectomy rates seem to vary according to the availability of cinacalcet. This change in treatment strategy is accompanied with increased preoperative parathyroid hormone levels, reflecting delayed surgery and increased disease severity.

BRAF V600E Confers Male Sex Disease-Specific Mortality Risk in Patients With Papillary Thyroid Cancer

Purpose To test whether the prognostic risk of male sex in papillary thyroid cancer (PTC) is determined by BRAF V600E and can thus be stratified by BRAF status. Patients and Methods We retrospectively investigated the relationship between male sex and clinicopathologic outcomes in PTC, particularly mortality, with respect to BRAF status in 2,638 patients (male, n = 623; female, n = 2,015) from 11 centers in six countries, with median age of 46 years (interquartile range, 35-58 years) at diagnosis and median follow-up time of 58 months (interquartile range, 26-107 months). Results Distant metastasis rates in men and women were not different in wild-type BRAF PTC but were different in BRAF V600E PTC: 8.9% (24 of 270) and 3.7% (30 of 817; P = .001), respectively. In wild-type BRAF PTC, mortality rates were 1.4% (five of 349) versus 0.9% (11 of 1175) in men versus women ( P = .384), with a hazard ratio (HR) of 1.59 (95% CI, 0.55 to 4.57), which remained insignificant at 0.70 (95% CI, 0.23 to 2.09) after clinicopathologic multivariable adjustment. In BRAF V600E PTC, mortality rates were 6.6% (18 of 272) versus 2.9% (24 of 822) in men versus women ( P = .006), with an HR of 2.43 (95% CI, 1.30 to 4.53), which remained significant at 2.74 (95% CI, 1.38 to 5.43) after multivariable adjustment. In conventional-variant PTC, male sex similarly had no effect in wild-type BRAF patients; mortality rates in BRAF V600E patients were 7.2% (16 of 221) versus 2.9% (19 of 662) in men versus women ( P = .004), with an HR of 2.86 (95% CI, 1.45 to 5.67), which remained significant at 3.51 (95% CI, 1.62 to 7.63) after multivariable adjustment. Conclusion Male sex is a robust independent risk factor for PTC-specific mortality in BRAF V600E patients but not in wild-type BRAF patients. The prognostic risk of male sex in PTC can thus be stratified by BRAF status in clinical application.

BRAF V600E Mutation-Assisted Risk Stratification of Solitary Intrathyroidal Papillary Thyroid Cancer for Precision Treatment

Background

Precise risk stratification-based treatment of solitary intrathyroidal papillary thyroid cancer (SI-PTC) that is larger than 1.0 cm and 4.0 cm or less is undefined.

Methods

A genetic-clinical risk study was performed on BRAF V600E in 955 patients (768 women and 187 men) with SI-PTC, with median age of 46 years and median clinical follow-up time of 64 months at 11 medical centers in six countries. The chi-square test or, for analyses with small numbers, Fisher's exact test was performed to compare recurrence rates. Recurrence-free probability was estimated by Kaplan-Meier (KM) analysis, and the independent effect of BRAF mutation on the recurrence was analyzed by Cox regression and Cox proportional hazard analyses. All statistical tests were two-sided.

Results

Recurrence of SI-PTC larger than 1.0 cm and 4.0 cm or less was 9.5% (21/221) vs 3.4% (11/319) in BRAF mutation vs wild-type BRAF patients, with a hazard ratio (HR) of 3.03 (95% confidence interval [CI] = 1.46 to 6.30) and a patient age- and sex-adjusted hazard ratio of 3.10 (95% CI = 1.49 to 6.45, P = .002). Recurrence rates of SI-PTC larger than 2.0 cm and 4.0 cm or less were 16.5% (13/79) vs 3.6% (5/139) in mutation vs wild-type patients (HR = 5.44, 95% CI = 1.93 to 15.34; and adjusted HR = 5.58, 95% CI = 1.96 to 15.85, P = .001). Recurrence rates of SI-PTC larger than 3.0 cm and 4 cm or less were 30.0% (6/20) vs 1.9% (1/54) in mutation vs wild-type patients (HR = 18.40, 95% CI = 2.21 to 152.98; and adjusted HR = 14.73, 95% CI = 1.74 to 124.80, P = .01). Recurrences of mutation-positive SI-PTC were comparable with those of counterpart invasive solitary PTC, around 20% to 30%, in tumors larger than 2.0 cm to 3.0 cm. BRAF mutation was associated with a statistically significant decrease in recurrence-free patient survival on KM analysis, particularly in SI-PTC larger than 2.0 cm and 4.0 cm or less. Similar results were obtained in conventional SI-PTC. The negative predictive values of BRAF mutation for recurrence were 97.8% (95% CI = 96.3% to 98.8%) for general SI-PTC and 98.2% (95% CI = 96.3% to 99.3%) for conventional SI-PTC.

Conclusions

BRAF V600E identifies a subgroup of SI-PTC larger than 1.0 cm and 4.0 cm or less, particularly tumors larger than 2.0 cm and 4.0 cm or less, that has high risk for recurrence comparable with that of invasive solitary PTC, making more aggressive treatment reasonable.

Multicentre study evaluating the surgical learning curve for posterior retroperitoneoscopic adrenalectomy

BACKGROUND

Posterior retroperitoneoscopic adrenalectomy has gained international popularity in the past decade. Despite major advantages, including shorter duration of operation, minimal blood loss and decreased postoperative pain, many surgeons still prefer laparoscopic transperitoneal adrenalectomy. It is likely that the unfamiliar anatomical environment, smaller working space and long learning curve impede implementation. The present study assessed the number of procedures required to fulfil the surgical learning curve for posterior retroperitoneoscopic adrenalectomy.

METHODS

The first consecutive posterior retroperitoneoscopic adrenalectomies performed by four surgical teams from university centres in three different countries were analysed. The primary outcome measure was duration of operation. Secondary outcomes were conversion to an open or laparoscopic transperitoneal approach, complications and recovery time. The learning curve cumulative sum (LC-CUSUM) was used to assess the learning curves for each surgical team.

RESULTS

A total of 181 surgical procedures performed by four surgical teams were analysed. The median age of the patients was 57 (range 15-84) years and 61·3 per cent were female. Median tumour size was 25 (range 4-85) mm. There were no significant differences in patient characteristics and tumour size between the teams. The median duration of operation was 89 (range 29-265) min. There were 35 perioperative and postoperative complications among the 181 patients (18·8 per cent); 17 of 27 postoperative complications were grade 1. A total of nine conversions to open procedures (5·0 per cent) were observed. The LC-CUSUM analysis showed that competency was achieved after a range of 24-42 procedures.

CONCLUSION

In specialized endocrine surgical centres between 24 and 42 procedures are required to fulfil the entire surgical learning curve for the posterior retroperitoneoscopic adrenalectomy.

Patient Age-Associated Mortality Risk Is Differentiated by BRAF V600E Status in Papillary Thyroid Cancer

Purpose For the past 65 years, patient age at diagnosis has been widely used as a major mortality risk factor in the risk stratification of papillary thyroid cancer (PTC), but whether this is generally applicable, particularly in patients with different BRAF genetic backgrounds, is unclear. The current study was designed to test whether patient age at diagnosis is a major mortality risk factor. Patients and Methods We conducted a comparative study of the relationship between patient age at diagnosis and PTC-specific mortality with respect to BRAF status in 2,638 patients (623 men and 2,015 women) with a median age of 46 years (interquartile range, 35 to 58 years) at diagnosis and a median follow-up time of 58 months (interquartile range, 26 to 107 months). Eleven medical centers from six countries participated in this study. Results There was a linear association between patient age and mortality in patients with BRAF V600E mutation, but not in patients with wild-type BRAF, in whom the mortality rate remained low and flat with increasing age. Kaplan-Meier survival curves rapidly declined with increasing age in patients with BRAF V600E mutation but did not decline in patients with wild-type BRAF, even beyond age 75 years. The association between mortality and age in patients with BRAF V600E was independent of clinicopathologic risk factors. Similar results were observed when only patients with the conventional variant of PTC were analyzed. Conclusion The long-observed age-associated mortality risk in PTC is dependent on BRAF status; age is a strong, continuous, and independent mortality risk factor in patients with BRAF V600E mutation but not in patients with wild-type BRAF. These results question the conventional general use of patient age as a high-risk factor in PTC and call for differentiation between patients with BRAF V600E and wild-type BRAF when applying age to risk stratification and management of PTC.

The Prognostic Value of Tumor Multifocality in Clinical Outcomes of Papillary Thyroid Cancer

CONTEXT

Multifocality is often treated as a risk factor for papillary thyroid cancer (PTC), prompting aggressive treatments, but its prognostic value remains unestablished.

OBJECTIVE

To investigate the role of tumor multifocality in clinical outcomes of PTC.

METHODS

Multicenter study of the relationship between multifocality and clinical outcomes of PTC in 2638 patients (623 men and 2015 women) with median [interquartile range (IQR)] age of 46 (35 to 58) years and median (IQR) follow-up time of 58 (26 to 107) months at 11 medical centers in six countries. Surveillance, Epidemiology and End Results (SEER) data were used for validation.

RESULTS

Disease recurrence in multifocal and unifocal PTC was 198 of 1000 (19.8%) and 221 of 1624 (13.6%) (P < 0.001), with a hazard ratio of 1.55 [95% confidence interval (CI), 1.28 to 1.88], which became insignificant at 1.13 (95% CI, 0.93 to 1.37) on multivariate adjustment. Similar results were obtained in PTC variants: conventional PTC, follicular-variant PTC, tall-cell PTC, and papillary thyroid microcarcinoma. There was no association between multifocality and mortality in any of these PTC settings, whereas there was a strong association between classic risk factors and cancer recurrence or mortality, which remained significant after multivariate adjustment. In 1423 patients with intrathyroidal PTC, disease recurrence was 20 of 455 (4.4%) and 41 of 967 (4.2%) (P = 0.892) and mortality was 0 of 455 (0.0%) and 3 of 967 (0.3%) (P = 0.556) in multifocal and unifocal PTC, respectively. The results were reproduced in 89,680 patients with PTC in the SEER database.

CONCLUSIONS

Tumor multifocality has no independent risk prognostic value in clinical outcomes of PTC; its indiscriminate use as an independent risk factor, prompting overtreatments of patients, should be avoided.

Characteristics of contralateral carcinomas in patients with differentiated thyroid cancer larger than 1 cm

Purpose

Traditionally, total thyroidectomy has been advocated for patients with tumors larger than 1 cm. However, according to the ATA and NCCN guidelines (2015, USA), patients with tumors up to 4 cm are now eligible for lobectomy. A rationale for adhering to total thyroidectomy might be the presence of contralateral carcinomas. The purpose of this study was to describe the characteristics of contralateral carcinomas in patients with differentiated thyroid cancer (DTC) larger than 1 cm.

Methods

A retrospective study was performed including patients from 17 centers in 5 countries. Adults diagnosed with DTC stage T1b-T3 N0-1a M0 who all underwent a total thyroidectomy were included. The primary endpoint was the presence of a contralateral carcinoma.

Results

A total of 1313 patients were included, of whom 426 (32 %) had a contralateral carcinoma. The contralateral carcinomas consisted of 288 (67 %) papillary thyroid carcinomas (PTC), 124 (30 %) follicular variant of a papillary thyroid carcinoma (FvPTC), 5 (1 %) follicular thyroid carcinomas (FTC), and 3 (1 %) Hürthle cell carcinomas (HTC). Ipsilateral multifocality was strongly associated with the presence of contralateral carcinomas (OR 2.62). Of all contralateral carcinomas, 82 % were ≤10 mm and of those 99 % were PTC or FvPTC. Even if the primary tumor was a FTC or HTC, the contralateral carcinoma was (Fv)PTC in 92 % of cases.

Conclusions

This international multicenter study performed on patients with DTC larger than 1 cm shows that contralateral carcinomas occur in one third of patients and, independently of primary tumor subtype, predominantly consist of microPTC.

Differential Clinicopathological Risk and Prognosis of Major Papillary Thyroid Cancer Variants

CONTEXT

Individualized management, incorporating papillary thyroid cancer (PTC) variant-specific risk, is conceivably a useful treatment strategy for PTC, which awaits comprehensive data demonstrating differential risks of PTC variants to support.

OBJECTIVE

This study sought to establish the differential clinicopathological risk of major PTC variants: conventional PTC (CPTC), follicular-variant PTC (FVPTC), and tall-cell PTC (TCPTC).

METHODS

This was a retrospective study of clinicopathological outcomes of 6282 PTC patients (4799 females and 1483 males) from 26 centers and The Cancer Genome Atlas in 14 countries with a median age of 44 years (interquartile range, 33-56 y) and median follow-up time of 37 months (interquartile range, 15-82 mo).

RESULTS

The cohort consisted of 4702 (74.8%) patients with CPTC, 1126 (17.9%) with FVPTC, and 239 (3.8%) with TCPTC. The prevalence of high-risk parameters was significantly different among the three variants, including extrathyroidal invasion, lymph node metastasis, stages III/IV, disease recurrence, mortality, and the use (need) of radioiodine treatment (all P < .001), being highest in TCPTC, lowest in FVPTC, and intermediate in CPTC, following an order of TCPTC > CPTC ≫ FVPTC. Recurrence and mortality in TCPTC, CPTC, and FVPTC were 27.3 and 6.7%, 16.1 and 2.5%, and 9.1 and 0.6%, corresponding to events per 1000 person-years (95% confidence interval [CI]) of 92.47 (64.66-132.26) and 24.61 (12.31-49.21), 34.46 (30.71-38.66), and 5.87 (4.37-7.88), and 24.73 (18.34-33.35) and 1.68 (0.54-5.21), respectively. Mortality hazard ratios of CPTC and TCPTC over FVPTC were 3.44 (95% CI, 1.07-11.11) and 14.96 (95% CI, 3.93-56.89), respectively. Kaplan-Meier survival analyses showed the best prognosis in FVPTC, worst in TCPTC, and intermediate in CPTC in disease recurrence-free probability and disease-specific patient survival. This was particularly the case in patients at least 45 years old.

CONCLUSION

This large multicenter study demonstrates differential prognostic risks of the three major PTC variants and establishes a unique risk order of TCPTC > CPTC ≫ FVPTC, providing important clinical implications for specific variant-based management of PTC.

Oxyphil Cell Parathyroid Adenomas Causing Primary Hyperparathyroidism: a Clinico-Pathological Correlation

Oxyphil cell parathyroid adenomas (OPA) are considered to be an uncommon cause of primary hyperparathyroidism (PHPT), and were historically thought to be clinically silent. It has been our clinical impression that these adenomas present more often than previously thought and may manifest a more severe form of primary hyperparathyroidism than classical adenoma. The aim of this study was to describe the incidence and clinical presentation of OPA. An observational case-control study was undertaken. The study group comprised patients undergoing parathyroidectomy for PHPT where the final pathology confirmed OPA. The controls were made up of an age- and sex-matched group of patients having parathyroidectomy in the same time period where the final pathology confirmed a classical or non-oxyphil adenoma. OPA were defined as parathyroid tumours containing >75% oxyphilic cells. The OPA cases were obtained by reviewing all histopathology slides over an 11-year period (2002-12) where the reports contained the words 'oxyphil' or 'oxyphilic' parathyroid adenomas. These were then reviewed by two independent pathologists to confirm a diagnosis of OPA. The primary outcome measures were preoperative serum calcium and parathyroid hormone (PTH) levels. Secondary outcome measures were symptoms at presentation, accuracy of preoperative localization studies, parathyroid gland weight following surgery, and type of surgery undertaken. In the period 2002-2012, 2739 patients underwent surgery for PHPT. Following pathological review, 91 cases were confirmed as being OPA and formed the study group. A control group (n = 91) from the same period was selected following matching on the basis of age at presentation and sex. OPA were associated with higher preoperative serum calcium (10.84 versus 10.48 mg/dL, p < 0.001) and parathyroid hormone (139 versus 64 ng/L, p < 0.001). At presentation, a lower proportion of OPA cases had asymptomatic disease (15 versus 29%, p = 0.03). There was a trend toward a higher rate of renal calculi at presentation in the OPA group (9 versus 3%, p = 0.07). Preoperative ultrasound was less accurate in localization of OPA when compared with classical adenoma. The rate of minimally invasive surgery was 67% for OPA and 78% for the control group (p = 0.06). All patients were cured of hypercalcaemia at 6-month follow up. There was no significant difference in the weight of removed parathyroid tissue between the groups (868 mg for OPA versus 789 mg for the control group, p = 0.6). OPA are frequently symptomatic and are associated with higher preoperative serum calcium and parathyroid hormone levels than classical types of parathyroid adenomas. OPA are less likely to be localised on preoperative ultrasound examination.

Reduced breast milk feeding subsequent to cosmetic breast augmentation surgery

OBJECTIVE

To determine the effect of cosmetic breast augmentation on subsequent infant feeding.

PARTICIPANTS, DESIGN AND SETTING

Population-based record linkage study of women giving birth in New South Wales, January 2006 - December 2011. Birth records were linked longitudinally to maternal hospitalisations up to 11 years before birth. Breast augmentation was identified by surgical procedure codes in hospital records.

MAIN OUTCOME MEASURES

Any breast milk feeding at discharge from birth care, and among infants receiving any breast milk, exclusive breast milk feeding. The before-and-after effect of breast augmentation was assessed among women who had the surgery between births.

RESULTS

Among 378 389 women who gave birth in the study period, 892 (0.2%) had prior breast augmentation. Among women with breast augmentation, 705 (79%) provided any breast milk to their infant at discharge, compared with 89% among women without augmentation. After adjusting for sociodemographic and pregnancy factors, infants of women with breast augmentation were less likely to receive breast milk at discharge than infants of women without augmentation (adjusted relative risk [ARR], 0.90; 95% CI, 0.87-0.93). However, infants receiving breast milk were not more or less likely to receive breast milk exclusively (ARR, 0.99; 95% CI, 0.97-1.01). Women with augmentation surgery between births changed their breastfeeding behaviour (reduced rates), while those with no augmentation or augmentation before both births did not.

CONCLUSIONS

Reduced rates of breast milk feeding among women who have undergone breast augmentation underscore the importance of identifying, supporting and encouraging women who are vulnerable to a lower likelihood of breastfeeding.

Patterns of structural recurrence in papillary thyroid cancer

BACKGROUND

Papillary thyroid carcinoma (PTC) is uncommonly associated with tumor-related mortality, although local recurrence can be a frequent and difficult problem. This study was conducted to clarify the pattern of structural locoregional recurrence in PTC.

MATERIAL AND METHOD

A retrospective cohort study of patients undergoing surgical intervention for PTC was undertaken. Data were collected from a comprehensive thyroid cancer database maintained within a single tertiary referral center. The primary outcome measure was cancer recurrence requiring surgical intervention. Secondary outcome measures were site of recurrence, time to recurrence, and risk factors for recurrence.

RESULTS

In the period 1980-2013, 1,183 patients with PTC were included in the study. The overall rate of structural recurrence requiring reoperative surgery was 7.9 %. The median time to reoperation was 31 months. Younger age, male gender, large primary tumor diameter, and number of positive lymph nodes at initial presentation were all significantly associated with disease recurrence. The lateral compartments (levels I, II, III, IV, V) were involved almost twice as frequently as the central compartment (level VI) (67 vs 32 %, P < 0.01). The distribution of recurrences was level I (1 %), level II (12 %), level III (18 %), level IV (18 %), level V (17 %), level VI (32 %), level VII (2 %).

CONCLUSIONS

In a center with a liberal approach to central compartment lymph node dissection for PTC, the lateral neck compartment is the most common site of structural recurrence requiring reoperative surgery.

Association between BRAF V600E mutation and recurrence of papillary thyroid cancer

PURPOSE

To investigate the prognostic value of BRAF V600E mutation for the recurrence of papillary thyroid cancer (PTC).

PATIENTS AND METHODS

This was a retrospective multicenter study of the relationship between BRAF V600E mutation and recurrence of PTC in 2,099 patients (1,615 women and 484 men), with a median age of 45 years (interquartile range [IQR], 34 to 58 years) and a median follow-up time of 36 months (IQR, 14 to 75 months).

RESULTS

The overall BRAF V600E mutation prevalence was 48.5% (1,017 of 2,099). PTC recurrence occurred in 20.9% (213 of 1,017) of BRAF V600E mutation-positive and 11.6% (125 of 1,082) of BRAF V600E mutation-negative patients. Recurrence rates were 47.71 (95% CI, 41.72 to 54.57) versus 26.03 (95% CI, 21.85 to 31.02) per 1,000 person-years in BRAF mutation-positive versus -negative patients (P < .001), with a hazard ratio (HR) of 1.82 (95% CI, 1.46 to 2.28), which remained significant in a multivariable model adjusting for patient sex and age at diagnosis, medical center, and various conventional pathologic factors. Significant association between BRAF mutation and PTC recurrence was also found in patients with conventionally low-risk disease stage I or II and micro-PTC and within various subtypes of PTC. For example, in BRAF mutation-positive versus -negative follicular-variant PTC, recurrence occurred in 21.3% (19 of 89) and 7.0% (24 of 342) of patients, respectively, with recurrence rates of 53.84 (95% CI, 34.34 to 84.40) versus 19.47 (95% CI, 13.05 to 29.04) per 1,000 person-years (P < .001) and an HR of 3.20 (95% CI, 1.46 to 7.02) after adjustment for clinicopathologic factors. BRAF mutation was associated with poorer recurrence-free probability in Kaplan-Meier survival analyses in various clinicopathologic categories.

CONCLUSION

This large multicenter study demonstrates an independent prognostic value of BRAF V600E mutation for PTC recurrence in various clinicopathologic categories.

Mutations in KCNJ5 determines presentation and likelihood of cure in primary hyperaldosteronism

INTRODUCTION

Primary hyperaldosteronism (PA) is a common cause of secondary hypertension. Two recurrent mutations (G151R and L168R) in the potassium channel gene KCNJ5 have been identified that affect the Kir3.4 potassium channel found in the cells of the zona glomerulosa of the adrenal gland. The aim of this study was to determine the prevalence of KCNJ5 mutations in an Australian cohort of patients and to correlate these findings with clinical outcome data, in order to describe the clinical impact on patients who harbour this mutation.

METHODS

Direct Sanger sequencing for KCNJ5 on DNA from adrenal tumour tissue of 83 patients with PA in a cohort study was undertaken and mutation status correlated with clinical outcome data.

RESULTS

Seventy-one of 83 patients (86%) had adrenocortical adenomas and 12 patients (14%) had bilateral adrenal hyperplasia. A total of 34 (41%) patients were found to have heterozygous somatic mutations in KCNJ5, G151R and L168R. No germ line mutations were identified. Patients with mutations were predominately female (68% versus 49%) and significantly younger at presentation (48 versus 55 years). When correlated with clinical data, our results demonstrated that patients with KCNJ5 mutations were more likely to be cured following surgery without the requirement for ongoing medications.

CONCLUSIONS

Our findings in a large Australian cohort show that patients with mutations in KCNJ5 present earlier with the signs and symptoms of PA benefit from surgical intervention. Moreover, our results highlight the importance of a thorough workup and management plan for younger patients who present with hypertension.

MicroRNA-222 and microRNA-146b are tissue and circulating biomarkers of recurrent papillary thyroid cancer

BACKGROUND

Papillary thyroid cancer (PTC) persistence or recurrence and the need for long-term surveillance can cause significant inconvenience and morbidity in patients. Currently, recurrence risk stratification is accomplished by using clinicopathologic factors, and serum thyroglobulin is the only commercially available marker for persistent or recurrent disease. The objective of this study was to determine microRNA (miRNA) expression in PTC and determine whether 1 or more miRNAs could be measured in plasma as a biomarker for recurrence.

METHODS

Patients with recurrent PTC (Rc-PTC) and those without recurrence (NR-PTC) were retrospectively recruited for a comparison of their tumor miRNA profiles. Patients with either newly diagnosed PTC or multinodular goiter who were undergoing total thyroidectomy were prospectively recruited for an analysis of preoperative and postoperative circulating miRNA levels. Healthy volunteers were recruited as the control group.

RESULTS

MicroRNA-222 and miR-146b were over-expressed 10.8-fold and 8.9-fold, respectively, in Rc-PTC tumors compared with NR-PTC tumors (P = .014 and P = .038, respectively). In plasma from preoperative PTC patients, levels of miR-222 and miR-146b were higher compared with the levels in plasma from healthy volunteers (P < .01 for both). Reductions of 2.7-fold and 5.1-fold were observed in the plasma levels of miR-222 and miR-146b, respectively, after total thyroidectomy (P = .03 for both).

CONCLUSIONS

This study demonstrated that tumor levels of miR-222 and miR-146b are associated with PTC recurrence and that miR-222 and miR-146b levels in the circulation correspond to the presence of PTC. The potential of these miRNAs as tumor biomarkers to improve patient stratification according to the risk of recurrence and as circulating biomarkers for PTC surveillance warrants further study.

Negative parafibromin staining predicts malignant behavior in atypical parathyroid adenomas

BACKGROUND

The histopathological criteria for carcinoma proposed by the World Health Organization (WHO) are imperfect predictors of the malignant potential of parathyroid tumors. Negative parafibromin (PF) and positive protein gene product 9.5 (PGP9.5) staining are markers of CDC73 mutation and occur commonly in carcinoma but rarely in adenomas. We investigated whether PF and PGP9.5 staining could be used to predict the behavior of atypical parathyroid adenomas--tumors with atypical features that do not fulfill WHO criteria for malignancy.

METHODS

Long-term outcomes were compared across four groups: group A, WHO-positive criteria/PF-negative staining; group B, WHO(+)/PF(+), group C; WHO(-)/PF(-); and group D, WHO(-)/PF(+).

RESULTS

Eighty-one patients were included in the period 1999-2012: group A (n = 13), group B (n = 14), group C (n = 21), and group D (n = 33). Mortality and recurrence rates, respectively, for group A were 15 and 38%, for group B 7 and 36%, for group C 0 and 10%, and for group D 0 and 0%. The PGP9.5(+) ratios for groups A to D were 85, 78, 71, and 12%, further informing prognosis. Five-year disease-free survival for groups A to D were 55, 80, 78, and 100%, respectively. Tumor recurrence was significantly associated with PF (p = 0.048) and PGP9.5 (p = 0.003) staining.

CONCLUSIONS

Although WHO criteria are essential to differentiate parathyroid carcinoma from benign tumors, the presence of negative PF staining in an atypical adenoma predicts outcome better, whereas PF-positive atypical adenomas do not recur and can be considered benign. PF-negative atypical adenomas have a low but real recurrence risk and should be considered tumors of low malignant potential.

Association between BRAF V600E mutation and mortality in patients with papillary thyroid cancer

IMPORTANCE

BRAF V600E is a prominent oncogene in papillary thyroid cancer (PTC), but its role in PTC-related patient mortality has not been established.

OBJECTIVE

To investigate the relationship between BRAF V600E mutation and PTC-related mortality.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective study of 1849 patients (1411 women and 438 men) with a median age of 46 years (interquartile range, 34-58 years) and an overall median follow-up time of 33 months (interquartile range, 13-67 months) after initial treatment at 13 centers in 7 countries between 1978 and 2011.

MAIN OUTCOMES AND MEASURES

Patient deaths specifically caused by PTC.

RESULTS

Overall, mortality was 5.3% (45/845; 95% CI, 3.9%-7.1%) vs 1.1% (11/1004; 95% CI, 0.5%-2.0%) (P < .001) in BRAF V600E-positive vs mutation-negative patients. Deaths per 1000 person-years in the analysis of all PTC were 12.87 (95% CI, 9.61-17.24) vs 2.52 (95% CI, 1.40-4.55) in BRAF V600E-positive vs mutation-negative patients; the hazard ratio (HR) was 2.66 (95% CI, 1.30-5.43) after adjustment for age at diagnosis, sex, and medical center. Deaths per 1000 person-years in the analysis of the conventional variant of PTC were 11.80 (95% CI, 8.39-16.60) vs 2.25 (95% CI, 1.01-5.00) in BRAF V600E-positive vs mutation-negative patients; the adjusted HR was 3.53 (95% CI, 1.25-9.98). When lymph node metastasis, extrathyroidal invasion, and distant metastasis were also included in the model, the association of BRAF V600E with mortality for all PTC was no longer significant (HR, 1.21; 95% CI, 0.53-2.76). A higher BRAF V600E-associated patient mortality was also observed in several clinicopathological subcategories, but statistical significance was lost with adjustment for patient age, sex, and medical center. For example, in patients with lymph node metastasis, the deaths per 1000 person-years were 26.26 (95% CI, 19.18-35.94) vs 5.93 (95% CI, 2.96-11.86) in BRAF V600E-positive vs mutation-negative patients (unadjusted HR, 4.43 [95% CI, 2.06-9.51]; adjusted HR, 1.46 [95% CI, 0.62-3.47]). In patients with distant tumor metastasis, deaths per 1000 person-years were 87.72 (95% CI, 62.68-122.77) vs 32.28 (95% CI, 16.14-64.55) in BRAF V600E-positive vs mutation-negative patients (unadjusted HR, 2.63 [95% CI, 1.21-5.72]; adjusted HR, 0.84 [95% CI, 0.27-2.62]).

CONCLUSIONS AND RELEVANCE

In this retrospective multicenter study, the presence of the BRAF V600E mutation was significantly associated with increased cancer-related mortality among patients with PTC. Because overall mortality in PTC is low and the association was not independent of tumor features, how to use BRAF V600E to manage mortality risk in patients with PTC is unclear. These findings support further investigation of the prognostic and therapeutic implications of BRAF V600E status in PTC.

Disease outcomes and nodal recurrence in patients with papillary thyroid cancer and lateral neck nodal metastases

BACKGROUND

The prognostic influence of lateral neck nodal metastases present at the time of diagnosis of papillary thyroid cancer (PTC) remains controversial. This study aims to document disease outcomes and nodal recurrence rates in such patients.

METHODS

Patients with PTC and lateral neck nodal metastases who underwent concurrent total thyroidectomy, central and lateral compartment neck dissection between 2000 and 2010 were identified from the prospectively maintained surgical databases of The University of Sydney and University of Wisconsin Endocrine Surgical Units. Disease outcomes and nodal recurrence rates were compared at 12 months post-operatively and in longer-term follow-up.

RESULTS

During this 11-year period, 121 patients were identified. Mean age was 45 years; 58% were female and 98% underwent post-operative radioactive iodine ablation. At a median follow-up of 31 months (range 12-140), there were no disease-specific deaths and disease-free survival (defined by stimulated serum thyroglobulin (Tg) < 2.0 μg/L, negative clinical and radiological examination) was 66%. Of the 50 patients with persistently elevated Tg measured 12 months post-operatively, 15 developed clinical lateral neck nodal recurrence. All have undergone re-operative surgery. Elevated stimulated Tg at 12 months post-operatively and a nodal ratio of >30% were significantly associated with an increased risk of lateral neck nodal recurrence.

CONCLUSION

With total thyroidectomy, formal compartmental neck dissection and radioactive iodine treatment, disease-free survival can be achieved in the majority of patients with PTC and synchronous lateral neck nodal metastases. A persistently elevated Tg post-operatively and a high ratio of metastatic nodes identify patients at increased risk of locoregional recurrence.

A prospective study of heart rate variability in endocrine surgery: surgical training increases consultant's mental strain

BACKGROUND

The aim of this study was to determine whether instructing surgical trainees in technically demanding procedures causes alterations in heart rate variability (HRV) and mental strain in supervising surgeons.

METHODS

A prospective study of HRV in two consultant surgeons and three endocrine surgical fellows undertaking 50 total thyroidectomy procedures was performed. Fellows and consultant surgeons performed 50 lobectomies as primary operator and 50 as assistants in a cross-over design. HRV was measured during dissection around the recurrent laryngeal nerve. The overall heart rate, time, and frequency domain parameters of HRV, specifically the low frequency/high frequency (LF/HF) ratio, which was used as a measure of cardiac and mental stress, were correlated with the surgical role, particularly teaching surgical fellows at critical points.

RESULTS

HRV data were collected between October 2009 and March 2010. There was no statistically significant difference in the mean heart rate for either group of participants regardless of role. Energy expenditure was greater for fellows when operating (p = 0.03). Fellows demonstrated a higher LF/HF ratio when acting as the primary operator (p = 0.02). All time domain parameters of HRV increased when attending surgeons were operating, denoting more cardiac relaxation. Similarly, the LF/HF ratio was significantly greater for attending surgeons when teaching (p = 0.05), suggesting an increase in mental strain.

CONCLUSIONS

The teaching of complex but common endocrine surgical procedures is associated with a measurable increase in mental strain of consultant surgeons, as determined by HRV. Fellows demonstrated increased levels of stress when acting as primary operators.

Post-operative partial hypoparathyroidism: an under-recognized disorder

BACKGROUND

Permanent hypoparathyroidism is a well-recognized complication of total thyroidectomy, and a commonly reported clinical indicator of that procedure. However, a small number of patients still require ongoing calcium supplementation post-operatively in order to avoid the symptoms of hypocalcaemia, despite a normal serum parathyroid hormone level. The aim of this study was to characterize this disorder of post-operative partial hypoparathyroidism and to identify any risk factors.

METHODS

A retrospective study of patients undergoing a total thyroidectomy was performed. Patients with permanent hypoparathyroidism were excluded. Patients completed a telephone interview and had serum calcium and parathyroid hormone (PTH) measured. Patient demographics, operative indications and intervention, the number of parathyroid glands autotransplanted, the presence of ongoing symptoms and calcium requirements were documented.

RESULTS

One hundred ninety-six patients participated. The overall rate of permanent hypoparathyroidism over the duration of the study was 0.77%. An additional 10 (5%) patients were identified with a normal PTH level but who were still requiring calcium supplementation to prevent the symptoms associated with hypocalcaemia and to maintain a normal serum calcium level. Nine patients were female with a mean age of 48.5 years. A mean of 1.4 parathyroid glands were autotransplanted and the mean PTH level was 3.95 pmol/L.

CONCLUSION

This study demonstrates that in a small group of patients following total thyroidectomy, re-vascularization of parathyroid cells may be partial, with inadequate parathyroid reserve to avoid symptoms despite measurable PTH levels. This disorder of partial hypoparathyroidism has not been previously described and represents a small but important complication of total thyroidectomy.

Mucoepidermoid carcinoma of the thyroid: a report of three cases and postulated histogenesis

BACKGROUND

Primary mucoepidermoid carcinoma (MEC) of the thyroid is a rare clinical and pathological entity that accounts for <0.5% of all thyroid malignancies. Although the histogenesis has been controversial, most investigators now favor it as arising from either metaplasia of thyroid follicular epithelium or heterologous de-differentiation from papillary thyroid carcinoma (PTC). We report three cases of thyroid MEC found in continuity with, and clearly arising from de-differentiation of, well-differentiated thyroid carcinomas (WDTCs).

PATIENT FINDINGS AND SUMMARY

The cases presented here included two women (aged 22 and 52) and one man (aged 58). One of these cases arose in conjunction with PTC, one with follicular thyroid carcinoma (FTC), and one with Hurthle cell carcinoma (HCC). In all three cases, there was a gradual transition in morphology between the areas of typical WDTC and the areas showing MEC differentiation. In addition, immunohistochemistry demonstrated a gradual loss of thyroid specific markers (thyroid transcription factor-1, thyroglobulin) mirroring the change in morphology.

CONCLUSION

We conclude that thyroid MEC can arise from metaplastic de-differentiation of WDTC, including FTC or HCC in addition to PTC. Currently, we recommend that after excision, each of the WDTC and MEC components of these tumors be treated with targeted adjuvant therapies, which may involve radioactive-iodine ablation, thyrotropin suppression, and external beam radiotherapy.

Reoperative surgery for bilateral multinodular goitre in the era of total thyroidectomy

Background

Total thyroidectomy, rather than bilateral subtotal thyroidectomy, is now accepted as the preferred management for bilateral benign multinodular goitre (BMNG) in order to reduce the need for reoperative surgery. The aim of this study was to examine whether this approach has had an impact on presentation for bilateral reoperative thyroid surgery.

Methods

This was a retrospective cohort study. The study group comprised patients presenting with recurrent BMNG who underwent bilateral reoperative thyroid surgery following previous bilateral subtotal or partial thyroidectomy. They were compared with patients undergoing unilateral reoperative thyroid surgery following previous lobectomy, and those undergoing primary total thyroidectomy for BMNG.

Results

Between 1 January 1987 and 31 December 2009, 12 354 consecutive thyroid procedures were undertaken. Among those with BMNG, primary total thyroidectomy was undertaken in 3298 patients, unilateral reoperative thyroidectomy in 337 and bilateral reoperative thyroidectomy in 191. Presentations of patients with recurrent BMNG declined gradually over the study period following the change in policy from subtotal to total thyroidectomy; only five patients (representing less than 0·5 per cent of all thyroid surgery) underwent bilateral reoperative surgery for BMNG in the last year of the study. Four of these patients had their initial operation before 1987 and in another unit, whereas the remaining patient initially had surgery overseas.

Conclusion

The introduction of a policy of initial total thyroidectomy for bilateral BMNG has essentially eliminated the need for bilateral reoperative surgery for recurrent goitre.

Predictive value of the Delphian and level VI nodes in papillary thyroid cancer

BACKGROUND

Recent published data has shown that metastatic involvement of the prelaryngeal or Delphian lymph node (DLN), the highest of the central (level VI) cervical lymph nodes, is highly predictive of advanced nodal disease in papillary thyroid cancer (PTC). The aims of this study were to determine the diagnostic accuracy of all the level VI cervical nodes in PTC and to determine which node group, if any, is the most accurate in predicting lateral node (N1b) disease.

METHODS

This was a retrospective cohort study. Data were obtained from the University of Sydney Endocrine Surgical Unit Database and through a review of the histopathology records. The study cohort was composed of 177 consecutive patients with a final diagnosis of PTC who underwent total thyroidectomy and lymph node dissection, spanning the period from May 2001 to December 2006.

RESULTS

Of the 177 patients with PTC, 86 had the DLN removed, 51 had a pretracheal node removed and 76 had the paratracheal group removed. DLN, paratracheal and pretracheal node disease was present in 21%, 39% and 46%, respectively. Lateral node (N1b) disease was present in 35%. Paratracheal node involvement was mildly predictive of further disease with patients 1.7 times more likely to have lateral node involvement (sensitivity=55%, specificity=68%). Pretracheal node involvement was moderately predictive of further disease with patients three times more likely to have lateral node involvement (sensitivity=72%, specificity=74%). DLN involvement was highly predictive of further node involvement with patients nine times more likely to have lateral node disease (sensitivity=53%, specificity=94%) and 40 times more likely to have any nodal disease (sensitivity=41%, specificity=100%).

CONCLUSION

This is the first study to examine the diagnostic accuracy of all level VI lymph nodes in PTC. While, metastatic involvement of all central nodal groups is indicative of further disease, the DLN is the most accurate predictor.

BRAF(V600E) mutation is associated with an increased risk of nodal recurrence requiring reoperative surgery in patients with papillary thyroid cancer

BACKGROUND

The role of the B-isoform of the Raf kinase (BRAF) mutation BRAF(V600E) as an independent prognostic factor in papillary thyroid cancer (PTC) remains controversial. Some studies suggest that tumors containing BRAF(V600E) have decreased radioiodine avidity and present a greater risk of nodal recurrence and distant metastases.

METHODS

Paraffin-embedded specimens from consecutive patients who underwent surgery for PTC before 2003 were independently reviewed by an endocrine pathologist. DNA was extracted, amplified by polymerase chain reaction, and the presence of the BRAF(V600E) mutation was determined by restriction digest. Tumor characteristics and long-term disease outcomes were analyzed according to BRAF(V600E) status.

RESULTS

BRAF(V600E) was identified in 60 (59%) of 101 patients. At a median follow-up of 106 months, the overall disease-free survival was 78%. Clinically evident nodal recurrence occurred in 11% of BRAF(V600E)-positive patients, and all patients required lateral neck dissection (P = .02). In contrast, subclinical nodal recurrence occurred in 7% of BRAF(V600E)-negative patients, and all recurrences were successfully ablated with radioactive iodine. There was a trend toward poorer disease-free survival among patients with stage III/IV PTC and BRAF(V600E) mutation (P = .08). All 5 disease-related deaths occurred in patients with BRAF(V600E)-positive primary tumors (P = .06).

CONCLUSION

The BRAF(V600E) mutation in PTC is associated with an increased risk of palpable nodal recurrence and the need for reoperative surgery.