Straddling medical specialties: should we have more comprehensive advanced training?

Over careers spanning 35 years each, we have witnessed great advances in medicine especially in genetics, imaging, immunotherapies and targeted cancer therapies. Our respective specialties of endocrinology and medical oncology have come to overlap significantly necessitating better communication and skills across both specialties. We will highlight common scenarios that straddle endocrinology and medical oncology. The same broad issues apply to other closely related specialties, albeit with different clinical challenges. At present, we see expensive and inefficient cross-referrals to other subspecialists or sometimes no referral at all, leading to significant clinical omissions. Opportunities for dual advanced training, or for more comprehensive single advanced training could more efficiently lead to enhanced patient care and communication.

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.

Pheochromocytomas in Multiple Endocrine Neoplasia Type 2.

Pheochromocytoma (PC) is a neuroendocrine tumor that originates from chromaffin cells of the adrenal medulla. The production of catecholamines, including epinephrine, norepinephrine and dopamine, may lead to haemodynamic instability. Over 30% of PCs are associated with germline mutations, including re-arranged in transfection (RET) mutations seen in multiple endocrine neoplasia type 2 (MEN2) syndromes. Around 40% of individuals with MEN2 develop PC, though it is rarely the presenting feature. Compared to sporadic PC, MEN2-associated PC is more likely to be epinephine secreting and demonstrate bilateral adrenal involvement, and is less likely to be malignant. The diagnosis of PC requires clinical suspicion and biochemical testing, followed by imaging studies. Novel nuclear medicine modalities, including FDG positron emission tomography (PET) and 68Ga DOTATATE PET have added to the conventional techniques of 123I-metaiodobenzylguanindine (MIBG) scintigraphy, computer tomography and magnetic resonance imaging. Treatment of PC is surgical and requires peri-operative alpha and, frequently, beta blockade. Novel surgical techniques, such as adrenal sparing surgery and a laparoscopic approach, have decreased peri-operative morbidity. Surveillance for PC is life long, due to the risk of metastatic disease.

A randomized controlled pilot trial comparing the impact of access to clinical endocrinology video demonstrations with access to usual revision resources on medical student performance of clinical endocrinology skills.

BACKGROUND: Demonstrating competence in clinical skills is key to course completion for medical students. Methods of providing clinical instruction that foster immediate learning and potentially serve as longer-term repositories for on-demand revision, such as online videos demonstrating competent performance of clinical skills, are increasingly being used. However, their impact on learning has been little studied. The aim of this study was to determine the value of adjunctive on-demand video-based training for clinical skills acquisition by medical students in endocrinology. METHODS: Following an endocrinology clinical tutorial program, 2nd year medical students in the pre-assessment revision period were recruited and randomized to either a set of bespoke on-line clinical skills training videos (TV), or to revision as usual (RAU). The skills demonstrated on video were history taking in diabetes mellitus (DMH), examination for diabetes lower limb complications (LLE), and examination for signs of thyroid disease (TE). Students were assessed on these clinical skills in an observed structured clinical examination two weeks after randomization. Assessors were blinded to student randomization status. RESULTS: For both diabetes related clinical skills assessment tasks, students in the TV group performed significantly better than those in the RAU group. There were no between group differences in thyroid examination performance. For the LLE, 91.7% (n = 11/12) of students randomized to the video were rated globally as competent at the skill compared with 40% (n = 4/10) of students not randomized to the video (p = 0.024). For the DMH, 83.3% (n = 10/12) of students randomized to the video were rated globally as competent at the skill compared with 20% (n = 2/10) of students not randomized to the video (p = 0.007). CONCLUSION: Exposure to high quality videos demonstrating clinical skills can significantly improve medical student skill performance in an observed structured clinical examination of these skills, when used as an adjunct to clinical skills face-to-face tutorials and deliberate practice of skills in a blended learning format. Video demonstrations can provide an enduring, on-demand, portable resource for revision, which can even be used at the bedside by learners. Such resources are cost-effectively scalable for large numbers of learners.

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.

Parathyroid carcinoma encountered after minimally invasive focused parathyroidectomy may not require further radical surgery.

BACKGROUND: Parathyroid carcinoma accounts for <1% of tumors in primary hyperparathyroidism (PHPT). Distinguishing parathyroid malignancy from benign disease is difficult both before and after initial surgery. Despite the improved specificity of a malignant diagnosis with immunohistochemistry for parafibromin and PGP9.5, proven metastatic behavior remains the gold standard of diagnosis. Minimally invasive focused parathyroidectomy (MIP) is widely performed in patients with PHPT and positive localization studies; thus, it is inevitable that some parathyroid carcinomas will be encountered at MIP. We present our experience of this rare entity. METHODS: The present study represents a surgical case series of patients with parathyroid carcinoma encountered after MIP. The clinicopathological features of benign and malignant parathyroid tumors were compared. Multiple regression analysis was undertaken to compare indicators of malignancy. RESULTS: Between May 1999 and April 2010, a total of 1,292 patients underwent MIP at the University of Sydney Endocrine Surgical Unit, and a histopathological diagnosis of parathyroid carcinoma was made in seven patients (0.5%). Staining for parafibromin and/or PGP9.5 was abnormal in five carcinomas (71%). Despite subsequent unilateral thyroid lobectomy and lymphadenectomy in six patients, no further malignancy was identified in any specimens. Compared to controls, preoperative calcium (p = 0.04) and parathyroid hormone (p = 0.01) were significantly higher in patients with malignancy. The positive predictive value of these parameters for carcinoma was 56 and 75%, respectively. CONCLUSIONS: In patients diagnosed with parathyroid carcinoma after MIP where preoperative imaging had already demonstrated localized disease, revision en bloc surgery did not reveal any residual disease. The benefits of further radical surgery for parathyroid carcinoma after MIP remain controversial.

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.

Adrenal incidentalomas: risk of adrenocortical carcinoma and clinical outcomes.

INTRODUCTION: The number of incidentally discovered adrenal lesions is increasing due to the widespread use of abdominal imaging. Although most incidentalomas are benign, larger suspicious lesions will require adrenalectomy. The aim of this study is to determine the risk of malignancy in patients undergoing surgery for adrenal incidentaloma; and to compare clinical outcomes in those with adrenocortical carcinoma (ACC) based on the mode of presentation. METHODS: A retrospective study of consecutive patients who underwent adrenalectomy between 1995 and 2008 was performed. Data were retrieved from a prospectively maintained adrenal tumor database. Those with adrenal incidentaloma were selected and histopathology reviewed. All patients with ACC (presenting with symptoms or incidentally) during the same time period were identified and clinical outcomes compared. RESULTS: Adrenalectomy was performed in 274 patients of whom 73 (27%) were characterized pre-operatively as incidentaloma. Benign, non-functioning adrenocortical adenoma was the most common histopathological finding (46 patients, 63%). There was a trend (P = 0.08) towards increased survival amongst the seven patients with ACC presenting incidentally compared to the nine patients with symptomatic ACC. CONCLUSIONS: Adrenal incidentalomas have a small but important risk of malignancy. ACC presenting as incidentaloma appear to have a more favorable prognosis than symptomatic or functioning ACC.

Hyperparathyroidism in pregnancy: options for localization and surgical therapy.

BACKGROUND: Hyperparathyroidism in pregnancy is a threat to the health of both mother and fetus. The mothers suffer commonly from nephrolithiasis, hyperemesis, or even hypercalcemic crisis. Untreated disease will commonly complicate fetal development and fetal death is a significant risk. Treatment options, including medical and surgical therapy, are debated in the literature. METHODS: This is a case series comprising seven patients with primary hyperparathyroidism in pregnancy. Data collected included symptoms at diagnosis, biochemical abnormalities, pathologic findings, treatment regimes, and subsequent maternal and fetal outcomes. RESULTS: Seven women, aged 20 to 39 years, presented with hyperparathyroidism during pregnancy. The earliest presented at 8 weeks and the latest at 38 weeks. Four of seven patients experienced renal calculi. Calcium levels were 2.7-3.5 mmol/l. All were found to have solitary parathyroid adenomas, of which two were in ectopic locations. Fetal complications included three preterm deliveries and one fetal death with no cases of neonatal tetany. Maternal and fetal complications could not be predicted based on duration or severity of hypercalcemia. Three patients were treated during pregnancy with surgery, and two of these had ectopic glands that required reoperations with a novel approach using Tc-99m sestamibi scanning during pregnancy to assist in localizing the abnormal gland. Four cases were treated postpartum with a combination of open and minimally invasive approaches after localization. No operative complications or fetal loss related to surgery were observed in this cohort. CONCLUSIONS: Primary hyperparathyroidism in pregnancy represents a significant risk for maternal and fetal complications that cannot be predicted by duration of symptoms or serum calcium levels. Surgical treatment should be considered early, and a minimally invasive approach with ultrasound is best suited to mitigating risk to mother and fetus. Equally important, Tc-99m sestamibi imaging may be used safely for localization of the parathyroids after negative cervical explorations.

Surgery alone for papillary thyroid microcarcinoma is less costly and more effective than long term active surveillance.

BACKGROUND: Papillary thyroid microcarcinoma is a subtype of thyroid cancer that may be managed with active surveillance rather than immediate surgery. Active surveillance decreases complication rates and may decrease health care costs. This study aims to analyze complication rates of thyroid surgery, papillary thyroid microcarcinoma recurrence, and survival rates. Additionally, the costs of surgery versus hypothetic active surveillance for papillary thyroid microcarcinoma are compared in an Australian cohort. METHODS: Papillary thyroid microcarcinoma patients were included from a prospectively collected surgical cohort of patients treated for papillary thyroid cancer between 1985 and 2017. The primary outcomes were the complications of thyroid surgery, recurrence-free survival, overall survival, and cost of surgical treatment and active surveillance. RESULTS: In a total of 349 patients with papillary microcarcinoma with a median age of 48 years (range, 18-90 years), the permanent operative complications rate was 3.7%. Postoperative radioactive iodine did not decrease recurrence-free survival (P = .3). The total cost of surgical treatment was $10,226 Australian dollars, whereas hypothetic active surveillance was at a yearly cost of $756 Australian dollars. Estimated cost of surgical papillary thyroid microcarcinoma treatment was equivalent to the cost of 16.2 years of active surveillance. CONCLUSION: Surgery may have a long-term economic advantage for younger Australian patients with papillary thyroid microcarcinoma who are likely to require more than 16.2 years of follow-up in an active surveillance scheme.

ACTH-secreting medullary thyroid cancer: a case series.

Medullary thyroid cancer (MTC) is a rare neuroendocrine tumour that originates from the parafollicular cells of the thyroid gland. The most common presentation of MTC is with a single nodule; however, by the time of diagnosis, most have spread to the surrounding cervical lymph nodes. Cushing's syndrome is a rare complication of MTC and is due to ectopic adrenocorticotrophic hormone (ACTH) secretion by tumour cells. Cushing's syndrome presents a challenging diagnostic and management issue in patients with MTC. Tyrosine kinase inhibitors (TKI) previously used for the management of metastatic MTC have become an important therapeutic option for the management of ectopic ACTH in metastatic MTC. The article describes three cases of ectopic ACTH secretion in MTC and addresses the significant diagnostic and management challenges related to Cushing's syndrome in metastatic MTC. LEARNING POINTS: Medullary thyroid cancer (MTC) is a rare neuroendocrine tumour.Cushing's syndrome is a rare complication of MTC that has a significant impact on patients' morbidity and mortality.Tyrosine kinase inhibitors (TKI) provide an important therapeutic option for the management of ectopic ACTH in metastatic MTC.

A robust assay for alternative lengthening of telomeres in tumors shows the significance of alternative lengthening of telomeres in sarcomas and astrocytomas.

PURPOSE AND EXPERIMENTAL DESIGN: Telomeres of tumor cells may be maintained by telomerase or by alternative lengthening of telomeres (ALT). The standard ALT assay requires Southern analysis of high molecular weight genomic DNA. We aimed to establish and validate an ALT assay suitable for archived paraffin-embedded tumors and to use it to examine the prevalence and clinical significance of ALT in various types of tumors that are often telomerase negative. RESULTS: To assay for ALT, we detected ALT-associated promyelocytic leukemia (PML) bodies (APBs) by combined PML immunofluorescence and telomere fluorescence in situ hybridization. APBs are PML nuclear domains containing telomeric DNA and are a known hallmark of ALT in cell lines. The APB assay concurred with the standard ALT assay in 62 of 62 tumors and showed that 35% of 101 soft tissue sarcomas (STS), 47% of 58 osteosarcomas (especially younger patients), 34% of 50 astrocytomas, and 0% of 17 papillary thyroid carcinomas were ALT positive (ALT+). The prevalence of ALT varied greatly among different STS subtypes: malignant fibrous histiocytomas, 77%; leiomyosarcomas, 62%; liposarcomas, 33%; synovial sarcomas, 9%; and rhabdomyosarcomas, 6%. ALT correlated with survival in glioblastoma multiforme and occurred more often in lower-grade astrocytomas, but ALT+ and ALT- sarcomas were equally aggressive in terms of grade and clinical outcome. CONCLUSION: The APB assay for ALT is suitable for paraffin-embedded tumors. It showed that a substantial proportion of STS, osteosarcomas, and astrocytomas, but not papillary thyroid carcinomas use ALT. APB positivity correlated strongly with survival of patients with astrocytomas.

New era: prophylactic surgery for patients with multiple endocrine neoplasia-2a.

BACKGROUND: The surgical management of patients with multiple endocrine neoplasia-2A (MEN-2A) continues to evolve with specific genotype-phenotype correlations allowing for a more tailored approach. In this study, we report the surgical management of one of the largest MEN-2A families with a rearranged during transfection (RET) codon 804 mutation. METHOD: This is a cohort study comprising all at-risk kindred within a single known MEN-2A family. Prophylactic total thyroidectomy with lymph node dissection was recommended to all mutation carriers aged 5 years and older. RESULTS: There were a total of 48 at-risk individuals in the MEN-2A kindred, with 22 patients undergoing thyroidectomy after appropriate preoperative evaluation. A total of 9 patients had medullary thyroid cancer including 5 with a normal preoperative calcitonin level. A total of 11 patients had C-cell hyperplasia and 7 showed histological evidence of parathyroid disease. Only the index case had a phaeochromocytoma. CONCLUSIONS: Genetic testing for germline mutations in the RET proto-oncogene has allowed precise identification of affected RET carriers and provided the opportunity for prophylactic or 'preclinical' surgery to treat and in fact to prevent medullary thyroid cancer. This concept of prophylactic surgery based on a genetic test is likely to be applied more widely as the tools of molecular biology advance.

The safety of vandetanib for the treatment of thyroid cancer.

INTRODUCTION: The tyrosine kinase inhibitor vandetanib was approved for use in 2012 for aggressive and symptomatic medullary thyroid cancer (MTC) in patients with unresectable locally advanced or metastatic disease. As the first effective systemic therapy for MTC, vandetanib is a major step forward and the phase III study suggests an important role for this agent. Trials have also been performed for its use in differentiated thyroid cancer (DTC) though it is not yet approved for use for this indication. AREAS COVERED: The efficacy and safety of vandetanib is discussed. Studies suggest improvement in progression-free survival (PFS) without clear overall survival benefit but with manageable low grade toxicities and improved quality of life on therapy. EXPERT OPINION: Vandetanib has an important role in the management of patients with progressive metastatic MTC. The use in patients with stable or asymptomatic disease has no proven benefit. The side effects can usually be managed with dose reduction, interruption, and/or specific symptomatic therapy.

A detailed clinicopathologic study of ALK-translocated papillary thyroid carcinoma.

Pathogenic ALK translocations have been reported in papillary thyroid carcinoma (PTC). We developed and validated a screening algorithm based on immunohistochemistry (IHC), followed by fluorescence in situ hybridization (FISH) in IHC-positive cases to identify ALK-rearranged PTC. IHC and FISH were performed in a cohort of 259 thyroid carcinomas enriched for aggressive variants. IHC was positive in 8 cases, 6 confirmed translocated by FISH (specificity 75%). All 251 IHC-negative cases were FISH negative (sensitivity 100%). Having validated this approach, we performed screening IHC, followed by FISH in IHC-positive cases in an expanded cohort. ALK translocations were identified in 11 of 498 (2.2%) of all consecutive unselected PTCs and 3 of 23 (13%) patients with diffuse sclerosing variant PTCs. No ALK translocations were identified in 36 PTCs with distant metastases, 28 poorly differentiated (insular) carcinomas, and 20 anaplastic carcinomas. All 14 patients with ALK translocations were female (P=0.0425), and translocations occurred at a younger age (mean 38 vs. 48 y, P=0.0289 in unselected patients). ALK translocation was an early clonal event present in all neoplastic cells and mutually exclusive with BRAF mutation. ALK translocation was not associated with aggressive clinicopathologic features (size, stage, metastasis, vascular invasion, extrathyroidal extension, multifocality, risk for recurrence, radioiodine resistance). We conclude that 2.2% of PTCs are ALK-translocated and can be identified by screening IHC followed by FISH. ALK translocations may be more common in young females and diffuse sclerosing variant PTC but do not connote more aggressive disease.

A preoperative nomogram for the prediction of ipsilateral central compartment lymph node metastases in papillary thyroid cancer.

BACKGROUND: Central compartment lymph node metastases in papillary thyroid carcinoma (PTC) are difficult to detect preoperatively, and the role of routine or prophylactic central compartment lymph node dissection (CLND) in managing PTC remains controversial. The aim of this project was to create a nomogram able to predict the occurrence of central compartment lymph node metastasis using readily available preoperative clinical characteristics. METHODS: Records from patients undergoing total thyroidectomy and lymph node dissection for PTC in the period 1968-2012 were analyzed. Nodal status was based on results of serial hematoxylin and eosin (H&E) examination. Age, sex, tumor size, tumor site, and multifocality were included in a multivariable logistic regression model to predict lymph node metastasis. A coefficient-based nomogram was developed and validated using an external patient cohort. RESULTS: The study population included 914 patients (80% females) with an average central compartment nodal yield of eight per patient. Central compartment lymph node metastases were present in 390 patients (42.7%). The variables with the strongest predictive value were age (p<0.001), male sex (p<0.001), increasing tumor size (p<0.001), and tumor multifocality (p<0.05). The nomogram had good discrimination with a concordance index of 76.4% [95% confidence interval 73.3-79.4], supported by an external validation point estimate of 61.5% [95% confidence interval 49.5-73.6]. An online calculator and smartphone application were developed for point of care use. CONCLUSIONS: A validated nomogram utilizing readily available preoperative variables has been developed to give a predicted probability of central lymph node metastases in patients presenting with PTC. This nomogram may help guide surgical decision making in PTC.