Early, Prophylactic Thyroidectomy in Hereditary Medullary Thyroid Carcinoma: A 26-year Monoinstitutional Experience.

PURPOSE: Prophylactic thyroidectomy has been encouraged for children with REarranged during Transfection (RET) germline mutations to prevent the onset, persistence, or recurrence of medullary thyroid carcinoma (MTC). The American Thyroid Association (ATA) recently published guidelines on the timing of prophylactic thyroidectomy. Our aim here was to seek information on the optimal timing of surgery for carriers of RET gene mutations with no clinical evidence of disease, bearing in mind the ATA recommendations. METHODS: From 1986 to 2012, total thyroidectomy was performed at our institute on 31 carriers of RET gene mutations, 28 of them found on family screening in the post-RET era, and the other 3 under 20 years of age and classified as "early cases" in the pre-RET era. The following parameters were studied: age at surgery, MTC risk, basal calcitonin (bCT) and pentagastrin-stimulated calcitonin (sCT), surgery outcomes, and persistence of disease. RESULTS: By family, the most prevalent mutation was codon 634 (30%) RET mutation. The youngest MTC patient was 5 years old. Overall, MTC was found in 68% of cases; 52% of the sample had a normal bCT and 25% had an sCT unresponsive to pentagastrin. The only factor predicting the risk of MTC at final histology was an ATA-RET risk level C. On receiver oparating curves analysis, a cutoff at age over 24 years predicted (P=0.06) a yield of MTC in the resected specimen. Interestingly, none of the patients with MTC had nodal involvement (0/21 patients with MTC). Yet, none of the patients had permanent nerve palsy, and only 1 patient had permanent hypocalcemia. bCT was normal postoperatively and during the follow-up in all but 3 patients. CONCLUSIONS: It is noteworthy that the yield of cancer in removed thyroid was 100% for codon 634 (9/9 patients, 5 families) and for codons 891 and 768 (2/2 patients in each of the 2 families with those codon mutations), followed by 67% for codon 609 (4/6 patients, 1 family), and 60% for codon 618 (3/5 patients in 4 families) RET mutation. In cases of ATA-RET levels B and C, waiting for an increase in bCT and/or sCT may not guarantee that prophylactic surgery is performed before MTC develops (which would assure patients a life free of diseases and a less-invasive surgical procedure, without any need for central lymph-node dissection).

18F-DOPA and 18F-FDG PET/CT, scintigraphic localization and radioguided surgery of recurrent medullary thyroid cancer: two case reports.

Medullary thyroid cancer (MTC) is considered as a rare thyroid cancer. Surgical approaches such as, total thyroidectomy and bilateral lymph node dissection, represent the first-line treatment. Persistent or increasing serum levels of tumor markers, such as CEA and calcitonin, imply residual or recurrent disease. An early and precise detection of recurrence is very important for guiding appropriate treatment. Recent developments in positron emission tomography (PET) imaging with different radiopharmaceuticals targeting specific hallmark of MTC, such as 18F-DOPA and 18F-FDG, have offered increased sensitivity for identifying recurrences. Moreover, the ability of conventional scintigraphic imaging to guide the surgical approach can be useful for the treatment of MTC recurrent patients. In the present work, we reported two cases of patients with recurrent MTC sending to surgical treatment guided by "nuclear medicine approaches".

Differential gene expression of medullary thyroid carcinoma reveals specific markers associated with genetic conditions.

Medullary thyroid carcinoma accounts for 2% to 5% of thyroid malignancies, of which 75% are sporadic and the remaining 25% are hereditary and related to multiple endocrine neoplasia type 2 syndrome. Despite a genotype-phenotype correlation with specific germline RET mutations, knowledge of pathways specifically associated with each mutation and with non-RET-mutated sporadic MTC remains lacking. Gene expression patterns have provided a tool for identifying molecular events related to specific tumor types and to different clinical features that could help identify novel therapeutic targets. Using transcriptional profiling of 49 frozen MTC specimens classified as RET mutation, we identified PROM1, LOXL2, GFRA1, and DKK4 as related to RET(M918T) and GAL as related to RET(634) mutation. An independent series of 19 frozen and 23 formalin-fixed, paraffin-embedded (FFPE) MTCs was used for validation by RT-qPCR. Two tissue microarrays containing 69 MTCs were available for IHC assays. According to pathway enrichment analysis and gene ontology biological processes, genes associated with the MTC(M918T) group were involved mainly in proliferative, cell adhesion, and general malignant metastatic effects and with Wnt, Notch, NFκB, JAK/Stat, and MAPK signaling pathways. Assays based on silencing of PROM1 by siRNAs performed in the MZ-CRC-1 cell line, harboring RET(M918T), caused an increase in apoptotic nuclei, suggesting that PROM1 is necessary for survival of these cells. This is the first report of PROM1 overexpression among primary tumors.

In papillary thyroid carcinoma BRAFV600E is associated with increased expression of the urokinase plasminogen activator and its cognate receptor, but not with disease-free interval.

CONTEXT: It has been suggested that patients with papillary thyroid cancer (PTC) harbouring the BRAF(V600E) mutation have a worse prognosis. We showed in PTC that high levels of urokinase plasminogen activator (uPA) and its cognate receptor (uPAR) inversely correlate with disease-free interval (DFI). OBJECTIVES: To investigate the effects of BRAF(V600E) on the expression of uPA and uPAR and to evaluate the prognostic relevance of BRAF(V600E) alone or in combination with uPA and uPAR. DESIGN/SETTING/PATIENTS/INTERVENTION: The case study included 91 patients with PTC. All patients underwent thyroidectomy and radioiodine therapy. Follow-up was available for 75 patients. MAIN OUTCOME MEASURES: The BRAF(V600E) mutation was analysed by sequencing and mutant allele-specific PCR amplification; uPA and uPAR expression by quantitative RT-PCR. RESULTS: BRAF(V600E) was found in 44 of the 91 patients and associated with older age, but not with high-risk clinicopathological features. Urokinase PA and uPAR mRNA levels were higher in tumour tissues by 9·51 ± 1·30 and 4·64 ± 0·44 fold, respectively, compared to normal matched tissues, being significantly higher in BRAF(V600E) -positive patients. In vitro induction of BRAF(V600E) in PCCL3 cells caused a significant increase in both uPA and uPAR mRNAs. Higher levels of uPA and uPAR correlated with lymph node metastases, TNM stage and disease recurrences. Kaplan-Meier and multivariate analyses demonstrated that uPA and uPAR were associated with shorter DFI, while the BRAF(V600E) was not. CONCLUSION: In PTC, BRAF(V600E) induces uPA and uPAR expression. The latter, but not BRAF(V600E) , associates with advanced stages and shorter DFI. If confirmed in larger case studies, they may represent reliable prognostic markers for more accurate risk stratification and postoperative decision-making in patients with PTC.

Aurora kinases are expressed in medullary thyroid carcinoma (MTC) and their inhibition suppresses in vitro growth and tumorigenicity of the MTC derived cell line TT.

BACKGROUND: The Aurora kinase family members, Aurora-A, -B and -C, are involved in the regulation of mitosis, and alterations in their expression are associated with cell malignant transformation. To date no information on the expression of these proteins in medullary thyroid carcinoma (MTC) are available. We here investigated the expression of the Aurora kinases in human MTC tissues and their potential use as therapeutic targets. METHODS: The expression of the Aurora kinases in 26 MTC tissues at different TNM stages was analyzed at the mRNA level by quantitative RT-PCR. We then evaluated the effects of the Aurora kinase inhibitor MK-0457 on the MTC derived TT cell line proliferation, apoptosis, soft agar colony formation, cell cycle and ploidy. RESULTS: The results showed the absence of correlation between tumor tissue levels of any Aurora kinase and tumor stage indicating the lack of prognostic value for these proteins. Treatment with MK-0457 inhibited TT cell proliferation in a time- and dose-dependent manner with IC50 = 49.8 ± 6.6 nM, as well as Aurora kinases phosphorylation of substrates relevant to the mitotic progression. Time-lapse experiments demonstrated that MK-0457-treated cells entered mitosis but were unable to complete it. Cytofluorimetric analysis confirmed that MK-0457 induced accumulation of cells with ≥ 4N DNA content without inducing apoptosis. Finally, MK-0457 prevented the capability of the TT cells to form colonies in soft agar. CONCLUSIONS: We demonstrate that Aurora kinases inhibition hampered growth and tumorigenicity of TT cells, suggesting its potential therapeutic value for MTC treatment.

Surgical versus conservative management for subclinical Cushing syndrome in adrenal incidentalomas: a prospective randomized study.

OBJECTIVE: To compare the clinical outcome of patients with subclinical Cushing syndrome (SCS) due to an adrenal incidentaloma (the autonomous hypersecretion of a small amount of cortisol, which is not enough to cause clinically-evident disease) who underwent surgery or were managed conservatively. SUMMARY BACKGROUND DATA: The most appropriate management of SCS patients is controversial, either adrenalectomy or close follow-up being recommended for their treatment. METHODS: Over a 15-year period, 45 SCS patients were randomly selected to undergo surgery (n = 23) or conservative management (n = 22). All surgical procedures were laparoscopic adrenalectomies performed by the same surgeon. All patients were followed up (mean, 7.7 years; range, 2-17 years) clinically by 2 experienced endocrinologists 6 and 12 months after surgery and then yearly, or yearly after joining the trial, particularly monitoring diabetes mellitus (DM), arterial hypertension, hyperlipidemia, obesity, and osteoporosis. The study end point was the clinical outcome of SCS patients who underwent adrenalectomy versus those managed conservatively. RESULTS: All 23 patients in the surgical arm had elective surgery. Another 3 patients randomly assigned to conservative management crossed over to the surgical group due to an increasing adrenal mass >3.5 cm. In the surgical group, DM normalized or improved in 62.5% of patients (5 of 8), hypertension in 67% (12 of 18), hyperlipidemia in 37.5% (3 of 8), and obesity in 50% (3 of 6). No changes in bone parameters were seen after surgery in SCS patients with osteoporosis. On the other hand, some worsening of DM, hypertension, and hyperlipidemia was noted in conservatively-managed patients. CONCLUSIONS: Based on the results of this study, laparoscopic adrenalectomy performed by skilled surgeons appears more beneficial than conservative management for SCS patients complying with our selection criteria. This trial is registered with Australian Clinical Trials Registry number, ANZCTR12608000567325.

Radioguided surgery of parathyroid adenomas and recurrent thyroid cancer using the "low sestamibi dose" protocol.

PURPOSE: The aim of this study was to establish the clinical efficacy of the "low sestamibi dose" (LSD) protocol to perform thyroid and parathyroid radioguided surgery in a large series of patients homogeneously studied and operated on by the same surgeon. The LSD protocol was initially developed in our center to cure primary hyperparathyroid (PHPT) patients with a high likelihood of a solitary parathyroid adenoma (PA) by minimally invasive radioguided surgery (MIRS). Since then, the same protocol has been applied to differentiated thyroid cancer (DTC) patients with 131I-negative, but sestamibi-positive, locoregional recurrent disease in order to obtain radical radioguided extirpation of tumoral lesions at reoperation. STUDY DESIGN: We reviewed the clinical charts of 453 consecutive patients referred at the surgical department at Padova University (Padova, Italy) to investigate a PHPT or a DTC recurrence: 336 patients (74.2%) met the inclusion criteria for radioguided surgery, and these patients were analyzed for the aim of this study. There were 298 patients affected by PHPT with a high likelihood of a solitary sestamibipositive PA and 38 DTC patients affected by 131I-negative, but sestamibi-positive, locoregional recurrence. All patients underwent a preoperative imaging work-up, including sestamibi scintigraphy (doubletracer subtraction scan in PHPT patients and single-tracer, wash-out scan in DTC patients) and high-resolution neck ultrasonography (US). The LSD protocol we developed consists of the intravenous injection of a very low (1 mCi) sestamibi dose in the operating theater just 10 minutes before commencing intervention for the purpose of radioguided surgery only. At variance with the traditional "high (20-25 mCi) sestamibi dose (HSD)" protocol in which imaging and radioguided surgery are obtained in the same day, in the LSD protocol, imaging and radioguided surgery are performed in different days. The LSD protocol allows some advantages over the HSD protocol: (1) more time for acquiring and interpreting preoperative imaging (planar scintigraphy, single-photon emission computed tomography [SPECT], US); (2) an accurate selection of patients to whom MIRS is offered, especially in countries where the prevalence of nodular goiter with sestamibi-avid thyroid nodules (exclusion criteria for MIRS) is relatively high, as in mid-south-European countries; (3) it facilitates the work planning in the operating theater (bilateral neck exploration requires an operating time of at least double to that of MIRS); and (4) the radiation exposure dose to operating theater personnel is very low-substantially negligible, using the LSD protocol: This aspect assumes great importance in countries where radioproteximetric rules are stringent, as in Europe. RESULTS: PHPT patients. MIRS was successfully performed by a 1.5-2-cm skin incision in 287 of 298 PHPT patients (96.3%) in whom such an approach was scheduled on the basis of preoperative imaging, including 41 of 57 patients (71.9%) who had previously received thyroid or unsuccessful parathyroid surgery in another center. No case of major intraoperative complication was recorded. No case of persistent or recurrent PHPT was observed during postsurgical follow-up. DTC patients. A total of 79 metastatic lesions were intraoperatively detected by the gamma probe and successfully removed (68 of them had been correctly visualized at preoperative sestamibi scintigraphy). During subsequent follow-up, 18 patients (72%) were considered disease-free, whereas 7 had persistent disease (increased serum thyroglobulin levels). The radiation exposure dose to the surgeon using the LSD protocol was 1.2 uSi/hour, that is, 20-30-fold lower than that delivered with the HSD protocol used for PHPT patients and with the 131I protocol used for DTC patients with recurrence. CONCLUSIONS: On the basis of our data, it can be concluded that the LSD protocol is a safe and effective protocol to perform in both MIRS in PHPT patients and radioguided reoperation in DTC patients with 131I-negative recurrence. Furthermore, from a radioproteximetric point of view, in comparison with other radioguided protocols used for the same purposes, the LSD protocol minimizes the radiation-exposure dose to the surgeon and operating theater personnel.

Minimally invasive radio-guided parathyroidectomy: long-term results with the 'low 99mTc-sestamibi protocol'.

BACKGROUND: This paper reports the results of minimally invasive radio-guided surgery (MIRS) performed in a large group of 280 consecutive patients affected by primary hyperparathyroidism (PHPT) and with a high probability of being affected by a solitary parathyroid adenoma before surgery. METHODS: The probability of a solitary parathyroid adenoma was established by evaluating the patients with a single-day imaging protocol based on parathyroid double-tracer scintigraphy and high resolution neck ultrasonography. MIRS was performed successfully in 269 (96.1%) patients. MIRS consisted of a very low dose (37 MBq (1 mCi)) of Tc-sestamibi, given by intravenous injection, in the operating theatre a few minutes before surgery, thus allowing the radiation exposure dose to the patient and operating theatre personnel to be minimized (< 1.5 muSv.h to the surgeon). RESULTS: No major intraoperative complication was recorded in our series. Transient hypocalcaemia was observed in 8% of patients. MIRS required a mean duration time of 33 min and a mean hospital stay of 1.2 days. Local anaesthesia was successfully performed in 71 patients, 63 of whom were elderly and with concomitant invalidating diseases contraindicating general anaesthesia. No case of disease relapse was observed during the subsequent follow-up. CONCLUSION: MIRS using the 'low sestamibi protocol' is a safe and effective treatment in PHPT patients with a high likelihood of a solitary parathyroid adenoma at preoperative imaging.