Radio-iodine refractory thyroid cancer patients: a tailored follow-up based on clinicopathological features.

OBJECTIVE: To report the experience of a single center for the selection of radioiodine-refractory (RAIR) thyroid cancer patients (RAIR-TC) who needed tyrosine kinase inhibitor (TKIs) treatment. PATIENTS AND METHODS: We evaluated all features of 279 RAIR-TC patients both at the time of diagnosis and at the RAIR diagnosis. RESULTS: Ninety-nine patients received indication to TKIs (Group A), while 180 remained under active surveillance (Group B). Group A had greater tumor size, more aggressive histotype, more frequent macroscopic extrathyroidal extension, distant metastases, advanced AJCC stage, and higher ATA risk of recurrence. After RAIR diagnosis, 93.9% of Group A had progression of disease (PD) after which TKIs' therapy was started. The remaining 6.1% of patients had a so severe disease at the time of RAIR diagnosis that TKIs' therapy was immediately started. Among Group B, 42.7% had up to 5 PD, but the majority underwent local treatments. The mean time from RAIR diagnosis to the first PD was shorter in Group A, and the evidence of PD within 25 months from RAIR diagnosis was associated with the decision to start TKIs. CONCLUSIONS: According to our results, a more tailored follow-up should be applied to RAIR-TC patients. A too strict monitoring and too many imaging evaluations might be avoided in those with less-aggressive features and low rate of progression. Conversely, RAIR-TC with an advanced stage at diagnosis and a first PD occurring within 25 months from RAIR diagnosis would require a more stringent follow-up to avoid a late start of TKIs.

Adrenal insufficiency in thyroid cancer patients treated with tyrosine kinase inhibitors and detected by ACTH stimulation test.

PURPOSE: Advanced thyroid cancer patients treated with tyrosine kinase inhibitors (TKI) can develop several adverse events (AEs), including adrenal insufficiency (AI). METHODS: We studied 55 patients treated with TKI for radioiodine-refractory or medullary thyroid cancer. The adrenal function was evaluated during follow-up by performing serum basal ACTH, and basal and ACTH-stimulated cortisol. RESULTS: Twenty-nine/55 (52.7%) patients developed subclinical AI during TKI treatment as demonstrated by a blunted cortisol response to ACTH stimulation. All cases showed normal values of serum sodium, potassium and blood pressure. All patients were immediately treated, and none showed an overt AI. Cases with AI were all negative for adrenal antibodies and did not show any adrenal gland alteration. Other causes of AI were excluded. The onset time of the AI, as measured in the subgroup with a first negative ACTH test, was < 12 months in 5/9 (55.6%), between 12 and 36 months in 2/9 (22.2%) and > 36 months in 2/9 (22.2%) cases. In our series, the only prognostic factor of AI was the elevated, although moderate, basal level of ACTH when the basal and stimulated cortisol were still normal. The glucocorticoid therapy improved fatigue in most patients. CONCLUSIONS: Subclinical AI can be developed in > 50% of advanced thyroid cancer patients treated with TKI. This AE can develop in a wide period ranging from < 12 to > 36 months. For this reason, AI must be looked for throughout the follow-up to be early recognized and treated. A periodic ACTH stimulation test, every 6-8 months, can be helpful.

Osteonecrosis of the jaw: a rare but possible side effect in thyroid cancer patients treated with tyrosine-kinase inhibitors and bisphosphonates.

Osteonecrosis of the jaw (ONJ) is a rare but very serious disease that can affect both jaws. It is defined as exposed bone in the maxillofacial region that does not heal within 8 weeks after a health care provider identification. ONJ can occur spontaneously or can be due to drugs like bisphosphonates (BPS) and anti-RANK agents, in patients with no history of external radiation therapy in the craniofacial region. Although in phase 3 trials of tyrosine kinase inhibitors (TKIs) used in thyroid cancer (TC) the ONJ was not reported among the most common side effects, several papers reported the association between ONJ and TKIs, both when they are used alone and in combination with a bisphosphonate. The appearance of an ONJ in a patient with metastatic radio-iodine refractory differentiated TC, treated with zoledronic acid and sorafenib, has put us in front of an important clinical challenge: when a ONJ occurred during TKIs treatment, it really worsens the patients' quality of life. We should consider that in the case of ONJ a TKI discontinuation becomes necessary, and this could lead to a progression of neoplastic disease. The most important aim of this review is to aware the endocrinologists/oncologists dealing with TC to pay attention to this possible side effect of BPS and TKIs, especially when they are used in association. To significantly reduced the risk of ONJ, both preventive measures before initiating not only antiresorptive therapy but also antiangiogenic agents, and regular dental examinations during the treatment should always be proposed.

Lenvatinib as a salvage therapy for advanced metastatic medullary thyroid cancer.

PURPOSE: Patients with advanced progressive metastatic medullary thyroid cancer (MTC), show poor prognosis and few available systemic therapeutic options. After the loss of clinical benefit with other tyrosine kinase inhibitors (TKI), we evaluated the use of lenvatinib as salvage therapy. METHODS: Ten patients who experienced the loss of clinical benefit after treatment with at least one previous TKI, were treated with lenvatinib. We assessed patient's response immediately before, at the first (first-EV) and last (last-EV) evaluation, after the beginning of treatment. RESULTS: At first-EV, one patient died, while all the remaining 9 showed a stable disease (SD) in the target lesions. At last-EV, SD was still observed in seven patients, while partial response (PR) and progressive disease (PD), in one patient each. Conversely, analyzing all target and non-target lesions, at first-EV, we observed PR in one patient and SD in eight patients. At last-EV, PR was shown in two patients and SD was shown in seven. Bone metastases showed stable disease control at both first-EV and last-EV in only approximately 60% of cases. Tumor markers (CTN and CEA) decreased at first-EV, while they increased at last-EV. Seven patients experienced at least one dose reduction during treatment with lenvatinib. CONCLUSIONS: In this real-life clinical experience, lenvatinib showed interesting results as salvage therapy in patients with advanced progressive metastatic MTC patients. Its usefulness could be effective in patients without any other available treatment, because previously used or unsuitable, especially with negative RET status with no access to the new highly selective targeted therapies.

Outcome of classical (CVPTC) and follicular (FVPTC) variants of papillary thyroid cancer: 15 years of follow-up.

PURPOSE: To compare the epidemiological, clinical, and pathological features of follicular (FVPTC) and classical (CVPTC) variants of papillary thyroid cancer and to correlate their outcomes according to different features. METHODS: Retrospective analysis of FVPTC and CVPTC patients selected at the moment of surgical treatment from 1999 to 2004, with a median follow-up of 15 years. RESULTS: Several significant differences were found between FVPTC and CVPTC such as the mean age at diagnosis, the presence of tumor capsule, the presence of thyroid capsule invasion, the presence of perithyroid soft tissue invasion, the lymph node metastases, the multifocality and bilaterality. At the end of follow-up only 9% (77/879) patients were not cured. However, a statistically significant lower percentage of persistent disease was found in the FVPTC than in the CVPTC group (3% vs. 14.5%, respectively, p < 0.0001). In multivariate analysis, the absence of the tumor capsule (OR = 6.75) or its invasion (OR = 7.89), the tumor size ≥4 cm (OR = 4.29), the variant CVPTC (OR = 3.35), and the presence of lymph node metastases (OR = 3.16) were all independent risk factors for the persistence of the disease. CONCLUSIONS: Despite an overall excellent prognosis of both variants, a higher percentage of CVPTC than FVPTC patients had a persistent disease. The absence of tumor capsule or its invasion, the tumor size ≥4 cm and the presence of lymph node metastases are other prognostic factors for the persistence of the disease. In contrast, the presence of an intact tumor capsule is the only good prognostic factor for their outcome.

Real-life management and outcome of thyroid carcinoma-related bone metastases: results from a nationwide multicenter experience.

PURPOSE AND PATIENTS: The M.O.S.CA.TI. (Metastases of the Skeleton from CArcinoma of the ThyroId) is a multicenter, retrospective study investigating the real-life outcome and management of bone metastases (BM) in 143 patients (63 M, 80 F; median age 64 years, range 11-87) with differentiated thyroid carcinoma (DTC). RESULTS: Radio-active iodine (RAI) treatment was performed in 131 patients (91.6%), surgical approach and/or external radiotherapy in 68 patients (47.6%), and anti-resorptive bone-active drugs in 32 patients (22.4%; in 31 zoledronate and in one denosumab). At the start of treatment, 24 patients (75.0%) receiving anti-resorptive bone-active drugs had at least one clinical skeletal-related event (SRE) (p < 0.001). One or more clinical SREs (pathological fractures and/or malignant hypercalcemia and/or spinal cord compression) developed in 53 patients (37.1%). Development of SREs was significantly associated with metachronous BM (hazard ratio (HR) 2.04; p = 0.04), localization of BM to cervical spine (HR 3.89; p = 0.01), and lack of avid RAI uptake (HR 2.66; p = 0.02). Thirty-nine patients (27.3%) died in correlation with development of SREs (HR 6.97; p = 0.006) and localization of BM to the hip (HR 3.86; p = 0.02). Moreover, overall mortality was significantly decreased by RAI therapy (HR 0.10; p = 0.02), whereas no significant effects were induced by bone-active drugs (p = 0.36), external radiotherapy (p = 0.54), and surgery (p = 0.43) of BM. CONCLUSIONS: SREs are very frequent in BM from DTC and they impact patient survival. In the real life, the use of bone-active drugs is currently limited to zoledronate in patients with pre-existing SREs. In this clinical setting, RAI therapy, but not zoledronate, decreased mortality.

Targeted Therapy in Thyroid Cancer: State of the Art.

Thyroid cancer typically has a good outcome following standard treatments, which include surgery, radioactive iodine ablation for differentiated tumours and treatment with thyrotropine hormone-suppressive levothyroxine. Thyroid cancers that persist or recur following these therapies have a poorer prognosis. Cytotoxic chemotherapy or external beam radiotherapy has a low efficacy in these patients. 'Target therapy' with tyrosine kinase inhibitors (TKIs) represent an important therapeutic option for the treatment of advanced cases of radioiodine refractory (RAI-R) differentiated thyroid cancer (DTC), medullary thyroid cancer (MTC) and possibly for cases of poorly differentiated (PDTC) and anaplastic thyroid cancer (ATC). In the last few years, several TKIs have been tested for the treatment of advanced, progressive and RAI-R thyroid cancers and some of them have been recently approved for use in clinical practice: sorafenib and lenvatinib for DTC and PDTC; vandetanib and cabozantinib for MTC. The objective of this overview is to present the current status of the treatment of advanced DTC, MTC, PDTC and ATC with the use of TKIs by describing the benefits and the limits of their use. A comprehensive analysis and description of the molecular basis of these drugs and the new therapeutic perspectives are also reported. Some practical suggestions are also given for the management to the potential side-effects of these drugs.

Classical point mutations of RET, BRAF and RAS oncogenes are not shared in papillary and medullary thyroid cancer occurring simultaneously in the same gland.

BACKGROUND: Papillary (PTC) and medullary (MTC) thyroid carcinomas represent two distinct entities, but quite frequently, they may occur simultaneously. AIM: To provide genetic analysis of PTC and MTC occurring in the same patient (PTC/MTC) to elucidate their origin. METHODS: Sequencing analysis of RAS, BRAF and RET oncogenes hot spots mutations in tumoral and normal tissues of 24 PTC/MTC patients. RESULTS: Two of 24 patients (8.3 %) were affected by familial MTC (FMTC) harboring RET germline mutations in all tissues. Eight of 22 (36.4 %) sporadic cases did not show any somatic mutation in the three tissue components. Considering the MTC component, 10/22 (45.4 %) patients did not show any somatic mutation, 7 of 22 (31.8 %) harbored the M918T RET somatic mutation and 4/22 (18.2 %) presented mutations in the H-RAS gene. In an additional case (1/22, 4.6 %), H-RAS and RET mutations were simultaneously present. Considering the PTC component, 1 of 24 (4.2 %) patients harbored the V600E BRAF mutation, 1 of 24 (4.2 %) the T58A H-RAS mutation and 1 of 24 (4.2 %) the M1T K-RAS mutation, while the remaining PTC cases did not show any somatic mutation. In one case, the MTC harbored a RET mutation and the PTC a BRAF mutation. None of the mutations found were present in both tumors. CONCLUSIONS: To our knowledge, this is the first study analyzing a possible involvement of RET, BRAF and RAS oncogene mutations in PTC/MTC. These data clearly suggest that the classical activating mutations of the oncogenes commonly involved in the pathogenesis of PTC and MTC may not be responsible for their simultaneous occurrence.

Prophylactic central compartment lymph node dissection in papillary thyroid carcinoma: clinical implications derived from the first prospective randomized controlled single institution study.

BACKGROUND: The benefits of prophylactic central compartment lymph node dissection (pCCND) in papillary thyroid cancer (PTC) are still under investigation. This treatment seems to reduce PTC recurrence/mortality rates but has a higher risk of surgical complications. The lack of prospective randomized trials does not allow definitive recommendations. The aim of this prospective randomized controlled study was to evaluate the clinical advantages and disadvantages of pCCND. PATIENTS: A total of 181 patients with PTC without evidence of preoperative/intraoperative lymph node metastases (cN0) were randomly assigned to either Group A (n = 88) and treated with total thyroidectomy (TTx) or Group B (n = 93) and treated with TTx + pCCND. RESULTS: After 5 years of followup, no difference was observed in the outcome of the two groups. However, a higher percentage of Group A were treated with a higher number of (131)I courses (P = .002), whereas a higher prevalence of permanent hypoparathyroidism was observed in Group B (P = .02). No preoperative predictors of central compartment lymph node metastases (N1a) were identified. Only three patients were upstaged, and the therapeutic strategy changed in only one case. CONCLUSIONS: cN0 patients with PTC treated either with TTx or TTx + pCCND showed a similar outcome. One advantage of TTx + pCCND was a reduced necessity to repeat (131)I treatments, but the disadvantage was a higher prevalence of permanent hypoparathyroidism. Almost 50% of patients with PTC had micrometastatic lymph nodes in the central compartment, but none of the presurgical features analyzed, including BRAF mutation, was able to predict their presence; moreover, to be aware of their presence does not seem to have any effect on the outcome.

New and old knowledge on differentiated thyroid cancer epidemiology and risk factors.

Differentiated thyroid cancer (DTC) represents 1-2% of all human malignancies. The annual incidence varies among countries and it is estimated that 1.2-2.6 men and 2.0-3.8 women/100,000 individuals are affected worldwide. This incidence has been increasing in the last decades, likely due to an "over-diagnosis" of small cancers that would have remained occult and that have been likely revealed because of an increased diagnostic scrutiny rather than a real increase of incidence. The annual mortality rate for DTC is 0.5/100,000 both in men and women. DTC is 2-4 times more frequent in females than in males. The mean age at diagnosis is 40-45 yr for papillary tumors (PTC) and 50-55 yr for follicular tumors (FTC). They are very rare in children. Ninety percent of DTC are represented by PTC hystotype, mainly follicular and classical variants. In the last years it has been observed an important change in the oncogenic pattern of PTC with a significant reduction of RET/PTC rearrangements and an increase of BRAFV600E mutation suggesting a change in pathogenic events. The unique well-demonstrated risk factor of DTC is the exposure to external radiation which is also correlated with the presence of RET/PTC rearrangements. Recently, other environmental factors (i.e. living in a volcanic area or in a iodine- either deficient or rich area) or some eating habits leading to obesity have been considered as potential DTC risk factors. However, at present, the favorite hypothesis is that a complex interaction between genetic and environmental factors is required to develop DTC.

Celecoxib, a cyclooxygenase-2 inhibitor, potentiates the chemotherapic effect of vinorelbine in the medullary thyroid cancer TT cell line.

We analyzed the in vitro effects of celecoxib, a COX-2 inhibitor, and determined if celecoxib can sensitize a human MTC-derived cell line (TT) to chemotherapeutics. We found that celecoxib induced apoptosis in TT cells and decreased drug efflux by reducing the expression of MDR-1 mRNA, which codes for the drug efflux pump P-gp. We also observed that TT cells were 10-fold more resistant to doxorubicin than to vinorelbine, mimicking what can be observed in clinical practice. In addition, we found that the combination of celecoxib and vinorelbine, but not doxorubicin, induced a significant reduction in cell viability and a significant increase in apoptosis. In conclusion, we showed that celecoxib was able to enhance the chemotherapeutic effect of vinorelbine. A clinical trial exploring the in vivo activities of celecoxib in MTC patients who cannot benefit from available treatments would be desirable, taking into account the possible risks of cardiovascular effects of this drug.

In silico and in vitro analysis of rare germline allelic variants of RET oncogene associated with medullary thyroid cancer.

Germline and somatic RET oncogene mutations are found in 98% hereditary and 40% sporadic medullary thyroid carcinomas. Our aim was to analyse by in silico and in vitro assays the transforming activity of six rare RET mutations (T338I, V648I, M918V, A883T, S904F and M848T). Six known RET mutations were used as controls. The in silico analysis showed the highest score value (i.e. 65) for S904F, M848T, M918T and C634R, whereas L790F, G691S, T338I and V648I had 0 score. Intermediate score values were obtained by A883T (score=55), M918V, V804M and Y791F (score=15). The in vitro focus formation assay showed that cells transfected with S904F, M918T, M848T or C634R generated the largest number of focus formation units (FFU). Intermediate numbers of FFU were observed in cells transfected with M918V, V804M, Y791F or A883T, while cells transfected with L790F, G691S, T338I or V648I showed a number of FFU similar to control cells. A positive correlation between the in silico score and in vitro FFU was found (P=0.0005). Only cells transfected with M918T or C634R grew faster and generated higher number of colonies in soft agar than control cells. However, the cells that were transfected with V804M produced an intermediate number of colonies. In conclusion, two of the six rare RET mutations, S904F and M848T possessed a relatively high transforming activity but a low aggressiveness; the other four mutations T338I, V648I, M918V and A883T were low or non-transforming, and their ability to induce tumoural transformation might be related to particular genetic conditions.

RET genetic screening of sporadic medullary thyroid cancer (MTC) allows the preclinical diagnosis of unsuspected gene carriers and the identification of a relevant percentage of hidden familial MTC (FMTC).

OBJECTIVE: This study was aimed to demonstrate the clinical benefits of rearranged during transfection (RET) genetic screening in patients with apparently sporadic medullary thyroid cancer (MTC) not only to identify the hereditary nature of the disease in the index case but also to discover family members harbouring the same germline mutations (i.e. gene carriers) who are unaware of their condition. CONTEXT: RET genetic screening allowed the identification of germline RET mutations in apparently sporadic MTC resulting in their re-classification as hereditary forms. PATIENTS AND MEASUREMENTS: RET genetic screening was performed in 729 apparently sporadic MTC patients by direct sequencing RET exons 5, 8, 10, 11 and 13-16. Clinical and biochemical evaluation of gene carriers was also performed. RESULTS: We discovered an unsuspected germline RET mutation in 47 of 729 (6·5%) apparently sporadic MTC who were re-classified as hereditary. We found 60 of 146 (41·1%) gene carriers, 35 of whom had biochemical or clinical evidence of MTC. Thirty gene carriers underwent total thyroidectomy and 27 of 30 (90%) were persistently cured after a mean follow-up of 6·0 years. As a further result of RET genetic screening, we observed a significantly higher prevalence of familial medullary thyroid cancer (FMTC) in our series with respect to the largest series of the International RET Consortium (P = 0·0002). CONCLUSIONS: RET genetic screening of patients with apparently sporadic MTC represents a major tool for the preclinical diagnosis and early treatment of unsuspected affected family members and allows the identification of a relevant percentage of hidden FMTC.

Recombinant human TSH (rhTSH) in 2009: new perspectives in diagnosis and therapy.

Thyrotropin stimulating hormone (TSH) exerts a physiological stimulus to growth, function and ability to take up iodine of both normal and malignant follicular cells. For this reason, the metastases deriving from well differentiated thyroid cancer (DTC) can be effectively treated with radioiodine but this procedure requires a strong TSH stimulus that can be obtained by withdrawing the L-thyroxine (LT4) therapy. However, both the social and personal life of patients while they are withdrawing the LT4 therapy are heavily affected by hypothyroidism. After more than a decade since the development of recombinant human TSH (rhTSH), this molecule has been introduced in the clinical practice (1998 in USA and 2001 in Europe) as a safe and reliable alternative to LT4 withdrawal. For several years the main clinical application of rhTSH was for diagnostic purposes (i.e. thyroglobulin stimulation) but, after the more recent demonstration of its efficacy in preparing DTC patients for radioiodine post surgical thyroid remnant ablation, also this application has been officially recognized worldwide. The validity of rhTSH has been also demonstrated in stimulating metastatic thyroid cancer cells but this employment is not yet officially approved and it can be used only in patients with contraindication to hypothyroidism (i.e. "compassionate use"). Other possible uses of rhTSH stimulation are related to its ability to enhance both 18FDG uptake during PET scan of metastatic DTC patients and the effectiveness of conventional chemotherapy. The aim of this review was to recall how the rhTSH has been developed and progressively introduced in the clinical management of DTC patients.

Re-differentiation of thyroid carcinoma cell lines treated with 5-Aza-2'-deoxycytidine and retinoic acid.

We studied cell growth rate, mechanisms of growth inhibition, phenotype re-differentiation, expression of RARalpha, beta, gamma and differentiation thyroid genes before and after combined treatment with 5-Aza-CdR and RA (5-Aza/RA) of human thyroid carcinoma cell lines (FRO, WRO, TT). Furthermore, the activity and localization of the re-expressed sodium-iodide-symporter (NIS) protein was analyzed. After 5-Aza/RA treatment, all cell lines showed a significant reduction in cell growth. This was associated with apoptosis in the TT, with inhibition of cell proliferation in the WRO, and with cell cycle impairment in FRO and WRO. FRO and WRO treated with 5-Aza/RA lost the ability to grow in soft agar. FRO re-expressed thyroid transcription factor-1 and thyroglobulin, TT and WRO re-expressed PAX-8 and FRO and TT re-expressed RARbeta and NIS mRNA. Despite this expression, they were unable to take up iodine: a cytoplasmic localization of NIS protein was demonstrated in FRO. In conclusion, besides a significant reduction in cell growth rate and in the ability to grow in soft agar, treatment with 5-Aza/RA partially re-differentiated FRO and induced expression of NIS mRNA and protein in FRO and TT, but this treatment was unable to restore the functional activity of NIS, likely because it was located into the cytoplasm without reaching the plasma membrane.

Retinoic acid receptor beta2 re-expression and growth inhibition in thyroid carcinoma cell lines after 5-aza-2'-deoxycytidine treatment.

The treatment of both undifferentiated and de-differentiated thyroid tumors, which are unresponsive to radioiodine, represents one of the biggest challenges for thyroidologists. The aim of the present study was to investigate in vitro the methylation status of retinoic acid receptors (RAR)beta2 promoter and the effect of the demethylating agent 5-aza-2'-deoxycytidine (5-Aza-CdR) on 5 human thyroid cancer cell lines. The methylation status of RARbeta2 promoter was analyzed by methylation-specific PCR. The effect of 5-Aza-CdR on cell growth and apoptosis was evaluated by cell counting, enzymelinked immunosorbent assay tests and fluorescence-activated cell sorting analysis, while the effect on the expression of RAR and thyroid-specific genes was measured by qualitative and quantitative RT-PCR. Methylation of RARbeta2 promoter was present only in ARO cells. 5-Aza-CdR determined growth inhibition in all cell lines, probably due to apoptosis in WRO, NPA, and ARO cells, and to inhibition of DNA synthesis in TT cells. Treatment with 5-Aza-CdR induced the expression of RARbeta mRNA in ARO and FRO cells, a slight increase of the expression of Tg, TPO and thyroid trancription factor 1 (TTF-1) mRNA and the new expression of low levels of NIS in TT cells. A significant increase of TTF-1 mRNA in FRO cells was also observed. In this study we demonstrated that RARbeta2 promoter was methylated in ARO cell line. However, the 5-Aza-CdR treatment induced RARbetamRNA expression not only in ARO but also in FRO and TT cell lines, whose RARbeta2 promoter was unmethylated. A significant reduction of cell growth, but not cell re-differentiation, was also observed after 5-Aza-CdR treatment.

Failure to use measurement of megalin secretory components complexed with serum thyroglobulin as a tool to identify metastases after surgery in papillary thyroid cancer.

When thyroid follicles are intact, some colloidal thyroglobulin (Tg) reaches the circulation by megalin-mediated transcytosis and is to various extents complexed with megalin secretory components. In contrast, in papillary thyroid cancer (PTC), serum Tg is not complexed with megalin because it is directly secreted by tumor cells. Here we attempted to use measurement of megalin secretory components to distinguish PTC patients with thyroid remnant plus metastases from those with thyroid remnant only, after thyroidectomy and before 131I ablation. Tg values in anti-Tg antibodies (TgAb)-free sera from 5 PTC patients with thyroid remnant plus metastases and 12 PTC patients with thyroid remnant only were measured following pre-adsorption with uncoupled protein A beads or with protein A beads coupled with antimegalin antibodies. The degree of Tg pre-adsorption with antimegalin antibodies was minimal, with no substantial differences between the two groups. Thus, we concluded that measurement of megalin secretory components is unlikely to be useful to identify the origin of serum Tg in PTC patients after thyroidectomy.

Video assisted prophylactic thyroidectomy and central compartment nodes clearance in two RET gene mutation adult carriers.

Activating point mutations of RET gene have been demonstrated to be causative of the familial form of medullary thyroid cancer (MTC), both isolated (FMTC) and associated to other endocrine neoplasia [multiple endocrine neoplasia (MEN) 2A and 2B]. In RET gene mutation carriers, who are prone to developing MTC, prophylactic thyroidectomy is recommended to obtain their definitive cure. The simultaneous excision of the central node compartment is mandatory when the stimulation pentagastrin test for serum calcitonin is positive. Although the minimally invasive video assisted thyroidectomy (MIVAT) is nowadays currently adopted in many centers, it has never been employed for the prophylactic thyroidectomy of RET gene mutation carriers. The fear of obtaining an incomplete lymphadenectomy of the central compartment was the main reason for this reluctance. Since RET gene mutation carriers have often normal thyroid volume and, if involved, small lymph nodes, they indeed represent the best candidates to this approach especially when considering that they are usually young and concerned about the cosmetic results and the period of hospitalization. The excellent results obtained by MIVAT in the last few years induced us to propose this procedure together with a central compartment lymphadenectomy to 2 RET gene mutation carriers recently found by genetic screening. As assessed by a negative pentagastrin stimulation test performed after 6 months from the MIVAT, they were definitively cured without any surgical complication with the exception of a transient hypoparathyroidism. They showed a great satisfaction for both the cosmetic results and the very short period of hospitalization, thus supporting the idea that MIVAT can be used in association with the central node dissection for the prophylactic treatment of RET mutation gene carriers whose thyroid volume is still normal.

Recombinant human thyrotropin-stimulated serum thyroglobulin combined with neck ultrasonography has the highest sensitivity in monitoring differentiated thyroid carcinoma.

Recombinant human TSH (rhTSH)-stimulated thyroglobulin (Tg) measurement and (131)I whole body scan (WBS) have been validated as informative tests in the postsurgical follow-up of differentiated thyroid carcinoma. We report the diagnostic accuracy of Tg measurement and diagnostic WBS, alone or in combination, after rhTSH stimulation in a retrospective, consecutive series of patients undergoing follow-up for differentiated thyroid cancer. Routine procedures also include neck ultrasound in every patient and post-therapy WBS when indicated. We studied 340 consecutive patients with differentiated thyroid carcinoma, previously treated with near-total thyroidectomy and (131)I thyroid ablation, scheduled for routine diagnostic tests. At baseline on L-T(4)-suppressive therapy, 294 patients had undetectable (<1 ng/ml) serum Tg and negative anti-Tg autoantibodies (TgAb), 25 patients had undetectable serum Tg and positive TgAb, and 21 patients had detectable serum Tg and negative TgAb. These patients were tested for the presence of active disease by rhTSH stimulation. The results of our study showed that rhTSH-stimulated Tg alone had a diagnostic sensitivity of 85% for detecting active disease and a negative predictive value (NPV) of 98.2%. After adding the results of neck ultrasound, sensitivity increased to 96.3%, and the NPV to 99.5%. rhTSH-stimulated WBS had a sensitivity of only 21% and a NPV of 89%. The combination of rhTSH-stimulated Tg and WBS had a sensitivity of 92.7% and a NPV of 99%. We conclude that the rhTSH-stimulated Tg test combined with neck ultrasonography has the highest diagnostic accuracy in detecting persistent disease in the follow-up of differentiated thyroid carcinoma. A detectable level of serum Tg on L-T(4), its conversion from undetectable to detectable after rhTSH, and/or a suspicious finding at ultrasound will allow the identification of patients requiring therapeutic procedures without the need for diagnostic WBS.