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.

Enlargement of a metastatic lymph node from differentiated thyroid cancer after COVID-19 vaccination

BACKGROUND

The massive vaccination campaign against COVID-19 has granted a high level of protection against the severe forms of the disease at the price of some mild adverse events.

OBJECTIVE

To underline that COVID-19 vaccination can induce a transient enlargement of lymph-node metastases in differentiated thyroid cancer patients.

CASE PRESENTATION

We describe the clinical, laboratory, and imaging features of a 60-year-old woman affected by paratracheal lymph-node relapse of Hurtle Cell Carcinoma who came to our attention after full COVID-19 vaccination because of neck swelling and pain. In April 2021, after 5 years of stable structural disease, the patient presented an enlargement of the metastatic lymph node, associated with a rise of serum thyroglobulin (from 4.6 to 14.7 pg/mL). Anti-inflammatory treatment was started and pain and swelling remitted after 15 days. At the subsequent evaluation, at neck ultrasound, the right paratracheal lesion was smaller and thyroglobulin dropped to 3.9 pg/mL.

CONCLUSIONS

We report the case of an enlargement of metastatic lymph node from differentiated thyroid cancer after COVID-19 vaccination. We warn clinicians to identify features of inflammatory response due to COVID-19 vaccination in order to prevent unwarranted surgical treatment.

Significance of Thyroglobulin Autoantibodies in Patients With Thyroid Cancer Treated With Lenvatinib

Context

Serum thyroglobulin (Tg) is a highly sensitive and specific tumor marker, employed in post-operative management of patients with differentiated thyroid carcinomas. Tumor shrinkage of radioiodine-refractory thyroid cancer (RAIR-DTC) treated with multitarget kinase inhibitors as lenvatinib, expressed according to the Response Evaluation Criteria in Solid Tumors (RECIST), is also associated with a drastic reduction of Tg levels. However, interference caused by circulating thyroglobulin autoantibodies (TgAb) represents the main limitation in the clinical use of Tg.

Objective

To evaluate if in RAIR-DTC TgAb could be considered a surrogate marker of Tg in monitoring response to treatment with lenvatinib.

Design

We retrospectively evaluated patients who had started lenvatinib and correlated serum Tg and TgAb with the radiological response across visits.

Setting

University of Pisa, Italy.

Patients

We selected 9/97 RAIR-DTC patients with detectable TgAb.

Intervention

None.

Main Outcome Measures

None.

Results

Tg values correlated neither with TgAb title nor with radiological response across visits. Greater decreases in TgAb titer correlated with favorable radiological response to lenvatinib after 1 month (Spearman's correlation = 0.74, P = .021) and 6 months (correlation = 0.61, P = .079). According to RECIST, patients with partial response showed a ∼10-fold greater decrease in TgAb compared to those with stable disease at 1 month (median TgAb decrease: -142 vs -14 IU/mL, P = .01) and those with progressive disease at 6 months (median TgAb decrease: -264 vs-24 IU/mL, P = .04).

Conclusion

TgAb evaluation may represent a reliable surrogate marker for Tg trend in evaluating response of RAIR-DTC to treatment with lenvatinib. A multicentric study would be useful to confirm our results.

Thyroid autoimmunity, thyroglobulin autoantibodies and thyroid cancer prognosis

Relevance of thyroid autoimmunity to prognosis of papillary thyroid carcinoma is still unsettled. We decided to investigate the impact of thyroid autoimmunity on prognosis of papillary thyroid carcinoma and the handling of TgAbs. We evaluated the clinical course of a large group of patients according to the presence (PTC-LT) or absence (PTC) of lymphocytic thyroiditis at histology. We studied 194 consecutive patients with a diagnosis of PTC and treated with total thyroidectomy plus ¹³¹I ablation between 2007 and 2009. Median follow-up (with 25th-75th percentiles) was 84·0 (56·4-118·0) months. The remission criteria were: basal Tg <0·2 ng/mL (or stimulated Tg <1), TgAbs <8 IU/mL (otherwise "decreasing TgAb trend", a decline of ≥20% in sequential TgAb measurements) and unremarkable imaging. PTC-LT and PTC patients had comparable treatment.TgAbs were detectable in 72·5% of PTC-LT and 16·5% of PTC patients. Time to remission was longer in the detectable than in the undetectable TgAb cohort (28·5 vs· 7·5 months [median]; HR 0·54, CI 0·35-0·83, p=0·005). When comparing PTC-LT to PTC patients the difference was maintained in the detectable TgAb (29·3 vs 13·0 months; HR 0·38, CI 0·18-0·80; p=0·01), but not in the undetectable TgAb cohort (7·7 vs 7·3 months; HR 0·90, CI 0·55-1·47; p=0·68). Using the decreasing TgAb trend, the influence of detectable TgAbs on time to remission was abolished. Thyroid autoimmunity does not influence the prognosis of papillary thyroid carcinoma. A decreasing TgAb trend seems an appropriate criterion to establish the remission of papillary thyroid carcinoma.

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.

Clinical evolution of sporadic medullary thyroid carcinoma with biochemical incomplete response after initial treatment

CONTEXT

The clinical response after surgery is a determinant in the management of patients with medullary thyroid carcinoma (MTC). In case of excellent or structural incomplete response, the follow-up strategies are well designed. Conversely, in case of biochemical incomplete response (BiR) the management is not clearly defined.

PURPOSE

To evaluate the overall and per-site prevalence of structural disease detection in sporadic MTC patients with BiR and to assess the predictive value of various clinical, biochemical, and genetics features.

METHODS

We evaluated data of 599 consecutive patients surgically treated for sporadic MTC (2000-2018) and followed-up at Endocrine Unit of the University Hospital of Pisa.

RESULTS

After a median of 5 months from surgery, 145/599 (24.2%) patients were classified as BiR. Structural disease was detected in 64/145 (44.1%), after a median time of 3.3 years. In 73.6% structural disease was detected at a single site, prevalently cervical lymph nodes. Among several others, at the time of first evaluation after surgery, only basal calcitonin (bCTN) and stage IVa/b were independent predictive factors. Also, structural disease was more frequent in patients with shorter CTN doubling time and somatic RET mutation.

CONCLUSIONS

In sporadic MTC patients with BiR the risk of detection of structural disease was about 50% at 10 years. Higher bCTN levels and staging predicted the risk of detecting structural disease. According to these findings, a stricter follow-up should be reserved to MTC with BiR and elevated values of bCTN and to those with an advanced stage. Long follow-up should anyway be considered for all BiR patients since 50% of them develop structural disease within 10 years.

Pros and cons of an aggressive initial treatment with surgery and radioiodine treatment in minimally invasive follicular thyroid carcinoma

BACKGROUND

Currently, surgery alone is the gold standard treatment for minimally invasive follicular thyroid cancer (mi-FTC).

CASE PRESENTATION

A case of a mi-FTC diagnosed in 1994 was treated with total thyroidectomy and radioiodine (RAI) ablation, according to the therapeutic algorithm used at that time. Nevertheless, he had a recurrence with distant metastasis after 24 years from the initial treatment.

CONCLUSION

Total thyroidectomy and RAI ablation might have delayed the development of distant metastasis but they were not sufficient to avoid disease recurrence. Certainly, remnant ablation simplified the follow-up and the monitoring of serum thyroglobulin allowed the early detection of the biochemical recurrence, but didn't change the outcome of the disease. Moreover, because of this early detection the patient was exposed to useless biochemical and imaging examinations. The aim of this report is to discuss the pros and cons of an aggressive treatment of a patient with mi-FTC.

Active surveillance in differentiated thyroid cancer: a strategy applicable to all treatment categories response

Currently, the differentiated thyroid cancer (DTC) management is shifted toward a tailored approach based on the estimated risks of recurrence and disease-specific mortality. While the current recommendations on the management of metastatic and progressive DTC are clear and unambiguous, the management of slowly progressive or indeterminate disease varies according to different centers and different physicians. In this context, active surveillance (AS) becomes the main tool for clinicians, allowing them to plan a personalized therapeutic strategy, based on the risk of an unfavorable prognosis, and to avoid unnecessary treatment. This review analyzes the main possible scenarios in treated DTC patients who could take advantage of AS.

Yttrium-90 transarterial radioembolization for liver metastases from medullary thyroid cancer

Objectives

Liver metastases occur in 45% of patients with advanced metastatic medullary thyroid cancer (MTC). Transarterial radioembolization (TARE) has been proposed to treat liver metastases (LM), especially in neuroendocrine tumors. The aim of this study was to investigate the biochemical (calcitonin and carcino-embryonic antigen) and objective response of liver metastases from MTC to TARE.

Methods

TARE is an internal radiotherapy in which microspheres loaded with β-emitting yttrium-90 (90Y) are delivered into the hepatic arteries that supply blood to LM. Eight patients with progressive multiple LM underwent TARE and were followed prospectively. They were clinically, biochemically and radiologically evaluated at 1, 4, 12 and 18 months after TARE.

Results

Two patients were excluded from the analysis due to severe liver injury and death due to extrahepatic disease progression, respectively. One month after TARE, a statistically significant (P = 0.02) reduction of calcitonin was observed in all patients and remained clinically relevant during follow-up; reduction of CEA, although not significant, was found in all patients. Significant reduction of liver tumor mass was observed 1, 4 and 12 months after TARE (P = 0.007, P = 0.004, P = 0.002, respectively). After 1 month, three of six patients showed partial response (PR) and three of six stable disease (SD) according to RECIST 1.1, while five of six patients had a PR and one of six a SD according to mRECIST. The clinical response remained relevant 18 months after TARE. Excluding one patient, all others showed only a slight and transient increase in liver enzymes.

Conclusions

TARE is effective in LM treatment of MTC. The absence of severe complications and the good tolerability make TARE a valid therapeutic strategy when liver LM are multiple and progressive.

Nutrition in Advanced Thyroid Cancer Patients

In the last decade, multikinase inhibitors (MKIs) have changed the paradigm of treatment of advanced and progressive thyroid cancer. Compared with the traditional treatment with chemotherapy and radiotherapy, these new drugs have shown a good efficacy in controlling the neoplastic disease, and also a different toxicity profile compared to traditional chemotherapy, milder but still present and involving mainly the nutritional profile. Weight loss, nausea, anorexia, stomatitis, diarrhea may be associated with malnutrition and cancer-related cachexia. The latter is characteristic of the advanced cancer stage and may be present before starting MKIs, or may develop afterwards. Adverse events with nutritional impact may cause a significant impairment of quality of life, often requiring dose reduction and sometimes drug discontinuation, but with a lower efficacy on the neoplastic disease. The aim of this paper was to discuss the role of nutritional therapy in advanced thyroid cancer and the importance of prevention, early recognition and careful management of malnutrition and cachexia during systemic therapy with MKIs.

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.

Active Surveillance in RET Gene Carriers Belonging to Families with Multiple Endocrine Neoplasia

Simple Summary

MEN2 has a very high penetrance for the development of medullary thyroid cancer. However, intra- and inter-familial variabilities have been described. Accordingly, in this precision medicine era, a personalized approach should be adopted in subjects harboring RET mutations. In these subjects, we showed that thyroid surgery could be safely timed according to basal and stimulated calcitonin, especially in children who can reach adulthood, avoiding the risks of thyroid surgery and decreasing the period of a long-life hypothyroidism treatment.

Abstract

Multiple Endocrine Neoplasia 2 (MEN2) is a hereditary cancer syndrome for developing medullary thyroid cancer (MTC) due to germline mutations of RET gene. Subjects harboring a germline RET mutation without any clinical signs of MTC are defined as gene carriers (GCs), for whom guidelines propose a prophylactic thyroid surgery. We evaluate if active surveillance of GCs, pursuing early thyroid surgery, can be safely proposed and if it allows safely delaying thyroid surgery in children until adolescence/adulthood. We prospectively followed 189 GCs with moderate or high risk germline RET mutation. Surgery was planned in case of: elevated basal calcitonin (bCT) and/or stimulated CT (sCT); surgery preference of subjects (or parents, if subject less than 18 years old); other reasons for thyroid surgery. Accordingly, at RET screening, we sub-grouped GCs in subjects who promptly were submitted to thyroid surgery (Group A, n = 67) and who were not (Group B, n = 122). Group B was further sub-grouped in subjects who were submitted to surgery during their active surveillance (Group B1, n = 22) and who are still in follow-up (Group B2, n = 100). Group A subjects presented significantly more advanced age, bCT and sCT compared to Group B. Mutation RET^V804M was the most common variant in both groups but it was significantly less frequent in Group A than B. Analyzing age, bCT, sCT and genetic landscape, Group B1 subjects differed from Group B2 only for sCT at last evaluation. Group A subjects presented more frequently MTC foci than Group B1. Moreover, Group A MTCs presented more aggressive features (size, T and N) than Group B1. Accordingly, at the end of follow-up, all Group B1 subjects presented clinical remission, while 6 and 12 Group A MTC patients had structural and biochemical persistent disease, respectively. Thank to active surveillance, only 13/63 subjects younger than 18 years at RET screening have been operated on during childhood and/or adolescence. In Group B1, three patients, while actively surveilled, had the possibility to reach the age of 18 (or older) and two patients the age of 15, before being submitted to thyroid surgery. In Group B2, 12 patients become older than 18 years and 17 older than 15 years. In conclusion, we demonstrated that an active surveillance pursuing an early thyroid surgery could be safely recommended in GCs. This patient-centered approach permits postponing thyroid surgery in children until their adolescence/adulthood. At the same time, we confirmed that genetic screening allows finding hidden MTC cases that otherwise would be diagnosed much later.

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.

Whole Tumor Capsule Is Prognostic of Very Good Outcome in the Classical Variant of Papillary Thyroid Cancer

CONTEXT

Tumor capsule integrity is becoming a relevant issue to predict the biological behavior of human tumors, including thyroid cancer.

OBJECTIVE

This work aims to verify whether a whole tumor capsule in the classical variant of papillary thyroid carcinoma (CVPTC) could have as a predictive role of a good outcome as for follicular variant (FVPTC).

METHODS

FVPTC (n = 600) and CVPTC (n = 554) cases were analyzed. We distinguished between encapsulated-FVPTC (E-FVPTC) and encapsulated-CVPTC (E-CVPTC) and, thereafter, invasive (Ei-FVPTC and Ei-CVPTC) and noninvasive (En-FVPTC and En-CVPTC) tumors, according to the invasion or integrity of the tumor capsule, respectively. Cases without a tumor capsule were indicated as invasive-FVPTC (I-FVPTC) and invasive-CVPTC (I-CVPTC). The subgroup of each variant was evaluated for BRAF mutations.

RESULTS

E-FVPTC was more frequent than E-CVPTC (P < .001). No differences were found between En-FVPTC and En-CVPTC or between Ei-FVPTC and Ei-CVPTC. After 18 years of follow-up, a greater number of not-cured cases were observed in Ei-CVPTC with respect to Ei-FVPTC, but not in En-CVPTC to En-FVPTC. Multivariate clustering analysis showed that En-FVPTC, En-CVPTC, and Ei-FVPTC have similar features but different from I-FVPTC and I-CVPTC and, to a lesser extent, from Ei-CVPTC. A total of 177 of 614 (28.8%) cases were BRAFV600E mutated, and 10 of 614 (1.6%) carried BRAF-rare alterations. A significantly higher rate of En-CVPTC (22/49, 44.9%) than En-FVPTC (15/195, 7.7%) (P < .0001) were BRAFV600E mutated.

CONCLUSION

En-CVPTC is less prevalent than En-FVPTC. However, it has good clinical/ pathological behavior comparable to En-FVPTC. This finding confirms the good prognostic role of a whole tumor capsule in CVPTC as well. New nomenclature for En-CVPTC, similar to that introduced for En-FVPTC (ie, noninvasive follicular thyroid neoplasm with papillary-like nuclear features; NIFTP) could be envisaged.

Prevalence and Risk Factors of Developing Fistula or Organ Perforation in Patients Treated with Lenvatinib for Radioiodine-Refractory Thyroid Cancer

INTRODUCTION

Tyrosine kinase inhibitors represent a better treatment in patients with radioiodine-refractory differentiated thyroid cancer (RAI-R DTC). Lenvatinib is usually well-tolerated, but sometimes, it is associated with serious and even life-threatening side effects. The aim of this study was to evaluate the prevalence of and the potential risk factors for fistula and/or organ perforation in RAI-R DTC patients treated with lenvatinib.

METHODS

This study included data from advanced and progressive RAI-R DTC patients treated with lenvatinib from February 2011 to February 2020 who were followed up at a single center. The clinical-pathological features and the biochemical and morphological results of the patients were collected at the time of starting lenvatinib and during the follow-up.

RESULTS

Fourteen of 95 (14.7%) locally advanced or metastatic RAI-R DTC patients treated with lenvatinib developed a fistula or organ perforation. Nine of 14 (64.3%) patients had tumor infiltration of the trachea, bronchus, esophagus, pleura, or bladder. Five of 14 (35.7%) had a bowel perforation, but only 2 had preexisting diverticulosis. Evaluation of the risk factors for developing a fistula or organ perforation showed that the presence of tumor infiltration and the tumor histology (papillary and poorly differentiated vs. follicular and Hurthle thyroid cancer) were significantly correlated with the development of a fistula or organ perforation (p = 0.003 and p = 0.02, respectively). In the subgroup of patients with tumor infiltration, we found that the papillary thyroid cancer histotype was the only potential predictor of fistula development. External beam radiation therapy (EBRT), the starting dose of lenvatinib, and the duration of treatment were not relevant for the development of fistula.

CONCLUSIONS

In metastatic thyroid cancer patients treated with lenvatinib, the presence of tumor infiltration and histological type should be considered as potential risk factors for the development of fistula or organ perforation, although they do not represent an absolute contraindication. Although EBRT and the presence of diverticulosis were not significantly associated with the development of fistula and organ perforation, they should be regarded as potential additional reasons for the development of these complications. According to our findings, there is no reason to start lenvatinib at a lower daily dose when tumor infiltration is present.

Ca19.9 Positivity and Doubling Time Are Prognostic Factors of Mortality in Patients with Advanced Medullary Thyroid Cancer with No Evidence of Structural Disease Progression According to Response Evaluation Criteria in Solid Tumors

Background: Serum Ca19.9 positivity is a prognostic factor for mortality in patients with advanced medullary thyroid cancer (aMTC), independently from calcitonin doubling time (DT). However, it is unknown whether aMTC patients who become positive for Ca19.9 also have progressive disease (PD) according to response evaluation criteria in solid tumors (RECIST) and whether Ca19.9 DT has a role in the management of aMTC patients. The aims of this study were to evaluate whether in aMTC, when serum Ca19.9 becomes positive, PD develops, and to determine the role of Ca19.9 DT in predicting mortality and PD. Patients and Methods: Serum Ca19.9 was periodically measured in 107 aMTC patients, and the DTs were calculated. Restaging of the disease was radiologically performed in 104 of 107 patients and PD was evaluated according to RECIST. Results: At the end of follow-up, 25 of 107 patients were Ca19.9 positive and PD was identified in 30 of 104 patients. No significant association was found between Ca19.9 positivity and PD, while there was a significant association between Ca19.9 positivity and mortality (p < 0.0001). Ca19.9 DTs <6 months and <1 year were not associated with PD but were associated with mortality (p < 0.0001 and p < 0.0001, respectively). In particular, 3 patients who had a Ca19.9 DT <6 months with no evidence of PD according to RECIST died of their disease after 6, 5, and 3 months, respectively. Conclusions: Serum Ca19.9 positivity and DTs <6 months and <1 year are prognostic factors for mortality but not for PD. Serum Ca19.9 positivity and DTs <6 months and <1 year should be considered in the decision-making process of whether to initiate systemic therapy even if there is no evidence of PD according to RECIST.

Thyroid cancer and COVID-19: experience at one single thyroid disease referral center

PURPOSE

Severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2) is challenging health systems all over the world. Cancer patients have a higher risk of being infected by SARS-Cov-2 and higher coronavirus disease 2019 (COVID-19) severity and mortality. Up to date, there were no data about COVID-19 in patients with thyroid cancer (TCs). The aim of the study was to describe the prevalence of COVID-19 in a well-characterized series of TC patients evaluated for the persistence of the neoplastic disease from March to September 2020; as secondary objective, we looked for the COVID-19 disease severity in a subgroup of multimetastatic TC patients.

METHODS

We evaluated 1464 patients affected by persistent TC: 67 patients who were taking multikinase inhibitors (MKIs) and 1397 under active surveillance for a persistent but stable disease. During the clinical evaluation, all patients were specifically investigated about a positive history of Sars-Cov-2 infection.

RESULTS

SARS-Cov-2 infection was identified in 4/1464 (0.3%) cases of patients affected by TC. We identified three cases among patients under active surveillance (0.2%), and one case among patients treated with MKI systemic therapy (1/67, 1.5%). This patient was taking vandetanib for metastatic medullary thyroid cancer (MTC), when he came to our attention referring severe fatigue, dyspnea for light physical activities. He presented a mild COVID-19 and he received exclusively supportive care. After a multidisciplinary consultation, we decided against the discontinuation of vandetanib. After 2 months from the infection, he did not present any signs of active infection, and the MTC metastatic disease was stable.

CONCLUSIONS

We showed that COVID-19 is not more frequent in TC patients than in general population, although a relatively higher prevalence in the group of TC patients treated with MKIs. A single patient with advanced TC and SARS-Cov-2 infection during MKIs treatment had a mild COVID-19 and did not require the discontinuation of MKI therapy. In cases of more severe COVID-19, an accurate evaluation from a multidisciplinary team would consider risks and benefits in taking the decision to continue or stop MKI treatment.

Thyroid Cancers: From Surgery to Current and Future Systemic Therapies through Their Molecular Identities

Differentiated thyroid cancers (DTC) are commonly and successfully treated with total thyroidectomy plus/minus radioiodine therapy (RAI). Medullary thyroid cancer (MTC) is only treated with surgery but only intrathyroidal tumors are cured. The worst prognosis is for anaplastic (ATC) and poorly differentiated thyroid cancer (PDTC). Whenever a local or metastatic advanced disease is present, other treatments are required, varying from local to systemic therapies. In the last decade, the efficacy of the targeted therapies and, in particular, tyrosine kinase inhibitors (TKIs) has been demonstrated. They can prolong the disease progression-free survival and represent the most important therapeutic option for the treatment of advanced and progressive thyroid cancer. Currently, lenvatinib and sorafenib are the approved drugs for the treatment of RAI-refractory DTC and PDTC while advanced MTC can be treated with either cabozantinib or vandetanib. Dabrafenib plus trametinib is the only approved treatment by FDA for BRAFV600E mutated ATC. A new generation of TKIs, specifically for single altered oncogenes, is under evaluation in phase 2 and 3 clinical trials. The aim of this review was to provide an overview of the current and future treatments of thyroid cancer with regards to the advanced and progressive cases that require systemic therapies that are becoming more and more targeted on the molecular identity of the tumor.

No difference in the outcome of metastatic thyroid cancer patients when using recombinant or endogenous TSH

OBJECTIVE

At present, recombinant TSH cannot be used for the treatment of metastatic differentiated thyroid cancer patients. The aim of this study was to evaluate if the type of TSH stimulation, recombinant or endogenous, had an impact on the outcome of these patients.

DESIGN AND METHODS

We compared the outcome of two propensity score-matched groups of metastatic patients, stimulated by either only recombinant TSH (n = 43) or only endogenous TSH (n = 34).

RESULTS

As expected from the matching procedure, the clinical-pathological features and the cumulative 131-I activities administered to the two groups were very similar. After 4 years of follow-up, 4% of patients were cured, 3% had biochemical disease and 93% had structural disease. However, 91% of patients obtained a clinical benefit from this therapy in terms of stabilization of the disease or complete remission or partial response. When considering the two groups separately, we did not find any difference in their outcome. When considering the response to 131-I therapy of the single type of metastases, 8% of lymph node metastases and 8% of lung metastases disappeared but none of the bone metastases. The response to 131-I therapy of the single type of metastases was similar when we looked at the two groups separately.

CONCLUSIONS

This study shows (i) an overall clinical benefit of the 131-I therapy, since the majority of patients remained affected but with a stable disease, and (ii) that the preparation with either recombinant or endogenous TSH has no impact on the 131-I therapy efficacy and the outcome of our two groups of patients.

Thyroglobulin Changes are Highly Dependent on TSH in Low-risk DTC Patients not Treated with Radioiodine

INTRODUCTION

Low-risk differentiated thyroid cancer (DTC) is currently rarely treated with radioiodine (131I) to ablate the postoperative remnant. Therefore, the interpretation of the serum thyroglobulin (Tg) values should be reconsidered. The aim of our study was to evaluate the changes in Tg values during follow-up with regard to the changing values in thyroid stimulating hormone (TSH).

MATERIALS AND METHODS

We evaluated 271 low-risk DTC patients, treated with total thyroidectomy but not 131I. To be included, patients had to be negative for Tg antibodies and have at least 3 evaluations in our department. All patients were on levothyroxine (L-T4) therapy.

RESULTS

After a median follow-up of 73 months, the overall Tg values were stable, while TSH values slightly increased. Therefore, we pooled data of Tg and TSH from all evaluations and a significant positive correlation was demonstrated (R = 0.2; P < 0.01), and was also demonstrated when we performed the analysis using time-weighted values (R = 0.14; P = 0.02). Moreover, when dividing patients into 3 groups according to first postoperative Tg (Group A [Tg < 0.2 ng/ml], Group B [Tg 0.2-1 ng/ml], and Group C [Tg > 1 ng/ml]) most patients showed stable values of Tg at the end of follow-up but TSH variations had a clear impact on the changes in Tg among the groups.

CONCLUSION

We demonstrated that in low-risk DTC not treated with 131I, serum Tg remains substantially stable over time, and the variations observed were correlated with the concomitant variations of TSH levels, mainly due to the modification of LT-4 therapy performed according to the ongoing risk stratification.

Nonthyroidal second primary malignancies in differentiated thyroid cancer patients: Is the incidence increased comparing to the general population and could it be a radioiodine therapy consequence?

The long-term survival of differentiated thyroid cancer (DTC) patients and the need to perform several treatments with radioiodine (131-I) lead to the question if the lifetime risk of developing a nonthyroidal second primary cancer (NTSPC) is increased in these patients. In our study, we assessed the prevalence of NTSPCs in thyroid cancer population and evaluated the possible causative role of 131-I treatment. We analyzed 1096 consecutive patients followed at our institution from 1964 to 1998. A total of 101 NTSPCs were observed in 92/1096 patients (8.4%) among which 17/101 (16.8%) diagnosed before DTC and 84/101 (83.2%) diagnosed after. The most frequent tumor sites observed were breast and bladder/urinary tract in the post-DTC group and breast and hematological system in the pre-DTC group. Regarding 131-I treatment, we did not observe any significant differences regarding either the number of treatments or the cumulative activity. The only significant parameter associated with an increased incidence of NTSPC was follow-up (P = .02): a longer follow-up period was associated with a higher number of NTSPCs. The mean latency between 131-I and NTSPC was 10.52 ± 7.69 years. Comparing with the general Italian population, independent of radioiodine treatment, the standard incidence ratio in our cohort was similar to that of the general population (SIR 1.07) and this result was confirmed by analyzing only the treated group. In conclusion, these results show that the risk of NTSPCs in the DTC patients' population is similar to that in the general population and 131-I treatment was not associated with an increased risk.

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.

OR21-01 Pre-Operative Calcitonin Value as a Predictive Factor of Cancer Related Death in Sporadic Medullary Thyroid Carcinoma

Introduction: Medullary thyroid carcinoma (MTC) is a rare tumor, it originates from the C cells producing calcitonin (CT) and can occur as sporadic or associated to germline RET mutation. The initial treatment is represented by total thyroidectomy associated with central compartment lymph nodes dissection and possible extension to the laterocervical compartment. CT is the main marker of follow-up of MTC, conversely its pre-operative role as diagnostic and prognostic factor is still debated. The aim of the present study was to evaluate several predictive factors of cancer related death in a large series of sporadic MTCs. Patients and Methods: We evaluated 537 consecutive patients surgically treated for sporadic MTC, from 2000 to 2019, and followed at the Operative Unit of Endocrinology 1 of the University of Pisa. We evaluated epidemiological, clinical and pathological data and pre and post-operative CT values, and their correlation with cancer related death. Results: At the end of the follow-up (average 75 months), 300/537 (55.9%) pts were cured, 100/537 (18.6%) pts showed biochemical disease, 88/537 (16.4%) pts showed metastatic disease and 49/537 (9.1 %) pts died for the disease. The factors significantly correlated with the cancer related death to the univariate analysis were the male gender, dimension of the primary tumor> 4 cm, the presence of lymph node metastasis to histology (N1) and/or distant metastasis (M1) at the time of diagnosis, multifocality, minimal extrathyroidal extension (mETE), initial staging, pre-operative CT values> 500 pg/ml and post-operative> 20 pg/ml. At multivariate analysis, statistical significance persisted only for pre- and post-operative CT and for the staging. Conclusions: 1) In our study we observed a significant improvement in the outcome and survival in the medium-long term of sporadic CMT patients, compared to the previous studies. 2) A more advanced staging at the time of diagnosis has been confirmed as a negative prognostic factor and it is evident that an early diagnosis is an essential requirement for improving cancer related death. 3) This is the first study that showed, in a large monocentric series of sporadic MTCs, as pre-operative CT represents a prognostic factor associated with cancer related death, as well as the value of post-operative CT.

MON-537 Primary Adrenal Insufficiency During Tyrosine Kinase Inhibitors Treatment in Advanced Thyroid Cancer Patients

Objective: Tyrosine kinase inhibitors (TKIs) are used for the treatment of metastatic differentiated (DTC), poorly differentiated (PDTC) and medullary (MTC) thyroid cancer. Several adverse events (AEs) have been reported in almost all patients (pts) treated with TKIs. One of the less known AE related to the use of these drugs is the primary adrenal insufficiency (PAI).

Methods: We analyzed the basal and stimulated adrenal function, ACTH levels, adrenal antibodies and electrolytes levels in 82 thyroid cancer pts treated with TKIs (vandetanib and cabozantinib in MTC pts, lenvatinib and sorafenib in DTC and PDTC pts) and we correlated these results with the clinical-pathological features of our pts.

Results: In our series, 25/82 (30.5%) pts showed a PAI after stimulation test with a progressive ACTH increase in 14/25 (56%) pts. Thirteen/25 (52%) pts with PAI were DTC, 8/25 (32%) pts were MTC and 4/25 (16%) pts were PDTC. Sixteen/25 (64%) pts were treated with lenvatinib, 8/25 (32%) were treated with vandetanib and 1/25 (4%) was treated with cabozantinib at the time of stimulation test. In 5/25 (20%) pts PAI occurred within 12 months from the TKIs treatment initiation, in 9/25 (36%) within 36 months and in 11/25 (44%) after 36 months of treatment. Eighteen/25 pts with PAI were older than 55 years. Twenty/25 (80%) of these pts were treated with cortisone acetate replacement therapy with the improvement of fatigue in a small part of these while other 5 pts were untreated due to the mild degree of PAI and the absence of specific symptoms (i.e fatigue). Moreover, in our pts the evaluation of adrenal antibodies was negative and the electrolytes levels were in the normal range. We also correlated the presence of PAI with the clinical-pathological features of our pts but we didn’t observe any significant correlation.

Conclusions: We observed that PAI, mainly subclinical, can occur during TKIs treatment in thyroid cancer pts. The appearance of fatigue, the typical symptom of PAI, could be multifactorial in these pts due also to the direct effect of TKIs treatment. Thus, in these cases is very difficult to recognize the cause of fatigue and to decide the appropriate treatment (cortisone acetate replacement therapy vs TKIs dose reduction). Moreover, the time of PAI appearance is variable since it can be early (<12 months) or late (>36 months) after TKIs treatment initiation and the adrenal function must be monitored during all TKIs treatment period. More studies are needed to know the pathophysiology of this “adverse event” during TKIs treatment and to improve the acknowledgments regarding the differential diagnosis and treatment of these pts, regardless of symptoms.

MON-495 Influence of Lymphocytic Thyroiditis at Histology and Serum Thyroglobulin Autoantibodies on the Course of Papillary Thyroid Carcinoma

PURPOSE Papillary thyroid carcinoma (PTC) is frequently associated with diffuse lymphocytic thyoiditis (LT) at histology and serum autoantibodies to thyroglobulin (TgAb) and to thyroperoxidase (TPOAb). The influence of LT and thyroid autoantibodies on the prognosis of PTC is debated. We evaluated the clinical course of a large group of PTC patients according to the presence or absence of LT (LT+ and LT-) and thyroid autoantibodies. METHODS We evaluated 194 consecutive and non-selected PTC patients treated with total thyroidectomy plus ¹³¹I ablation between 2007 and 2009, followed for 7.2 years (mean). 72 patients had follicular variant of PTC, 97 classic, 16 tall cells and the remaining 9 others variants (solid or oxyphilic cells). LT was diagnosed in presence of >10 lymphocytes/field (40x). At the time of ablation, all patients underwent measurement of Tg, TgAb and TPOAb, neck ultrasound and whole body scan. After ablation, patients underwent Tg (Beckman Coulter), TgAb and TPOAb (Tosoh) measurement and neck ultrasound (associated with other imaging if required) every 6-12 months. PTC was considered in remission according to the following criteria: un-stimulated Tg <0.2 ng/mL or stimulated Tg <1 ng/mL with TgAb <8 IU/mL and no evidence of structural disease. PTC was considered as persistent when un-stimulated Tg was ≥0.2 ng/mL or stimulated Tg was ≥1 ng/mL, or when TgAb were ≥8 IU/mL, or there was evidence of structural disease. RESULTS LT was found in 47% of patients, with a F/M ratio of 6.6/1, and was associated with a hypoechoic pattern at thyroid ultrasound (p = 0.05). At the end of follow-up 44/194 (22.7%) had persistent disease. Among them, 17/72 (23.6%) were follicular, 19/97 (19.6%) classic, 6/16 (37.5%) tall cells and 2/9 (22.2%) other variants. The time to remission was longer in the LT+ compared to the LT- patients (19.5 vs 7.5 months) (median) (p <0.001), in TgAb positive compared to TgAb negative patients (28.5 vs 7.5 months) (p <0.001) and in TPOAb positive compared to TPOAb negative patients (28.0 vs 8.0 months) (p = 0.005). At multivariate analysis TgAb were the only independent factor influencing the time to remission (0.54; 0.35-0.83; HR and confidence interval) (p = 0.001). However, evaluating only the 111 TgAb negative patients, the time to remission (undetectable un-stimulated or stimulated Tg and no evidence of structural disease) was similar in the LT+ and LT- groups (8.0 months for both). At variance, in 83 TgAb positive patients the time to remission was longer in LT+ than in LT- patients (29.3 vs 13.0 months) (p=0.01). CONCLUSIONS The time to remission is longer in LT+ compared to LT- PTC patients treated with total thyroidectomy plus ¹³¹I ablation. This is due to the frequent association of LT with TgAb, because undetectable TgAb is required to define the remission of PTC. Indeed, coexistent LT does not influence the time to remission when the analysis is restricted to TgAb negative patients.

MON-490 Calcitonin-Based Thyroidectomy Is a Safe Approach in Patients with Germline RET Mutation and Permits to Delay Surgery in Children

Introduction: Medullary thyroid cancer (MTC) arises from C cells secreting calcitonin. In familial MTC cases, a germline RET mutation is discovered in 98% of cases. Nowadays, an early diagnosis and radical surgery are the only curative approach. However, thyroidectomy in children is associated with a higher rate of surgical adverse events, compared to surgery in adults. The best clinical approach in patient harboring germline RET mutation (gene carriers, GC) is still undefined. Methods and materials: since 1994 to 2018 we identified 174 GC by RET screening. 56 GC underwent total thyroidectomy and lymph node dissection for the evidence of high calcitonin levels at the first clinical evaluation, whereas 27 GC underwent surgery for high stimulated calcitonin levels during the active surveillance (median 16 months, range 13-118). 90 GC are still in follow up. Results: In the group of 27 GC patients who underwent surgery during the active surveillance, 15 GC had only C cells hyperplasia (CCH) foci and 12 were affected by MTC. These carcinomas were all confined to the thyroid, without any lymph node and distant metastasis. All these patients are still in clinical remission, after a median follow-up of 4 years (range 1-11). At time of the surgery, the patients affected by MTC were significantly older than patients harboring only CCH (median 49 vs 30 years old, respectively). Among these 27 GC, 7 were diagnosed as GC when they were younger than 18 years (median 7 years old, range 2-18) and they underwent surgery after a median period of 3 years (range 1-10 years), when they were all older than 7 years. In this group, 6 of 7 were affected by CCH and only one case by a microMTC. There were not any persistent surgical adverse events and all of them are still in clinical remission. 41 of 90 GC, who are still in active surveillance, were younger than 18 years at time of RET screening: nowadays, 10/41 are older than 18 years and 15/41 are older than 14 years, all with calcitonin still in the normal range. Conclusions: we demonstrated that the calcitonin-based thyroidectomy is a safe approach in GC. Intriguingly, this approach seems to be interesting especially in children in order to perform still an early and safe surgery but when they are older, possibly adults.

Active Surveillance in Papillary Thyroid Microcarcinomas is Feasible and Safe: Experience at a Single Italian Center

CONTEXT

The dramatic rise in the incidence of thyroid cancer over the last 30 years is largely attributable to the increasing diagnosis of papillary microcarcinomas (mPTCs). Current guidelines endorse an observational management approach in properly selected cases.

OBJECTIVE

To evaluate the feasibility of active surveillance in mPTC in Italy, its impact on real life, and to identify risk factors of progression.

DESIGN AND SETTING

In 2014 we started a prospective-observational study of active surveillance in mPTC patients.

PATIENTS

Included patients demonstrated a single Thy4 or Thy5 thyroid nodule, with largest diameter ≤1.3 cm, and no suspicious laterocervical lymph nodes by neck ultrasonography. Of 185 eligible subjects, 50.3% (93/185) enrolled in the observational management protocol while the others opted for surgery and were excluded from this analysis.

INTERVENTION

Enrolled patients were followed with neck ultrasound at 6- to 12-month intervals. Disease progression was defined as the appearance of abnormal lymph nodes or nodule enlargement during follow-up. In these cases, patients were directed to surgery.

RESULTS

Three patients (3/93, 3%) showed clinical progression and required surgery. Another 19 patients (19/93, 20%) decided to transition to surgical intervention even though there was no evidence of disease progression. All operated patients had excellent response to initial treatment despite the delayed surgery.

CONCLUSIONS

Within an Italian medical context, active surveillance appears to be a feasible and safe alternative to immediate surgery in healthy mPTC patients. Only 3% of mPTC demonstrated disease progression during a median follow-up of 19 months (range 6-54) and importantly demonstrated excellent outcomes after surgical intervention in a short-term follow-up.

Medullary thyroid cancer treated with vandetanib: predictors of a longer and durable response

Vandetanib is an important treatment option for advanced metastatic medullary thyroid cancer. The aims of this study were to evaluate the predictors of both a longer response to vandetanib and the outcome. Medical records of 79 medullary thyroid cancer patients treated with vandetanib at our center were analysed. Twenty-five patients were treated for <12 months, 54 were treated for ≥12 months and 24 of these latter were treated for ≥48 months (short-, long- and very long-term). The median progression free survival of the long and very long-term treated patients was significantly longer than in the ZETA trial. When comparing the groups of short - and long-term treated patients the only significant difference was that these latter were less frequently previously treated with a tyrosine kinase inhibitor. However, the long-term treated patients had a younger age, both at diagnosis and enrolment, which was statistically significant in the very long-term treated patients. In the long-term treated group, younger age, enrolment for symptoms and development of adverse events were significantly correlated with a better outcome. The enrolment for symptoms remained the only statistically significant predictor of a good outcome in the very long-term treated patients. In conclusion, early treatment with vandetanib, when patients are younger, with a good ECOG performance status and symptomatic disease, not necessarily progressing for RECIST, seem to be the best predictors of a longer and durable response. Further studies are needed to confirm these results

DELAYED 131-I FIRST TREATMENT AFTER SURGERY HAS NO IMPACT ON THE MEDIAN TERM OUTCOME OF PATIENTS WITH INTERMEDIATE RISK DIFFERENTIATED THYROID CANCER

Objective: In intermediate risk (IR) differentiated thyroid cancer (DTC) patients, selective use of radioiodine (131-I) for remnant ablation and/or as adjuvant therapy (RRA) is advocated. The recently suggested postoperative evaluation could delay the use of RRA. The aim of this study was to evaluate if a delayed RRA can worsen the clinical outcome of IR-DTC patients. Methods: Four hundred and fourteen consecutive IR-DTC patients were divided according to the time elapsed from surgery to RRA, <6 months (group A, 186/414 [44.9%]), or ≥6 months (group B, 228/414 [55.1%]). Clinical and biochemical data were collected, and clinical outcome was analyzed at the first evaluation (EV) after RRA (first-EV) and after a median of 6 years of follow-up (last-EV). Results: No difference in the clinical outcome of group A and B was found. Since a different activity of 131-I could have an impact on the outcome, we separately analyzed the groups according to the 131-I activity (low-activity group: 1,110 MBq/30 mCi [n = 320], and high-activity group: 3,700 MBq/100 mCi [n = 94]), further subdivided according to the time elapsed from surgery to RRA. No major differences were found in both the low- and high-activity groups when comparing the features of their subgroups A and B, as far as in their clinical outcome. Conclusion: The time elapsed between surgery and the first 131-I treatment does not influence the clinical outcome of IR-DTC patients. This finding allows a more relaxed attitude in the decision making process whether to perform the RRA in IR-DTC cases in which a selective use of 131-I is recommended. Abbreviations: ATA = American Thyroid Association; DTC = differentiated thyroid cancer; EV = evaluation; HR = high risk; 131-I = radioiodine; IR = intermediate risk; LR = low risk; rhTSH = recombinant human thyroid-stimulating hormone; RRA = radioiodine for remnant ablation; Tg = thyroglobulin; TgAb = thyroglobulin autoantibody; US = ultrasound.

Fifty Years After the First Description, MEN 2B Syndrome Diagnosis Is Still Late: Descriptions of Two Recent Cases

BACKGROUND

Multiple endocrine neoplasia type 2B (MEN 2B) is a very rare syndrome characterized by a very peculiar phenotype with mucosal neuromas, marfanoid habitus, and bumpy lips associated with medullary thyroid cancer (MTC) and pheochromocytoma (PHEO). Although the syndrome was first described 50 years ago, it is still diagnosed too late, when the MTC is metastatic and frequently when the PHEO has already developed.

CASE PRESENTATIONS

We report on two cases of MEN 2B that were diagnosed too late, preventing a cure. The cases involve two females who were 25 and 12 years old. Both were previously treated for congenital skeletal abnormalities; however, despite their bumpy lips and mucosal neuromas, MEN 2B syndrome was not recognized. When they arrived at our center for both the presence of thyroid nodules and elevated serum calcitonin values, the MTC was already metastatic, and the older patient had already developed a bilateral PHEO. After 3 years and 1 year of follow-up, the two patients are still alive but with persistent structural and biochemical disease.

DISCUSSION

These two cases show that knowledge of this syndrome is still insufficient and that the lack of knowledge impairs the ability to obtain an early diagnosis and cure. Because most patients with MEN 2B have no familial history, the only way to ensure a timely diagnosis is to recognize the MEN 2B phenotype on a clinical basis.

Less than 2% of the Low- and Intermediate-Risk Differentiated Thyroid Cancers Show Distant Metastases at Post-Ablation Whole-Body Scan

BACKGROUND

Recently, there has been a trend to reduce the use of radioiodine remnant ablation (RRA) in patients with low-risk (LR) and intermediate-risk (IR) differentiated thyroid cancer (DTC).

OBJECTIVES

The aim of this paper was to evaluate the diagnostic role of whole-body scan (ptWBS) performed after RRA in LR and IR DTC patients.

METHODS

We analyzed 545 DTC patients treated with total thyroidectomy and RRA in hypothyroidism followed by a ptWBS. Neck ultrasound (US) and serum thyroglobulin measurement were performed. According to the American Thyroid Association guidelines, patients were classified as LR (n = 345) and IR (n = 200).

RESULTS

In addition to the thyroid remnant, the ptWBS showed the presence of further areas of ¹³¹I uptake in 16/545 (2.9%) cases. ptWBS showed laterocervical lymph node metastases in 11/16 patients (10/11 were also detected by US), mediastinal uptake in 1/16, lung metastases in 3/16, and bone metastases in 1/16. Only 6/545 (1.1%) metastases were detected by ptWBS alone. After 7.8 years, 8/16 patients were free of disease, and 8 had persistent disease: 4 "biochemical" and 4 "structural." Remission was achieved in 3 cases after one single ¹³¹I course, in 1 case after surgery, and in the last 4 cases after several ¹³¹I courses.

CONCLUSIONS

The ptWBS diagnostic role was clinically relevant for the therapeutic strategies of our patients only in 1.1% of the cases. The cost-effectiveness of performing RRA and ptWBS in all LR and IR patients to find 1-2% of the cases with distant metastases remains controversial.

Changing Trend of Thyroglobulin Antibodies in Patients With Differentiated Thyroid Cancer Treated With Total Thyroidectomy Without 131I Ablation

BACKGROUND

Thyroglobulin (Tg) antibodies (TgAb) can interfere with Tg measurement and can be used as "Tg surrogate" in patients with differentiated thyroid cancer (DTC) treated with total thyroidectomy (TTx) and radioiodine remnant ablation (RRA). In contrast, few data, and in patients usually followed for a short-term follow-up, have been reported about the changes of TgAb levels in patients treated with TTx but without RRA. The aims of this study were to evaluate the changes of TgAb levels in DTC patients treated with TTx but not RRA and to identify the factors that influence these changes.

METHODS

The change in TgAb levels in 107 DTC (<1 cm) patients submitted to TTx but not RRA was evaluated. Patients were followed for a median of 6.3 years, and all had at least three determinations of TgAb and neck ultrasound (nUS).

RESULTS

TgAb levels showed a progressive decrease during follow-up. Initial TgAb levels and degree of lymphocytic infiltration influenced the time but not the rate of TgAb disappearance. No influence on time and rate of the decrease in TgAb was observed when the association with thyroperoxidase antibodies (TPOAb) levels were considered. A TgAb cutoff value of 61.9 IU/mL at first postoperative evaluation was a good indicator for disappearance of the TgAb within six years. No tumor recurrence was observed in the series. In one case, the progressive increase in TgAb anticipated the reappearance of benign thyroid tissue with lymphocytic infiltration.

CONCLUSIONS

TgAb levels decline in the majority of DTC patients treated with TTx but not ablated with radioiodine. The levels decrease rapidly after the surgical treatment and continue to decrease over time. The time of disappearance is influenced by the initial TgAb levels and the degree of lymphocytic infiltration. No influence of the actual TPOAb levels has been observed. An increase in TgAb levels should not be overlooked, since it can indicate the presence or reappearance of either normal thyroid tissue or tumor recurrence.

Clinical, pathological and genetic features of anaplastic and poorly differentiated thyroid cancer: A single institute experience

Anaplastic (ATC) and poorly differentiated thyroid cancer (PDTC) are very aggressive cancers whose histological diagnosis is not always straightforward. Clinical, pathological and genetic features may be useful to improve the identification of these rare histotypes. In the present study the clinical, pathological and genetic features of two groups of ATC (n=21) and PDTC (n=21) patients were analyzed. Clinical data were retrieved from a computerized database. The oncogenic profiles were studied using the Sanger sequencing method of a selected series of oncogenes and/or tumor suppressor genes known to be altered in these tumors. The presence of macrophages in both series of tissues was evaluated by immunohistochemistry. Patients with ATC were older and affected by a more advanced disease at diagnosis than those with PDTC. The median survival was significantly shorter in ATC compared with PDTC patients (P=0.0014). ATC showed a higher prevalence of TP53 and TERT mutations (10/21, 47.6% and 9/21, 42.8%, respectively) while TERT and BRAF mutations were the most prevalent in the PDTC group (7/21, 33.3% and 4/23, 19% respectively). Genetic heterogeneity (i.e., >2 mutations) was more frequent in ATC (10/21, 28.6%) compared with in PDTC (3/21, 4.7%) (P=0.03). Macrophages were more frequently present in ATC, particularly in those cases with TP53 mutations. In conclusion, these data indicate that ATC and PDTC may be characterized by different clinical, pathological and genetic profiles. In particular ATC, but not PDTC, were positive for TP53 and PTEN alterations. Complex mutations were also found in ATC but not in PDTC. Moreover, genetic heterogeneity was more frequent in ATC than PDTC. Finally, TP53 mutation and the accumulation of several mutations correlated with a shorter survival time.

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.

Lung Recurrence of Papillary Thyroid Cancer Diagnosed With Antithyroglobulin Antibodies After 10 Years From Initial Treatment

Introduction: Papillary thyroid cancer (PTC) is the most common endocrine malignancy. More than 98% of patients achieve an excellent response with no evidence of clinical, biochemical, or structural disease after initial treatment. In these patients structural recurrence is rare, more frequently diagnosed in the first 5 years from initial treatment and almost invariably localized in neck lymph nodes. Patient: We report the case of a woman affected by PTC who presented with rapidly rising anti-thyroglobulin antibodies (TgAb) level after 10 years from clinical, morphological and biochemical remission. Diagnosis and Treatment: In 2003, a 56 year old patient was treated with total thyroidectomy and radioiodine remnant ablation (RRA) for a PTC (2 cm) with minimal extrathyroidal extension (T3N1aM0 according to the 6th AJCC TNM staging system) associated with diffuse lymphocytic thyroiditis. In 2004 the patient was free of disease defined as undetectable Tg after recombinant human TSH administration in the absence of TgAb and structural disease. Since February 2012 the appearance and progressive increase of TgAb titer was observed and in 2014 a ¹⁸FDG-PET scan documented three hypermetabolic lesions suggestive of lung micrometastases. The lung lesions were cytologically confirmed as PTC metastases. Both the primary tissue and the lung metastasis were positive for BRAF V600E mutation. The patient was treated with 131-radioiodine that showed radioiodine avid lung lesions that lose the ability to take up iodine at the following treatment. The patient is still alive and the lung lesions are growing slowly. Conclusions: Structural recurrence in patients that demonstrated an excellent response after initial treatment for PTC is extremely rare, and distant metastases exceptional but possible. This case is peculiar because recurrence was early identified after 10 years from initial treatment for the presence of detectable TgAb in a patient that had an histological diagnosis of lymphocytic thyroiditis but with an atypical clinical presentation (normal thyroid at neck ultrasound and undetectable TgAb and anti-thyroid peroxidase antibodies). For this reason TgAb should be tested with Tg in patients with a history of lymphocytic thyroiditis, either histological or humoral, also when TgAb is in the normal range and not suggestive of autoimmune thyroiditis.

Anaplastic thyroid carcinoma: from clinicopathology to genetics and advanced therapies

Anaplastic thyroid carcinoma (ATC) is a rare malignancy, accounting for 1-2% of all thyroid cancers. Although rare, ATC accounts for the majority of deaths from thyroid carcinoma. ATC often originates in a pre-existing thyroid cancer lesion, as suggested by the simultaneous presence of areas of differentiated or poorly differentiated thyroid carcinoma. ATC is characterized by the accumulation of several oncogenic alterations, and studies have shown that an increased number of oncogenic alterations equates to an increased level of dedifferentiation and aggressiveness. The clinical management of ATC requires a multidisciplinary approach; according to recent American Thyroid Association guidelines, surgery, radiotherapy and/or chemotherapy should be considered. In addition to conventional therapies, novel molecular targeted therapies are the most promising emerging treatment modalities. These drugs are often multiple receptor tyrosine kinase inhibitors, several of which have been tested in clinical trials with encouraging results so far. Accordingly, clinical trials are ongoing to evaluate the safety, efficacy and effectiveness of these new agents. This Review describes the updated clinical and pathological features of ATC and provides insight into the molecular biology of this disease. The most recent literature regarding conventional, newly available and future therapies for ATC is also discussed.

KIF5B/RET Rearrangement in a Carcinoma of the Thyroid Gland: A Case Report of a Fatal Disease

BACKGROUND

The diffuse sclerosing variant of papillary thyroid cancer (DSV-PTC) is a rare variant of papillary thyroid cancer (PTC) with different clinicopathological features compared with conventional PTC.

CASE

An advanced DSV-PTC was diagnosed in a 39-year-old man. The radioiodine posttherapeutic whole-body-scan showed only an uptake in the central neck, whereas the computerized tomography showed multiple latero-cervical and mediastinum lymph node metastases, a single and spiculated lung lesion and multiple bilateral cerebellum metastases. The patient died after 6 months from the initial diagnosis. The histological revision of the thyroid tumor confirmed the diagnosis of DSV-PTC, and its molecular analysis revealed a KIF5B/RET rearrangement that, until now, was described only in a minority of lung adenocarcinoma. Other 18 cases of DSV-PTC were then studied for the presence of KIF5B/RET rearrangement, but all of them were negative.

CONCLUSIONS

This was a case of DSV-PTC positive for KIF5B/RET rearrangement, but considering that this alteration has been described only in lung adenocarcinoma and that the clinical course was more typical of lung carcinoma, we cannot completely rule out the possibility that this was a metastatic lesion from a lung tumor mimicking a DSV-PTC. As an alternative, we can also hypothesize that this was a case of fusion of two tumoral tissues deriving from a DSV-PTC and a metastasis of a KIF5B/RET positive lung adenocarcinoma. The question of whether the molecular findings, particularly when specifically reported only in some subtypes of human tumors, can overcome the morphological diagnosis is a matter of discussion.

Protein kinase inhibitors for the treatment of advanced and progressive radiorefractory thyroid tumors: From the clinical trials to the real life

The last ten years have been characterized by the introduction in the clinical practice of new drugs named tyrosine kinase inhibitors for the treatment of several human tumors. After the positive conclusion of two international multicentric, randomized phase III clinical trials, two of these drugs, sorafenib and lenvatinib, have been recently approved and they are now available for the treatment of advanced and progressive radioiodine refractory thyroid tumors. We have been involved in most clinical trials performed with different tyrosine kinase inhibitors in different histotypes of thyroid cancer thus acquiring a lot of experience in the management of both drugs and their adverse events. Aim of this review is to give an overview of both the rationale for the use of these inhibitors in thyroid cancer and the major results of the clinical trials. Some suggestions for the management of treated patients in the real life are also provided.

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.

Postoperative Thyroglobulin and Neck Ultrasound in the Risk Restratification and Decision to Perform 131I Ablation

CONTEXT

There is much debate surrounding the choice of which patient should be submitted to postsurgical remnant radioiodine remnant ablation (RRA), particularly in low-risk (LR) and intermediate-risk (IR) differentiated thyroid cancer (DTC).

OBJECTIVE

The aim of this study was to evaluate the role of postoperative high-sensitive thyroglobulin (Tg) on L-thyroxine (LT4-HSTg) and postoperative neck ultrasound (US) in risk restratification and decision to perform RRA.

PATIENTS

We evaluated 505 patients with LR or IR DTC 3 to 4 months after total thyroidectomy (TTx). All patients underwent RRA and a posttherapeutic whole body scan (ptWBS).

RESULTS

After TTx, 29.7% DTC patients had LT4-HSTg <0.1 ng/mL (Group A) and could be restratified as cured: 1 of 150 had lymph node metastases (LN mets) detected by neck US but negative at ptWBS. 56.8% DTC patients had LT4-HSTg between 0.1 and ≤1 ng/mL (Group B) and could be restratified either as cured or not cured. In this group, 15 of 287 (5.2%) had metastases but only 7 were detected by ptWBS; 13.5% DTC patients had LT4-HSTg >1 ng/mL (Group C) and could not be considered as cured by definition. LN mets were present in 11 of 68(16.2%) cases, all detected by neck US. No correlation was found with the presence of metastases and serum LT4-HSTg values or with the level of risk.

CONCLUSIONS

LT4-HSTg measured 3 to 4 months after TTx is important in the risk restratification of DTC patients but is less relevant than neck US in the decision to perform RRA.

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.

Treatment of advanced thyroid cancer with targeted therapies: ten years of experience

Thyroid cancer is rare, but it is the most frequent endocrine malignancy. Its prognosis is generally favorable, especially in cases of well-differentiated thyroid cancers (DTCs), such as papillary and follicular cancers, which have survival rates of approximately 95% at 40 years. However, 15-20% of cases became radioiodine refractory (RAI-R), and until now, no other treatments have been effective. The same problems are found in cases of poorly differentiated (PDTC) and anaplastic (ATC) thyroid cancers and in at least 30% of medullary thyroid cancer (MTC) cases, which are very aggressive and not sensitive to radioiodine. Tyrosine kinase inhibitors (TKIs) represent a new approach to the treatment of advanced cases of RAI-R DTC, MTC, PDTC, and, possibly, ATC. In the past 10 years, several TKIs have been tested for the treatment of advanced, progressive, and RAI-R thyroid tumors, and some of them have been recently approved for use in clinical practice: sorafenib and lenvatinib for DTC and PDTC and vandetanib and cabozantinib for MTC. The objective of this review is to present the current status of the treatment of advanced thyroid cancer with the use of innovative targeted therapies by describing both the benefits and the limits of their use based on the experiences reported so far. A comprehensive analysis and description of the molecular basis of these therapies, as well as new therapeutic perspectives, are reported. Some practical suggestions are given for both the choice of patients to be treated and their management, with particular regard to the potential side effects.

Polymorphisms within base and nucleotide excision repair pathways and risk of differentiated thyroid carcinoma

The thyrocytes are exposed to high levels of oxidative stress which could induce DNA damages. Base excision repair (BER) is one of the principal mechanisms of defense against oxidative DNA damage, however recent evidences suggest that also nucleotide excision repair (NER) could be involved. The aim of present work was to identify novel differentiated thyroid cancer (DTC) risk variants in BER and NER genes. For this purpose, the most strongly associated SNPs within NER and BER genes found in our previous GWAS on DTC were selected and replicated in an independent series of samples for a new case-control study. Although a positive signal was detected at the nominal level of 0.05 for rs7689099 (encoding for an aminoacid change proline to arginine at codon 117 within NEIL3), none of the considered SNPs (i.e. rs7990340 and rs690860 within RFC3, rs3744767 and rs1131636 within RPA1, rs16962916 and rs3136166 in ERCC4, and rs17739370 and rs7689099 in NEIL3) was associated with the risk of DTC when the correction of multiple testing was applied. In conclusion, a role of NER and BER pathways was evoked in the susceptibility to DTC. However, this seemed to be limited to few polymorphic genes and the overall effect size appeared weak.

Elevated level of serum carbohydrate antigen 19.9 as predictor of mortality in patients with advanced medullary thyroid cancer

BACKGROUND

Medullary thyroid cancer (MTC) is capable of secreting several proteins, such as calcitonin (Ct), carcinoembryonic antigen (CEA), chromogranin and others. Recently, we observed an aggressive MTC with high levels of serum carbohydrate antigen 19.9 (Ca 19.9) and a rapid evolution to death.

OBJECTIVE

The aim of this study was to evaluate whether high levels of serum Ca 19.9 could be a prognostic factor of death in patients with advanced MTC.

PATIENTS AND METHODS

We measured Ca 19.9, CEA and Ct in 100 advanced structural recurrent/persistent MTC patients and in 100 cured or biochemically affected MTC patients. Clinical and pathological data were also collected.

RESULTS

Sixteen percent of the patients with advanced MTC had high levels of Ca 19.9. The group with abnormal Ca 19.9 levels had significantly higher levels of CEA and Ct compared with the group with normal values of Ca 19.9 (P<0.0001 for both Ct and CEA). At variance, all 100 patients in the MTC control group showed normal levels of Ca 19.9. Moreover, among the advanced cases, the Ca 19.9-positive group showed a higher mortality rate than the group with normal levels. A logistic regression analysis demonstrated that an elevated level of Ca 19.9 is a predictor of mortality (OR=3.78, P=0.04), independent from Ct doubling time.

CONCLUSIONS

These results demonstrated that an elevated value of serum Ca 19.9 appears to be a predictive factor of poor prognosis in advanced MTC patients and identifies those cases with a higher risk of mortality in the short term.

Twenty years of lesson learning: how does the RET genetic screening test impact the clinical management of medullary thyroid cancer?

OBJECTIVE

Medullary thyroid carcinoma (MTC) is a rare disease that can be inherited or sporadic; its pathogenesis is related to activating mutations in the RET gene.

DESIGN

This study describes our 20-year experience regarding RET genetic screening in MTC.

PATIENTS AND METHODS

We performed RET genetic screening in 1556 subjects, 1007 with an apparently sporadic MTC, 95 with a familial form and 454 relatives of RET-positive patients with MTC.

RESULTS

A germline RET mutation was found in 68 of 1007 (6·7%) patients with sporadic MTC, while 939 patients with MTC were negative for germline RET mutations. We then identified a total of 137 gene carriers (GC). These subjects initiated a clinical evaluation for the diagnosis of MEN 2. A total of 139 MEN 2 families have been followed: 94 FMTC, 33 MEN 2A and 12 MEN 2B. Thirty-three different germline RET mutations were identified. Codon 804 was the most frequently altered codon particularly in FMTC (32/94, 34%), while codon 634 was the most frequently altered codon in MEN 2A (31/33, 94%); MEN 2B cases were exclusively associated with an M918T mutation at exon 16.

CONCLUSIONS

Our 20-year study demonstrated that RET genetic screening is highly specific and sensitive, and it allows the reclassification as hereditary of apparently sporadic cases and the identification of GC who require an adequate follow-up. We confirmed that FMTC is the most prevalent MEN 2 syndrome and that it is strongly correlated with noncysteine RET mutations. According to these findings, a new paradigm of follow-up of hereditary MTC cases might be considered in the next future.

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.

Detection of metastases from differentiated thyroid cancer by different imaging techniques (neck ultrasound, computed tomography and [18F]-FDG positron emission tomography) in patients with negative post-therapeutic ¹³¹I whole-body scan and detectable serum thyroglobulin levels

INTRODUCTION

DTC patients having detectable Tg and negative post-therapeutic (131)I-WBS have to be investigated by different imaging techniques to detect metastases.

PURPOSE

Comparison of neck US, CT and [18F]-FDG PET scan.

METHODS

In 49 DTC patients with biochemical disease, neck was examined by US, CT and [18F]-FDG PET. FNA was performed and Tg was determined by FNA-Tg in selected cases of suspicious lymph nodes. Thorax was examined by CT and PET. Serum Tg was measured on LT4 therapy (basal Tg) and after the stimulation with recombinant human TSH (peak Tg).

RESULTS

A thyroid remnant was seen by US, CT and PET in eight patients; recurrences were seen by US, CT and PET in six, five and five patients, respectively. Two metastatic nodes were identified by US and CT but not by PET. Lung micronodules were detected by CT in 7/49 (14.3 %) patients and by FDG PET in three of them. Basal Tg ranged from 0.5-1,725 ng/ml while peak Tg ranged from 0.5 to 2,135 ng/ml: the distribution between positive and negative patients was similar. Bone scan was negative in all cases.

CONCLUSIONS

In DTC patients with detectable Tg and negative I-131 post-therapy WBS, imaging examination revealed remnant or metastases in 43 % of cases. Remnant and recurrences were equally detected by the three techniques; US was better than [18F]-FDG PET for lymph node metastases since this latter method can give false both positive and negative results; chest examination is best made by CT versus FDG PET due to its higher spatial resolution.