Sentinel lymph node mapping: current applications and future perspectives in thyroid carcinoma

Sentinel lymph node (SLN) mapping is a standard, minimally-invasive diagnostic method in the surgical treatment of many solid tumors, as for example melanoma and breast cancer, for detecting the presence of regional nodal metastases. A negative SLN accurately indicates the absence of metastases in the other regional lymph nodes (LN), thus avoiding unnecessary lymph nodal dissection. Papillary thyroid carcinoma (PTC) is the most common type of thyroid carcinoma (TC) with cervical LN metastases at diagnosis in 20-90%, and nodal involvement correlates with local persistence/recurrence. The SLN in PTC is an intraoperative method for staging preoperative N0 patients and for detecting metastatic LNs "in and outside" the cervical LN central compartment; it represents an alternative method to prophylactic central neck node dissection. In this review we summarize different methods and results of the use of SLN in TC. The SLN identification techniques currently used include the selective vital-dye (VD) method, 99mTc-nanocolloid planar lymphoscintigraphy with intraoperative use of a hand-held gamma probe (LS), the combination LS + VD, and the combination LS and preoperative SPECT-CT (LS + SPECT/CT). The application of the SLN procedure in TC has been described in many studies, however, the techniques are heterogeneous, and the role of SLN in TC, with indications, results, advantages and limits, is still debated.

Medullary thyroid carcinoma

INTRODUCTION

Medullary thyroid carcinoma (MTC) constitutes approximately 5-10% of all thyroid cancers. Although the tumor forms in the thyroid, it doesn't originate from thyroid cells, but from the C cells or parafollicular cells which produce and release a hormone called calcitonin (CT). Starting from the second half of the 1900s, MTC was progressively studied and defined.

AREAS COVERED

This study aims to analyze the history, clinical presentation and biological behavior of MTC, bio-humoral and instrumental diagnosis, molecular profiling, genetic screening, preoperative staging and instrumental procedures, indispensable in expert and dedicated hands, such as high-resolution ultrasonography, CT-scan, MRI and PET/TC. We examine recommended and controversial surgical indications and procedures, prophylactic early surgery and multiple endocrine neoplasia surgery. Also, we discuss pathological anatomy classification and targeted therapies. The role of serum CT is valued both as undisputed and constant preoperative diagnostic marker, obscuring cytology and as early postoperative marker that predicts disease persistence.

EXPERT OPINION

With a complete preoperative study, unnecessary or useless, late and extended interventions can be reduced in favor of tailored surgery that also considers quality of life. Finally, great progress has been made in targeted therapy, with favorable impact on survival.

An Unusual Case of Medullary Thyroid Carcinoma and A Revision of Current Literature

BACKGROUND

Medullary thyroid cancer (MTC) accounts for 5% of all thyroid cancers and occurs either sporadically or in a hereditary pattern. Routine calcitonin (CT) measurement is suggested for MTC screening in patients with nodular thyroid disease.

PATIENT FINDINGS

A 45 years-old woman incidentally discovered, with neck ultrasound, the presence of thyroid micronodules. Fine-needle aspiration (FNA) on thyroid prevailing nodule did not demonstrate cellular atypia. During follow-up, FNA was repeated on the previously analyzed nodule suspicious for Hürthle cell nodule suspicious for follicular neoplasm and on another hypoechoic right nodule which showed cellular atypia. CT was <2 pg/ml (normal values <18.2 pg/ml), anti-thyroid antibodies were positive and the patient showed a normal thyroid function. The patient also was diagnosed with primary hyperparathyroidism with an enlarged parathyroid gland behind the right thyroid lobe. Therefore, she underwent total thyroidectomy and a selective parathyroidectomy was performed. Histology showed an encapsulated microMTC (pT1aNxMx) associated with diffuse C-cell hyperplasia and lymphocytic thyroiditis. The neoplasm was positive for calcitonin and chromogranin A and negative for thyroglobulin. A right parathyroid adenoma was also diagnosed. One month after surgery basal and stimulated CT were <2 ng/ml. Genetic analysis did not reveal mutation of RET proto-oncogene. Twelve months after surgery, neck ultrasonography, chest and abdomen computed tomography did not demonstrated residual/recurrent disease with undetectable serum CT.

CONCLUSION

In the literature, few MTC cases with normal serum CT have been reported. Although MTC without elevated plasma CT is extremely rare, normal or low CT levels, do not entirely exclude this diagnosis.

The Extent of Surgery for Thyroid Medullary Cancer

Aims

Evaluation of the impact of the extent of primary surgery and reintervention on the outcome of patients with medullary thyroid carcinoma.

Methods

Seventy-two patients with medullary thyroid carcinoma (MTC) were surgically treated between 1967 and 1992.

Results

Fifty-five cases were sporadic, 5 patients had MEN 2A, 4 MEN 2B syndrome and 8 familial non-MEN MTC; 1 patient had stage I disease, 30 patients stage II, 36 stage III and 5 stage IV. Sixty-four had their initial treatment at our center, and 8 came for subsequent treatment. At first treatment, 8 patients were subjected to partial thyroidectomy, 10 to total thyroidectomy, 53 to total thyroidectomy with neck dissection, and 1 to only radical neck dissection; postoperative serum calcitonin (Ct) levels returned to normal in 3, 6 and 27 patients, respectively. In the patient with only radical neck dissection, Ct levels remained elevated. No patient with Ct normalization after surgery became responsive to pentagastrin in the follow-up. Thirteen patients had a reoperation due to nodal relapse. At a mean follow-up of 5.7 years (6-252 months), the 10-year survival rate was 84.5% with a significant difference between patients under and over 40 years of age (96.4 vs 57%), between stage I-II (100%) and stage III, IV (83.8%, 0% respectively). At the last follow-up, 36 (50%) patients were alive and disease free and 26 were alive with disease (15 with distant metastases). Of the 10 deaths, 7 were due to tumor recurrence, 3 to 120 months after surgery.

Conclusions

Data suggest that an earlier diagnosis rather than more extensive surgery could improve survival and reduce recurrences. However, the least treatment required is total thyroidectomy plus central neck and upper mediastinum clearance and in addition, according to the extent of nodal involvement, mono- or bilateral neck dissection. To avoid ineffective reoperation due to distant (mainly liver) micro-metastases, persistent residual microscopic disease requires a more aggressive restaging.

Predictivity of clinical, laboratory and imaging findings in diagnostic definition of palpable thyroid nodules. A multicenter prospective study

PURPOSE

To assess the role of clinical, biochemical, and morphological parameters, as added to cytology, for improving pre-surgical diagnosis of palpable thyroid nodules.

METHODS

Patients with a palpable thyroid nodule were eligible if surgical intervention was indicated after a positive or suspicious for malignancy FNAC (TIR 4-5 according to the 2007 Italian SIAPEC-IAP classification), or two inconclusive FNAC at a ≥3 months interval, or a negative FNAC associated with one or more risk factor. Reference standard was histological malignancy diagnosis. Likelihood ratios of malignancy, sensitivity, specificity, negative (NPV), and positive predictive value (PPV) were described. Multiple correspondence analysis (MCA) and logistic regression were applied.

RESULTS

Cancer was found in 433/902 (48%) patients. Considering TIR4-5 only as positive cytology, specificity, and PPV were high (94 and 91%) but sensitivity and NPV were low (61 and 72%); conversely, including TIR3 among positive, sensitivity and NPV were higher (88 and 82%) while specificity and PPV decreased (52 and 63%). Ultrasonographic size ≥3 cm was independently associated with benignity among TIR2 cases (OR of malignancy 0.37, 95% CI 0.18-0.78). In TIR3 cases the hard consistency of small nodules was associated with malignity (OR: 3.51, 95% CI 1.84-6.70, p < 0.001), while size alone, irrespective of consistency, was not diagnostically informative. No other significant association was found in TIR2 and TIR3.

CONCLUSIONS

The combination of cytology with clinical and ultrasonographic parameters may improve diagnostic definition of palpable thyroid nodules. However, the need for innovative diagnostic tools is still high.

99MTc-mibi Radio-guided Surgery in Primary Hyperparathyroidism: A Prospective Study of 128 Patients

Aims and study design

We investigated the role of an intraoperative gamma probe (IGP) technique in 128 patients with primary hyperparathyroidism (HPT). The patients were evaluated before surgery by 99mTcO4/MIBI scintigraphy and neck ultrasound and then operated on by the same surgical team. The IGP technique consisted of the injection of a low dose (37 MBq) of 99mTc-MIBI in the operating room shortly before the start of surgery. Quick parathyroid hormone (QPTH) was routinely measured during the operation.

Results

In 94/97 patients (96.9%) with a preoperative diagnosis of solitary parathyroid adenoma (PA) minimally invasive radioguided surgery (MIRS) was successfully performed; in the other 3/97 patients (3.1%) conversion to bilateral neck exploration (BNE) was required because of the intraoperative diagnosis of parathyroid carcinoma in two cases and multiglandular disease (MGD) in one. MIRS was successfully performed also in 23 patients who had undergone previous thyroid or parathyroid surgery. In 31 patients with a preoperative diagnosis of MGD (n = 5) or concomitant nodular goiter (n = 26) the IGP technique was used during a bilateral neck exploration. Among these patients IGP was useful in localizing an ectopic parathyroid gland in the thymus in one case of MGD and a PA located deep in the neck (n = 2) or ectopic at the carotid bifurcation (n = 1) in three cases with nodular goiter. However, in several other patients with nodular goiter it was difficult for the probe to distinguish intraoperatively between thyroid nodules and PA located close to the thyroid gland.

Conclusions

It can be concluded that a) in primary HPT patients with a high likelihood (according to scintigraphic and ultrasound findings) of being affected by a single PA and with a normal thyroid gland, the IGP technique appears useful in MIRS; b) a 99mTc-MIBI dose as low as 37 MBq appears to be adequate to perform MIRS; c) the measurement of QPTH is strongly recommended in HPT patients selected for MIRS to confirm the radicality of parathyroidectomy; d) MIRS can be useful also in HPT patients who underwent previous parathyroid or thyroid surgery to limit the surgical trauma of reoperation and minimize complications; e) with the exception of PAs located at ectopic sites or deep in the neck, the IGP technique does not seem to be recommendable in HPT patients with concomitant nodular goiter.

Thyroid Cancer in Children and Adolescents

Aims and background

It was the aim of this paper to report clinical and pathologic characteristics and outcome of treatment in terms of relapse-free and overall survival in 36 patients under 20 years of age and treated for thyroid cancer at Padua University Hospital from January 1968 to December 1988 and followed until December 1992.

Methods

The median follow-up was 112 months (range 3 to 228 months). Age at diagnosis ranged from 4 to 20 years with a mean age of 15 years and a male/female ratio of 1:2.9. A thyroid nodule or a laterocervical mass was the most frequent sign of presentation. The routine diagnosis schedule included thyroid scintigram, neck echotomography and in the last decade fine needle aspiration biopsy.

Results

Sixteen (28%) patients had a family history of thyroid disease. Histology revealed that papillary carcinoma was present in 43 patients (76.8%), follicular carcinoma in 9 (16%), medullary carcinoma in 2 (3.6%) and lymphoma in 2 (3.6%). Fifty-four patients were treated with total thyroidectomy, of these 34 had bilateral neck dissection and 20 unilateral nodal dissection; 2 patients underwent simple lobectomy with unilateral dissection. Nodal involvement was present in 41 (73%) cases, and synchronous visceral metastases were detected with scan and/or chest X-ray in 10 (18%) cases. In the case of differentiated thyroid carcinoma, patients with residual disease or thyroid remnants were treated with 131I metabolic therapy. All patients were put on suppressive hormone therapy. At this writing, 52 (93%) patients were in complete remission and 4 (7%) had persistent disease. Recurrences developed in 2 (3.5%) patients: one presented lung metachronus metastases and one local recurrence; no deaths have occurred.

Conclusions

From this experience, total thyroidectomy appears to be the appropriate approach for differentiated tumors in children and adolescents because the disease is often diffuse, secondary deposits may be easily detected, and the value of thyroglobulin measurement can be improved. Following this strategy, overall recurrence risk was low and 131I therapy was curative in patients with nodal and lung metastases.

Prognostic Value of Early Postoperative Calcitonin Level in Medullary Thyroid Carcinoma

Aims

Serum calcitonin (CT) assay is commonly used in the diagnosis and follow-up of medullary thyroid carcinoma (MTC). The aim of this study was to ascertain whether serum CT levels, measured in the first few days after surgery, could be used to evaluate the efficacy of treatment.

Methods

A group of 33 patients was studied. In all patients the follow-up was more than 20 months.

Results

Preoperatively basal CT serum levels were high in all patients. Twenty-four hours after surgery CT serum levels dropped to within the normal range in 8 patients and 72 hours after operation in 7 others. In this group 1 patient was at stage I, 11 at stage II and 3 at stage III. Basal and pentagastrin stimulated CT levels continued to be in the normal range in these 15 patients 6 and 12 months after surgery and at the subsequent year by follow-up visits. No clinical or radiological evidence of disease was found during the follow-up in this group. In the other 18 patients CT was reduced but still high 72 hours after surgery; 6 months later basal serum CT levels continued to be elevated or responsive to pentagastrin stimulation. In this group restaging showed tumor relapse in the thyroid bed in 2 patients, cervical lymphadenopathy in 11, and distant metastases (bone, liver) in 3.

Conclusions

Immediate postoperative CT serum levels seem to be the most useful index to evaluate the efficacy of surgical treatment and the presence of residual neoplastic tissue.

Frequency of Thyroid Carcinoma in a Recent Series of 539 Consecutive Thyroidectomies for Multinodular Goiter

Aims and background

The aim of the study was to analyze the frequency of thyroid carcinoma in a consecutive series of 539 thyroidectomies for multinodular goiter (MNG) and to assess the influence of sex and age as cancer risk factors.

Methods

In a 2-year period, 539 patients underwent subtotal or total thyroidectomy for MNG at the Institute of General Surgery, University of Padova, Padova, Italy: 455 were females and 84 males (F/M = 5.5/1); mean age was 46 years (min. 17, max 78). Only 17 patients (3.1%) (16 females and 1 male) were aged 21 years or less.

Results

A malignancy was found in 41 patients: 38 females and 3 males; 39 older and 2 younger than 21 years. The frequency of cancer in MNG was 7.6%: 8.3% in females and 3.6% in males; 7.5% in patients older than 21 and 11.7% under 21 years.

Conclusions

The combination of MNG and carcinoma should always be carefully considered but not overemphasized, and the policy of surgically treating all patients with MNG is not justified. Sex and age cannot be considered as factors of a higher risk of cancer.

Favorable Long Term Results in Patients with Small Differentiated Thyroid Cancer not Treated with Radioiodine

Data on a group of 110 patients with differentiated thyroid cancer not treated by radioiodine are reported. Most of them had intrathyroid (stage I) papillary or capsuled follicular cancer of less than 3 cm diameters. They all received thyroxine at TSH suppressive doses. The follow-up ranged between 4 and 25 years, mean 8.7. No patient died of tumor. Two very old patients died free of disease. Four recurrences occurred, within 8 years, all in patients over 45 years, all local or nodal, all papillary, 3 out of 4 after total thyroidectomy. This study shows that radioiodine therapy may be avoided and that lobectomy may be sufficient in patients under 45 years with small papillary or capsuled follicular cancer.

High Prevalence of Occult Papillary Thyroid Carcinoma in a Surgical Series for Benign Thyroid Disease

In a surgical series of 277 consecutive patients operated on the thyroid for benign diseases, a high prevalence rate (10.5%) of occult papillary carcinoma was found by means of an accurate histologic examination. Indications for surgery were euthyroid multinodular goiter in 25 patients, autonomously hyperfunctioning adenoma in 2 and Graves’ disease in 2 patients. Neoplastic foci were unilaterally found in 25 cases but multifocally in 6 and bilaterally in 4 cases: the diameters ranged from 2-10 mm. After operation (14 subtotal and 15 total thyroidectomies), all patients received TSH-suppressive doses of T4. At a mean follow-up of 5.6 years, neither local recurrences nor lymph node or distant metastases had occurred; no patient died of the tumor. In keeping with other surgical and autopsy series, the prevalence of occult thyroid carcinoma in a normal population is calculated to be about 5-10%, whereas it is known that the prevalence of clinically evident thyroid cancer is only 0.05%. This means that only 1-2% of occult carcinomas may evolve in an overt tumor during life. In view of such an epidemiologic difference and the favorable course of our patients, although the mean follow-up is rather short, we suggest that lobectomy plus T4 treatment may be considered an adequate therapeutic approach in patients with occult papillary thyroid carcinoma.

Primary Squamous Cell Carcinoma of the Thyroid: Immunohistochemical Profile and Literature Review

Background

Squamous cell carcinoma accounts for 1% of primary thyroid malignancies and is characterized by a rapidly unfavorable outcome.

Case Presentation

A 64-year-old woman presented with a painless mass in the left neck, coexisting with thyroid goiter. Total thyroidectomy with lymphadenectomy was performed and a primary thyroid squamous cell cancer was confirmed histo-logically after excluding any other possible primary malignancies. The tumor's immunohistochemical profile was explored using a large panel of antibodies. The tumor featured a positive immunoreaction to cytokeratins 7–19 and to squamous cell carcinoma antigen. Low-molecular-weight cytokeratins 5–6 and epithelial membrane antigen were also expressed. The neoplasm's proliferative index (Mib1) was 60%. No immunostaining was detected for cytokeratins 10–20, thyroglobulin, TTF-1, CD5, galectin-3 or p53.

Conclusions

This case of primary thyroid squamous cell carcinoma immunohistochemically profiled using a large panel of immunoreactions may offer useful information on the histological differentiation of thyroid squamous cell carcinoma from other (uncommon) thyroid carcinomas and the distinction between primary and secondary thyroid cancers.

Specifying the molecular pattern of sporadic parathyroid tumorigenesis-The Y282D variant of the GCM2 gene

OBJECTIVE

Sporadic carcinoma of the parathyroid glands is a rare malignant neoplasia. The GCM2 gene encodes a transcription factor that is crucial to embryonic parathyroid development. The Y282D variant of GCM2 exhibits increased transcriptional activity, and the presence of this variant is significantly associated with a higher prevalence of primitive hyperparathyroidism. The present study investigated the prevalence of the Y282D variant of the GCM2 gene and its association with clinical parameters in patients with a definitive histological diagnosis of sporadic parathyroid carcinoma (SPC) or atypical adenoma (AA).

Aberrant right subclavian artery ("arteria lusoria") without the known associated nerve anomaly: an "anomaly of the anomaly"? A clinical case and review of the literature

The "non-recurrent" course of the inferior laryngeal nerve (ILN) is an anatomical variant which must be borne in mind during thyroid surgery. The "non-recurrent" course of the ILN on the right side is associated with the aberrant right subclavian artery (arteria lusoria), and, on the left, is described in situs viscerum inversus. We present a case in which the "arteria lusoria" was not associated with the non-recurrent right ILN. The aims of this paper are to report this "anomaly of the anomaly" to surgeons who may be unaware of it on the one hand and on the other to emphasize that this is the only case so far reported in the literature. Moreover we proposed to explain embryologically these unexpected findings.

Surgical treatment of thyroid follicular neoplasms: results of a retrospective analysis of a large clinical series

The most appropriate surgical management of "follicular neoplasm/suspicious for follicular neoplasm" lesions (FN), considering their low definitive malignancy rate and the limited predictive power of preoperative clinic-diagnostic factors, is still controversial. On behalf of the Italian Association of Endocrine Surgery Units (U.E.C. CLUB), we collected and analyzed the experience of 26 endocrine centers by computerized questionnaire. 1379 patients, surgically treated after a FN diagnosis from January 2012 and December 2103, were evaluated. Histological features, surgical complications, and medium-term outcomes were reported. Total thyroidectomy (TT) was performed in 1055/1379 patients (76.5 %), while hemithyroidectomy (HT) was carried out in 324/1379 cases (23.5 %). Malignancy rate was higher in TT than in HT groups (36.4 vs. 26.2 %), whereas the rates of transient and definitive hypoparathyroidism following TT were higher than after HT. Consensual thyroiditis (16.8 vs. 9.9 %) and patient age (50.9 vs. 47.9 %) also differed between groups. A cytological FN diagnosis was associated to a not negligible malignancy rate (469/1379 patients; 34 %), that was higher in TT than in HT groups. However, a lower morbidity rate was observed in HT, which should be considered the standard of care in solitary lesions in absence of specific risk factors. Malignancy could not be preoperatively assessed and clinical decision-making is still controversial. Further efforts should be spent to more accurately preoperatively classify FN thyroid nodules.

Estrogen and thyroid cancer is a stem affair: A preliminary study

Gender influences Papillary Thyroid Cancer (PTC) with an incidence of 3:1 when comparing women to men with different aggressiveness. This gender discrepancy suggests some role of sex hormones in favoring the malignant progression of thyroid tissue to cancer. Estrogens are known to promote Stem Cell self-renewal and, therefore, may be involved in tumor initiation. The goals of these studies are to investigate the underlying causes of gender differences in PTC by studying the specific role of estrogens on tumor cells and their involvement within the Cancer Stem Cell (CSC) compartment. Exposure to 1nmoll^-1 Estradiol for 24h promotes growth and maintenance of PTC Stem Cells, while inducing dose-dependent cellular proliferation and differentiation following Estradiol administration. Whereas mimicking a condition of hormonal imbalance led to an opposite phenotype compared to a continuous treatment. In vivo we find that Estradiol promotes motility and tumorigenicity of CSCs. Estradiol-treated mice inoculated with Thyroid Cancer Stem Cell-enriched cells developed larger tumor masses than control mice. Furthermore, Estradiol-pretreated Cancer Stem cells migrated to distant organs, while untreated cells remained circumscribed. We also find that the biological response elicited by estrogens on Papillary Thyroid Cancer in women differed from men in pathways mediated. This could explain the gender imbalance in tumor incidence and development and could be useful to develop gender specific treatment of (PTC).

BRAF analysis before surgery for papillary thyroid carcinoma: correlation with clinicopathological features and prognosis in a single-institution prospective experience

Background:

Risk stratification in patients with papillary thyroid carcinoma (PTC) currently relies on postoperative parameters. Testing forBRAFmutations preoperatively may serve as a novel tool for identifying PTC patients at risk of persistence/recurrence after surgery.

Methods:

The study involved 185 consecutive patients with a histological diagnosis of PTC andBRAFanalysis performed on thyroid fine-needle aspiration biopsy (FNAB). We assessedBRAFstatus in FNAB specimens obtained before thyroidectomy for PTC, and examined its association with the clinicopathological characteristics identified postoperatively, and with outcome after a mean 55±15 months of follow-up.

Results:

One hundred and fifteen of 185 (62%) PTCs carried aBRAFmutation. Univariate analysis showed thatBRAFstatus correlated with the histological variant of PTC, cancer size, and stage at diagnosis, but not with gender, age, multifocality, or lymph node involvement.BRAF-mutated cases had a higher prevalence of persistent/recurrent disease by the end of the follow-up (11% vs. 8%), but this difference was not statistically significant. The Kaplan-Meier curve shows that among the patients with persistent/recurrent disease,BRAF-mutated patients needed a second treatment earlier than patients withBRAFwild-type, although the difference did not completely reach the statistical significance.

Conclusions:

Our study confirmed that preoperatively-identifiedBRAFmutation are associated with certain pathological features of PTC that correlate with prognosis. We speculate that it has a role in identifying PTCs that would generally be considered low-risk but that may reveal an aggressive behavior during their follow-up.

Diagnostic, therapeutic and health-care management protocol in thyroid surgery: a position statement of the Italian Association of Endocrine Surgery Units (U.E.C. CLUB)

PURPOSE

The diagnostic, therapeutic and health-care management protocol (Protocollo Gestionale Diagnostico-Terapeutico-Assistenziale, PDTA) by the Association of the Italian Endocrine Surgery Units (U.E.C. CLUB) aims to help treat the patient in a topical, rational way that can be shared by health-care professionals.

METHODS

This fourth consensus conference involved: a selected group of experts in the preliminary phase; all members, via e-mail, in the elaboration phase; all the participants of the XI National Congress of the U.E.C. CLUB held in Naples in the final phase. The following were examined: diagnostic pathway and clinical evaluation; mode of admission and waiting time; therapeutic pathway (patient preparation for surgery, surgical treatment, postoperative management, management of major complications); hospital discharge and patient information; outpatient care and follow-up.

RESULTS

A clear and concise style was adopted to illustrate the reasons and scientific rationales behind behaviors and to provide health-care professionals with a guide as complete as possible on who, when, how and why to act. The protocol is meant to help the surgeon to treat the patient in a topical, rational way that can be shared by health-care professionals, but without influencing in any way the physician-patient relationship, which is based on trust and clinical judgment in each individual case.

CONCLUSIONS

The PDTA in thyroid surgery approved by the fourth consensus conference (June 2015) is the official PDTA of U.E.C. CLUB.

The expression of the truncated isoform of somatostatin receptor subtype 5 associates with aggressiveness in medullary thyroid carcinoma cells

The truncated somatostatin receptor variant sst5TMD4 associates with increased invasiveness and aggressiveness in breast cancer. We previously found that sst5 activation may counteract sst2 selective agonist effects in a medullary thyroid carcinoma (MTC) cell line, the TT cells, and that sst5TMD4 is overexpressed in poorly differentiated thyroid cancers. The purpose of this study is to evaluate sst5TMD4 expression in a series of human MTC and to explore the functional role of sst5TMD4 in TT cells. We evaluated sst5TMD4 and sst5 expression in 36 MTC samples. Moreover, we investigated the role of sst5TMD4 in TT cells evaluating cell number, DNA synthesis, free cytosolic calcium concentration ([Ca(2+)]i), calcitonin and vascular endothelial growth factor levels, cell morphology, protein expression, and invasion. We found that in MTC the balance between sst5TMD4 and sst5 expression influences disease stage. sst5TMD4 overexpression in TT cells confers a greater growth capacity, blocks sst2 agonist-induced antiproliferative effects, modifies the cell phenotype, decreases E-cadherin and phosphorylated β-catenin levels, increases vimentin, total β-catenin and phosphorylated GSK3B levels (in keeping with the development of epithelial to mesenchymal transition), and confers a greater invasion capacity. This is the first evidence indicating that sst5TMD4 is expressed in human MTC cells, where it associates with more aggressive behavior, suggesting that sst5TMD4 might play a functionally relevant role.

Synergistic antitumour activity of RAF265 and ZSTK474 on human TT medullary thyroid cancer cells

Medullary thyroid cancer (MTC) is an aggressive malignancy responsible for up to 14% of all thyroid cancer-related deaths. It is characterized by point mutations in the rearranged during transfection (RET) proto-oncogene. The activated RET kinase is known to signal via extracellular signal regulated kinase (ERK) and phosphoinositide 3-kinase (PI3K), leading to enhanced proliferation and resistance to apoptosis. In the present work, we have investigated the effect of two serine/threonine-protein kinase B-Raf (BRAF) inhibitors (RAF265 and SB590885), and a PI3K inhibitor (ZSTK474), on RET-mediated signalling and proliferation in a MTC cell line (TT cells) harbouring the RETC634W activating mutation. The effects of the inhibitors on VEGFR2, PI3K/Akt and mitogen-activated protein kinases signalling pathways, cell cycle, apoptosis and calcitonin production were also investigated. Only the RAF265+ ZSTK474 combination synergistically reduced the viability of treated cells. We observed a strong decrease in phosphorylated VEGFR2 for RAF265+ ZSTK474 and a signal reduction in activated Akt for ZSTK474. The activated ERK signal also decreased after RAF265 and RAF265+ ZSTK474 treatments. Alone and in combination with ZSTK474, RAF265 induced a sustained increase in necrosis. Only RAF265, alone and combined with ZSTK474, prompted a significant drop in calcitonin production. Combination therapy using RAF265 and ZSTK47 proved effective in MTC, demonstrating a cytotoxic effect. As the two inhibitors have been successfully tested individually in clinical trials on other human cancers, our preclinical data support the feasibility of their combined use in aggressive MTC.

The PDCD4/miR-21 pathway in medullary thyroid carcinoma

Programmed cell death 4 (PDCD4) is a tumor suppressor gene involved in tumorogenesis. MicroRNA-21 (miR-21) specifically targets PDCD4, and recent studies suggest that PDCD4 is also regulated by Akt (antiapoptotic regulator within phosphatidylinositol 3-kinase). Medullary thyroid carcinoma (MTC) is a rare neuroendocrine cancer, and disease stage at diagnosis represents the main prognostic indicator. A consecutive series of 64 MTCs was considered. REarranged during Transfection (RET) and rat sarcoma (RAS) mutation status was assessed by direct sequencing. Quantitative real-time polymerase chain reaction was used to quantify mature hsa-miR-21. PDCD4 and Ki-67 immunostaining was performed with an automated platform. Immunoblot analysis of PI3K/Akt pathway was done on thyroid tissues. MTCs were consistently associated with miR-21 up-regulation (P < .0016) and featured significant PDCD4 nuclear down-regulation. An inverse correlation emerged between miR-21 overexpression and PDCD4 down-regulation (P = .0013). At enrollment, high miR-21 levels were associated with high calcitonin levels (P = .0003), lymph node metastases (P = .001), and advanced stages (P = .0003). At the end of follow-up, high miR-21 levels were associated with biochemically persistent disease (P = .0076). At enrollment, instead, PDCD4 nuclear down-regulation was associated with high calcitonin levels (P = .04), more advanced stages of disease (P < .01), and persistent disease after the follow-up (P = .02). p-Akt was more expressed in RAS-mutated MTC than in nonmutated cancers and normal tissue. This study showed, in MTCs, that miR-21 regulates PDCD4 expression and also that the miR-21/PDCD4 pathway correlates with clinicopathological variables and prognosis. Further studies should investigate the role of miR-21 as a prognostic biomarker and the feasibility of using PDCD4-restoring strategies as a therapeutic approach to MTC.

Complications in thyroid resurgery: a single institutional experience on 233 patients from a whole series of 4,752 homogeneously treated patients

The aim of this study was to examine a homogeneous, consecutive recent series of patients who underwent reoperation on the thyroid bed to assess the incidence of the complications commonly correlated with resurgery. We reviewed clinical charts of 233 patients who underwent resurgery taken from a total of 4,752 patients previously operated on for benign and malignant thyroid diseases from 2006 to 2010 by the same surgical team. We evaluated the incidence of postoperative hemorrhage, hypoparathyroidism, and recurrent laryngeal nerve (RLN) palsy. Analyses were done separately in relation to the type of the type of resurgery adopted: (A) monolateral completion; (B) bilateral completion, after monolateral (B1) or bilateral prior surgery (B2); and (C) lymph node dissection. We also separately analyzed patients according to their final histological diagnosis of benign or malignant disease. Regarding hemorrhage, 6/233 patients (2.5 %) underwent surgical revision of the thyroid within 12 h for postoperative hemorrhage. They included 2 (1.5 %) of the 129 monolateral reoperations (A), 3 (4 %) of the 74 bilateral reoperations (B), and 1 (3.3 %) of the 30 central dissections for nodal relapse (C). Transient and definitive postoperative hypoparathyroidism was recorded in 78 (36.4 %) and 7 (3.3 %) of the 214 eligible patients. Transient RLN palsy occurred in 21 RLNs at risk (7 %) and definitive RLN palsy in 5 (1.7 %). Elective total thyroidectomy cannot always be supported as an effective policy for preventing recurrences in patients with a single, benign node: lobectomy, preferably with extemporaneous histological examination, unquestionably represents the best minimal approach to thyroid resection.

AHR over-expression in papillary thyroid carcinoma: clinical and molecular assessments in a series of Italian acromegalic patients with a long-term follow-up

AIM

Acromegaly reportedly carries an increased risk of malignant and benign thyroid tumors, with a prevalence of thyroid cancer of around 3-7%. Germline mutations in the aryl-hydrocarbon receptor (AHR) interacting protein (AIP) have been identified in familial forms of acromegaly. The molecular and endocrine relationships between follicular thyroid growth and GH-secreting pituitary adenoma have yet to be fully established. Our aim was to study the prevalence of differentiated thyroid cancer (DTC) in acromegaly, focusing on the role of genetic events responsible for the onset of thyroid cancer.

METHODS

Germline mutations in the AIP gene were assessed in all patients; BRAF and H-N-K RAS status was analyzed by direct sequencing in thyroid specimens, while immunohistochemistry was used to analyze the protein expression of AIP and AHR. A set of PTCs unrelated to acromegaly was also studied.

RESULTS

12 DTCs (10 papillary and 2 follicular carcinomas) were identified in a cohort of 113 acromegalic patients. No differences in GH/IGF-1 levels or disease activity emerged between patients with and without DTC, but the former were older and more often female. BRAF V600E was found in 70% of the papillary thyroid cancers; there were no RAS mutations. AIP protein expression was similar in neoplastic and normal cells, while AHR protein was expressed more in PTCs carrying BRAF mutations than in normal tissue, irrespective of acromegaly status.

CONCLUSIONS

The prevalence of DTC in acromegaly is around 11% and endocrinologists should bear this in mind, especially when examining elderly female patients with uninodular goiter. The DTC risk does not seem to correlate with GH/IGF-1 levels, while it may be associated with BRAF mutations and AHR over-expression. Genetic or epigenetic events probably play a part in promoting thyroid carcinoma.

Hyperhomocysteinemia is an independent predictor of sub-clinical carotid vascular damage in subjects with grade-1 hypertension

Although the role of homocysteinemia (Hcy) as a coronary risk factor (RF) has been scaled down, hyper-Hcy and carotid vascular damage (CVD) are still considered as RFs for cerebrovascular events. In 276 grade-1 hypertensives (160 men and 116 women aged 59.6 ± 15.0 years) without known cardiovascular disease and having hyper-Hcy (≥15 μM/L), subclinical CVD was evaluated by ultrasonographic carotid-wall intima media thickness (IMT). Hcy was divided into quartiles and C667→T polymorphism codifying for methylenetetrahydrofolate reductase (MTHFR) was determined. According to the genotype, subjects were divided into CC (wild), CT (heterozygote) and TT (homozygous mutation). Differences between continuous variables were evaluated by analysis of variance, while gender specific odds ratio (OR) and 95 % confidence intervals (CI) of CVD (IMT >0.9 mm or plaque) were calculated by multivariate logistic regression analysis. Blood pressure (BP) values were not different across the quartiles of Hcy. In 46.4 % of cases, sub-clinical CVD was found, with a prevalence increasingly distributed in the quartiles of Hcy (31.9, 42, 52.2, 59.4 %, p < 0.001). Prevalence of TT allele of the MTHFR genotype was also significantly distributed in the quartiles of Hcy (13.6, 12.3, 23.5 and 50.6 %, p < 0.0001), whereas no relationship was found between genotype and CVD. The last quartile of Hcy predicted CVD (OR 1.32, CI 1.12-2.2, p = 0.02) independent of age (OR 1.23, CI 1.002-1.56, p = 0.0001), systolic BP (OR 1.52, CI 1.24-2.10), diabetes (OR 2.11, CI 1:32-2.88, p = 0.01) and smoking (OR 1.45, CI 1.14-1.98, p = 0.04). Adding gender did not modify the model. In hypertensives, Hcy values >36.5 μM/L independently predict CVD and in those who are also diabetic and smokers, Hcy assessment without MTHFR genotype should be recommended to obtain a better stratification of global cerebrovascular risk.

High-throughput mutation profiling improves diagnostic stratification of sporadic medullary thyroid carcinomas

Sporadic medullary thyroid carcinoma (MTC) harbors RET gene somatic mutations in up to 50 % of cases, and RAS family gene mutations occur in about 10 %. A timely and comprehensive characterization of molecular alterations is needed to improve MTC diagnostic stratification and design-tailored therapeutic approaches. Twenty surgically resected sporadic MTCs, previously analyzed for RET mutations by Sanger sequencing using DNA from formalin-fixed paraffin-embedded samples, were investigated for intragenic mutations in 50 cancer-associated genes applying a multigene Ion AmpliSeq next-generation sequencing (NGS) technology. Thirteen (65 %) MTCs harbored a RET mutation; 10 were detected at both Sanger and NGS sequencing, while 3 undetected by Sanger were revealed by NGS. One of the 13 RET-mutated cases also showed an F354L germline mutation in STK11. Of the seven RET wild-type MTCs, four cases (57.1 %) harbored a RAS mutation: three in HRAS (all Q61R) and one in KRAS (G12R). The three remaining MTCs (15 %) resulted as wild-type for all the 50 cancer-related genes. Follow-up was available in all but one RET-mutated case. At the end of follow-up, 7 of 12 (58 %) RET-mutated patients had relapsed, while the 4 RAS-mutated MTC patients were disease-free. Two of the three patients with MTC wild-type for all 50 genes relapsed during the follow-up period. Detection of mutations by NGS has the potential to improve the diagnostic stratification of sporadic MTC.

Refining calcium test for the diagnosis of medullary thyroid cancer: cutoffs, procedures, and safety

CONTEXT

Calcitonin (CT) measurement is crucial to the early diagnosis and the follow-up of medullary thyroid cancer (MTC). If the evaluation of stimulated CT levels is required, a provocative test can be performed, being the high-dose Ca test recently reintroduced in clinical practice.

OBJECTIVE

Our objective was to identify gender-specific thresholds for MTC diagnosis in a large series of patients who underwent the Ca test.

PATIENTS AND METHODS

A total of 91 patients (49 females and 42 males) underwent the Ca test (calcium gluconate, 25 mg/kg) before thyroidectomy and both basal CT (bCT) and stimulated CT (sCT) were compared with histological results by receiver operating characteristic plot analyses. To evaluate possible side effects of Ca administration, cardiac function has been extensively studied.

RESULTS

bCT levels were found to harbor the same accuracy as sCT in the preoperative diagnosis of MTC. The best Ca thresholds for the identification of MTC were >26 and >68 for bCT and >79 and >544 pg/mL for sCT in females and males, respectively. The high tolerability and safety of the Ca test was demonstrated and advice offered to be followed before and during the test.

CONCLUSIONS

Gender-specific bCT and sCT cutoffs for the identification of C-cell hyperplasia and/or MTC have been defined. The bCT and sCT were found to have a similar accuracy, indicating that serum CT assays with improved functional sensitivity may likely decrease the relevance of the stimulation test in several conditions. Finally, systematic cardiac monitoring confirms the safety of the Ca test.

Prevalence, tumorigenic role, and biochemical implications of rare BRAF alterations

BACKGROUND

Papillary thyroid carcinoma (PTC) is the most common malignant tumor of the thyroid gland, accounting for 74-80% of all thyroid cancers. The 1799T>A transversion is an activating mutation of the BRAF oncogene that is common in and specific to conventional PTC. We studied the prevalence, tumorigenic role, and biochemical implications of rare BRAF variants in a large cohort of patients.

METHODS

A total of 2131 fine-needle aspiration biopsy samples were collected and subjected to BRAF mutation analysis. BRAF genetic variants were analyzed by Western blot, immunofluorescence, and in silico analysis.

RESULTS

BRAF mutations were found in 50% (347/700) of thyroid cancers (644 PTCs, 22 anaplastic thyroid carcinomas, 34 follicular thyroid carcinomas). They were the classic (c.1799T>A, p.V600E) mutation in 96.8% (336/347) and rare genetic variants in 3.2% (11/347). In all, five infrequent BRAF alterations were detected: (i) c.1795_1797dupACA (p.T599dup); (ii) c.1801A>G (p.K601E); (iii) c.1799_1801delTGA (p.V600_K601>E); (iv) c.1799_1814>A (p.V600_S605>D); and (v) c.1798_1810delinsA (p.V600_W604>R). The last BRAF variant has never been described in the literature. Western blot analysis and immunofluorescence both revealed a variegated reactivity pattern, again emphasizing the peculiar role of every specific BRAF genetic alteration. In silico analysis of the samples studied revealed a stabilization of the "active" geometrical conformation of the B-raf enzyme associated with the activated and productive state of the kinase domain.

CONCLUSIONS

Rare BRAF variants were found in 1.6% of all thyroid malignancies, all clustered around the codon V600, in the binding pocket named A-loop, confirming its crucial role in the enzymatic activation of the B-Raf protein. These mutations were associated mainly with the activation of key effectors in the mitogen-activated protein kinase pathway, but a simultaneous stimulation of the PI3k/Akt cascade was demonstrated in some cases. The rare BRAF variants were not generally associated with an aggressive behavior of the PTC. To our knowledge, this is the largest series of thyroid cancers analyzed to identify and functionally characterize rare BRAF variants.

A very rare bilateral adrenal tumor

We report a case of very rare adrenal tumor. A 54-year-old patient was classified as affected by bilateral adrenal incidentaloma that surprisingly, on histology resulted solitary fibrous tumors. Solitary fibrous tumor (SFT) is an uncommon mesenchymal neoplasm. Only five cases of localization of SFT in adrenal gland are reported in the literature, while the frequency of retroperitoneum localization is more frequent, about 30 cases. Immunohistochemically, SFT can be positive for CD34 antigen, vimentin, CD99, and bcl-2 and usually negative for cytokeratins, chromogranin A, NSE, neurofilaments, synoptophysin, and S-100. Surgical excision remains the main treatment in fact the recurrence is locoregional and correlated with positive margins due to incomplete excision, while distant metastases are correlated with atypical or malignant features.

Incidental medullary thyroid microcarcinoma revealed by mild increase of preoperative serum calcitonin levels: therapeutic implications

To investigate whether further, diagnostic procedures should be recommended in patients with slight increase of preoperative serum basal calcitonin (bCT) levels in whom surgical treatment can be recommendable. Fourteen consecutive patients with nodular thyroid disease underwent thyroidectomy in our center for suspected medullary thyroid microcarcinoma (MTC) because their serum bCT levels were slightly higher than the upper limit of normal range. Serum bCT was measured by radioimmunoassay, normality range = 0-20 ng/L. Surgical specimens were examined by the same pathologist using histologic and immunohistochemistry techniques. An extensive search for parafollicular C-cell hyperplasia (CCH) and/or microscopic MTC foci was performed. At preoperative ultrasound, a single thyroid nodule was depicted in three patients while a multinodular goiter in 11. The bCT values ranged between 24.4 and 94.6 ng/L, median 42.2 ng/L while the pentagastrin-stimulated CT (sCT) values by pentagastrin test ranged between 61.5 and 1,262 ng/L, median 245.0 ng/L. Total thyroidectomy was performed in 13 patients, and lobectomy in the other one; central node dissection was also performed in eight cases. At histology, MTC was diagnosed in nine patients (64.3 %), showing a median maximum diameter of 6.1 mm (range, 1.5-17 mm); CCH was diagnosed in the other five patients (35.7 %). The pentagastrin stimulation test was obtained in all patients. It is worth noting that a very high increase of sCT >100 ng/mL was observed in 5/9 patients with MTC and in 2/4 patients with HCC, therefore suggesting the absence of a relationship between the entity of response to pentagastrin test with a specific pathology (MTC vs. HCC). In six patients, the MTC was the nodule on which preoperative FNAC had been performed, while in other three patients preoperative FNAC had been performed on a different nodule from the MTC. Based on our experience, in case of the pentagastrin stimulation test with sCT <100 ng/L and a single nodule, the CT assay on FNAC may be useful, subsequently lobectomy with definitive histological diagnosis is recommended. In case of the Pg test with sCT <100 ng/L and bilateral goiter, total thyroidectomy with histological diagnosis is recommended. In this way, as for the surgical procedure, total thyroidectomy is recommended in cases of bilateral goiter, while lobectomy can be offered for cases with single nodes with serum dosage of bCT in the strict follow up. In case of the pentagastrin stimulating test with sCT <100 ng/L and bilateral goiter, total thyroidectomy with histological diagnosis is recommended.

The role of BRAF(V600E) mutation as poor prognostic factor for the outcome of patients with intrathyroid papillary thyroid carcinoma

BACKGROUND

BRAF(V600E) mutation, which represents the most frequent genetic mutation in papillary thyroid carcinoma (PTC), is widely considered to have an adverse outcome on PTC outcome, however its real predictive value is not still well stated. The aim of the present study was to evaluate if BRAF(V600E) mutation could be useful to identify within patients with intrathyroid ultrasound-N0 PTC those who require more aggressive treatment, by central neck node dissection (CLND) or subsequent postoperative (131)I treatment.

METHODS

Among the whole series of 931 consecutive PTC patients operated on at 2nd Clinical Surgery of University of Padova and at General Surgery Department of University of Trieste during a period from January 2007 to December 2012, we selected 226 patients with an intrathyroid tumor and no metastases (preoperative staging T1-T2, N0, M0). BRAF(V600E) mutation was evaluated by PCR-single-strand conformation polymorphism analysis and direct genomic sequencing. We analyzed the correlation between the presence/absence of the BRAF(V600E) mutation in the fine-needle aspiration (FNA) and the clinical-pathological features: age, gender, extension of surgery, node dissection, rate of cervical lymph node involvement, tumor size, TNM stage, variant of histotype, mono/plurifocality, association with lymphocitary chronic thyroiditis, radioactive iodine ablation doses, and outcome.

RESULTS

The BRAF(V600E) mutation was present in 104 of 226 PTC patients (47.8%). BRAF(V600E) mutation correlated with multifocality, more aggressive variants, infiltration of the tumoral capsule, and greater tumor's diameter. BRAF(V600E) mutation was the only poor prognostic factor in these patients.

DISCUSSION

In our series, BRAF(V600E) mutation demonstrated to be an adverse prognostic factor indicating aggressiveness of disease and it could be useful in the management of low-risk PTC patients, as supplementary prognostic factor to assess the preoperative risk stratification with the aim to avoid unnecessary central neck node dissection (BRAF pos.) or to perform complementary (131)I-therapy (BFAF neg.).

Diagnostic, therapeutic and healthcare management protocols in parathyroid surgery: II Consensus Conference of the Italian Association of Endocrine Surgery Units (U.E.C. CLUB)

AIM

To update the Diagnostic-Therapeutic-Healthcare Protocol (Protocollo Diagnostico-Terapeutico-Assistenziale, PDTA) created by the U.E.C. CLUB (Association of the Italian Endocrine Surgery Units) during the I Consensus Conference in 2008.

METHODS

In the preliminary phase, the II Consensus involved a selected group of experts; the elaboration phase was conducted via e-mail among all members; the conclusion phase took place during the X National Congress of the U.E.C. CLUB. The following were examined: diagnostic pathway and clinical evaluation; mode of admission and waiting time; therapeutic pathway (patient preparation for surgery, surgical treatment, postoperative management, management of major complications); hospital discharge and patient information; outpatient care and follow-up.

CONCLUSIONS

The PDTA for parathyroid surgery approved by the II Consensus Conference (June 2013) is the official PDTA of the U.E.C. CLUB.

Estrogens and stem cells in thyroid cancer

Recent discoveries highlight the emerging role of estrogens in the initiation and progression of different malignancies through their interaction with stem cell (SC) compartment. Estrogens play a relevant role especially for those tumors bearing a gender disparity in incidence and aggressiveness, as occurs for most thyroid diseases. Although several experimental lines suggest that estrogens promote thyroid cell proliferation and invasion, their precise contribution in SC compartment still remains unclear. This review underlines the interplay between hormones and thyroid function, which could help to complete the puzzle of gender discrepancy in thyroid malignancies. Defining the association between estrogen receptors' status and signaling pathways by which estrogens exert their effects on thyroid cells is a potential tool that provides important insights in pathogenetic mechanisms of thyroid tumors.

CDC73 mutational status and loss of parafibromin in the outcome of parathyroid cancer

Inactivating mutations of the CDC73 tumor suppressor gene have been reported in parathyroid carcinomas (PC), in association with the loss of nuclear expression of the encoded protein, parafibromin. The aim of this study was to further investigate the role of the CDC73 gene in PC and evaluate whether gene carrier status and/or the loss of parafibromin staining might have an effect on the outcome of the disease. We performed genetic and immunohistochemical studies in parathyroid tumor samples from 35 patients with sporadic PC. Nonsense or frameshift CDC73 mutations were detected in 13 samples suitable for DNA sequencing. Six of these mutations were germline. Loss of parafibromin expression was found in 17 samples. The presence of the CDC73 mutation as well as the loss of parafibromin predicted a high likelihood of subsequent recurrence and/or metastasis (92.3%, P=0.049 and 94.1%, P=0.0017 respectively), but only the latter was associated with a decreased overall 5- and 10-year survival rates (59%, P=0.107, and 23%, P=0.0026 respectively). The presence of both the CDC73 mutation and loss of parafibromin staining compared with their absence predicted a lower overall survival at 10- (18 vs 84%, P=0.016) but not at 5-year follow-up. In conclusion, loss of parafibromin staining, better than CDC73 mutation, predicts the clinical outcome and mortality rate. The added value of CDC73 mutational analysis is the possibility of identifying germline mutations, which will prompt the screening of other family members.

Thyroid surgical practices shaping thyroid cancer incidence in North-Eastern Italy

AIM

To investigate the effects of changing surgical practices on thyroid cancer incidence in the Veneto Region (North-Eastern Italy).

METHODS

Hospital discharge records of the period 2000-2010 were analyzed to detect trends in thyroid surgery rates by type of surgery and diagnosis. The association between surgery rates for benign and malignant diseases across the 21 Local Health Units (LHUs) was assessed by Poisson regression. In a second step, clinical and pathological charts of the year 2010 were retrieved from the larger regional surgical center. The proportions of total and incidental papillary thyroid micro carcinoma (PTMC) were compared with historical data. Factors influencing an incidental diagnosis of PTMC were analyzed by logistic regression.

RESULTS

Among 26,000 procedures performed in the Region, there was an increase with time in the proportion of total thyroidectomies (from 67% to 78%) and surgeries with a diagnosis of thyroid cancer (from 17% to 28%). Cancer surgery rates across LHUs resulted associated to surgery rates for benign diseases (P<0.001). In the largest regional center, the proportion of PTMC increased from 35% to 56%, of whom almost 60% were incidental cases. The probability of finding an incidental PTMC was higher in total thyroidectomies than in other procedures (odds ratio=1.84, 95% confidence interval 1.08-3.14).

CONCLUSION

Data from the Veneto Region suggest that the increase in PTMC is due to several factors: increased preoperative diagnosis, total gland removal, extensive histological examination. Moreover, geographical variations in cancer incidence were associated to surgery rates for benign diseases.

Pancreatic mucinous cystic tumor in Turner syndrome: How a tumor bends to a genetic disease

INTRODUCTION

Mucinous cystic neoplasms (MCN) are uncommon tumors of the pancreatic corpus/tail occurring mostly in middle-aged women, with a variable clinico-biological behavior. On histology, MCNs concurrently show an epithelial mucosecreting component with ovarian-type stromal cells.

PRESENTATION OF CASE

This report describes the first case of a pancreatic MCN with no ovarian-type stroma in a patient with Turner syndrome (TS).

DISCUSSION

The mesenchymal component of MCN presumably results from the intra-pancreatic entrapment of ovarian stroma during embryogenesis. In our case, the absence of such stromal component may relate to the “dysgenetic” changes in the ovary involved in TS.

CONCLUSION

The present case of primary pancreatic MCN arising in a TS-patient triggers some original speculation on the morphogenesis of pancreatic MCN, also expanding the current clinico-pathological knowledge of this extremely rare entity.

Functional significance of the novel H-RAS gene mutation M72I in a patient with medullary thyroid cancer

Medullary thyroid cancer (MTC) accounts for around 5-10% of all thyroid cancers. Though usually sporadic, 1 in 4 cases are of genetic origin, with germinal mutations in the RET proto-oncogene in familial forms and somatic mutations both in RET and in the RAS family genes in sporadic ones.This study aimed to characterize a rare H-RAS sequence variant -M72I- in a patient with sporadic MTC, focusing on its functional significance.Mutation analysis was performed for the RET, N-RAS, K-RAS and H-RAS genes by direct sequencing. Western blot analysis was done on 4 thyroid tissues from 1 patient carrying the M72I mutation in H-RAS, 1 with the Q61R mutation in H-RAS, 1 with no RET, H-RAS, K-RAS or N-RAS gene mutations, and 1 normal thyroid, using different antibodies against Erk1/2, phospho-Erk1/2 (Thr202/Tyr204), Akt and phospho-Akt (Ser473). Large-scale molecular dynamics simulations were completed for H-RAS wt and H-RAS M72I.Western blot analysis demonstrated that both MAPK and PI3K/Akt pathways were activated in the MTC patient carrying the M72I variant. In silico results showed conformational changes in H-RAS that could influence its activation by Sos and phosphate binding. Results of molecular dynamics were consistent with Western blot experiments.The M72I mutation may contribute effectively to proliferation and survival signaling throughout the MAPK and PI3K/Akt pathways. This work underscores the importance of studying genetic alterations that may lead to carcinogenesis.

Circulating cell-free DNA, SLC5A8 and SLC26A4 hypermethylation, BRAF(V600E): A non-invasive tool panel for early detection of thyroid cancer

PURPOSE

In the latest years, high levels of circulating cell-free DNA (cf-DNA) have been found to be associated with cancer diagnosis and progression, and cf-DNA has become a potential candidate as biomarker for tumor detection. cf-DNA has been investigated in plasma or serum of many tumor patients affected by different malignancies, but not yet in thyroid cancer (TC). Furthermore, in TC cells the capability to metabolize iodine is frequently lost. SLC5A8 and SLC26A4 genes are both involved in the iodine metabolism, and SLC5A8 hypermethylation status is associated with the BRAF(V600E) mutation, which is the most frequent genetic event underlying the development of papillary TC. The aim of our study is the development of a new non-invasive tool for the diagnosis and prognosis of TC based on cf-DNA, SLC5A8 and SLC26A4 hypermethylation, and BRAF(V600E) analysis.

METHODS

cf-DNA was measured by quantitative real-time PCR in nine cases of anaplastic thyroid cancer (ATC), 58 medullary thyroid cancers (MTC), five of synchronous medullary and follicular thyroid cancers (SMFC), 23 follicular adenomas (FA), 86 papillary thyroid cancers (PTC). A control group of 19 healthy subjects was taken. Moreover, in the PTC group we analyze the state of hypermethylation of SLC5A8 and SLC26A4, BRAF(V600E) mutation, and their involvement in the loss of function of the thyroid.

RESULTS

cf-DNA showed a high ability to discriminate healthy individuals from cancer patients. cf-DNAALU83 and cf-DNAALU244 values were significantly correlated with the histological type of TC (P-value < 0.0001). A significant increase in the amount of cf-DNAALU83 and cf-DNAALU244 when methylation occurs was observed (P-value = 0.02). A correlation between BRAF(V600E) and cf-DNAALU244/ALU83 was also found (P-value = 0.02).

CONCLUSIONS

According to our experimental results, the panel including cf-DNA, SLC5A8 and SLC26A4 hypermethylation, and BRAF(V600E) analysis appears easy, reproducible, and non-invasive for the diagnosis on TC. Its possible implication in clinical setting remains to be elucidated.

Open versus endoscopic adrenalectomy in the treatment of localized (stage I/II) adrenocortical carcinoma: results of a multiinstitutional Italian survey

BACKGROUND

We compared the oncologic effectiveness of open adrenalectomy and endoscopic adrenalectomy in the treatment of patients with localized adrenocortical carcinoma.

METHODS

One hundred fifty-six patients with localized adrenocortical carcinoma (stage I/II) who underwent R0 resection were included in an Italian multiinstitutional surgical survey. They were divided into 2 groups based on the operative approach (either conventional or endoscopic).

RESULTS

One hundred twenty-six patients underwent open adrenalectomy and 30 patients underwent endoscopic adrenalectomy. The 2 groups were well matched for age, sex, lesion size, and stage (P = NS). The mean follow-up time was similar for the 2 groups (P = NS). The local recurrence rate was 19% for open adrenalectomy and 21% for endoscopic adrenalectomy, whereas distant metastases were recorded in 31% of patients in the conventional adrenalectomy group and 17% in the endoscopic adrenalectomy group (P = NS). The mean time to recurrence was 27 ± 27 months in the conventional open adrenalectomy group and 29 ± 33 months in the endoscopic adrenalectomy group (P = NS). No significant differences were found between the 2 groups in terms of 5-year disease-free survival (38.3% vs 58.2%) and 5-year overall survival rates (48% vs 67%; P = NS).

CONCLUSION

The operative approach does not affect the oncologic outcome of patients with localized adrenocortical carcinoma, if the principles of surgical oncology are respected.

Comparison of the diagnostic accuracy of combined elastosonography and BRAF analysis vs cytology and ultrasonography for thyroid nodule suspected of malignancy

OBJECTIVE

Diagnosing thyroid nodules preoperatively using traditional diagnostic tools - ultrasonography (US) and cytology - still carries a considerable degree of uncertainty, and surgery is recommended for a far from negligible number of patients simply for diagnostic purposes. Thyroid elastosonography (USE) and BRAF analysis have recently proved useful in detecting thyroid malignancies. The aim of this study is to establish whether combining USE and BRAF testing ameliorates preoperative diagnosis of thyroid nodule candidates for intervention by conventional approaches, thereby avoiding the need for diagnostic surgical procedures.

DESIGN AND PATIENTS

We retrospectively analysed the files of 155 consecutive patients with 164 nodules, all assessed by ultrasonography, cytology, USE and BRAF testing, who underwent thyroid surgery.

RESULTS

Of the 164 nodules, 74 (45%) were benign and 90 (55%) were malignant at final histology. Combining ultrasonography and cytology identified 21 (13%) as benign, 93 (57%) as malignant or probably malignant and 50 (30%) as 'suspended' (when the combined test was not able to classify the node as benign or malignant) with a 99% sensitivity, 28% specificity, 63% PPV, 95% NPV and 67% accuracy. Combining USE and BRAF testing indicated that 59 (36%) were benign, 74 (45%) were malignant and 31 (19%) were in a 'suspended' category, with a 95% sensitivity, 74% specificity, 82% PPV, 93% NPV and 86% accuracy.

CONCLUSIONS

In assessing thyroid nodules suspected of malignancy, the combined analysis of USE and BRAF is equally sensitive and more specific than conventional procedures, achieving more accurate preoperative diagnoses than US and cytology combined. USE and BRAF analysis for thyroid nodule evaluation might reduce the number of unnecessary surgical procedures.

MicroRNA profiles in familial and sporadic medullary thyroid carcinoma: preliminary relationships with RET status and outcome

BACKGROUND

MicroRNAs (miRNAs) are involved in the pathogenesis of human cancers, including medullary thyroid carcinoma (MTC). The aim of this study was to test the hypothesis that different miRNA profiles are related to RET status and prognosis in patients with hereditary MTC (hMTC) and sporadic MTC (sMTC).

METHODS

We analyzed the expression of nine miRNAs (miR-21, miR-127, miR-154, miR-224, miR-323, miR-370, miR-9*, miR-183, and miR-375) by quantitative real-time-polymerase chain reaction in 34 cases of sMTC, 6 cases of hMTC, and 2 cases of C-cell hyperplasia (CCH). We also analyzed the immunohistochemical expression of PDCD4, an miR-21 gene target. sMTC (n=34) was genotyped for somatic RET and RAS mutations. Disease status was defined on the basis of the concentration of serum calcitonin at the latest follow-up and other parameters as indicated in the results.

RESULTS

MTC and CCH were both characterized by a significant overexpression of the whole set of miRNAs (the increase being 4.2-fold for miR-21, 6.7-fold for miR-127, 8.8-fold for miR-154, 6.6-fold for miR-224, 5.8-fold for miR-323, 6.1-fold for miR-370, 13-fold for miR-9*, 6.7-fold for miR-183, and 10.1 for miR-375, p<0.0001). PDCD4 expression was significantly downregulated in MTC samples, consistent with miR-21 upregulation. Significantly lower miR-127 levels were observed in sMTC carrying somatic RET mutations in comparison to sMTC carrying a wild-type RET. In sMTC and familial MTC, the miR-224 upregulation correlated with the absence of node metastases, lower stages at diagnosis, and with biochemical cure during follow-up.

CONCLUSIONS

miRNAs are significantly dysregulated in MTC, and this dysregulation is probably an early event in C-cell carcinogenesis. miR-224 upregulation could represent a prognostic biomarker associated with a better outcome in MTC patients.

Coronary microvascular dysfunction induced by primary hyperparathyroidism is restored after parathyroidectomy

BACKGROUND

Symptomatic primary hyperparathyroidism (PHPT) is associated with increased cardiovascular mortality. However, data on the association between asymptomatic PHPT and cardiovascular risk are lacking. We assessed coronary flow reserve (CFR) as a marker of coronary microvascular function in asymptomatic PHPT of recent onset.

METHODS AND RESULTS

We studied 100 PHPT patients (80 women; age, 58±12 years) without cardiovascular disease and 50 control subjects matched for age and sex. CFR in the left anterior descending coronary artery was detected by transthoracic Doppler echocardiography, at rest, and during adenosine infusion. CFR was the ratio of hyperemic to resting diastolic flow velocity. CFR was lower in PHPT patients than in control subjects (3.0±0.8 versus 3.8±0.7; P<0.0001) and was abnormal (≤2.5) in 27 patients (27%) compared with control subjects (4%; P=0.0008). CFR was inversely related to parathyroid hormone (PTH) levels (r=-0.3, P<0.004). In patients with CFR ≤2.5, PTH was higher (26.4 pmol/L [quartiles 1 and 3, 16 and 37 pmol/L] versus 18 [13-25] pmol/L; P<0.007), whereas calcium levels were similar (2.9±0.1 versus 2.8±0.3 mmol/L; P=0.2). In multivariable linear regression analysis, PTH, age, and heart rate were the only factors associated with CFR (P=0.04, P=0.01, and P=0.006, respectively). In multiple logistic regression analysis, only PTH increased the probability of CFR ≤2.5 (P=0.03). In all PHPT patients with CFR ≤2.5, parathyroidectomy normalized CFR (3.3±0.7 versus 2.1±0.5; P<0.0001).

CONCLUSIONS

PHPT patients have coronary microvascular dysfunction that is completely restored after parathyroidectomy. PTH independently correlates with the coronary microvascular impairment, suggesting a crucial role of the hormone in explaining the increased cardiovascular risk in PHPT.

Protein kinase C: a putative new target for the control of human medullary thyroid carcinoma cell proliferation in vitro

We investigate the role of protein kinase C (PKC) in the control of medullary thyroid carcinoma (MTC) cell proliferation by a PKC inhibitor, Enzastaurin, in human MTC primary cultures and in the TT cell line. We found that PKC inhibition reduces cell proliferation by inducing caspase-mediated apoptosis and blocks the stimulatory effect of IGF-I on calcitonin secretion. Enzastaurin reduces PKCβII (Thr500) phosphorylation, indicating a direct involvement of this isoform as well as the phosphorylated levels of Akt (Ser 473) and glycogen synthase kinase (Ser9), PKC pathway downstream targets and pharmacodynamic markers for PKC inhibition. PKCβII and PKCδ enzyme isoforms expression and localization were investigated. These data indicate that in vitro PKC is involved in the control of human MTC proliferation and survival by modulating apoptosis, with a mechanism that implicates PKCβII inhibition and translocation in different subcellular compartments. Targeting PKC may represent a useful therapeutic approach for controlling MTC proliferation.

Comparison of calcium and pentagastrin tests for the diagnosis and follow-up of medullary thyroid cancer

CONTEXT

The evaluation of basal calcitonin (bCT) and stimulated calcitonin (sCT) can be used for the diagnosis and follow-up of medullary thyroid cancer (MTC).

OBJECTIVE

The aim of this study was to evaluate the reliability of high-calcium (Ca) test and to identify gender-specific thresholds for MTC diagnosis.

PATIENTS

Patients with MTC in remission (n=24) or in persistence (n=18), RET gene mutations carriers (n=14), patients with nodular goiter (n=69), and healthy volunteers (n=16) were submitted to pentagastrin and Ca (25 mg/kg) tests.

RESULTS

In all groups, the levels of calcitonin (CT) stimulated by either pentagastrin or Ca were significantly correlated. The prevalence of both C-cell hyperplasia (CCH) and MTC in women and men paralleled the increasing basal and peak CT levels in a gender-specific manner. Receiver operating characteristic plot analyses showed that the best levels of bCT to separate normal and CCH cases from MTC patients were above 18.7 pg/ml in females and above 68 pg/ml in males. Furthermore, Ca sCT above 184 pg/ml in females and above 1620 pg/ml in males had the highest accuracy to distinguish normal and CCH cases from patients with MTC. At the C-cell immunohistochemical examination, Ca sCT below 50 pg/ml corresponded to a mean number of 30 cells per 10 fields, whereas higher sCT associated with a mean number of 400 cells per 10 fields, often displaying a diffuse and nodular distribution pattern.

CONCLUSIONS

High-dose Ca test is a potent and well-tolerated procedure that can be applied worldwide at a low cost. Reference ranges for Ca sCT levels in different groups of patients and CT thresholds to diagnose CCH/MTC have been identified.

BRAF(K601E) mutation in a patient with a follicular thyroid carcinoma

BACKGROUND

BRAF mutations, the most common genetic alteration associated with papillary thyroid carcinoma (PTC), have never been associated with follicular thyroid carcinoma (FTC) except for one possible case, which, however, had some cellular features of the follicular variant of PTC. Here, we present a patient with a BRAF mutation within a FTC.

SUMMARY

A 78-year-old man presented with a nodular lesion 8 cm in size in the right thyroid lobe, coexisting with a goiter. Fine-needle aspiration samples were obtained for cytology, immunocytology, and molecular analysis. Immunoblot analysis on thyroid tissues was performed to evaluate the most important tumor activating pathways. Cytology was consistent with "follicular neoplasia" (negative for galectin-3 immunostaining); molecular analysis on the cytology sample detected a K601E mutation in the exon 15 of the BRAF gene. After total thyroidectomy with lymph-node dissection, the diagnosis of FTC was established by histopathological examination. The BRAF(K601E) mutation was confirmed in DNA obtained from different areas of the FTC. In addition, an activating mutation (E545A) in the PKI3CA oncogene was found in the FTC. As expected, immunoblot analysis showed activation of the PI3K/Akt pathway.

CONCLUSION

This article describes what may be the first case of a classical FTC carrying a BRAF mutation. Unlike the most common BRAF mutation seen in PTC carcinoma (BRAF(V600E)), this patient's mutation was a BRAF(K601E) mutation that previously has been associated with some cases of the follicular variant of PTC. The BRAF(K601E) mutation should be included in the spectrum of genetic alterations in FTC.