A Prospective Multicenter Study Examining the Relationship Between Thyroid Cancer Treatment Outcomes and the Presence of Autoimmune Thyroiditis.

Background: There is some controversy on the potential relationship between autoimmune processes and clinicopathologic features as well as prognosis of differentiated thyroid cancer (DTC), and the evidence is limited by its largely retrospective nature. We examined the relationship between the presence of autoimmune thyroiditis (AT) and 1-year thyroid cancer treatment outcomes in a large multicenter study using prospectively collected data. Methods: We included data from consecutive DTC patients enrolled in the Italian Thyroid Cancer Observatory (ITCO) database (NCT04031339). We divided the groups according to the presence (AT) or absence (no autoimmune thyroiditis [noAT]) of associated AT. We used propensity score matching to compare the clinical features and outcomes between the two groups at 1-year follow-up. Results: We included data from 4233 DTC patients, including 3172 (75%) females. The American Thyroid Association (ATA) risk levels were as follows: 51% (2160/4233) low risk, 41.3% (1750/4233) intermediate risk, and 7.6% (323/4233) high risk. There were 1552 patients (36.7%) who had AT. Before propensity score matching, AT patients were significantly younger and had a smaller and bilateral tumor (p < 0.0001). Patients with AT more frequently fell into the low- and intermediate-risk categories, while the ATA high risk was more frequent among noAT patients (p = 0.004). After propensity score matching, patients with AT more frequently showed evidence of disease (structural/biochemical incomplete response) versus excellent/indeterminate response, compared with patients without AT (7.3% vs. 4.5%, p = 0.001), with an odds ratio of 1.86 ([confidence interval: 1.3-2.6], p = 0.0001). However, when considering only structural persistence as the outcome, no statistically significant differences were observed between patients with or without AT (3.4% vs. 2.7%, p = 0.35). The elevated risk associated with the ATA intermediate and high risk at diagnosis remained consistently statistically significant. Conclusions: In this large prospective series, biochemical persistence was more frequent, at 1-year follow-up, in AT patients. However, there was no significant association between the presence of AT and structural persistence of disease. These findings may be explained by the presence of a residual thyroid tissue.

Recurrence and mortality rate in an Italian multi-center case series of parathyroid atypical adenomas and carcinomas.

Introduction: There are few data regarding the clinical outcome of patients with parathyroid carcinoma (PC) and atypical adenoma (AA) after surgery. Aim of our study was to investigate disease recurrence and mortality rate as well as their predictors in a series of patients with PC or AA. Methods: Clinical and biochemical parameters, histological features, incidence of disease recurrence and mortality rate were retrospectively assessed in 39 patients (51% males, mean age 56.2 ± 17.2 years) diagnosed with PC (n=24) or AA (n=15) and followed up for 6.8 ± 5.0 years after surgery. Results: No differences in baseline characteristics were registered between the two groups, except for higher KI67 values in PC than AA (6.9 ± 3.9% vs 3.4 ± 2.1%, p<0.01). Eight patients (21%) experienced recurrence after a mean follow-up of 5.1 ± 2.7 years, with higher relapse rate in PC than AA (25% vs 13%), though this difference did not reach statistical significance. Mortality rate was 10% in the whole sample, without significant differences between PC and AA. Relapsing cases had been undergone the most extensive surgery more frequently and they had a higher mortality rate in comparison to non relapsing patients (38% vs 6% and 38% vs 3%, respectively, p<0.03 for both). In comparison to survivors, deceased patients were submitted to the most extensive surgery more frequently (50% vs 9%), they were older (74.8 ± 4.6 vs 53.2 ± 16.3 years), and they had higher KI67 values (11.7 ± 4.9 vs 4.8 ± 2.8, p<0.03 for all comparisons). Conclusions: During seven-year follow-up after surgery, no significant differences in recurrence and mortality rate were observed between PC and AA patients. Death was associated with disease relapse, older age and higher KI67 values. These findings suggest a similar and careful long-term follow-up in both parathyroid tumors, especially in older patients, and emphasize the need of further studies in large cohorts to throw light on this crucial clinical issue.

Immune-related thyroid dysfunctions during anti PD-1/PD-L1 inhibitors: new evidence from a single centre experience.

The role of anti-thyroid peroxidase antibodies (anti-TPO Abs) in the development of abnormal thyroid function tests (DYSTHYR) during treatment with immune checkpoint inhibitors (ICIs) is not fully understood; moreover, controversial data exist about the relationship between ICI-related thyroid dysfunction (TD) and survival. We retrospectively analyzed the onset or the worsening of DYSTHYR in patients treated with programmed cell death protein-1 (PD-1) or its ligand (PD-L1) inhibitors between 2017 and 2020. In patients without previous TD, we focused on the association between baseline anti-TPO Abs level and DYSTHYR. Furthermore, the relationship between DYSTHYR and progression-free survival (PFS) or overall survival (OS) was explored. We included 324 patients treated with anti PD-1 (95.4%) or anti PD-L1 inhibitors. After a median of 3.3 months, DYSTHYR was registered in 24.7%, mostly hypothyroidism alone (17%). Patients with pre-existing TD (14.5% of the sample) were at higher risk of DYSTHYR compared to patients without previous TD (adjusted OR 2.44; 95% IC 1.26-4.74). In patients without known previous TD, high anti-TPO Abs level, even below the positivity cut-off, was a risk factor for developing DYSTHYR (adjusted OR 5.52; 95% IC 1.47-20.74). DYSTHYR was associated with a longer 12-month OS (87.3% vs 73.5%, p = 0.03); no statistically significant difference in terms of PFS was observed between the DYSTHYR+ and DYSTHYR- group. DYSTHYR is common during anti PD-1/anti PD-L1 treatment, especially in patients with pre-existing TD. In subjects without known previous TD, high anti-TPO Abs level at baseline can be a predictive biomarker of DYSTHYR. An improved OS is observed in patients with anti PD-1/anti PD-L1-induced DYSTHYR.

A Data-Driven Approach to Refine Predictions of Differentiated Thyroid Cancer Outcomes: A Prospective Multicenter Study.

CONTEXT: The risk stratification of patients with differentiated thyroid cancer (DTC) is crucial in clinical decision making. The most widely accepted method to assess risk of recurrent/persistent disease is described in the 2015 American Thyroid Association (ATA) guidelines. However, recent research has focused on the inclusion of novel features or questioned the relevance of currently included features. OBJECTIVE: To develop a comprehensive data-driven model to predict persistent/recurrent disease that can capture all available features and determine the weight of predictors. METHODS: In a prospective cohort study, using the Italian Thyroid Cancer Observatory (ITCO) database (NCT04031339), we selected consecutive cases with DTC and at least early follow-up data (n = 4773; median follow-up 26 months; interquartile range, 12-46 months) at 40 Italian clinical centers. A decision tree was built to assign a risk index to each patient. The model allowed us to investigate the impact of different variables in risk prediction. RESULTS: By ATA risk estimation, 2492 patients (52.2%) were classified as low, 1873 (39.2%) as intermediate, and 408 as high risk. The decision tree model outperformed the ATA risk stratification system: the sensitivity of high-risk classification for structural disease increased from 37% to 49%, and the negative predictive value for low-risk patients increased by 3%. Feature importance was estimated. Several variables not included in the ATA system significantly impacted the prediction of disease persistence/recurrence: age, body mass index, tumor size, sex, family history of thyroid cancer, surgical approach, presurgical cytology, and circumstances of the diagnosis. CONCLUSION: Current risk stratification systems may be complemented by the inclusion of other variables in order to improve the prediction of treatment response. A complete dataset allows for more precise patient clustering.

Management of Progressive Radioiodine-Refractory Thyroid Carcinoma: Current Perspective.

Patients with thyroid cancer (TC) usually have an excellent prognosis; however, 5-10% of them develop an advanced disease. The prognosis of this subgroup is still favourable if the lesions respond to radioactive iodine (RAI) treatment. Nearly two-thirds of advanced TC patients become RAI-refractory (RAI-R), and their management is challenging. A multidisciplinary approach in the context of a tumour board is essential to define a personalized strategy. Systemic therapy is not always the best option. In case of slow neoplastic growth and low tumour burden, active surveillance may represent a valuable choice. Local approaches might be considered if the disease progression is limited to a single or few lesions, also in combination and during systemic therapy. Antiresorptive treatment may be started in presence of bone metastases. In case of rapid and/or symptomatic progression involving multiple lesions and/or organs, systemic therapy has to be considered, in absence of contraindications. The multi-kinase inhibitors (MKIs) lenvatinib and sorafenib are currently available as first-line treatment for advanced progressive RAI-R TC. Among second-line options, cabozantinib has been recently approved in RAI-R TC who progressed during MKIs targeting the vascular endothelial growth factor receptor (VEGFR). In the last few years, next-generation sequencing (NGS) assays have been increasingly employed, permitting identification of the genetic alterations harboured by TC, with a significant impact on patients' management. Novel selective targeted therapies have been introduced for the treatment of RAI-R TC in selected cases: REarranged during Transfection (RET) inhibitors (selpercatinib and pralsetinib) and Tropomyosin Receptor Kinase (TRK) inhibitors (larotrectinib and entrectinib) have recently expanded the panorama of the therapeutic options. Moreover, immune checkpoint inhibitors (ICIs) have shown promising results, and they are still under investigation.

External Validation of Three Available Grading Systems for Medullary Thyroid Carcinoma in a Single Institution Cohort.

Medullary thyroid carcinoma (MTC) is a rare thyroid carcinoma with a variable clinical behavior. Potential clinical and pathological prognostic markers have been investigated, but studies are limited and controversial. In neuroendocrine neoplasms of various other sites, necrosis and proliferation (mitotic activity and/or Ki67 index) are integrated to provide a histological grade. Recently, an International Medullary Thyroid Carcinoma Grading System (IMTCGS) has been designed to define high- or low-grade MTC by combining proliferative activity and necrosis. This proposal integrates two previously published grading schemes by American (2-tiered grading, low- and high-grade MTC) and Australian authors (3-tiered grading, low-, intermediate-, and high-grade MTC). To validate the clinical role of these systems, their prognostic impact was evaluated in an independent cohort of 111 MTCs. Necrosis, which was the only parameter integrated into the 3 grading systems, proved to be individually correlate with tumor relapse, while no association was found with the proliferation (mitotic count and Ki67 index); however, by combining the different parameters according to all three grading systems, "high-grade" MTCs turned out to be significantly associated with the disease recurrence (p < 0.005) in all systems. In disease-free survival analysis, the IMTCGS stratification was the only one that demonstrated a significant impact at Cox regression analysis (p = 0.004), further confirmed by the Kaplan-Meier curves (p = 0.002). Similar findings were also reproduced when analysis was restricted to sporadic MTCs (68 cases). In conclusion, our results confirm the prognostic role of IMTCGS, supporting the importance of incorporating this information into the pathology report. However, none of the systems proved to predict the overall survival in this validation cohort.

Prognostic Value of Whole-Body PET Volumetric Parameters Extracted from 68Ga-DOTATOC PET/CT in Well-Differentiated Neuroendocrine Tumors.

Our objective was to evaluate the prognostic value of somatostatin receptor tumor burden on 68Ga-DOTATOC PET/CT in patients with well-differentiated (WD) neuroendocrine tumors (NETs). Methods: We retrospectively analyzed the 68Ga-DOTATOC PET/CT scans of 84 patients with histologically confirmed WD NETs (51 grade 1, 30 grade 2, and 3 grade 3). For each PET/CT scan, all 68Ga-DOTATOC-avid lesions were independently segmented by 2 operators using a customized threshold based on the healthy liver SUVmax (LIFEx, version 5.1). Somatostatin receptor-expressing tumor volume (SRETV) and total lesion somatostatin receptor expression (TLSRE = SRETV × SUVmean) were extracted for each lesion, and then whole-body SRETV and TLSRE (SRETVwb and TLSREwb, respectively) were defined as the sum of SRETV and TLSRE, respectively, for all segmented lesions in each patient. Time to progression (TTP) was defined as the combination of disease-free survival in patients undergoing curative surgery (n = 10) and progression-free survival for patients with unresectable or metastatic disease (n = 74). TTP and overall survival were calculated by Kaplan-Meier analysis, log-rank testing, and the Cox proportional-hazards regression model. Results: After a median follow-up of 15.5 mo, disease progression was confirmed in 35 patients (41.7%) and 14 patients died. A higher SRETVwb (>39.1 cm3) and TLSREwb (>306.8 g) correlated significantly with a shorter median TTP (12 mo vs. not reached; P < 0.001). In multivariate analysis, SRETVwb (P = 0.005) was the only independent predictor of TTP regardless of histopathologic grade and TNM staging. Conclusion: According to our results, SRETVwb and TLSREwb extracted from 68Ga-DOTATOC PET/CT could predict TTP or overall survival and might have important clinical utility in the management of patients with WD NETs.

Nephrotoxicity in advanced thyroid cancer treated with tyrosine kinase inhibitors: An update.

Over the past decade, the prognosis of advanced thyroid cancer (TC) patients has dramatically improved thanks to the introduction of tyrosine kinase inhibitors (TKIs). Despite their effectiveness, these drugs are burdened with several side effects that can negatively affect quality of life and compromise therapy continuation. Among renal adverse events (RAEs), proteinuria is the most frequently reported in clinical trials and real-life experiences, especially during treatment with lenvatinib or cabozantinib. This peculiar toxicity is commonly associated with targeted therapies with anti-angiogenic activity, even if the mechanisms underlying its onset and progression are not entirely clear. RAEs should be early recognized and properly managed to avoid renal function worsening and life-threatening consequences. Aiming at providing a comprehensive summary that can help clinicians to identify and manage TKIs-related RAEs in TC patients, we reviewed the current evidence about this topic, from pathogenesis and potential risk factors to diagnosis and treatment.

Minimal Extrathyroidal Extension in Predicting 1-Year Outcomes: A Longitudinal Multicenter Study of Low-to-Intermediate-Risk Papillary Thyroid Carcinoma (ITCO#4).

Background: The role of minimal extrathyroidal extension (mETE) as a risk factor for persistent papillary thyroid carcinoma (PTC) is still debated. The aims of this study were to assess the clinical impact of mETE as a predictor of worse initial treatment response in PTC patients and to verify the impact of radioiodine therapy after surgery in patients with mETE. Methods: We reviewed all records in the Italian Thyroid Cancer Observatory database and selected 2237 consecutive patients with PTC who satisfied the inclusion criteria (PTC with no lymph node metastases and at least 1 year of follow-up). For each case, we considered initial surgery, histological variant of PTC, tumor diameter, recurrence risk class according to the American Thyroid Association (ATA) risk stratification system, use of radioiodine therapy, and initial therapy response, as suggested by ATA guidelines. Results: At 1-year follow-up, 1831 patients (81.8%) had an excellent response, 296 (13.2%) had an indeterminate response, 55 (2.5%) had a biochemical incomplete response, and 55 (2.5%) had a structural incomplete response. Statistical analysis suggested that mETE (odds ratio [OR] 1.16, p = 0.65), tumor size >2 cm (OR 1.45, p = 0.34), aggressive PTC histology (OR 0.55, p = 0.15), and age at diagnosis (OR 0.90, p = 0.32) were not significant risk factors for a worse initial therapy response. When evaluating the combination of mETE, tumor size, and aggressive PTC histology, the presence of mETE with a >2 cm tumor was significantly associated with a worse outcome (OR 5.27 [95% confidence interval], p = 0.014). The role of radioiodine ablation in patients with mETE was also evaluated. When considering radioiodine treatment, propensity score-based matching was performed, and no significant differences were found between treated and nontreated patients (p = 0.24). Conclusions: This study failed to show the prognostic value of mETE in predicting initial therapy response in a large cohort of PTC patients without lymph node metastases. The study suggests that the combination of tumor diameter and mETE can be used as a reliable prognostic factor for persistence and could be easily applied in clinical practice to manage PTC patients with low-to-intermediate risk of recurrent/persistent disease.

Pituitary metastases from neuroendocrine neoplasms: case report and narrative review.

PURPOSE: Pituitary metastases (PM) are uncommon findings and are mainly derived from breast and lung cancers. No extensive review of PM from neuroendocrine neoplasms (NENs) is on record. Here we describe a clinical case of PM from pancreatic NEN and review the clinical features of PM from NENs reported in the literature. METHODS: A case of PM from a pancreatic NEN followed at our institution is described. We also reviewed the 43 cases of PM from NENs reported in the literature. RESULTS: A 59-year old female patient, previously submitted to duodeno-cephalo-pancreasectomy for a well-differentiated pancreatic NEN, with known hepatic metastases, underwent a 68 Ga-DOTATOC PET/CT that revealed an uptake in the pituitary gland. A subsequent MRI displayed a pituitary lesion, with suprasellar extension. After a hormonal and genetic diagnostic workup that excluded the diagnosis of MEN 1, the worsening of headache and visual impairment and the growth of the lesion lead to its surgical removal. A pituitary localization of the pancreatic NEN was identified. Regarding the published cases of PM from NENs, the most common tumour type was small cell lung cancer (SCLC), accounting for nearly half of the cases, followed by bronchial and pancreatic well differentiated NENs. The most frequent symptom was a variable degree of visual impairment, while headache was reported in half of the cases. Partial or total anterior hypopituitarism was present in approximately three quarters of the cases, while diabetes insipidus was less common. The most frequent treatment for PM was surgical resection, followed by radiotherapy and chemotherapy. The clinical outcome was in line with previous reports of PM from solid tumours, with a median survival of 14 months. Surgery of PM was associated with prolonged survival. CONCLUSIONS: PM from NENs have clinical features similar to metastases derived from other solid tumours, albeit the involvement of the anterior pituitary seems more frequent; a thorough pituitary hormonal evaluation is mandatory, after focused radiological studies, particularly if a surgical approach is considered. The optimal management of PM remains disputed and seems mainly driven by the aggressiveness of the primary tumour and the presence of symptoms. In well-differentiated NENs, particularly in the case of symptomatic PM, surgical removal may be a reasonable approach.

Interventional Radiology Approaches for Liver Metastases from Thyroid Cancer: A Case Series and Overview of the Literature.

BACKGROUND: Liver metastases (LMs) from thyroid cancer (TC) are relatively uncommon in clinical practice and their management is challenging. Interventional radiology loco-regional treatments (LRTs), including radiofrequency ablation (RFA) and trans-arterial chemoembolization (TACE), have been successfully employed to treat LMs from various types of cancer. METHODS: We analyzed the role of LRTs in the management of unresectable LMs from differentiated and medullary TCs performed at our institution from 2015 to 2020. A review of the available English literature regarding this topic was also performed. RESULTS: Six hepatic LRTs were performed in 4 TC patients with LMs, in 2 cases after the start of treatment with a tyrosine kinase inhibitor (TKI). A partial response was obtained in 2 patients; the diameter of the largest targeted lesion was 18 mm in both of them. The remaining procedures were performed on larger lesions and a stable disease was achieved in all but one case. Acute LRT-related complications were transient and mild. In literature, the largest studies were focused on TACE in LMs from MTC, showing good tolerance and remarkable disease control, especially in case of limited liver tumour involvement. CONCLUSION: LRTs for LMs represent a valuable option for the treatment of metastatic TC in case of isolated hepatic progression or for symptoms relief, also after the start of TKI treatment as part of a multimodal approach. The best disease control is obtained when hepatic metastatic burden is limited. These procedures are generally well tolerated; however, a cautious multidisciplinary selection of the candidates is mandatory.

Quality of Life during Treatment with Lenvatinib for Thyroid Cancer: The Patients' Perspective beyond the Medical Evaluation.

BACKGROUND: Lenvatinib (LEN) has shown great efficacy but important toxicity in patients with advanced radioactive iodine-refractory (RAI-R) thyroid cancer (TC); a focused evaluation of its impact on patients' quality of life (QoL) is still lacking. Our prospective study investigated the impact of this drug on QoL in a group of RAI-R TC patients treated at our centre. METHODS: All patients filled in two questionnaires before and during treatment: (1) the Patient-Reported Outcomes version of the Common Terminology Criteria for Adverse Events adapted questionnaire, assessing prevalence, severity, and/or interference on daily activities of the most frequent symptomatic adverse events (AEs) reported in previous clinical trials during therapy with LEN, and (2) the European Quality of Life 5 Dimensions 3 Levels (EQ-5D-3L) questionnaire, providing the EQ-5D index and the EQ visual analogue scale (EQ-VAS). Data from baseline questionnaires were compared with those obtained 3, 6, and 12 months after the start of treatment. RESULTS: In our population (n = 20), an overall increased perception of symptomatic AEs emerged during treatment (statistically significant for abdominal pain, asthenia/fatigue, decreased appetite, and xerostomia). The median EQ-5D index and EQ-VAS scores after 3 months of treatment were lower than at baseline, almost returning to initial values after 12 months. CONCLUSION: RAI-R TC patients reported a general increase in prevalence and interference on daily activities of symptomatic AEs during therapy with LEN. Self-perceived QoL initially decreased during therapy. However, our data suggest that QoL could be restored after 12 months; this trend might partly reflect the impact of therapy optimisation.

The Challenge of Evaluating Response to Peptide Receptor Radionuclide Therapy in Gastroenteropancreatic Neuroendocrine Tumors: The Present and the Future.

The NETTER-1 study has proven peptide receptor radionuclide therapy (PRRT) to be one of the most effective therapeutic options for metastatic neuroendocrine tumors (NETs), improving progression-free survival and overall survival. However, PRRT response assessment is challenging and no consensus on methods and timing has yet been reached among experts in the field. This issue is owed to the suboptimal sensitivity and specificity of clinical biomarkers, limitations of morphological response criteria in slowly growing tumors and necrotic changes after therapy, a lack of standardized parameters and timing of functional imaging and the heterogeneity of PRRT protocols in the literature. The aim of this article is to review the most relevant current approaches for PRRT efficacy prediction and response assessment criteria in order to provide an overview of suitable tools for safe and efficacious PRRT.

Parathyroid Carcinoma: An Up-to-Date Retrospective Multicentric Analysis.

Parathyroid carcinoma (PC) is a rare disease responsible for about 1% of primary hyperparathyroidism (PHPT) cases. PC usually has an indolent course, tough to differentiate from the benign causes of PHPT, and the only certain diagnosis is histologic. The gold standard surgical treatment is the en bloc resection associated with the homolateral thyroid loboistmectomy. The aim of this study was to underline the main differences between PC and benign PHPT, along with gathering epidemiological knowledge relative to PC in our region. Data from the regional cancer network (Rete Oncologica del Piemonte e della Valle d'Aosta) since 2007 have been reported, including 21 patients from three hospitals (AO S. Croce e Carle of Cuneo, AOU Città della Salute of Turin, and ASL Città di Torino). The incidence of the disease, gender, age at time of diagnosis, presence of renal and bone symptoms, serum calcium and PTH levels, surgical technique performed, and percentage of recurrence were analysed. PC data were than compared with a series of patients affected by benign PHPT, referred to ASL Città di Torino, Maria Vittoria Hospital, from 2007 to 2019. A PC incidence of 0.05 cases per 100,000 inhabitants was found in our region. Benign forms occurred more frequently in females (p=0.0002), while PC equally occurred in males and females and affected younger patients (p=0.026). Serum calcium and PTH levels were significantly higher in PC patients; accordingly, typical PHPT symptoms were more frequently reported in PC than in benign PHPT. In the PC group, the en bloc resection shows a 13 times lower risk for relapse compared with all the other surgical techniques. PC is equally gender distributed, and the average patients' age is in the fifth decade of life. It is usually functioning, with greater biochemical activity and multiple symptoms. A not-radical surgical resection is associated with a higher recurrence rate. A meticulous presurgical evaluation of PHPT patients showing PC's evocative features is mandatory to obtain a complete disease extirpation.

68Ga-DOTATOC PET/CT-Based Radiomic Analysis and PRRT Outcome: A Preliminary Evaluation Based on an Exploratory Radiomic Analysis on Two Patients.

Aim: This work aims to evaluate whether the radiomic features extracted by 68Ga-DOTATOC-PET/CT of two patients are associated with the response to peptide receptor radionuclide therapy (PRRT) in patients affected by neuroendocrine tumor (NET). Methods: This is a pilot report in two NET patients who experienced a discordant response to PRRT (responder vs. non-responder) according to RECIST1.1. The patients presented with liver metastasis from the rectum and pancreas G3-NET, respectively. Whole-body total-lesion somatostatin receptor-expression (TLSREwb-50) and somatostatin receptor-expressing tumor volume (SRETV wb-50) were obtained in pre- and post-PRRT PET/CT. Radiomic analysis was performed, extracting 38 radiomic features (RFs) from the patients' lesions. The Mann-Whitney test was used to compare RFs in the responder patient vs. the non-responder patient. Pearson correlation and principal component analysis (PCA) were used to evaluate the correlation and independence of the different RFs. Results: TLSREwb-50 and SRETVwb-50 modifications correlate with RECIST1.1 response. A total of 28 RFs extracted on pre-therapy PET/CT showed significant differences between the two patients in the Mann-Whitney test (p < 0.05). A total of seven second-order features, with poor correlation with SUVmax and PET volume, were identified by the Pearson correlation matrix. Finally, the first two PCA principal components explain 83.8% of total variance. Conclusion: TLSREwb-50 and SRETVwb-50 are parameters that might be used to predict and to assess the PET response to PRRT. RFs might have a role in defining inter-patient heterogeneity and in the prediction of therapy response. It is important to implement future studies with larger and more homogeneous patient populations to confirm the efficacy of these biomarkers.

Predictors of recurrence of pheochromocytoma and paraganglioma: a multicenter study in Piedmont, Italy.

The available data on the natural history of pheochromocytomas and paragangliomas after radical surgery are heterogeneous and discordant. The aim of our retrospective multicenter study was to find predictors of recurrence in patients with pheochromocytomas and sympathetic paragangliomas submitted to radical surgery in Piedmont (a region in northwest Italy). We collected data from 242 patients diagnosed between 1990 and 2016. Forty-two patients (17.4%) had disease recurrence. Multivariate analysis showed that genetic mutation (HR = 3.62; 95% CI 1.44-9.13; p = 0.006), younger age (HR = 0.97; 95% CI 0.95-0.99; p = 0.031) and larger tumor size (HR = 1.01; 95% CI 1.00-1.02; p = 0.015) were independently associated with a higher recurrence risk of pheochromocytoma and paraganglioma; in pheochromocytomas, genetic mutation (HR = 3.4; 95% CI 1.00-11.48; p = 0.049), younger age (HR = 0.97; 95% CI 0.94-0.99; p = 0.02), higher tumor size (HR = 1.01; 95% CI 1.00-1.03; p = 0.043) and PASS value (HR = 1.16; 95% CI 1.03-1.3; p = 0.011) were associated with recurrence. Moreover, tumor size was the only predictor of metastatic pheochromocytoma and paraganglioma (HR = 4.6; 95% CI 1.4-15.0; p = 0.012); tumor size (HR = 3.93; 95% CI 1.2-16.4; p = 0.026) and PASS value (HR = 1.27; 95% CI 1.06-1.53; p = 0.007) were predictors of metastatic pheochromocytoma. In conclusion, our findings suggest that the recurrence of pheochromocytoma and sympathetic paraganglioma develops more frequently in younger subjects, patients with a family history of chromaffin tissue neoplasms, mutations in susceptibility genes, larger tumors and higher values of PASS. We recommend genetic testing in all patients with PPGL and strict follow-up at least on an annual basis.

Symptomatic Biliary Disorders During Lenvatinib Treatment for Thyroid Cancer: An Underestimated Problem.

Background: The prognosis of several human malignancies has dramatically improved after the introduction of tyrosine kinase inhibitors (TKIs); however, their use has been associated with a large spectrum of adverse events, including symptomatic biliary disorders. In the phase III trial of lenvatinib in radioactive iodine (RAI)-refractory differentiated thyroid cancer (DTC) patients, gallbladder (GB) and biliary duct (BD) diseases and complications were reported. We evaluated symptomatic biliary disorders during treatment with lenvatinib in real-life practice to provide a more exhaustive understanding of its toxicity. Methods: We retrospectively evaluated all consecutive patients treated with lenvatinib in our center for progressive RAI-refractory DTC, excluding those who underwent cholecystectomy before the start of therapy. We report all radiologically confirmed symptomatic GB/BD disorders, which were subsequently treated with cholecystectomy, and we describe their management along with relevant biochemical and histological findings. All available GB/BD imaging of patients who developed biliary toxicity during lenvatinib was reviewed by a single experienced radiologist, including computed tomography scans performed for tumor assessment at baseline and during TKI therapy. Results: Five patients (14.7%) developed symptomatic radiologically confirmed biliary disease after a median time of 4.4 months of lenvatinib treatment [interquartile range 3.4-14.4 months] and thus underwent cholecystectomy. A scheduled surgical approach was possible only in two cases; in the remaining patients, presurgical TKI interruption was shorter than one week. After wound healing, treatment was resumed by all subjects. Three patients showed mild biochemical alterations in the two previous monthly follow-up visits. Before the start of treatment, GB/BD abnormalities were radiologically detected only in one case. Conclusions: In our cohort, an unexpectedly high proportion of RAI-refractory DTC patients treated with lenvatinib developed a symptomatic biliary disorder with the need of surgical intervention. Further studies are required to optimize the diagnosis and treatment of patients at higher risk of developing a symptomatic GB/BD disease during assumption of lenvatinib.

Parathyroid carcinoma. A single Institution experience and a review of the international literature.

INTRODUCTION: Parathyroid carcinoma (PC) is a slow-growing and very rare malignancy, representing less than 0.005% of all cancers. The rarity of PC makes it hard to create large-scale published series of patients affected by this condition. MATERIALS AND METHODS: We present four cases of PC treated in our Institution and analyze the most salient aspects of this disease highlighted in recent international literature. DISCUSSION AND COMMENTS: In our experience, in 3/4 cases, the clinical presentation of PC was not different compared to adenoma; therefore, the diagnosis was a post-operative histopathological surprise. We noticed a clear, preoperative laboratory evidence of higher values of PTH and calcemia in patients with PC compared to adenoma. In our experience, a surgical approach consisting in parathyroidectomy associated with ipsilateral loboisthmectomy and central neck lymph node dissection offers the best prognostic chance. Moreover, surgery should be performed only in referral centers where an interdisciplinary management is guaranteed. We are confident in suggesting the surgical approach also in patients with poor clinical status due to high calcemia. If performed by experienced surgeons, the surgical risk of parathyroidectomy is low and we assisted to a progressive restoration of neurological function and an improvement in the patient's quality of life. Finally, even if our experience is limited, we observed an association between PC and thyroid cancer that deserves a validation through more comprehensive further studies. CONCLUSION: PC remains a complex disease in which a valid surgical approach represents the only curative treatment. KEY WORDS: Parathyroid, Parathyroid carcinoma, Parathyroidectomy, hormone, Surgical oncology.