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Purpose: To evaluate the efficacy and safety of dabrafenib-trametinib-131I for the treatment of radioactive iodine refractory metastatic differentiated thyroid cancer (DTC) with a BRAF p.V600E mutation. Patients and Methods: A prospective phase II trial including patients with RECIST progression within 18 months and no lesion > 3 cm. Following a baseline recombinant human (rh)TSH-stimulated diagnostic whole-body scan (dc1-WBS), dabrafenib and trametinib were given for 42 days. A second rhTSH-stimulated dc WBS (dc2-WBS) was done at day 28 and 131I (5.5 GBq–150 mCi after rhTSH) was administered at day 35. Primary endpoint was the 6-month RECIST objective response rate. In case of partial response (PR) at 6 or 12 months, a second treatment course could be given. Among 24 enrolled patients, 21 were evaluable at 6 months. Results: Abnormal 131I uptake was present on 5%, 65%, and 95% of the dc1-WBS, dc2-WBS, and post-therapy scans, respectively. At 6 months, PR was achieved in 38%, stable disease in 52%, and progressive disease (PD) in 10%. Ten patients received a second treatment course: one complete response and 6 PRs were observed at 6 months. The median progression-free survival (PFS) was not reached. The 12- and 24-month PFS were 82% and 68%, respectively. One death due to PD occurred at 24 months. Adverse events (AE) occurred in 96% of the patients, with 10 grade 3–4 AEs in 7 patients. Conclusions: Dabrafenib-trametinib is effective in BRAF p.V600E-mutated DTC patients for restoring 131I uptake with PR observed 6 months after 131I administration in 38% of the patients.

Context Pheochromocytomas and paragangliomas (PPGL) are rare neuroendocrine tumors that are frequently associated with succinate dehydrogenase (SDH) germline mutations. When mutated, SDH losses its function, thus leading to succinate accumulation. Objective In this study, we evaluated serum succinate levels as a new metabolic biomarker in SDHx-related carriers. Methods Retrospective monocentric study of 88 PPGL patients (43 sporadic, 35 SDHB, 10 SDHA/C/D), 17 tumor-free familial asymptomatic carriers (13 SDHB, 4 SDHC/D), and 60 healthy controls. Clinical, biological, and imaging data were reviewed. Serum succinate levels (n = 280) were quantified by an ultra-performance liquid chromatography coupled to a tandem mass spectrometry method and correlated to SDHx mutational status, disease extension, and other biological biomarkers. Results Serum succinate levels > 7 μM allowed identification of tumor-free asymptomatic SDHB-mutated cases compared to a healthy control group (100% specificity; 85% sensitivity). At PPGL diagnosis, SDHB-mutated patients had a significantly increased median succinate level (14 μM) compared to sporadic patients (8 μM) (P Conclusions In this pilot study, we showed that serum succinate level is an oncometabolic biomarker that should be useful to identify SDHB-related carriers. Succinate levels are also a marker of metabolic tumor burden in patients with a metastatic PPGL and a potential marker of treatment response and follow-up.

Adrenocortical carcinoma (ACC) is a very rare and aggressive malignant disease. Therefore, overall survival (OS) has long been considered as the best endpoint. Yet, a unique endpoint is not optimal to take into account the heterogeneity in tumor profile and the diversification of therapeutic option. The purpose of this mini review was to describe endpoints used in the past, present and future in the field of ACC.Pubmed and Clinicaltrial.gov were used to identify relevant studies.Before year 2000 only three endpoints were regularly used: OS, recurrence-free survival (RFS) and response rate. These endpoints were used because ACC was seen as a homogeneous diseases with a high recurrence rate and low rate of long-term survival. Since 2000; along with the apparition of new class of drug, progression-free survival (PFS) has been more and more used. Other endpoints as "time to chemotherapy" or "Progression-free survival 2" were used to evaluate multimodal therapies or treatment with a delayed action. Finally, there is a hope that in the near future, quality of life along with other patient-reported outcomes may be used more frequently.While OS and PFS are currently the most used endpoints in ACC, new endpoints are needed to better take into account the challenges offered by different situations and treatment strategies.

We present a thorough review of the literature on Riedel thyroiditis (RT) with emphasis on aetiology, diagnosis and management, using the PubMed, Sinomed, and China National Knowledge Infrastructure databases. Although the exact aetiology of RT remains obscure, the histopathological features are consistent with a localized form of IgG4-related systemic disease (IgG4-RSD). Nevertheless, IgG4-RSD as a systemic fibroinflammatory disorder per se rarely affects the thyroid in the context of multiorgan manifestations. The initial diagnosis of RT is based on clinical history and imaging, but confirmation by histopathological examination is mandatory. In contrast to the historical surgical approach, glucocorticosteroid therapy is currently considered first line therapy, in line with the RT currently being viewed as a manifestation of, or analogous to, IgG4-RSD. For disease relapse, immunomodulatory agents (azathioprine, methotrexate, rituximab) can be used.

Waterfall plot of the RECIST response

Quality of Life scores

Purpose:To evaluate the efficacy and safety of dabrafenib-trametinib-131I for the treatment of radioactive iodine refractory metastatic differentiated thyroid cancer (DTC) with a BRAF p.V600E mutation.Patients and Methods:A prospective phase II trial including patients with RECIST progression within 18 months and no lesion > 3 cm. Following a baseline recombinant human (rh)TSH-stimulated diagnostic whole-body scan (dc1-WBS), dabrafenib and trametinib were given for 42 days. A second rhTSH-stimulated dc WBS (dc2-WBS) was done at day 28 and 131I (5.5 GBq–150 mCi after rhTSH) was administered at day 35. Primary endpoint was the 6-month RECIST objective response rate. In case of partial response (PR) at 6 or 12 months, a second treatment course could be given. Among 24 enrolled patients, 21 were evaluable at 6 months.Results:Abnormal 131I uptake was present on 5%, 65%, and 95% of the dc1-WBS, dc2-WBS, and post-therapy scans, respectively. At 6 months, PR was achieved in 38%, stable disease in 52%, and progressive disease (PD) in 10%. Ten patients received a second treatment course: one complete response and 6 PRs were observed at 6 months. The median progression-free survival (PFS) was not reached. The 12- and 24-month PFS were 82% and 68%, respectively. One death due to PD occurred at 24 months. Adverse events (AE) occurred in 96% of the patients, with 10 grade 3–4 AEs in 7 patients.Conclusions:Dabrafenib-trametinib is effective in BRAF p.V600E-mutated DTC patients for restoring 131I uptake with PR observed 6 months after 131I administration in 38% of the patients.

“Juvenile-like (hyperplastic/inflammatory) mucosal polyp” is a term proposed for rare benign mesenchymal lesions of the gastro-intestinal tract so far reported only in patients with type 1 neurofibromatosis (NF1). We report here a first sporadic case of NF1-associated mucosal inflammatory polyp of the colon. The diagnosis was made in a 53-year old female patient with a large polypoid tumor of the cecum. The lesion was predominantly mucosal, made of fibroblast-like cells associated with inflammatory infiltrates rich in eosinophils and containing entrapped, distorted epithelial glands, responsible for the juvenile-like appearance. Whole exome sequencing showed a pathogenic variant of NF1. The patient had no evidence of NF1; no NF1 mutation was detected in normal tissues. Our observation may support the existence of juvenile-like inflammatory polyps associated with NF1 alterations, either germline or somatic. This justifies to test NF1 in difficult-to-classify gastrointestinal mesenchymal tumors.

Lymph node metastases in non-well differentiated thyroid cancer (non-WDTC) are common, both in the central compartment (levels VI and VII) and in the lateral neck (Levels II to V). Nodal metastases negatively affect prognosis and should be treated to maximize locoregional control while minimizing morbidity. In non-WDTC, the rate of nodal involvement is variable and depends on the histology of the tumor. For medullary thyroid carcinomas, poorly differentiated thyroid carcinomas, and anaplastic thyroid carcinomas, the high frequency of lymph node metastases makes central compartment dissection generally necessary. In mucoepidermoid carcinomas, malignant peripheral nerve sheath tumors, sarcomas, and malignant thyroid teratomas or thyroblastomas, central compartment dissection is less often necessary, as clinical lymphnode involvement is less common. We aim to summarize the medical literature and the opinions of several experts from different parts of the world on the current philosophy for managing the neck in less common types of thyroid cancer. ispartof: CANCERS vol:15 issue:4 ispartof: location:Switzerland status: published

Thyroid cancer runs the gamut from indolent micropapillary carcinoma to highly aggressive metastatic disease. Today, using prognostic algorithms, treatment and follow-up can be tailored to each patient in order to decrease overtreatment and over-medicalization of indolent disease. Active surveillance of papillary thyroid carcinoma less than 1cm avoids surgery and thyroid hormone replacement in a large proportion of patient whose tumors remain stable for years. Total thyroidectomy, once a dogma in the treatment of all thyroid cancer, is being supplanted by thyroid lobectomy for low-risk cancers, thereby decreasing the surgical risks involved and improving patients' quality of life. Indications for prophylactic central neck dissection, once mandatory, are now being adapted to the risk of cancer recurrence. Radioactive iodine therapy, also previously mandatory for all, is now only employed according to risk factors and expected outcomes. Follow-up is also being tailored to risk factors for recurrence, with less frequent visits and less use of ultrasound and scintigraphy. For more advanced disease, molecular therapies tailored to somatic mutations are opening opportunities for redifferentiation of aggressive tumors which become amenable to radioactive iodine therapy which carries fewer side effects than other systemic therapies. These advances in the management of thyroid cancer with a personalized approach and de-escalation of treatment and follow-up are improving the way we treat thyroid cancer, avoiding overtreatment and improving patients' quality of life.

Hurthle cell carcinoma (HCC) comprises about 5% of thyroid carcinoma cases. Partly because of its rarity there is much we still need to know about HCC as compared to other histological cancer subtypes. We conducted a systematic literature review following PRISMA guidelines and meta-analysis, from 2000 to 2020, to investigate the main characteristics of HCC and clarify information concerning tumor behavior and treatment. Our review included data from 9638 patients reported in 27 articles over the past 20 years. This tumor occurred more frequently in women (67.5%). The mean age was 57.6 years, and the mean size of the neoplasm at diagnosis was 30 mm. Extrathyroidal extension was common (24%) but lymph node metastasis was not (9%). Total thyroidectomy was the most common surgical approach, with neck dissection usually performed in cases with clinically apparent positive neck nodes. Radioiodine therapy was frequently applied (54%), although there is no consensus about its benefits. The mean 5- and 10-year overall survival was 91% and 76%, respectively. This review serves to further elucidate the main characteristics of this malignancy. HCC of the thyroid is rare and most often presents with a relatively large nodule, whereas lymph node metastases are rare. Given the rarity of HCC, a consensus on their treatment is needed, as doubts remain concerning the role of specific tumor findings and their influence on management.

Objective The presence of extrathyroidal extension (ETE) is generally considered as an indication for total thyroidectomy for differentiated thyroid cancer. The accuracy of neck ultrasound for the diagnosis of ETE is controversial. The aim of this study was to assess the diagnostic accuracy of preoperative ultrasound evaluation of ETE. Methods The retrospective and observational study of consecutive patients operated between 2016 and 2019 for cytologically suspicious or indeterminate thyroid nodules were analyzed. US images obtained preoperatively were retrospectively reviewed to identify signs of minimal or gross ETE. Histology was considered as the golden standard for diagnosis of ETE. The sensitivity, specificity, positive (PPV) and negative predictive values (NPV), and accuracy of US were evaluated. Results A cohort of 305 patients (75% females, median age 48 years) with 378 nodules (median size 18 mm) was studied. Seventy-five percent of the nodules (n = 228) were malignant on histology and ETE was present in 106 cases (28%): 83 minimal ETE and 23 gross ETE. Suspicion of minimal ETE on preoperative ultrasound was found in 50 (13%) with a sensitivity of 30%, a specificity of 93%, a PPV of 62% and an NPV of 78%, with an accuracy of 76%. Gross ETE on ultrasound was found in 19 (5%) nodules with a sensitivity of 78%, a specificity of 99.7% a PPV of 94.7% an NPV of 98.6% and an accuracy of 98%. Conclusions Preoperative US is very specific and accurate in diagnosing gross ETE which impacts the extent of initial surgery for thyroid cancers.

Current guidelines favor thyroid lobectomy for intrathyroidal cT1bT2cN0 papillary thyroid carcinoma. Prophylactic neck dissection (PND) is not recommended for these low-risk tumors due to the lack of high-level evidence on improvement in outcomes, but the information from PND may be used for staging. The aim of this study was to evaluate the rate of upstaging with ipsilateral PND.Retrospective study of patients with intrathyroidal unifocal cT1bT2cN0 papillary thyroid carcinoma from 2008 to 2021. All patients underwent total thyroidectomy and PND. Tumors were classified as low or intermediate risk based on the information from pathological analysis of the primary tumor and then from adding the analysis of the lymph nodes. The difference between the tumor-only and the PND-added risk staging was evaluated.Three hundred three patients (241 women, median age 45, median tumor size 17 mm) were included. Microscopic extrathyroidal extension was found in 23.4%, aggressive histology in 6.6%, vascular invasion in 29.3%, and lymph node metastases in 37.3%. One hundred ten patients (36.3%) were intermediate-risk based on the primary tumor. An additional 26 (8.6%) were upstaged to intermediate-risk based on the ipsilateral PND and 2% based on the contralateral PND. Kaplan-Meier 10-year event-free survival in tumors upstaged with ipsilateral PND was not statistically different from intermediate-risk tumors based on the primary tumor characteristics (92% versus 90.9%, Log Rank p = 0.943).Ipsilateral PND upstaged low-risk cT1bT2cN0 patients to intermediate risk in only 8.6% of cases, and contralateral PND in an additional 2%. Routinely performing PND may not be warranted.

Histologic and pTNM classification of differentiated thyroid cancer (DTC) is mandatory to assess risk of relapse, risk of death, and radioactive iodine administration. The impact of an expert central review of external pathology reports has not yet been reported. Monocentric retrospective study to evaluate the difference between initial and second-opinion histopathologic diagnosis for DTC patients referred for post-operative radioactive iodine administration between January 2014 and December 2016. We evaluated major discordance (change of diagnosis from malignant to benign or in main histological subtype or a description of aggressive pathological subtypes), minor discordance (change in histological subtype or description of an aggressive component, multifocality or extrathyroidal extension), and change in ATA classification. A second-opinion histological diagnosis was available for 199 patients. A major discordance was observed in 42 (21%) cases (changes in malignancy in 4 cases, changes in main histological subtype in 22, changes in aggressive pathology variants of PTC in 16). One hundred and four minor discordances were observed regarding 92 patients. These histopathological changes led to changes in the ATA 2015 risk stratification classification in 61 (31%) of cases. There were no predictive factors of major/minor histologic changes or ATA risk stratification changes. Expert central review of pathology has an impact on the 2015 ATA risk stratification classification that can lead to changes in the management of patients with differentiated thyroid cancer.

Objective: Thyroid cancer encasing the recurrent nerve is rare, and the decision to resect or preserve the nerve is multifactorial. The objective of this study was to histopathologically analyze resected encased nerves to assess the rate of nerve invasion and risk factors. Materials and Methods: A retrospective study was carried out on consecutive patients with resection of the recurrent nerve for primary or recurrent follicular cell-derived or medullary thyroid carcinoma from 2005 to 2020. Demographics, pathology, locoregional invasion, metastases, recurrences and survival were analyzed. Slides were reviewed blindly by two specialized pathologists (AAG, RC) for diagnosis of invasion deep to the epineurium. Results: Fifty-two patients were included: 25 females; average age, 55 (range 8–87). In total, 87% percent (45/52) were follicular cell-derived with 17/45 (37.8%) aggressive variants; 13% (7/52) were medullary carcinoma. Preoperative vocal fold (VF) paralysis was present in 16/52 (30.7%). Pathologically, the nerve was invaded in 44/52 cases (85%): 82% of follicular cell-derived tumors (37/45), 88% of pediatric cases, and 100% of medullary carcinomas (7/7). Nerve invasion was observed in 11/16 (69%) with preoperative VF paralysis and 33/36 (92%) with normal VF function. Only aggressive histology was correlated with nerve invasion in follicular cell-derived tumors (p = 0.019). Conclusions: The encased nerves were pathologically invaded in 82% of follicular cell-derived tumors and in 100% of medullary carcinomas. Nerve invasion was statistically correlated with aggressive histopathological subtypes and was observed in the absence of VF paralysis in 92% of cases.

Introduction: Anaplastic thyroid cancer (ATC) is one of the most lethal diseases known to humans with a median survival of 5 months. The American Thyroid Association (ATA) recently published guidelines for the treatment of this dreadful thyroid malignancy. Areas covered: This review presents the current therapeutic landscape of this challenging disease. We also present the results from trials published over the last five years and summarize currently active clinical trials. Expert opinion: Recent attempts to improve the prognosis of these tumors are moving toward personalized medicine, basing the treatment decision on the specific genetic profile of the individual tumor. The positive results of dabrafenib and trametinib for ATC harboring the BRAF V600E mutation have provided a useful treatment option. For the other genetic profiles, different drugs are available and can be used to individualize the treatment, likely using drug combinations. Combinations of drugs act on different molecular pathways and achieve inhibition at separate areas. With new targeted therapies, average survival has improved considerably and death from local disease progression or airway compromise is less likely with improvement in quality of life. Unfortunately, the results remain poor in terms of survival.

PURPOSE Medullary thyroid carcinoma (MTC) is an aggressive neuroendocrine tumor (NET) arising from the calcitonin-producing C cells. Unlike other NETs, there is no widely accepted pathologic grading scheme. In 2020, two groups separately developed slightly different schemes (the Memorial Sloan Kettering Cancer Center and Sydney grade) on the basis of proliferative activity (mitotic index and/or Ki67 proliferative index) and tumor necrosis. Building on this work, we sought to unify and validate an internationally accepted grading scheme for MTC. PATIENTS AND METHODS Tumor tissue from 327 patients with MTC from five centers across the United States, Europe, and Australia were reviewed for mitotic activity, Ki67 proliferative index, and necrosis using uniform criteria and blinded to other clinicopathologic features. After reviewing different cutoffs, a two-tiered consensus grading system was developed. High-grade MTCs were defined as tumors with at least one of the following features: mitotic index ≥ 5 per 2 mm2, Ki67 proliferative index ≥ 5%, or tumor necrosis. RESULTS Eighty-one (24.8%) MTCs were high-grade using this scheme. In multivariate analysis, these patients demonstrated decreased overall (hazard ratio [HR] = 11.490; 95% CI, 3.118 to 32.333; P < .001), disease-specific (HR = 8.491; 95% CI, 1.461 to 49.327; P = .017), distant metastasis-free (HR = 2.489; 95% CI, 1.178 to 5.261; P = .017), and locoregional recurrence-free (HR = 2.114; 95% CI, 1.065 to 4.193; P = .032) survivals. This prognostic power was maintained in subgroup analyses of cohorts from each of the five centers. CONCLUSION This simple two-tiered international grading system is a powerful predictor of adverse outcomes in MTC. As it is based solely on morphologic assessment in conjunction with Ki67 immunohistochemistry, it brings the grading of MTCs in line with other NETs and can be readily applied in routine practice. We therefore recommend grading of MTCs on the basis of mitotic count, Ki67 proliferative index, and tumor necrosis.

The thyroid is an unusual site for metastasis, and metastases in a preexisting primary thyroid tumor are exceedingly rare. We report the first case of a patient with colon cancer who was diagnosed with a thyroid metastasis in a noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP). A 55-year-old male patient presented with a 19 mm thyroid nodule in the inferior left lobe. It was EU-TIRADS 5 on echography and suspicious of papillary thyroid carcinoma (Bethesda V) on cytology. Macroscopically, the nodule was fleshy and completely encapsulated. At frozen section examination, it demonstrated follicular architecture with mild atypia. Inside the nodule was a focus of tumor with glandular architecture, marked cellular atypia, and necrosis. These findings suggested a secondary malignancy. The patient’s medical history was significant for metastatic colon cancer. The definitive histology showed features of metastatic colorectal adenocarcinoma within a NIFTP. Immunohistochemical studies were confirmatory with expression of CDX2 and CK20 localized to the metastatic focus. PAX8, TG, and TTF were negative in the metastasis but expressed in the surrounding NIFTP lesion. The possibility of a metastasis to the thyroid may be considered in patients presenting with a solitary thyroid nodule with a previous history of cancer. Metastatic colorectal adenocarcinoma occurring in a NIFTP has never been reported before now, although metastases to the thyroid are documented in the literature. In cases of a secondary malignancy to the thyroid, treatment is controversial.

Refractory thyroid cancers include radio-iodine-refractory cancers, metastatic or locally advanced unresectable medullary and anaplastic thyroid cancers. Their management has been based for several years on the use of multi-target kinase inhibitors, with anti-angiogenic action, with the exception of anaplastic cancers usually treated with chemo- and radiotherapy. The situation has recently evolved due to the availability of molecular genotyping techniques allowing the discovery of rare but targetable molecular abnormalities. New treatment options have become available, more effective and less toxic than the previously available multi-target kinase inhibitors. The management of refractory thyroid cancers is therefore becoming more complex both at a diagnosis level with the need to know when, how and why to look for these molecular abnormalities but also at a therapeutic level, innovative treatments being hardly accessible. The cost of molecular analyzes and the access to treatments need also to be homogenized because disparities could lead to inequality of care at a national or international level. Finally, the strategy of identifying molecular alterations and treating these rare tumors reinforces the importance of a discussion in a multidisciplinary consultation meeting., Les cancers thyroïdiens réfractaires regroupent les cancers de souche folliculaire réfractaires à l’iode, les cancers médullaires métastatiques ou localement avancés non résécables et les cancers anaplasiques. Leur prise en charge est basée depuis quelques années sur l’utilisation d’inhibiteurs de kinase multicibles, à action principalement anti-angiogénique, exception faite des cancers anaplasiques habituellement traités par chimio- et radiothérapie. La situation a récemment évolué en raison de la mise à disposition de techniques de génotypage moléculaire permettant la découverte d’anomalies moléculaires rares mais ciblables, et de nouveaux traitements, possiblement plus efficaces et moins toxiques que les inhibiteurs de kinase multicibles préalablement disponibles. La prise en charge de ces cancers se complexifie donc à la fois au niveau diagnostique avec la nécessité de savoir quand, comment et pourquoi rechercher ces anomalies moléculaires mais également au niveau thérapeutique, avec la question de la disponibilité des traitements innovants et de l’accès aux essais cliniques. Le coût des analyses moléculaires et l’accès aux médicaments sont à harmoniser car des disparités pourraient conduire à une inégalité des soins au niveau national ou international. Enfin, la stratégie d’identification des altérations moléculaires et de traitement pour ces tumeurs rares renforce l’importance d’une discussion en réunion de concertation pluridisciplinaire.

Background: Pediatric differentiated thyroid cancer (P-DTC) frequently presents with advanced disease. The study aim was to evaluate the outcome of P-DTC and a modified 2015 American Thyroid Association risk classification (ATA-R). Methods: A retrospective study of consecutive P-DTC patients was performed. The ATA-R for P-DTC was used with a cut-off of ≤ 5 N1a for low-risk. The outcome could be excellent response (ER) (thyroglobulin &lt, 1 ng/mL and no evidence of disease (EoD) at imaging), biochemical incomplete response (BIR) (thyroglobulin ≥ 1 ng/mL and no EoD at imaging) or structural incomplete response (SIR) (EoD at imaging). Results: We studied 260 P-DTC (70% females, median age at diagnosis 14 years, 93% total thyroidectomy and 82% lymph node dissection). The ATA-R was low in 30% cases, intermediate in 15% and high in 55%, including 31.5% with distant metastases. Radioiodine treatment was administered in 218 (83.8%), and further radioiodine and surgery was performed in 113 (52%) and 76 (29%) patients, respectively. After a median follow-up of 8.2 years, the outcome was ER in 193 (74.3%), BIR in 17 (6.5%) and SIR in 50 (19.2%). Independent predictors of SIR or BIR at first and last visits were ATA-R intermediate or high. Conclusion: P-DTC has an excellent prognosis. Modified ATA-R is a useful prognostic tool in P-DTC to guide management.

Context Patients with adrenocortical carcinoma (ACC) are frequently on mitotane therapy for a long time period. The drug exerts adrenolytic activity requiring glucocorticoid supplementation, which can be potentially detrimental for bone. Objective To explore whether mitotane with/without chemotherapy is associated with an increased proportion of morphometric vertebral fractures (VFs) in ACC patients. Secondary objectives were proportion of patients with VF progression, or worsening of the spinal deformity index (SDI) during mitotane therapy; and to explore predictive factors of VF progression and a prognostic role of VF progression. Methods Multicenter, retrospective cohort study of patients with ACC who received mitotane alone or in association to chemotherapy, recruited from January 2010 to January 2020 in 2 reference centers in Italy and France. Results A significant increase in the frequency of VFs before and after mitotane therapy was seen both in Italian (28.3% vs 47.8%, P = .04) and French (17.8% vs 35.6%, P = .04) series. VF progression was observed in 39.1%, and 28.9% of patients, respectively. Baseline VFs and increased patient body mass index, but not the dose of cortisol supplementation, showed an independent association with VF progression at multivariate analysis. Among the 72 advanced ACC patients, progression of VFs was associated with a poorer survival. Conclusion The administration of mitotane with/without chemotherapy in ACC patients impairs bone health independently from cortisol supplementation. Appropriate preventive measures to decrease the fracture risk should be implemented in these patients.

Thyroid cancer runs the gamut from indolent micropapillary carcinoma to highly aggressive metastatic disease. Today, using prognostic algorithms, treatment and follow-up can be tailored to each patient in order to decrease overtreatment and over-medicalization of indolent disease. Active surveillance of papillary thyroid carcinoma less than 1cm avoids surgery and thyroid hormone replacement in a large proportion of patient whose tumors remain stable for years. Total thyroidectomy, once a dogma in the treatment of all thyroid cancer, is being supplanted by thyroid lobectomy for low-risk cancers, thereby decreasing the surgical risks involved and improving patients' quality of life. Indications for prophylactic central neck dissection, once mandatory, are now being adapted to the risk of cancer recurrence. Radioactive iodine therapy, also previously mandatory for all, is now only employed according to risk factors and expected outcomes. Follow-up is also being tailored to risk factors for recurrence, with less frequent visits and less use of ultrasound and scintigraphy. For more advanced disease, molecular therapies tailored to somatic mutations are opening opportunities for redifferentiation of aggressive tumors which become amenable to radioactive iodine therapy which carries fewer side effects than other systemic therapies. These advances in the management of thyroid cancer with a personalized approach and de-escalation of treatment and follow-up are improving the way we treat thyroid cancer, avoiding overtreatment and improving patients' quality of life.

Radioiodine treatment (RAI) represents the most widespread and effective therapy for differentiated thyroid cancer (DTC). RAI goals encompass ablative (destruction of thyroid remnants, to enhance thyroglobulin predictive value), adjuvant (destruction of microscopic disease to reduce recurrences), and therapeutic (in case of macroscopic iodine avid lesions) purposes, but its use has evolved over time. Randomized trial results have enabled the refinement of RAI indications, moving from a standardized practice to a tailored approach. In most cases, low-risk patients may safely avoid RAI, but where necessary, a simplified protocol, based on lower iodine activities and human recombinant TSH preparation, proved to be just as effective, reducing overtreatment or useless impairment of quality of life. In pediatric DTC, RAI treatments may allow tumor healing even at the advanced stages. Finally, new challenges have arisen with the advancement in redifferentiation protocols, through which RAI still represents a leading therapy, even in former iodine refractory cases. RAI therapy is usually well-tolerated at low activities rates, but some concerns exist concerning higher cumulative doses and long-term outcomes. Despite these achievements, several issues still need to be addressed in terms of RAI indications and protocols, heading toward the RAI strategy of the future.

Context European and French guidelines for ENSAT stage IV low tumor burden or indolent adrenocortical carcinoma (ACC) recommend a combination of mitotane and locoregional treatments (LRT) as first-line treatment. Nevertheless, the benefit of LRT in combination with mitotane has never been evaluated in this selected group of patients. Objective This work aimed to evaluate the therapeutic strategy of LRT combined with mitotane in patients with low tumor burden stage IVA ACC. Methods A retrospective chart review was performed from 2003 to 2018 of patients with stage IV ACC with 2 or fewer tumoral organs who received mitotane in our center. The primary end point was the delay between mitotane initiation and first systemic chemotherapy. Secondary end points were progression-free survival (PFS) and overall survival (OS) from mitotane initiation. Adjusted analyses were performed on the main prognostic factors. Results Out of 79 included patients, 48 (61%) patients were female and the median age at stage IVA diagnosis was 49.8 years (interquartile range [IQR], 38.8-60.0 years). Metastatic sites were mainly lungs (76%) and liver (48%). Fifty-eight (73%) patients received LRT including adrenal bed radiotherapy (14 patients, 18%), surgery (37 patients, 47%), and/or interventional radiology (35 patients, 44%). Median time between mitotane initiation and first chemotherapy administration was 9 months (IQR, 4-18 months). Median PFS1 (first tumor-progression) was 6.0 months (95% CI, 4.5-8.6). Median OS was 46 months (95% CI, 41-68). PFS1, PFS2, and OS were statistically longer in the mitotane plus LRT group compared to the mitotane-only group (hazard ratio [HR] = 0.39; 95% CI, 0.22-0.68; HR = 0.35; 95% CI, 0.20-0.63; and HR = 0.27; 95% CI, 0.14-0.50, respectively). Ten (13%) patients achieved complete response (CR), all from the mitotane plus LRT group. Conclusion Our results endorse European and French guidelines for stage IV ACC with 2 or fewer tumor organs and favor the combination of mitotane and LRT as first-line treatment. For the first time, a significant number of CRs were observed. Prospective studies are expected to confirm these findings.

Refractory thyroid cancers include radio-iodine-refractory cancers, metastatic or locally advanced unresectable medullary and anaplastic thyroid cancers. Their management has been based for several years on the use of multi-target kinase inhibitors, with anti-angiogenic action, with the exception of anaplastic cancers usually treated with chemo- and radiotherapy. The situation has recently evolved due to the availability of molecular genotyping techniques allowing the discovery of rare but targetable molecular abnormalities. New treatment options have become available, more effective and less toxic than the previously available multi-target kinase inhibitors. The management of refractory thyroid cancers is therefore becoming more complex both at a diagnosis level with the need to know when, how and why to look for these molecular abnormalities but also at a therapeutic level, innovative treatments being hardly accessible. The cost of molecular analyzes and the access to treatments need also to be homogenized because disparities could lead to inequality of care at a national or international level. Finally, the strategy of identifying molecular alterations and treating these rare tumors reinforces the importance of a discussion in a multidisciplinary consultation meeting.

Simple Summary Total thyroidectomy used to be recommended for all thyroid cancers. We now know that some thyroid cancers have a relatively low risk of recurrence. Today, for some of these cancers, depending on the type of tumor, its’ size and other tumor characteristics, a thyroid lobectomy (or hemithyroidectomy) can be performed without increasing the patient’s risk of cancer recurrence. Thyroid lobectomy has the advantages of having less risk of surgical complications and a less frequent need for thyroid hormone replacement therapy. This approach is not optimal for all thyroid cancers, however, and careful tumor and patient selection are necessary. This review explains the rationale and criteria for patient selection for thyroid lobectomy for selected thyroid cancers. Abstract Many recent publications and guidelines have promoted a “more is less” approach in terms of treatment for low to intermediate risk differentiated thyroid cancer (DTC), which comprise the vast majority of thyroid cancers: less extensive surgery, less radioactive iodine, less or no thyroid hormone suppression, and less frequent or stringent follow-up. Following this approach, thyroid lobectomy has been proposed as a means of decreasing short- and long-term postoperative morbidity while maintaining an excellent prognosis for tumors meeting specific macroscopic and microscopic criteria. This article will examine the pros and cons of thyroid lobectomy for low to intermediate risk cancers and discuss, in detail, criteria for patient selection and oncological outcomes.

Context The behavior of locally advanced pheochromocytoma (LAP) remains unknown. Objective We characterized the population with LAP and recurrence-free survival (RFS). Methods This retrospective multicentric study was run within the ENDOCAN-COMETE network and French Group of Endocrine Tumors (GTE) from 2003 to 2018, including patients from 11 French referral centers with LAP as defined by capsular invasion, vascular invasion, adipose tissue invasion, and/or positive locoregional lymph nodes at diagnosis without evidence of distant metastasis. The main outcome measure was recurrence, defined as tumor reappearance, including local site and/or distant metastasis. The primary endpoint was RFS analysis; secondary endpoints were characterization, overall survival (OS), and prognostic factors of recurrence. Results Among 950 patients, 90 (9%) exhibited LAP criteria and 55 met inclusion criteria (median age, 53 years; 61% males; 14% with germline mutation; 84% with catecholamine excess). LAP was defined by 31 (56%) capsular invasions, 27 (49%) fat invasions, 6 (11%) positive lymph nodes, and 22 (40%) vascular invasions. After median follow-up of 54 months (range, 6-180), 12 patients (22%) had recurrences and 3 (5%) died of metastatic disease. Median RFS was 115 months (range, 6-168). Recurrences were local in 2 patients, distant in 2, and both local and distant in 8 patients. Median OS of patients was not reached. Size above 6.5 cm (P = 0.019) and Ki-67 > 2% (P = 0.028) were identified as independent significant prognostic factors in multivariate analysis. Conclusion LAP represents 9% of pheochromocytoma’s population and has a metastatic behavior. This study paves the way for future pathological TNM classification.

Histologic and pTNM classification of differentiated thyroid cancer (DTC) is mandatory to assess risk of relapse, risk of death, and radioactive iodine administration. The impact of an expert central review of external pathology reports has not yet been reported.Monocentric retrospective study to evaluate the difference between initial and second-opinion histopathologic diagnosis for DTC patients referred for post-operative radioactive iodine administration between January 2014 and December 2016. We evaluated major discordance (change of diagnosis from malignant to benign or in main histological subtype or a description of aggressive pathological subtypes), minor discordance (change in histological subtype or description of an aggressive component, multifocality or extrathyroidal extension), and change in ATA classification.A second-opinion histological diagnosis was available for 199 patients. A major discordance was observed in 42 (21%) cases (changes in malignancy in 4 cases, changes in main histological subtype in 22, changes in aggressive pathology variants of PTC in 16). One hundred and four minor discordances were observed regarding 92 patients. These histopathological changes led to changes in the ATA 2015 risk stratification classification in 61 (31%) of cases. There were no predictive factors of major/minor histologic changes or ATA risk stratification changes.Expert central review of pathology has an impact on the 2015 ATA risk stratification classification that can lead to changes in the management of patients with differentiated thyroid cancer.

Advanced adrenocortical carcinoma (ACC) has poor but heterogeneous prognosis. Apart from Ki67 index, no prognostic or predictive biomarker has been validated in advanced ACC, so far. We aimed at analyzing expression of a large panel of proteins involved in known altered pathways in ACC (cell cycle, Wnt/ß-catenin, methylation) to identify and prioritize potential prognostic or predictive parameters metastatic ACC population. We conducted a retrospective multicentric study. Overall survival (OS) and partial response according to RECIST 1.1 were primary endpoints. TMA was set up and 16 markers were analyzed. Modified ENSAT and GRAS parameters were characterized for prognostic adjustment. Results: We included 66 patients with a mean age at metastatic diagnosis of 48.7 ± 15.5 years. Median survival was 27.8 months. After adjustment to mENSAT-GRAS parameters, p53 and PDxK were prognostic of OS. No potential biomarker has been identified as predictive factor of response. We identified for the first time P53 as an independent prognostic marker of metastatic adrenocortical carcinoma after mENSAT-GRAS parameter adjustment. Prognostic impact of Wnt/ß-catenin alterations was not confirmed in this cohort of metastatic ACC.

Anaplastic thyroid carcinoma (ATC) is a rare and undifferentiated form of thyroid cancer. Its prognosis is poor: the median overall survival (OS) of patients varies from 4 to 10 months after diagnosis. However, a doubling of the OS time may be possible owing to a more systematic use of molecular tests for targeted therapies and integration of fast-track dedicated care pathways for these patients in tertiary centers. The diagnostic confirmation, if needed, requires an urgent biopsy reread by an expert pathologist with additional immunohistochemical and molecular analyses. Therapeutic management, defined in multidisciplinary meetings, respecting the patient’s choice, must start within days following diagnosis. For localized disease diagnosed after primary surgical treatment, adjuvant chemo-radiotherapy is recommended. In the event of locally advanced or metastatic disease, the prognosis is very poor. Treatment should then involve chemotherapy or targeted therapy and decompressive cervical radiotherapy. Here we will review current knowledge on ATC and provide perspectives to improve the management of this deadly disease.

Thyroid carcinoma on struma ovarii (TCSO) is a rare ovarian tumour, derivate from monodermic teratomas. It represents about 0.01% of overall ovarian tumours and 5 to 10% of struma ovarii. The diagnosis is histologic and retrospective after pelvic surgery; radiographic imaging being unspecific. Because of its rarity, the treatment of TCSO is not consensual and should be validated in multidisciplinary team involved in rare ovarian carcinoma. The first treatment is a surgical removal, with a laparoscopic approach. A fertility-conservative surgery is recommended for young women. If the tumour is unresectable and/or with metastatic spread, an adjuvant iodine 131 treatment might be proposed after thyroidectomy. Recurrence of TCSO should be taken care of as a thyroid carcinoma with tyrosine kinase inhibitor in case of progressive distant relapse, refractory to iodine 131 treatment. If the recurrence is localised, a complete surgery is the preferred option. There is no gold standard for the follow up.

Bone metastases (BM) and skeletal-related events (SRE) are frequent in patients with malignant pheochromocytoma and paraganglioma (PPM) and the best modality of prevention unknown. The role of interventional radiology (IR) techniques for the prevention of SRE in the multidisciplinary management of malignant PPM has not been evaluated in that setting. Single referral center retrospective review of all patients with malignant PPM with BM from 2000 to 2016. The primary endpoint was the time to first serious SRE (TTSRE). At time of inclusion, patients with high bone tumor burden disease were defined as those having more than five BM with the biggest exceeding 2 cm (Group A) and patients with moderate bone tumor burden disease were defined as those having five or less BM or no BM exceeding 2 cm (Group B). A total of 28 patients were included in this study. Thirteen were treated by IR techniques for prevention of first serious SRE. After a median follow-up of 48.2 months, the median TTSRE was not reached in patients treated by IR techniques and was 26.0 months in patients without IR procedures (p = .058). When comparing patients in group B, TTSRE was significantly higher in patients treated by IR (10 patients) when compared to patients without IR procedures (12 patients) (p = .021). IR techniques may help to delay the occurrence of first serious SRE in patients with malignant PPM with moderate bone tumor burden disease. Prospective studies are expected to confirm these results.

Aims: The BRAFV600E oncogene, reported in 40%–60% of papillary thyroid cancer (PTC), has an important role in the pathogenesis of PTC. It is associated with the loss of thyroid iodide-metabolizing genes, such as sodium/iodide symporter (NIS), and therefore with radioiodine refractoriness. Inhibition of mitogen-activated protein kinase (MAPK) pathway, constitutively activated by BRAFV600E, is not always efficient in resistant tumors suggesting that other compensatory mechanisms contribute to a BRAFV600E adaptive resistance. Recent studies pointed to a key role of transforming growth factor β (TGF-β) in BRAFV600E-induced effects. The reactive oxygen species (ROS)-generating NADPH oxidase NOX4, which is increased in PTC, has been identified as a new key effector of TGF-β in cancer, suggestive of a potential role in BRAFV600E-induced thyroid tumors. Results: Here, using two human BRAFV600E-mutated thyroid cell lines and a rat thyroid cell line expressing BRAFV600E in a conditional manner, we show tha...

The SF-1 transcription factor target gene FATE1 encodes a cancer-testis antigen that has an important role in regulating apoptosis and response to chemotherapy in adrenocortical carcinoma (ACC) cells. Autoantibodies directed against FATE1 were previously detected in patients with hepatocellular carcinoma. In this study, we investigated the prevalence of circulating anti-FATE1 antibodies in pediatric and adult patients with adrenocortical tumors using three different methods (immunofluorescence, ELISA and Western blot). Our results show that a pervasive anti-FATE1 immune response is present in those patients. Furthermore, FATE1 expression is a robust prognostic indicator in adult patients with ACC and is associated with increased steroidogenic and decreased immune response gene expression. These data can open perspectives for novel strategies in ACC immunotherapy.

Simple Summary Cytopathology cannot distinguish benign from malignant follicular lesions in 20–30% of cases. These indeterminate cases includes the so-called follicular neoplasms (FNs) according to The Bethesda System for Reporting Thyroid Cytopathology. Frozen samples from 66 classic follicular adenomas (cFAs) and carcinomas (cFTCs) studied by array-comparative genomic hybridization identified three specific alterations of cFTCs (losses of 1p36.33-35.1 and 22q13.2-13.31, and gain of whole chromosome X) confirmed by fluorescent in situ hybridization (FISH) in a second independent series of 60 touch preparations from frozen samples of cFAs and cFTCs. In a third independent set of 27 cases of already stained pre-operative fine-needle aspiration cytology samples diagnosed as FNs and histologically verified, FISH analysis using these three markers identified half of cFTCs. Specificity of our assay for identifying cFTCs is higher than 98% which might be comparable with BRAF600E testing in cases of suspicion of classic papillary thyroid carcinomas. Abstract Although fine-needle aspiration cytology (FNAC) is helpful in determining whether thyroid nodules are benign or malignant, this distinction remains a cytological challenge in follicular neoplasms. Identification of genomic alterations in cytological specimens with direct and routine techniques would therefore have great clinical value. A series of 153 cases consisting of 72 and 81 histopathologically confirmed classic follicular adenomas (cFAs) and classic follicular thyroid carcinomas (cFTCs), respectively, was studied by means of different molecular techniques in three different cohorts of patients (pts). In the first cohort (training set) of 66 pts, three specific alterations characterized by array comparative genomic hybridization (aCGH) were exclusively found in half of cFTCs. These structural abnormalities corresponded to losses of 1p36.33-35.1 and 22q13.2-13.31, and gain of whole chromosome X. The second independent cohort (validation set) of 60 pts confirmed these data on touch preparations of frozen follicular neoplasms by triple DNA fluorescent in situ hybridization using selected commercially available probes. The third cohort, consisting of 27 archived cytological samples from an equal number of pts that had been obtained for preoperative FNAC and morphologically classified as and histologically verified to be follicular neoplasms, confirmed our previous findings and showed the feasibility of the DNA FISH (DNA fluorescent in situ hybridization) assay. All together, these data suggest that our triple DNA FISH diagnostic assay may detect 50% of cFTCs with a specificity higher than 98% and be useful as a low-cost adjunct to cytomorphology to help further classify follicular neoplasms on already routinely stained cytological specimens.

A 59-year-old woman with locally invasive poorly differentiated thyroid cancer with synchronous lung, mediastinal, and bone metastases and a somatic

Classification of thyroid cancer of follicular origin. The 2017-WHO histological classification individualizes 4 groups of differentiated thyroid cancer of follicular origin: papillary the most frequent with several subtypes, follicular, oncocytic and poorly differentiated. This histological classification is closely related to genomic abnormalities found in these cancers. Initial estimate of the risk of cancer related death is based on the TNM classification and that of the risk of recurrence on the American Thyroid Association stratification; these two risk estimates will guide the extent of initial treatment. Then, a dynamic classification that can be modified at each work-up will appreciate the tumoral status and thus the risk of recurrence and of cancer related death.Classification des carcinomes thyroïdiens de souche folliculaire. La classification histologique 2017 de l’Organisation mondiale de la santé individualise parmi les cancers de la thyroïde de souche folliculaire quatre groupes : papillaire, le plus fréquent avec plusieurs sous-types, folliculaire, oncocytaire et peu différencié. Cette classi- fication histologique est bien corrélée avec les anomalies génomiques mises en évidence dans ces cancers. L’estimation initiale du risque de décès par cancer repose sur la classification TNM et celle du risque de rechute sur la classification de l’ American Thyroid Association ; ces deux estimations du risque vont guider l’étendue du traitement initial. Par la suite, une classification dynamique qui peut être modifiée lors de chaque bilan va apprécier le statut tumoral et ainsi le risque de rechute et de décès par cancer.

Recent developments in the treatment of adrenocortical carcinoma (ACC) include diagnostic and prognostic risk stratification algorithms, increasing evidence of the impact of historical therapies on overall survival, and emerging targets from integrated epigenomic and genomic analyses. Advances include proper clinical and molecular characterization of all patients with ACC, standardization of proliferative index analyses, referral of these patients to large cancer referral centers at the time of first surgery, and development of new trials in patients with well-characterized ACC. Networking and progress in the molecular characterization of ACC constitute the basis for significant future therapeutic breakthroughs.

International audience; Oncocytic adrenocortical tumors are a rare subtype of adrenal tumors with challenging diagnosis and histoprognostic assessment. It is usually believed that oncocytic adrenocortical tumors have a more indolent clinical behavior than conventional adrenocortical tumors. As the Weiss score overestimates the malignancy of oncocytic adrenocortical tumors owing to intrinsic parameters, alternative scores have been proposed. The Lin-Weiss-Bisceglia score is currently recommended. We performed a large nationwide multicenter retrospective clinicopathologic study of oncocytic adrenocortical tumors. Among the 43 patients in our cohort, 40 patients were alive without disease, 2 patients died of their disease and 1 patient was alive with relapse after a median follow-up of 38 months (20-59). Our data revealed that over 50% of the oncocytic adrenocortical tumor cases were diagnosed as carcinoma whatever the classification systems used, including the Lin-Weiss-Bisceglia score. The exception is the Helsinki score, which incorporates the Ki-67 proliferation index and was the most specific prognostic score for oncocytic adrenocortical tumor malignancy without showing a loss in sensitivity. A comparison of malignant oncocytic adrenocortical tumors with conventional adrenocortical carcinomas matched for age, sex, ENS@T stage and surgical resection status showed significant better overall survival of malignant oncocytic adrenocortical tumors.

Thyroid carcinoma on struma ovarii (TCSO) is a rare ovarian tumour, derivate from monodermic teratomas. It represents about 0.01% of overall ovarian tumours and 5 to 10% of struma ovarii. The diagnosis is histologic and retrospective after pelvic surgery; radiographic imaging being unspecific. Because of its rarity, the treatment of TCSO is not consensual and should be validated in multidisciplinary team involved in rare ovarian carcinoma. The first treatment is a surgical removal, with a laparoscopic approach. A fertility-conservative surgery is recommended for young women. If the tumour is unresectable and/or with metastatic spread, an adjuvant iodine 131 treatment might be proposed after thyroidectomy. Recurrence of TCSO should be taken care of as a thyroid carcinoma with tyrosine kinase inhibitor in case of progressive distant relapse, refractory to iodine 131 treatment. If the recurrence is localised, a complete surgery is the preferred option. There is no gold standard for the follow up.

The purpose of this review is to present an overview regarding the renaming of encapsulated follicular variant of papillary thyroid cancer as 'noninvasive follicular thyroid neoplasm with papillary-like nuclear features'.A recent retrospective study has shown the excellent clinical outcomes of noninvasive encapsulated follicular variant of papillary thyroid cancer, for which the diagnosis is based on a thorough examination of all tumor tissue and its capsule to exclude any vascular or capsular invasion. Given the extremely low malignant potential of this entity, the term cancer was eliminated from its name, as this tumor requires less aggressive follow-up and treatment.The low-risk tumor was previously treated conservatively prior to its renaming. However, elimination of the term cancer from its name may decrease the psychological and social consequences of its diagnosis.

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Metastatic pheochromocytomas and paragangliomas (MPPs) present clinicians with three major challenges: scarcity, complexity of characterization, and heterogeneous behavior and prognosis. As with the treatment for all neuroendocrine tumors, the control of hormonal symptoms and tumor growth is the main therapeutic objective in MPP patients. A significant number of MPP patients still die from uncontrolled hormone secretion. In addition, the management of MPPs remains palliative. Steps forward include proper characterization of MPP patients at large cancer referral centers with multidisciplinary teams; improved strategies to stratify patients prognostically; and implementation of trials within national and international networks. Progress in the molecular characterization and staging of MPPs constitutes the basis for significant treatment breakthroughs.

Mitotane (o,p'DDD) is the most effective treatment of advanced adrenocortical carcinoma (ACC) but its mechanism of action remains unknown. Previous studies suggested that o,p'DDA may represent the active metabolite of mitotane. We aimed at reevaluating the potential role and pharmacological effects of o,p'DDA. Functional consequences of o,p'DDA exposure were studied on proliferation, steroidogenesis, and mitochondrial respiratory chain in human H295R and SW13 adrenocortical cells. Mitotane and its metabolites were quantified using high-performance liquid chromatography combined to an ultraviolet detection in these cells treated with o,p'DDD or o,p'DDA and in human adrenal tissues. Dose-response curves up to 300 μM showed that, as opposed to o,p'DDD, o,p'DDA did not inhibit cell proliferation nor alter respiratory chain complex IV activity, gene expression nor induce mitochondrial biogenesis, oxidative stress, or apoptosis. However, whereas mitotane drastically decreased expression of genes involved in steroidogenesis, o,p'DDA slightly reduced expression of some steroidogenic enzymes and exerts weak anti-secretory effects only at high doses. While o,p'DDD concentration was significantly reduced by 40 % in H295R cell supernatants after 48 h incubation, o,p'DDA levels remained unchanged suggesting that o,p'DDA was not efficiently transported into the cells. o,p'DDA was not detected in cell homogenates or supernatants after 48 h exposure to o,p'DDD, consistent with the absence of o,p'DDA production in these models. Finally, unlike o'p'DDD, we found that o,p'DDA content was undetectable in two ACC and one normal adrenal gland of mitotane-treated patients, suggesting a lack of cellular uptake and in situ production. Our results demonstrate that o,p'DDD, but not o,p'DDA, induces functional alterations in adrenal cells.

Cyclophosphamide-dacarbazine-vincristine regimen is recommended for the treatment of malignant pheochromocytoma and paraganglioma (MPP); however, dacarbazine is the only recognized active drug in neuroendocrine tumours. We investigated the therapeutic benefit of temozolomide (TMZ), an oral alternative to dacarbazine, in patients with MPP. This is a retrospective study of consecutive patients with documented progressive MPP. We examined the correlation between Succinate dehydrogenase B (SDHB) mutation and O(6)-methylguanine-DNA methyltransferase (MGMT) promoter methylation and MGMT expression in the French nation-wide independent cohort of 190 pheochromocytomas or paragangliomas (PP). Progression-free survival (PFS) according to RECIST 1.1 and PERCIST 1.0 criteria was the primary end point. Fifteen consecutive patients with MPP were enrolled; ten (67%) carried a mutation in SDHB. The mean dose intensity of TMZ was 172 mg/m(2) /d for 5 days every 28 days. Median PFS was 13.3 months after a median follow-up of 35 months. There were five partial responses (33%), seven stable (47%) and three progressive diseases (20%). Grade 3 toxicities were lymphopenia in two patients and hypertension in one. Partial responses were observed only in patients with mutation in SDHB. MGMT immunohistochemistry was negative in tumour samples from four patients who responded to treatment. SDHB germline mutation was associated with hypermethylation of the MGMT promoter and low expression of MGMT in 190 samples of the French nation-wide independent cohort. This study demonstrates that TMZ is an effective antitumour agent in patients with SDHB-related MPP. The silencing of MGMT expression as a consequence of MGMT promoter hypermethylation in SDHB-mutated tumours may explain this finding.