The Incidence and Survival of Rare Cancers of the Thyroid, Parathyroid, Adrenal, and Pancreas

Unraveling molecular signatures in rare bone tumors and navigating the cancer pathway landscapes for targeted therapeutics

Rare cancers (RCs), which account for over 20% of cancer cases, face significant research and treatment challenges due to their limited prevalence. This results in suboptimal outcomes compared to more common malignancies. Rare bone tumors (RBTs) constitute 5-10% of rare cancer cases and pose unique diagnostic complexities. The therapeutic potential of anti-cancer drugs for RBTs remains largely unexplored. Identifying molecular alterations in cancer-related genes and their associated pathways is essential for precision medicine in RBTs. Small molecule inhibitors and monoclonal antibodies targeting specific RBT-associated proteins show promise. Ongoing clinical trials aim to define RBT biomarkers, subtypes, and optimal treatment contexts, including combination therapies and immunotherapeutic agents. This review addresses the challenges in diagnosing, treating, and studying RBTs, shedding light on the current state of RBT biomarkers, potential therapeutic targets, and promising inhibitors. Rare cancers demand attention and innovative solutions to improve clinical outcomes.

Parathyroid carcinoma: Three case reports

BACKGROUND

Parathyroid carcinoma (PC) is a rare, slow-growing malignant tumor and a rare cause of primary hyperfunctioning of the parathyroid, with a highly variable clinical course, depending on the aggressiveness of the individual tumor and the degree of hypercalcemia.

CASE SUMMARY

The aim of this report is to summarize the diagnosis and treatment of three cases of PC and to review and conclude aspects regarding the three collected cases with reference to other relevant cases to explore the value of ultrasound in the diagnosis of PC. All three patients had hypercalcemia, consisting of a high serum calcium level and a high level of parathyroid hormone that was > 2-fold (even > 30-fold) of the normal upper limit. The ultrasonographic findings of the parathyroid gland showed that the glands were all > 30 mm, and the internal echo was uneven. All patients underwent surgery. PC in three cases was confirmed by routine histopathology and immunohistochemistry.

CONCLUSION

As clinical signs and laboratory results are nonspecific, it is difficult to diagnose PC preoperatively, so imaging examinations are often needed.

Parathyroid carcinoma: Current management and outcomes – A systematic review

OBJECTIVE

Parathyroid carcinoma is rarely encountered in clinical practice. When faced with this clinical challenge, there is currently a paucity of evidence available for the optimal management of patients with parathyroid carcinoma. This systematic review synthesizes the available literature to evaluate the optimal management approach, thus providing guidance for future management.

METHODS

A systematic review was conducted according to PRISMA guidelines using Ovid MEDLINE, EMBASE, and PubMed databases for studies, published in English, reporting on parathyroid carcinoma. Full text of potentially eligible articles were reviewed by two authors independently and eligible studies selected. Treatment options and associated outcomes were evaluated. Descriptive statistics were used to describe pooled patient cohorts.

RESULTS

3203 articles were initially identified using the search criteria with 59 full-text articles then screened for eligibility. Seven articles, all retrospective studies, concerning 2307 patients (median 224/study). Parathyroidectomy alone was the most frequently utilised surgical approach across all studies, followed by en-bloc resection (with adjacent thyroid and/or nodal tissue). There was no difference in post-operative morbidity, mortality or survival between surgical approaches (p < 0.005). Patients who underwent either form of surgery had longer overall survival than those managed non-operatively (p < 0.005).

CONCLUSION

Surgical resection is the optimal treatment of parathyroid carcinoma. However there remains no consensus on the optimal extent of surgery, and as such future randomised prospective studies are necessary to evaluate the effects of different surgical approaches on morbidity, mortality and oncologic outcomes. Following resection, long-term surveillance with PTH is advised.

Differentiating between adrenocortical carcinoma and lipid-poor cortical adenoma: A novel cross-sectional imaging-based score

BACKGROUND

Discrimination between adrenocortical carcinoma and lipid-poor cortical adenoma preoperatively is frequently difficult as these two entities have overlapping imaging characteristics. Differentiation will allow for the selection of the most appropriate operative approach and may help prevent over-treatment. We aimed to identify imaging features that could preoperatively differentiate adrenocortical carcinoma from lipid-poor cortical adenoma and use them in a novel imaging-based score.

METHODS

We conducted a retrospective analysis of patients with pathologically proven adrenocortical carcinoma and lipid-poor cortical adenoma who underwent resection in a single tertiary referral center between March 1998 and August 2020. The inclusion criteria were diameter >1 cm, attenuation >10 Hounsfield units on nonenhanced computed tomography, and histopathologic diagnosis. Patients with metastatic or locally advanced adrenocortical carcinoma adenoma (stages 3-4) were excluded. We developed a score using binary logistic multivariate regression model in 5-fold derivation (∼70%) cohorts with stepwise backward conditional regression as feature selection. Standardized mean regression weight was used as variable score points.

RESULTS

We identified 232 adrenals resected across 211 patients. By comparing the imaging characteristics of adrenocortical carcinoma (n = 56) and lipid-poor cortical adenoma (n = 156), we revealed statistically significant differences between the groups in 9 parameters: size, attenuation, thin and thick rim enhancement patterns, heterogeneity, calcification, necrosis, fat infiltration, and lymph node prominence. The score mean performance was 100% sensitivity for the exclusion of adrenocortical carcinoma, 80% specificity (95% confidence interval, 68.3-91.5), 66% positive predictive value (95% confidence interval, 52.3-78.7), and 100% negative predictive value with area under the curve of 0.974.

CONCLUSION

We defined and evaluated a novel 9-variable, imaging-based score. This score outperformed any single variable and could facilitate safe preoperative discrimination of adrenocortical carcinoma and lipid-poor cortical adenoma.

Effect of HIV-1 Protease Inhibitor on IL-18 and IL-1β in Rats with Insulinoma

This study is aimed at investigating the treatment effectiveness of HIV-1 protease inhibitor for rats with insulinoma and its effects on interleukin-1β (IL-1β) and interleukin-18 (IL-18). A total of 40 6-week-old nude mice were included in this study. We randomly assigned 20 rats for insulinoma modeling and divided them into model A and B groups. Another 20 rats were randomly divided into control A and B groups. Rats from the model A and control A groups were given HIV-1 protease inhibitors. The expression profiles of IL-18 and IL-1β, clinical indicators, water maze test results, oxidative stress damage, and changes in neurological functions in rats from each group were recorded. The expression levels of IL-18 and IL-1β, insulin level, the ratio of immunoreactive insulin to plasma glucose (IRI/G), escape latency, reactive oxygen species (ROS), and amyloid β-protein (Aβ) level were lower in the model A group than in the model B group while fasting blood glucose, platform crossing times, and superoxide dismutase (SOD) were higher in the model A group than in the model B group. The insulin level and hippocampus Aβ level were lower in the control A group than in the control B group. In contrast, other indicators in the control A group were not significantly different from those in the model B group. HIV-1 protease inhibitor is effective in the treatment of insulinoma in rats. It can significantly reduce IL-18 and IL-1β and protect the neurological functions in rats and has broad prospects for clinical application.

Diagnosis and treatment of liver metastases of parathyroid carcinoma

INTRODUCTION

Parathyroid carcinoma (PC) is a very rare endocrine malignancy occurring in less than 1% of all cases of primary hyperparathyroidism (pHPT). The liver is the second most common target organ for distant metastases of PC, but no guidelines are available for the diagnosis and treatment of liver metastases. In this study, we attempted to summarize the characteristics of the diagnosis and treatment of liver metastases based on our patients and other cases reported in the literature.

MATERIALS AND METHODS

The files of all patients diagnosed with PC with liver metastases summarized at our center between 2000 and 2022 were reviewed, and three datasets from Medline, Web of Science, and Embase were systematically searched to identify relevant articles.

RESULTS

Three patients with liver metastases from our center and 11 patients from the literature were included in the study. All patients had pHPT with borderline remission of hypercalcemia after each operation. A total of 71.4% of the patients' liver lesions were found by abdominal CT scans, while 35.7% were found by MRI, PET-CT, and fine-needle aspiration biopsy (FNAB), which were also helpful for diagnosis. Eight of nine patients (88.9%) who underwent surgery, radiofrequency ablation (RFA), or transcatheter arterial embolization (TAE) were alive, and only one postoperative patient died after a follow-up of 60 months.

CONCLUSIONS

PC is a rare malignant tumor prone to recurrence and metastasis, and postoperative reviews should be carried out routinely. Abnormally elevated parathyroid hormone (PTH) and serum calcium can indicate recurrence or metastasis. Enhanced CT and MRI can provide valuable support for the diagnosis of liver metastases, but whether [18F]FDG-PET-CT, [18F]FCH-PET-CT, or [11C]choline-PET-CT can be used as a diagnostic basis requires further study. Resection of liver metastases, segmental hepatectomy, or RFA can significantly improve patients' symptoms.

Whole-genome Sequencing of Follicular Thyroid Carcinomas Reveal Recurrent Mutations in MicroRNA Processing Subunit DGCR8

BACKGROUND

The genomic and transcriptomic landscape of widely invasive follicular thyroid carcinomas (wiFTCs) and Hürthle cell carcinoma (HCC) are poorly characterized, and subsets of these tumors lack information on genetic driver events.

OBJECTIVE

The aim of this study was to bridge this gap.

METHODS

We performed whole-genome and RNA sequencing and subsequent bioinformatic analyses of 11 wiFTCs and 2 HCCs with a particularly poor prognosis, and matched normal tissue.

RESULTS

All wiFTCs exhibited one or several mutations in established thyroid cancer genes, including TERT (n = 4), NRAS (n = 3), HRAS, KRAS, AKT, PTEN, PIK3CA, MUTYH, TSHR, and MEN1 (n = 1 each). MutSig2CV analysis revealed recurrent somatic mutations in FAM72D (n = 3, in 2 wiFTCs and in a single HCC), TP53 (n = 3, in 2 wiFTCs and a single HCC), and EIF1AX (n = 3), with DGCR8 (n = 2) as borderline significant. The DGCR8 mutations were recurrent p.E518K missense alterations, known to cause familial multinodular goiter via disruption of microRNA (miRNA) processing. Expression analyses showed reduced DGCR8 messenger RNA expression in FTCs in general, and the 2 DGCR8 mutants displayed a distinct miRNA profile compared to DGCR8 wild-types. Copy number analyses revealed recurrent gains on chromosomes 4, 6, and 10, and fusion gene analyses revealed 27 high-quality events. Both HCCs displayed hyperploidy, which was fairly unusual in the FTC cohort. Based on the transcriptome data, tumors amassed in 2 principal clusters.

CONCLUSION

We describe the genomic and transcriptomic landscape in wiFTCs and HCCs and identify novel recurrent mutations and copy number alterations with possible driver properties and lay the foundation for future studies.

Multiple endocrine neoplasia type 1 (MEN-1) and neuroendocrine neoplasms (NENs)

Neuroendocrine neoplasms (NENs) are relatively rare neoplasms with 6.4-times increasing age-adjusted annual incidence during the last four decades. NENs arise from neuroendocrine cells, which release hormones in response to neuronal stimuli and they are distributed into organs and tissues. The presentation and biological behaviour of the NENs are highly heterogeneous, depending on the organ. The increased incidence is mainly due to increased awareness and improved detection methods both in the majority of sporadic NENs (non-inherited), but also the inherited groups of neoplasms appearing in at least ten genetic syndromes. The most important one is multiple endocrine neoplasia type 1 (MEN-1), caused by mutations in the tumour suppressor gene MEN1. MEN-1 has been associated with different tumour manifestations of NENs e.g. pancreas, gastrointestinal tract, lungs, thymus and pituitary. Pancreatic NENs tend to be less aggressive when arising in the setting of MEN-1 compared to sporadic pancreatic NENs. There have been very important improvements over the past years in both genotyping, genetic counselling and family screening, introduction and validation of various relevant biomarkers, as well as newer imaging modalities. Alongside this development, both medical, surgical and radionuclide treatments have also advanced and improved morbidity, quality of life and mortality in many of these patients. Despite this progress, there is still space for improving insight into the genetic and epigenetic factors in relation to the biological mechanisms determining NENs as part of MEN-1. This review gives a comprehensive update of current evidence for co-occurrence, diagnosis and treatment of MEN-1 and neuroendocrine neoplasms and highlight the important progress now finding its way to international guidelines in order to improve the global management of these patients.

Complete Radiological Response of Recurrent Metastatic Adrenocortical Carcinoma to Pembrolizumab and Mitotane

Adrenocortical carcinoma (ACC) is a rare malignancy with a poor prognosis. Treatment options for ACC are limited, with resection the main intervention. Most cases present in late metastatic cases, and data regarding effective therapies is limited. We report a case of ACC in a 40-year-old woman with history of ACC postadrenalectomy, who presented with recurrent metastatic ACC in the left perinephric space. She was started on pembrolizumab which was added to her mitotane maintenance therapy. Complete radiological response was achieved after 4 cycles of pembrolizumab. As far as we know, this is the first case to achieve complete radiological response with mitotane and pembrolizumab in recurrent metastatic ACC, with negative prognostic markers and no prior radiotherapy. As our findings are in the setting of one clinical case, we suggest the need to perform a trial to assess the benefit of combining mitotane and pembrolizumab in treating metastatic ACC.

Parathyroid carcinoma with sarcomatoid differentiation: a case report and literature review

Background

Parathyroid carcinoma (PC) is a rare thyroid tumor. PC with sarcomatoid differentiation(PCSD) is even rarer and its exact etiology remains unclear. We here report a case of PCSD, and present the clinicopathological features and pathological diagnosis and review the literature.

Case presentation

A 71-year-old man presented with a mass of 4.5 cm × 3.5 cm in the right neck. The tumor was composed of nest-like transparent cells, and the septum had heterotypic rhabdoid cells with sarcomatoid differentiation. Immunophenotype was as follows: myogenic differentiation 1(MyoD1), myogenin and desmin were positive; clear cells were positive for chromogranin A(CGA), synaptophysin(Syn) and GATA-3; and Ki-67 proliferation index was 40%. Hematoxylin and eosin staining and immunohistochemistry were performed. The patient was diagnosed with PCSD, and died 6 months after surgery.

Conclusions

PCSD is a rare type of primary parathyroid tumor with high malignancy and poor prognosis. Definitive diagnosis should be based on histopathological morphology and immunophenotype, and surgical treatment should be performed as soon as possible.

Transcription Factor Profiling Identifies Spatially Heterogenous Mediators of Follicular Thyroid Cancer Invasion

While minimally invasive follicular thyroid cancer (miFTC) generally has low risk of recurrence or death, encapsulated angioinvasive (eaFTC) or widely invasive (wiFTC) histological subtypes display significantly worse prognosis. Drivers of invasion are incompletely understood. Therefore, tissue samples including miFTC, eaFTC, and wiFTC tumors, as well as histologically normal thyroid adjacent to benign follicular adenomas, were selected from a cohort (n = 21) of thyroid tumor patients, and the gene expression of selected transcription factors was characterized with quantitative PCR. Invasion-relevant spatial expression patterns of selected transcription factors were subsequently characterized with immunohistochemistry. E2F1 was over-expressed in all 3 subtypes (p<0.01). SP1 was differentially expressed in eaFTC and wiFTC compared with normal (p=0.01 and 0.04, respectively). TCF7L2 was significantly upregulated in wiFTC specifically (p<0.05). While these findings were mRNA specific, immunohistochemistry of additional cancer-associated transcription factors revealed differential expression along the tumor invasive front relative to the central tumor, and histone acetylation modulators emerged as putative invasion markers. These findings may have significant implications for the interpretation of bulk gene expression analysis of thyroid tumor samples or for the development of targeted therapeutics for this rare but aggressive thyroid cancer variant.

The survival and prognosis analysis of synovial sarcoma subtypes: a Surveillance, Epidemiology, and End Results population-based analysis

PURPOSE

By comparing epidemiologic and prognostic data of synovial sarcoma subtypes, this study aims to clarify the difference in prognosis and risk factors among different synovial sarcoma subtypes.

METHODS

In total, 1692 patients with synovial sarcoma in the USA who were diagnosed during 1975 through 2016 and retrieved from the Surveillance, Epidemiology, and End Results (SEER) program were studied.

RESULTS

There were statistically significant differences in the distribution of age and race among three synovial sarcoma subtypes, while no major differences in the distribution of sex, tumor stage, and tumour size were found. The highest five and ten year survival rates were found in the biphasic subtype (69%, 60%), followed by the monophasic subtype (59%, 49%), and lowest in the epithelioid subtype (32%, 26%). Age and SEER historic stage were the two demographic factors that found to have statistically significant impact on survival in all subtypes. Radiation was found to be protective in the monophasic subtype (HR 0.61, p < 0.001).

CONCLUSION

Among different synovial sarcoma subtypes, the biphasic subtype favoured the best survival, while the epithelioid cell subtype was associated with the worst. Male and black race were independently associated with worse survival only in the monophasic subtype. Radiotherapy could provide significant benefit for patients with the monophasic synovial sarcoma.

GABPA-dependent down-regulation of DICER1 in follicular thyroid tumours

Mutations in the miRNA enzyme gene DICER1 have been reported in several endocrine malignancies and is associated with the rare tumour-predisposing DICER1 syndrome. DICER1 mutations have been reported in subsets of follicular thyroid carcinoma (FTC), but the role of DICER1 in follicular thyroid tumorigenesis has not been extensively studied. In this study, we investigate the role of DICER1 in 168 follicular thyroid tumours and in an FTC cell line. We found rare DICER1 mutations in paediatric FTC cases and a general DICER1 down-regulation in FTCs visualized both on mRNA and protein level, especially pronounced in Hürthle cell carcinoma (HuCC). The down-regulation was also evident in follicular thyroid adenomas (FTAs), suggesting a potential early step in tumorigenesis. The expression of DICER1 was lower in FTCs of older patients in which TERT promoter mutations are more frequent. In FTCs, DICER1 down-regulation was not caused by gene copy number loss but significantly correlated to expression of the transcription factor GABPA in clinical cases. GABPA was found to bind to the DICER1 promoter and regulate DICER1 expression in vitro, as GABPA depletion in FTC cell lines reduced DICER1 expression. This in turn stimulated cell proliferation and affected the miRNA machinery, evident by altered miRNA expression. To conclude, we show that GABPA directly regulates DICER1 in FTC, acting as a tumour suppressor and displaying down-regulation in clinical samples. We also show reduced expression of DICER1 in benign and malignant follicular thyroid tumours, suggesting a potentially early tumorigenic role of this gene aberrancy.

Parathyroid cancer: An update

Parathyroid cancer (PC) is a rare malignant tumor which comprises 0.5-5% of patients with primary hyperparathyroidism (PHPT). Most of these cancers are sporadic, although it may also occur as a feature of various genetic syndromes including hyperparathyroidism-jaw tumor syndrome (HPT-JT) and multiple endocrine neoplasia (MEN) types 1 and 2A. Although PC is characterized by high levels of serum ionized calcium (Ca) and parathyroid hormone (PTH), the challenge to the clinician is to distinguish PC from the far more common entities of parathyroid adenoma (PA) or hyperplasia, as there are no specific clinical, biochemical, or radiological characteristic of PC. Complete surgical resection is the only known curative treatment for PC with the surgical approach during initial surgery strongly influencing the outcome. In order to avoid local recurrence, the lesion must be removed en-bloc with clear margins. PC has high recurrence rates of up to 50% but with favorable long-term survival rates (10-year overall survival of 60-70%) due to its slow-growing nature. Most patients die not from tumor burden directly but from uncontrolled severe hypercalcemia. In this article we have updated the information on PC by reviewing the literature over the past 10 years and summarizing the findings of the largest series published in this period.

Resveratrol Inhibits the Tumorigenesis of Follicular Thyroid Cancer via ST6GAL2-Regulated Activation of the Hippo Signaling Pathway

Follicular thyroid carcinoma (FTC) is a common endocrine malignancy with highly aggressive features. In this study, next-generation sequencing technology was used to identify aberrant expression of sialyltransferase (ST) family members in FTC. Aberrant high expression of alpha-2,6-sialyltransferase 2 (ST6GAL2) was demonstrated to promote tumorigenesis of FTC in vitro and in vivo. Furthermore, ST6GAL2 promoted tumorigenesis by inactivating the Hippo signaling pathway. Resveratrol is a native compound extracted from Vitis species, and many studies have confirmed its protective cardiovascular and antineoplastic effects. Here we found that resveratrol can inhibit the tumorigenesis of FTC by suppressing the expression of ST6GAL2, further activating the Hippo pathway. In summary, this study revealed the role of the ST6GAL2-Hippo signaling pathway in FTC tumorigenesis and indicated that resveratrol, a commonly found antineoplastic compound, could inhibit tumorigenesis of FTC by regulating the abovementioned pathways.

Whole-genome sequencing of synchronous thyroid carcinomas identifies aberrant DNA repair in thyroid cancer dedifferentiation

The genetics underlying thyroid cancer dedifferentiation is only partly understood and has not yet been characterised using comprehensive pan-genomic analyses. We investigated a unique case with synchronous follicular thyroid carcinoma (FTC), poorly differentiated thyroid carcinoma (PDTC), and anaplastic thyroid carcinoma (ATC), as well as regional lymph node metastases from the PDTC and ATC from a single patient using whole-genome sequencing (WGS). The FTC displayed mutations in CALR, RB1, and MSH2, and the PDTC exhibited mutations in TP53, DROSHA, APC, TERT, and additional DNA repair genes - associated with an immense increase in sub-clonal somatic mutations. All components displayed an overrepresentation of C>T transitions with associated microsatellite instability (MSI) in the PDTC and ATC, with borderline MSI in the FTC. Clonality analyses pinpointed a shared ancestral clone enriched for mutations in TP53-associated regulation of DNA repair and identified important sub-clones for each tumour component already present in the corresponding preceding lesion. This genomic characterisation of the natural progression of thyroid cancer reveals several novel genes of interest for future studies. Moreover, the findings support the theory of a stepwise dedifferentiation process and suggest that defects in DNA repair could play an important role in the clonal evolution of thyroid cancer. © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Response to Immunotherapy in Combination With Mitotane in Patients With Metastatic Adrenocortical Cancer

Adrenocortical carcinoma (ACC) is a rare orphan disease with a dismal prognosis. Surgery remains the first-line treatment, but most patients eventually develop metastatic disease. Mitotane is often used with chemotherapy with modest success. Little information is available concerning the efficacy of immunotherapy in combination with mitotane. We conducted a retrospective review of our initial six patients with metastatic ACC, for whom mitotane alone or with chemotherapy failed, and who were subsequently treated with a combination of pembrolizumab and mitotane, between July 2016 and March 2019. Imaging was analyzed per Response Evaluation Criteria in Solid Tumours 1.1 criteria. Two patients had a partial response and four patients had stable disease (8 to 19 months). One patient had grade 3 hepatitis and pembrolizumab was discontinued after 8 months. She died with disease progression 16 months after initiating pembrolizumab. One patient developed brain metastasis after 19 months of treatment and was transitioned to hospice. One patient had focal pneumonitis after 18 months of treatment, and pembrolizumab was discontinued. Three remaining patients continue pembrolizumab plus mitotane at the time of this writing. The current standard of care for ACC is a combination of etoposide, doxorubicin, cisplatin, and mitotane with an overall survival of 14.8 months. All six patients lived for at least 16 months after starting pembrolizumab added to mitotane therapy. The therapy appeared to be effective in both microsatellite instability-high and microsatellite stable tumors, suggesting some synergistic effect with mitotane. Combined immunotherapy and mitotane should be considered in future clinical trials in patients with ACC.

The who, when, and why of primary adrenal malignancies: Insights into the epidemiology of a rare clinical entity

BACKGROUND

Primary malignancies of the adrenal glands are rare. Epidemiologic assessment of primary adrenal malignancies is lacking and has been limited to case reports and series. Population-level data can provide a better understanding of the incidence, distribution, and prognostic factors associated with these rare malignancies.

METHODS

The Surveillance, Epidemiology, and End Results database (1973-2013) was queried for all patients who were diagnosed with primary adrenal malignancies, categorized in 5 histologic groups: adrenocortical carcinoma (ACC), pheochromocytoma and paraganglioma (PH), neuroblastoma (NE), non-Hodgkin lymphoma (NHL), and sarcoma (SA). Age-adjusted incidence, distribution trends, and cancer-specific survival (CSS) for each group were analyzed.

RESULTS

In total, 4695 patients with primary adrenal malignancies were identified, including 2057 with ACC, 512 with PH, 1863 with NE, 202 with NHL, and 61 with SA. The age-adjusted incidence of all 5 histologic subtypes was rising. Age at presentation differed substantially by histologic group: NE was the most prevalent during the first decade of life, whereas ACC predominated after age 30 years, and NHL outnumbered PH after age 70 years. Patient-specific factors were not associated with advanced disease at the time of presentation. The 5-year CSS rate for each histologic subtype was 38% for ACC, 69% for PH, 64% for NE, 38% for NHL, and 42% for SA. Survival outcomes for patients with ACC, NHL, PH and SA remained unchanged over the 40-year study period. Multimodal therapy was associated with higher CSS in patients with NE.

CONCLUSIONS

This first population-level analysis of all primary adrenal malignancies provides important initial data regarding presentation and clinical outcomes. Notably, except for patients with NE, the survival of patients with these rare cancers has not improved over the past 40 years.

Thyroid cancer burden and economic impact on the Brazilian public health system

OBJECTIVE

Recent data indicates an increasing incidence of thyroid cancer not accompanied by a proportional increase in mortality, suggesting overdiagnosis, which may represent a big public health problem, particularly where resources are scarce. This article aims to describe and evaluate the procedures related to investigation of thyroid nodules and treatment and follow-up of thyroid cancer and the costs for the Brazilian public health system between 2008 and 2015.

MATERIALS AND METHODS

Data on procedures related to investigation of thyroid nodules and treatment/follow-up of thyroid cancer between 2008 and 2015 in Brazil were collected from the Department of Informatics of the Brazilian Unified Health System (Datasus) website.

RESULTS

A statistically significant increase in the use of procedures related to thyroid nodules investigation and thyroid cancer treatment and follow-up was observed in Brazil, though a reduction was noted for procedures related to the treatment of more aggressive thyroid cancer, such as total thyroidectomy with neck dissection and higher radioiodine activities such as 200 and 250 milicuries (mCi). The procedures related to thyroid nodules investigation costs increased by 91% for thyroid ultrasound (p = 0.0003) and 128% in thyroid nodule biopsy (p < 0.001). Costs related to treatment and follow-up related-procedures increased by 120%.

CONCLUSION

The increase in the incidence of thyroid cancer in Brazil is directly associated with an increased use of diagnostic tools for thyroid nodules, which leads to an upsurge in thyroid cancer treatment and followup-related procedures. These data suggest that substantial resources are being used for diagnosis, treatment and follow-up of a potentially indolent condition.

Comprehensive Genetic Analysis of Follicular Thyroid Carcinoma Predicts Prognosis Independent of Histology

CONTEXT

Follicular thyroid carcinoma (FTC) is classified into minimally invasive (miFTC), encapsulated angioinvasive (eaFTC), and widely invasive (wiFTC) subtypes, according to the 2017 World Health Organization guidelines. The genetic signatures of these subtypes may be crucial for diagnosis, prognosis, and treatment but have not been described.

OBJECTIVE

Identify and describe the genetic underpinnings of subtypes of FTC.

METHODS

Thirty-nine tumors, comprising 12 miFTCs, 17 eaFTCs, and 10 wiFTCs, were whole-exome sequenced and analyzed. Somatic mutations, constitutional sequence variants, somatic copy number alterations, and mutational signatures were described. Clinicopathologic parameters and mutational profiles were assessed for associations with patient outcomes.

RESULTS

Total mutation burden was consistent across FTC subtypes, with a median of 10 (range 1 to 44) nonsynonymous somatic mutations per tumor. Overall, 20.5% of specimens had a mutation in the RAS subfamily (HRAS, KRAS, or NRAS), with no notable difference between subtypes. Mutations in TSHR, DICER1, EIF1AX, KDM5C, NF1, PTEN, and TP53 were also noted to be recurrent across the cohort. Clonality analysis demonstrated more subclones in wiFTC. Survival analysis demonstrated worse disease-specific survival in the eaFTC and wiFTC cohorts, with no recurrences or deaths for patients with miFTC. Mutation burden was associated with worse prognosis, independent of histopathological classification.

CONCLUSIONS

Though the number and variety of somatic variants are similar in the different histopathological subtypes of FTC in our study, mutational burden was an independent predictor of mortality and recurrence.

Increasing incidence of thyroid cancer in the Nordic countries with main focus on Swedish data

BACKGROUND

Radiofrequency radiation in the frequency range 30 kHz-300 GHz was evaluated to be Group 2B, i.e. 'possibly' carcinogenic to humans, by the International Agency for Research on Cancer (IARC) at WHO in May 2011. Among the evaluated devices were mobile and cordless phones, since they emit radiofrequency electromagnetic fields (RF-EMF). In addition to the brain, another organ, the thyroid gland, also receives high exposure. The incidence of thyroid cancer is increasing in many countries, especially the papillary type that is the most radiosensitive type.

METHODS

We used the Swedish Cancer Register to study the incidence of thyroid cancer during 1970-2013 using joinpoint regression analysis.

RESULTS

In women, the incidence increased statistically significantly during the whole study period; average annual percentage change (AAPC) +1.19 % (95 % confidence interval (CI) +0.56, +1.83 %). Two joinpoints were detected, 1979 and 2001, with a high increase of the incidence during the last period 2001-2013 with an annual percentage change (APC) of +5.34 % (95 % CI +3.93, +6.77 %). AAPC for all men during 1970-2013 was +0.77 % (95 % CI -0.03, +1.58 %). One joinpoint was detected in 2005 with a statistically significant increase in incidence during 2005-2013; APC +7.56 % (95 % CI +3.34, +11.96 %). Based on NORDCAN data, there was a statistically significant increase in the incidence of thyroid cancer in the Nordic countries during the same time period. In both women and men a joinpoint was detected in 2006. The incidence increased during 2006-2013 in women; APC +6.16 % (95 % CI +3.94, +8.42 %) and in men; APC +6.84 % (95 % CI +3.69, +10.08 %), thus showing similar results as the Swedish Cancer Register. Analyses based on data from the Cancer Register showed that the increasing trend in Sweden was mainly caused by thyroid cancer of the papillary type.

CONCLUSIONS

We postulate that the whole increase cannot be attributed to better diagnostic procedures. Increasing exposure to ionizing radiation, e.g. medical computed tomography (CT) scans, and to RF-EMF (non-ionizing radiation) should be further studied. The design of our study does not permit conclusions regarding causality.