Endocrine side-effects of anti-cancer drugs: thyroid effects of tyrosine kinase inhibitors

Graphene Oxide (GO) for the Treatment of Bone Cancer: A Systematic Review and Bibliometric Analysis

Cancer is a severe disease that, in 2022, caused more than 9.89 million deaths worldwide. One worrisome type of cancer is bone cancer, such as osteosarcoma and Ewing tumors, which occur more frequently in infants. This study shows an active interest in the use of graphene oxide and its derivatives in therapy against bone cancer. We present a systematic review analyzing the current state of the art related to the use of GO in treating osteosarcoma, through evaluating the existing literature. In this sense, studies focused on GO-based nanomaterials for potential applications against osteosarcoma were reviewed, which has revealed that there is an excellent trend toward the use of GO-based nanomaterials, based on their thermal and anti-cancer activities, for the treatment of osteosarcoma through various therapeutic approaches. However, more research is needed to develop highly efficient localized therapies. It is suggested, therefore, that photodynamic therapy, photothermal therapy, and the use of nanocarriers should be considered as non-invasive, more specific, and efficient alternatives in the treatment of osteosarcoma. These options present promising approaches to enhance the effectiveness of therapy while also seeking to reduce side effects and minimize the damage to surrounding healthy tissues. The bibliometric analysis of photothermal and photochemical treatments of graphene oxide and reduced graphene oxide from January 2004 to December 2022 extracted 948 documents with its search strategy, mainly related to research papers, review papers, and conference papers, demonstrating a high-impact field supported by the need for more selective and efficient bone cancer therapies. The central countries leading the research are the United States, Iran, Italy, Germany, China, South Korea, and Australia, with strong collaborations worldwide. At the same time, the most-cited papers were published in journals with impact factors of more than 6.0 (2021), with more than 290 citations. Additionally, the journals that published the most on the topic are high impact factor journals, according to the analysis performed, demonstrating the high impact of the research field.

Aneurysm and Artery Dissection After Oral VEGFR-TKI Use in Adults With Cancer

Importance

The association of tyrosine kinase inhibitors targeting vascular endothelial growth factor receptors (VEGFR-TKIs) with aneurysm and artery dissection (AAD) has been frequently reported in spontaneous reporting databases.

Objective

To investigate the risk and incidence of AAD occurrence in patients with cancer treated with oral VEGFR-TKIs, with capecitabine as an active comparator.

Design, Setting, and Participants

This national, historical cohort study was conducted using national claims data from the National Health Insurance Service in Korea from 2007 to 2020, with a 1-year follow-up. Patients with cancer aged 40 years or older prescribed oral VEGFR-TKIs or capecitabine were enrolled. Data were analyzed from September 2022 through April 2023.

Exposure

Oral VEGFR-TKIs (sorafenib, regorafenib, vandetanib, sunitinib, lenvatinib, axitinib, and pazopanib) or capecitabine as a comparator.

Main Outcomes and Measures

Hazard ratios (HRs) were used to investigate the association between VEGFR-TKI use and AAD after propensity score matching. The primary outcome was AAD, and secondary outcomes were aortic aneurysm and dissection and AAD with rupture. Outcomes were defined using International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10) diagnosis codes.

Results

Among 127 710 patients with cancer eligible for the study (80 386 males [62.9%]; mean [SD] age, 62.6 [10.9] years), 37 308 patients received VEGFR-TKIs and 90 402 patients received capecitabine. Among 27 535 matched patients receiving VEGFR-TKIs, the incidence of AAD within 1 year of treatment initiation was 6.0 per 1000 person-years. The median (IQR) time to AAD onset in the matched AAD group was 114 (67-257) days after treatment initiation, with the highest incidence observed during the first 3 months (45 incidents vs 31, 17, and 16 incidents during 3- to 6-month, 6- to 9-month, and 9- to 12-month periods, respectively). Cox regression modeling showed that the risk of AAD occurrence was significantly higher among patients prescribed VEGFR-TKIs than those receiving capecitabine (HR, 1.48; 95% CI, 1.08-2.02); similar results were obtained among females (HR, 2.08; 95% CI, 1.26-3.42), older adults (aged ≥65 years; HR, 1.42; 95% CI, 1.01-1.99), and patients with dyslipidemia (HR, 1.58; 95% CI, 1.11-2.24).

Conclusions and Relevance

In this study, the use of oral VEGFR-TKIs was associated with an increased risk of AAD occurrence. These findings elucidate vascular toxic effects and may provide a substantial reference for reducing the socioeconomic burden of adverse events associated with VEGFR-TKI use.

Thyroid dysfunction during treatment with systemic antineoplastic therapy for childhood cancer: A systematic review

Thyroid dysfunction is known to occur following radiotherapy or chemotherapy for childhood cancer. Thyroid dysfunction during treatment for childhood cancer has, however, not been studied extensively, although thyroid hormones are of utmost importance during childhood. This information is needed to develop adequate screening protocols and may be of special importance with upcoming drugs, such as checkpoint inhibitors, which are highly associated with thyroid dysfunction in adults. In this systematic review we have evaluated the occurrence and risk factors for thyroid dysfunction in children during treatment with systemic antineoplastic drugs, up to three months after the end of therapy. Two review authors independently performed the study selection, data extraction and risk of bias assessment of included studies. After an extensive search (January 2021), in total six heterogeneous articles were included, reporting on 91 childhood cancer patients with a thyroid function test during treatment with systemic antineoplastic therapy for childhood cancer. All studies had risk of bias issues. Primary hypothyroidism was found in 18% of children treated with high dose interferon-α (HDI-α) and in 0-10% after tyrosine kinase inhibitors (TKIs). Transient euthyroid sick syndrome (ESS) was common (in 42-100%) during treatment with systematic multi-agent chemotherapy. Only one study addressed possible risk factors, showing different types of treatment to increase the risk. However, the exact prevalence, risk factors and clinical consequences of thyroid dysfunction remain unclear. Prospective high-quality studies including large study samples are needed to longitudinally assess the prevalence, risk factors and possible consequences of thyroid dysfunction during childhood cancer treatment.

Anticancer Therapeutic Effects of Green Tea Catechins (GTCs) When Integrated with Antioxidant Natural Components

After decades of research and development concerning cancer treatment, cancer is still at large and very much a threat to the global human population. Cancer remedies have been sought from all possible directions, including chemicals, irradiation, nanomaterials, natural compounds, and the like. In this current review, we surveyed the milestones achieved by green tea catechins and what has been accomplished in cancer therapy. Specifically, we have assessed the synergistic anticarcinogenic effects when green tea catechins (GTCs) are combined with other antioxidant-rich natural compounds. Living in an age of inadequacies, combinatorial approaches are gaining momentum, and GTCs have progressed much, yet there are insufficiencies that can be improvised when combined with natural antioxidant compounds. This review highlights that there are not many reports in this specific area and encourages and recommends research attention in this direction. The antioxidant/prooxidant mechanisms of GTCs have also been highlighted. The current scenario and the future of such combinatorial approaches have been addressed, and the lacunae in this aspect have been discussed.

Immune checkpoint blockade PD-1 therapy for primary liver cancer: incidence and influencing factors of thyroid dysfunction

OBJECTIVES

To investigate the incidence and influencing factors of thyroid dysfunction (TD) in patients with primary liver cancer (PLC) induced by PD-1 monoclonal antibodies.

METHODS

Clinical data were collected from 195 PLC patients treated with PD-1. They were divided into TD group and normal thyroid function (NTF) group, and further divided into TD subgroups, the differences between groups and subgroups were analyzed.

RESULTS

A total of 113 of 195 (57.9%) PLC patients developed TD. The positive rate of thyroid antibody (20.6% vs. 0%, P = 0.041) and the median value of TSH (6.20 vs. 2.16 mU/L, P = 0.000) in TD group were higher than those in NTF group. Ten patients (8.8%) had the CTCAE grade of TD above grade 3, of which 2 patients died of liver failure. There were 20 patients (17.7%) in hyperthyroidism group and 93 patients (82.3%) in hypothyroidism group. The decompensated cirrhosis in hyperthyroidism group was lower than that in hypothyroidism group (33.3% vs. 65.6%, P = 0.010), and the proportion of patients who had previously received surgical treatment was higher than that in hypothyroidism group (35.0% vs. 9.7%, P = 0.003); The proportion of clinical hyperthyroidism was higher than that of clinical hypothyroidism (70.0% vs. 31.2%, P = 0.001), the proportion of decompensated liver cirrhosis in clinical hyperthyroidism group was lower than that in clinical hypothyroidism group (23.1% vs. 68.0%, P = 0.022), and the proportion of previous or combined surgical resection was much higher than that in clinical hypothyroidism group (42.9% vs. 7.1%, P = 0.018); The proportion of decompensated cirrhosis in primary TD group was lower than that in secondary TD group (36.5% vs. 83.3%, P = 0.002), and the proportion of patients using antitumor targeted drugs was higher than that in secondary TD group (73.1% vs. 45.0%, P = 0.014).

CONCLUSION

Patients with PLC had high incidence of TD after receiving PD-1 treatment, primary or subclinical hypothyroidism was the main manifestation type, which was related to the degree of disease and treatment.

Regulation of the THRA gene, encoding the thyroid hormone nuclear receptor TRα1, in intestinal lesions

The THRA gene, encoding the thyroid hormone nuclear receptor TRα1, is expressed in an increasing gradient at the bottom of intestinal crypts, overlapping with high Wnt and Notch activities. Importantly, THRA is upregulated in colorectal cancers, particularly in the high-Wnt molecular subtype. The basis of this specific and/or altered expression pattern has remained unknown. To define the mechanisms controlling THRA transcription and TRα1 expression, we used multiple in vitro and ex vivo approaches. Promoter analysis demonstrated that transcription factors important for crypt homeostasis and altered in colorectal cancers, such as transcription factor 7-like 2 (TCF7L2; Wnt pathway), recombining binding protein suppressor of hairless (RBPJ; Notch pathway), and homeobox protein CDX2 (epithelial cell identity), modulate THRA activity. Specifically, although TCF7L2 and CDX2 stimulated THRA, RBPJ induced its repression. In-depth analysis of the Wnt-dependent increase showed direct regulation of the THRA promoter in cells and of TRα1 expression in murine enteroids. Given our previous results on the control of the Wnt pathway by TRα1, our new results unveil a complex regulatory loop and synergy between these endocrine and epithelial-cell-intrinsic signals. Our work describes, for the first time, the regulation of the THRA gene in specific cell and tumor contexts.

Frequency and Severity of Hypothyroidism During TKI Therapy in the Pediatric and Young Adult Population

Tyrosine kinase inhibitors that target vascular endothelial growth factor receptor [VEGFR-TKI] are a class of targeted therapies approved for treatment of several malignancies and are increasingly used in the pediatric population. Development of hypothyroidism during VEGFR-TKI therapy is well described in adults; however, there are no available data in children. Importantly, hypothyroidism during childhood can negatively impact growth and neurodevelopment. This retrospective study is the first to document frequency and severity of VEGFR-TKI induced hypothyroidism in pediatric and young adult patients. Patients included were ≤25 years of age and treated with at least one VEGFR-TKI between 2010 and 2018 at Cincinnati Children's Hospital Medical Center. After review of clinical and demographic data, 69 patients were identified. Of these, 19 (27.5%) developed thyroid dysfunction defined as Thyroid-stimulating hormone≥5 mIU/mL during therapy. Twelve of those patients had overt hypothyroidism with documentation of low free thyroxine and/or levothyroxine initiation. Mean exposure time to VEGFR-TKI before thyroid dysfunction was 2.8 (0.5-10.4) months. These results suggest moderate risk of developing thyroid dysfunction during VEGFR-TKI therapy in pediatric and young adult patients. Baseline thyroid hormone screening should be performed and repeated frequently during the first year of therapy in the pediatric population.

Elevated TSH Level, TgAb, and Prior Use of Ramucirumab or TKIs as Risk Factors for Thyroid Dysfunction in PD-L1 Blockade

BACKGROUND

Thyroid dysfunction is frequently caused by treatment with antiprogrammed cell death-1 ligand 1 antibodies (PD-L1-Abs) and anticancer drugs, including ramucirumab (RAM) and multitargeted tyrosine kinase inhibitors (multi-TKIs), which are often used prior to PD-L1-Ab treatment in cancer patients.

METHODS

A total of 148 patients treated with PD-L1-Abs were evaluated for antithyroid antibodies at baseline and for thyroid function every 6 weeks for 24 weeks after treatment initiation and then were observed until the visits stopped.

RESULTS

Of the 148 patients, 15 (10.1%) developed thyroid dysfunction after PD-L1-Ab treatment (destructive thyroiditis in 8 and hypothyroidism without preceding thyrotoxicosis in 7). The prevalence of an elevated thyroid-stimulating hormone (TSH) level at baseline (3/15 [20.0%] vs 4/133 [3.0%], P < .05), positive antithyroglobulin antibodies (TgAbs) at baseline (4/15 [26.7%] vs 5/133 [3.8%], P < .05) and prior treatment with RAM or multi-TKIs (3/15 [20.0%] vs 5/133 [3.8%], P < .05) were significantly higher in patients with vs without thyroid dysfunction. In a multivariate analysis, elevated TSH level at baseline, TgAb positivity at baseline, and prior treatment with RAM or multi-TKIs were significantly associated with the development of thyroid dysfunction, with ORs of 7.098 (95% CI 1.154-43.638), 11.927 (95% CI 2.526-56.316), and 8.476 (95% CI 1.592-45.115), respectively.

CONCLUSION

The results of this real-world study suggest that the risk of thyroid dysfunction induced by PD-L1-Abs can be predicted by the TSH level at baseline, TgAb positivity at baseline, and prior treatment with RAM or multi-TKIs.

Increased Risk of Thyroid Dysfunction by PD-1 and CTLA-4 Blockade in Patients Without Thyroid Autoantibodies at Baseline

BACKGROUND

Previous studies showed that although the risk of thyroid dysfunction [thyroid immune-related adverse events (irAEs)] induced by anti-programmed cell death-1 antibodies (PD-1-Ab) was as low as 2% to 7% in patients negative for anti-thyroid antibodies (ATAs) at baseline, it was much higher (30%-50%) in patients positive for ATAs. However, whether a similar increase occurs with combination therapy using PD-1-Ab plus anti-cytotoxic T-lymphocyte antigen-4 antibody (CTLA-4-Ab) is unknown.

METHODS

A total of 451 patients with malignancies treated with PD-1-Ab, CTLA-4-Ab, or a combination of PD-1-Ab and CTLA-4-Ab (PD-1/CTLA-4-Abs) were evaluated for ATAs at baseline and for thyroid function every 6 weeks for 24 weeks after treatment initiation and then observed until the last clinical visit.

RESULTS

Of the 451 patients, 51 developed thyroid irAEs after immunotherapy [41 of 416 (9.9%) treated with PD-1-Ab, 0 of 8 (0%) treated with CTLA-4-Ab, and 10 of 27 (37.0%) treated with PD-1/CTLA-4-Abs]. The cumulative incidence of thyroid irAEs was significantly higher in patients who were positive vs negative for ATAs at baseline after both PD-1-Ab [28/87 (32.2%) vs 13/329 (4.0%), P < 0.001] and PD-1/CTLA-4-Abs [6/10 (60.0%) vs 4/17 (23.5%), P < 0.05] treatments. The risk of thyroid irAEs induced by PD-1/CTLA-4Abs, which was significantly higher than that induced by PD-1-Ab, in patients negative for ATAs at baseline was not statistically different from that induced by PD-1-Ab in patients positive for ATAs at baseline.

CONCLUSIONS

This study showed that the incidence of thyroid irAEs was high and not negligible after PD-1/CTLA-4-Abs treatment even in patients negative for ATAs at baseline.

Fatigue and its management in cancer patients undergoing VEGFR-TKI therapy

INTRODUCTION

Fatigue is the most common side effect of cancer and cancer treatment and is often called cancer fatigue or cancer-related fatigue. For cancer patients, cancer-related fatigue has a negative impact on participation in work and social activities, mood, and daily activities, significantly impairing quality of life. Vascular endothelial growth factor receptor tyrosine kinase inhibitors (VEGFR-TKIs) sometimes cause fatigue, and early detection and appropriate management of fatigue in cancer patients treated with a VEGFR-TKI prevent fatigue from becoming more severe, thus maximizing the benefits of the treatment.

AREAS COVERED

This paper focuses on fatigue and discusses its frequency, assessment, risk factors, and management methods.

EXPERT OPINION

The drugs currently available for treating cancer-related fatigue are not effective enough, and their mechanisms of action are not fully understood. Some agents have demonstrated efficacy as treatments for fatigue due to pharmacotherapy, and further elucidation of their mechanisms is expected, together with the development of new drugs. Since fatigue has a range of causes, its treatment requires not only medication, but also exercise, nutrition, and other therapeutic approaches. The successful treatment of fatigue will therefore need multidisciplinary therapy involving the establishment of systems of cooperation across various specialties.

Thyroid dysfunction in non-small cell lung cancer patients treated with epidermal growth factor receptor and anaplastic lymphoma kinase inhibitors: Results of a prospective cohort

OBJECTIVES

Epidermal Growth Factor Receptor (EGFR) and Anaplastic Lymphoma Kinase (ALK) Tyrosine Kinase Inhibitors (TKIs) are the preferred treatment option for patients with advanced/metastatic non-small cell lung cancer (NSCLC) harboring EGFR mutations and ALK rearrangements respectively. TKIs can theoretically induce thyroid dysfunction via actions on many levels of the hypothalamic-pituitary-thyroid axis. However, there are no published studies on occurrence of thyroid dysfunction related to use of EGFR/ALK TKIs in lung cancer. The current study aimed to prospectively and comprehensively evaluate incidence of thyroid dysfunction in NSCLC patients treated with EGFR and ALK inhibitors.

METHODS

This prospective observational study at a tertiary care referral hospital included histologically/cytologically proven advanced/metastatic NSCLC patients treated with EGFR and ALK inhibitors over a period of 15 months. Thyroid function tests (including anti-TPO antibody) were done at baseline and repeated every month for first three months and then every three monthly for 12 months.

RESULTS

Six different drugs (EGFR and ALK inhibitors) were used for treatment of 50 NSCLC patients enrolled. Of these, four drugs caused thyroid dysfunction (EGFR inhibitors erlotinib, gefitinib and ALK inhibitors ceritinib, crizotinib). Thyroid dysfunction typically occurred at 1 month following start of TKI treatment. Prevalence of thyroid dysfunction was 8%. Distribution of subclinical (not requiring treatment) and overt thyroid dysfunction (requiring specific treatment) was 4% each. All patients were asymptomatic. Both patients with overt thyroid dysfunction had hypothyroidism while subclinical dysfunction was equally distributed between hypo- and hyper- thyroidism. All patients who developed thyroid dysfunction derived expected clinical benefit and none required TKI dose interruption or stoppage.

CONCLUSIONS

NSCLC patients may need to be monitored for occurrence of thyroid dysfunction during treatment with EGFR and ALK TKIs.

Management of Side Effects of Systemic Therapies for Hepatocellular Carcinoma: Guide for the Hepatologist

Historically, systemic treatment of advanced hepatocellular carcinoma was limited to the tyrosine kinase inhibitor sorafenib. With the recent approval of several new agents the armamentarium of treatment options available to providers and patients has expanded. Although these promising advances offer hope for patients with advanced hepatocellular carcinoma, they also present new and challenging adverse effects that threaten to limit their efficacy. Immunotherapy with checkpoint inhibitors introduce immune-related adverse events, which may affect a wide array of organ systems. With prompt recognition, however, common side effects of systemic therapies for hepatocellular carcinoma are predictable, manageable, and many improve with appropriate intervention.

New Oral Anti-Cancer Drugs and Medication Safety

BACKGROUND

Many oral anti-cancer drugs have come onto the market in the past 20 years. For example, kinase inhibitors, such as the BCR-ABL and BRAF inhibitors, have markedly improved the treatment of chronic myeloid leukemia and melanoma. In this review, we discuss the special challenges posed by poor adherence, drug-drug interactions with other substances, and side effects, among other problems, and the ways in which these challenges can be met.

METHODS

A selective search was carried out in PubMed for original and review articles on the safety of new oral anti-cancer drugs. Guidelines and current Summaries of Product Characteristics (SmPC) were also considered in the analysis.

RESULTS

Review articles have pointed out numerous safety concerns with oral anti-cancer drugs. One of these is adherence, on which highly variable figures are available (with mean non-adherence rates ranging from 0 to 54%). The absorption of approximately half of these drugs is influenced by the patient's diet, and that of approximately 20% by gastric pH (Caution: proton-pump inhibitors may influence bioavailability). 70% of the active substances are metabolized primarily by CYP3A4, which means that their pharmacokinetics can be altered by grapefruit juice and CYP3A4 modulators. The prevention, detection, and treatment of side effects (which can be gastrointestinal, cutaneous, cardiovascular, or other) is a highly important matter.

CONCLUSION

The increasing use of oral anti-cancer drugs confronts patients and treatment teams with special challenges. To optimize treatment outcomes, a multidisciplinary approach should be taken, involving physicians, pharmacists, and nurses. To improve medication safety, medication and side-effect management should be performed, and adherence should be regularly checked and systematically encouraged.

Regression of Papillary Thyroid Cancer during Nivolumab for Renal Cell Cancer

Immune checkpoint inhibitors have been recently approved for cancer treatment. Nivolumab is a monoclonal antibody specific for programmed cell death-1 (PD-1) that modulates T-cell response. It was initially used for the treatment of malignant melanoma and then approved in other cancers, such as non-small cell lung cancer and clear cell renal cell carcinoma (ccRCC). So far, the activity of nivolumab in patients with thyroid malignancies has been reported in a single case of anaplastic thyroid cancer. Here, we report the case of a patient with ccRCC who developed a papillary thyroid carcinoma (PTC) under first-line sunitinib treatment. During nivolumab, the second-line treatment for ccRCC, we unexpectedly observed a complete regression of PTC.

Ceritinib-associated hyperglycemia in the Japanese Adverse Drug Event Report Database

Genetic rearrangements of anaplastic lymphoma kinase contribute to the pathogenesis of non-small-cell lung cancer; the anaplastic lymphoma kinase inhibitor, ceritinib, is widely used, as it is effective even in patients with non-small-cell lung cancer resistant to other anaplastic lymphoma kinase inhibitors. Although a case of possible ceritinib-induced hyperglycemia was reported, the association of ceritinib with hyperglycemia remains to be investigated. Disproportionality analysis was carried out using the Japanese Adverse Drug Event Report database, which contains all pharmacovigilance data based on spontaneous reports of adverse events between April 2004 and November 2018 to the Pharmaceuticals and Medical Devices Agency. The reporting odds ratio of ceritinib for hyperglycemia was 2.25 (95% confidence interval [CI] 1.24-4.08], whereas those of crizotinib and alectinib were 0.07 (95% CI 0.01-0.40) and 0.94 (95% CI 0.30-2.94), respectively. Among reported events without antidiabetes agent use, the reporting odds ratio of ceritinib was still 2.54 (95% CI 1.27-5.12). Thus, the possibility of hyperglycemia should be carefully monitored in patients receiving ceritinib.

Thyroid Hormone Transporters

Thyroid hormone transporters at the plasma membrane govern intracellular bioavailability of thyroid hormone. Monocarboxylate transporter (MCT) 8 and MCT10, organic anion transporting polypeptide (OATP) 1C1, and SLC17A4 are currently known as transporters displaying the highest specificity toward thyroid hormones. Structure-function studies using homology modeling and mutational screens have led to better understanding of the molecular basis of thyroid hormone transport. Mutations in MCT8 and in OATP1C1 have been associated with clinical disorders. Different animal models have provided insight into the functional role of thyroid hormone transporters, in particular MCT8. Different treatment strategies for MCT8 deficiency have been explored, of which thyroid hormone analogue therapy is currently applied in patients. Future studies may reveal the identity of as-yet-undiscovered thyroid hormone transporters. Complementary studies employing animal and human models will provide further insight into the role of transporters in health and disease. (Endocrine Reviews 41: 1 - 55, 2020).

Thyroid disorders in programmed death 1 inhibitor-treated patients: Is previous therapy with tyrosine kinase inhibitors a predisposing factor?

BACKGROUND

Programmed death 1 (PD-1) inhibitors are frequently associated with thyroid-related adverse events (TAEs), but many aspects remain unclear. This study aims to evaluate the incidence and characteristics of such events and to find any predictive factor for its development.

METHODS

We retrospectively analysed data from patients with advanced solid tumours (non-small-cell lung carcinoma, renal cell carcinoma, metastatic melanoma) treated with PD-1 inhibitors (nivolumab, pembrolizumab) in Oncology Unit B, Policlinico Umberto I of Rome, from June 2015 to December 2018. All patients underwent baseline thyroid function evaluations repeated monthly.

RESULTS

The cohort consisted of 126 patients (66.7% male, mean age 66.4 ± 9.7 years). One hundred and seven received nivolumab and 19 pembrolizumab. Twenty-three per cent of patients experienced TAEs (mainly CTCAE grade 1), with hypothyroidism in 15.1% (subclinical: 11.9%, overt: 3.2%) and hyperthyroidism in 8.0% (subclinical: 4.8%, overt: 3.2%). Median time to TAE onset was 8.7 ± 6.8 weeks (10.4 ± 7.6 weeks for hypothyroidism, 5.4 ± 3.0 weeks for hyperthyroidism). Most TAEs (89.7%) appeared within the first 3 months, none after 8 months. Most hypothyroid patients (63.2%) had previously been treated with a tyrosine kinase inhibitor (TKI). Logistic regression analysis showed that pretreatment with a TKI was a major predisposing factor for the development of hypothyroidism (OR 9.2, 95% CI: 1.4-59.9, P = .020).

CONCLUSIONS

TAEs are common during anti-PD-1 therapy and usually occur within the first 3 months of treatment. This is the first study evaluating the impact of previous oncologic therapies on TAEs, identifying TKI as a major risk factor for the development of hypothyroidism in patients treated with anti-PD-1.

Current and coming challenges in the management of the survivorship population

With the widespread adoption of multimodality treatment, 5-year survival of children diagnosed with cancer has improved dramatically in the past several decades from approximately 60% in 1970 to greater than 85% currently. As a result, there are an estimated nearly half a million long-term survivors of childhood cancer living in the United States today. However, survivors have, on average, significantly greater serious medical and psychosocial late effects compared with the general population. In this review, we will discuss the current epidemiology of childhood cancer survivorship, including new methods to estimate the burden of late effects and genetic susceptibility toward late effects. We will also review the development of surveillance guidelines for childhood cancer survivors and early toxicity signals from novel agents now being tested and used increasingly to treat pediatric and adult cancers. We conclude with an overview of current models of survivorship care and areas for future research.

Thyroid Sequelae of Pediatric Cancer Therapy

The hypothalamic-pituitary-thyroid axis is a common site of unintended, acquired disease either during or after the treatment of cancer. Children treated with external radiation therapy are at the highest risk for developing a thyroid-related late effect, but thyroid dysfunction and second primary thyroid neoplasms can also occur after treatment with radiopharmaceutical agents such as 131I-metaiodobenzylguanidine. Increasingly recognized is the development of early thyroid dysfunction as an off-target consequence of the more novel cancer therapeutics such as the tyrosine kinase inhibitors and immune checkpoint inhibitors. Thyroid sequelae resulting from irradiation may manifest only after years to decades of follow-up, and their resultant clinical symptoms may be indolent and non-specific. Therefore, lifelong monitoring of the childhood cancer survivor at risk for thyroid disease is paramount. In this comprehensive review, the myriad thyroid adverse effects resulting from pediatric cancer treatment are discussed and an overview of screening and treatment of these thyroid sequelae provided.

Lenvatinib-induced thyroid abnormalities in unresectable hepatocellular carcinoma

Lenvatinib has anti-tumor activity against advanced hepatocellular carcinoma (HCC). Hypothyroidism is also a frequent complication in patients treated with lenvatinib. However, studies on lenvatinib-induced thyroid toxicity and destructive thyroiditis are limited. Therefore, this study aimed to clarify the frequency and timing of thyroid abnormalities in lenvatinib for unresectable HCC. This retrospective study enrolled 50 patients with advanced HCC treated with lenvatinib. Patients were classified to have euthyroid, subclinical hypothyroidism, overt hypothyroidism, and thyrotoxicosis. The timing of thyroid dysfunction was assessed, and risk factors for incident hypothyroidism or thyrotoxicosis were evaluated using multivariate models. Subclinical hypothyroidism, overt hypothyroidism, and thyrotoxicosis occurred in 7 (14.0%), 26 (52.0%), and 5 (10.0%) patients, respectively. In the 33 patients with hypothyroidism, 27 (84.4%) developed the condition within 2 weeks of starting lenvatinib treatment. Of the 5 patients with thyrotoxicosis, 3 developed the condition within 8 weeks of starting lenvatinib administration. One patient developed thyrotoxicosis in only 1 week of the initiation of treatment. No correlation between the presence of antibodies and the incidence and severity of thyroid dysfunction due to the autoimmune mechanism was observed. The progression-free survival was significantly better in the hypothyroidism group. Lenvatinib treatment for unresectable HCC not only causes hypothyroidism, but also thyrotoxicosis. Moreover, these thyroid conditions develop within the early period of treatment at a higher prevalence. Patients with thyroid dysfunction had better prognosis. Based on these results, in patients administered with lenvatinib, there is need for careful assessment for the possibility of thyroid dysfunction from the onset of treatment.

2019 European Thyroid Association Guidelines on the Management of Thyroid Dysfunction following Immune Reconstitution Therapy

Thyroid dysfunction (TD) frequently occurs as an autoimmune complication of immune reconstitution therapy (IRT), especially in individuals with multiple sclerosis treated with alemtuzumab, a pan-lymphocyte depleting drug with subsequent recovery of immune cell numbers. Less frequently, TD is triggered by highly active antiretroviral therapy (HAART) in patients infected with human immunodeficiency virus (HIV), or patients undergoing bone-marrow/hematopoietic-stem-cell transplantation (BMT/HSCT). In both alemtuzumab-induced TD and HIV/HAART patients, the commonest disorder is Graves' disease (GD), followed by hypothyroidism and thyroiditis; Graves' orbitopathy is observed in some GD patients. On the contrary, GD is rare post-BMT/HSCT, where hypothyroidism predominates probably as a consequence of the associated radiation damage. In alemtuzumab-induced TD, the autoantibodies against the thyrotropin receptor (TRAb) play a major role, and 2 main aspects distinguish this condition from the spontaneous form: (1) up to 20% of GD cases exhibit a fluctuating course, with alternating phases of hyper- and hypothyroidism, due to the coexistence of TRAb with stimulating and blocking function; (2) TRAb are also positive in about 70% of hypothyroid patients, with blocking TRAb responsible for nearly half of the cases. The present guidelines will provide up-to-date recommendations and suggestions dedicated to all phases of IRT-induced TD: (1) screening before IRT (recommendations 1-3); (2) monitoring during/after IRT (recommendations 4-7); (3) management of TD post-IRT (recommendations 8-17). The clinical management of IRT-induced TD, and in particular GD, can be challenging. In these guidelines, we propose a summary algorithm which has particular utility for nonspecialist physicians and which is tailored toward management of alemtuzumab-induced TD. However, we recommend prompt referral to specialist endocrinology services following diagnosis of any IRT-induced TD diagnosis, and in particular for pregnant women and those considering pregnancy.

Thyroxine promotes lung cancer growth in an orthotopic mouse model

Thyroid hormones are important for physiology and homeostasis. In addition to nuclear thyroid hormone receptors, the plasma membrane protein integrin αvβ3 has been recognized as a receptor for both thyroxine (T4) and triiodothyronine (T3). Here, we studied whether thyroid hormone promotes growth of murine lung cancer via αvβ3 in vivo. Murine Lewis lung carcinoma cells (3LL), stably transfected with luciferase, were injected into mouse lungs. Tumor growth in untreated mice was compared to hypothyroid mice and hypothyroid mice treated with T3 or T4 with or without the αvβ3 inhibitor 3,5,3',5'-tetraiodothyroacetic acid (Tetrac). Tumor progression was determined by serial in vivo imaging of bioluminescence emitted from the tumor. Tumor weight was recorded at the end of the experiment. Neoangiogenesis was determined by immunohistochemistry for CD31. Tumor growth was reduced in hypothyroidism and increased by T4 treatment. Strikingly, only T4 but not T3 treatment promoted tumor growth. This T4 effect was abrogated by the αvβ3 inhibitor Tetrac. Tumor weight and neoangiogenesis were also significantly increased only in T4-treated mice. The T4 effect on tumor weight and neoangiogenesis was abolished by Tetrac. In vitro, T4 did not stimulate 3LL cell proliferation or signaling pathway activation. We conclude that T4 promotes lung cancer growth in this orthotopic mouse model. The tumor-promoting effect is mediated via the plasma membrane integrin αvβ3 and increased neoangiogenesis rather than direct stimulation of 3LL cells. These data suggest that such effects of levothyroxine may need to be considered in cancer patients on T4 substitution.

Doxorubicin Loaded Magnesium Oxide Nanoflakes as pH Dependent Carriers for Simultaneous Treatment of Cancer and Hypomagnesemia

Doxorubicin (DOX) is an anticancer drug commonly used in treating cancer; however, it has severe cytotoxicity effects. To overcome both the adverse effects of the drug and mineral deficiency (i.e., hypomagnesemia) experienced by cancer patients, we have developed magnesium oxide (MgO) nanoflakes as drug carriers and loaded them with DOX for use as a targeted drug delivery (TDD) system for potential application in cancer therapy. The synthesis employed herein affords pure, highly porous MgO nanoparticles that are void of the potentially harmful metal contaminants often discussed in the literature. Purposed for dual therapy, the nanoparticles exhibit an impressive 90% drug loading capacity with pH dependent drug releasing rates of 10% at pH 7.2, 50.5% at pH 5.0, and 90.2% at pH 3. Results indicate that therapy is achievable via slow diffusion where MgO nanoflakes degrade (i.e., dissolve) under acidic conditions releasing the drug and magnesium ions to the cancerous region. The TDD system therefore minimizes cytotoxicity to healthy cells while supplying magnesium ions to overcome hypomagnesemia.

A Turn-On Optoacoustic Probe for Imaging Metformin-Induced Upregulation of Hepatic Hydrogen Sulfide and Subsequent Liver Injury

Metformin is currently the most prescribed oral agent for diabetes treatment; however the overdose or long-term use may cause some severe side effects such as liver injury. Researches indicate that metformin-induced liver injury is closely related to upregulation of hepatic H2S. Hence, monitoring hepatic H2S generation induced by metformin could be an effective approach for evaluating hepatoxicity of the drug. Methods: We present a novel turn-on and dual-mode probe for detecting and imaging metformin-induced liver injury by specifically tracking the upregulation of hepatic H2S with fluorescent and optoacoustic methods. After reaction with H2S, the strong electron-withdrawing group dinitrophenyl ether (which acts as both the recognition moiety and the fluorescence quencher) was cleaved and replaced by an electron-donating group hydroxyl. This correspondingly leads to the changes of the probe's electronic state and absorption red-shifting as well as the subsequent turn-on fluorescent and optoacoustic signals. Results: The probe was applied to the colon tumor-bearing mice model and the metformin-induced liver injury mice model to achieve tumor imaging and liver injury assessment. The biosafety of the probe was verified by histological analysis (hematoxylin and eosin staining) and serum biochemical assays. Conclusion: The probe responds quickly to H2S in tumors and the liver, and MSOT imaging with the probe offers cross-secitonal and 3D spatial information of liver injury. This study may provide an effective approach for accessing medication side effects by tracking drug-metabolism-related products.

Laboratory Testing in Thyroid Conditions - Pitfalls and Clinical Utility

Thyroid disorders are common, affecting more than 10% of people in the US, and laboratory tests are integral in the management of these conditions. The repertoire of thyroid tests includes blood tests for thyroid-stimulating hormone (TSH), free thyroxine, free triiodothyronine, thyroglobulin (Tg), thyroglobulin antibodies (Tg-Ab), thyroid peroxidase antibodies (TPO-Ab), TSH receptor antibodies (TRAb), and calcitonin. TSH and free thyroid hormone tests are frequently used to assess the functional status of the thyroid. TPO-Ab and TRAb tests are used to diagnose Hashimoto's thyroiditis and Graves' disease, respectively. Tg and calcitonin are important tumor markers used in the management of differentiated thyroid carcinoma and medullary thyroid carcinoma (MTC), respectively. Procalcitonin may replace calcitonin as a biomarker for MTC. Apart from understanding normal thyroid physiology, it is important to be familiar with the possible pitfalls and caveats in the use of these tests so that they can be interpreted properly and accurately. When results are discordant, clinicians and laboratorians should be mindful of possible assay interferences and/or the effects of concurrent medications. In addition, thyroid function may appear abnormal in the absence of actual thyroid dysfunction during pregnancy and in critical illness. Hence, it is important to consider the clinical context when interpreting results. This review aims to describe the above-mentioned blood tests used in the diagnosis and management of thyroid disorders, as well as the pitfalls in their interpretation. With due knowledge and care, clinicians and laboratorians will be able to fully appreciate the clinical utility of these important laboratory tests.

Navigating Systemic Therapy in Advanced Thyroid Carcinoma: From Standard of Care to Personalized Therapy and Beyond

Thyroid cancer, with the exception of anaplastic thyroid cancer, typically has very favorable outcomes with the standard therapy. However, those that persist, recur, or metastasize are associated with a worse prognosis. Targeted therapy with kinase inhibitors has shown promise in advanced cases of thyroid cancer, and currently five drug regimens are approved for use in clinical practice in the treatment of differentiated, medullary, and anaplastic thyroid cancer, with more options in the pipeline. However, one of the greatest dilemmas is when and how to initiate one of these drugs, and this is discussed herein.

New Agents, Emerging Late Effects, and the Development of Precision Survivorship

Incremental improvements in the treatment of children and adolescents with cancer have led to 5-year survival rates reaching nearly 85%. In the past decade, impressive progress has been made in understanding the biology of many pediatric cancers. With that understanding, multiple new agents have become available that offer the promise of more-effective and less-toxic treatment. These include agents that target various cell surface antigens and engage the adaptive immune system, as well as those that interfere with key signaling pathways involved in tumor development and growth. For local control, surgery and radiation techniques also have evolved, becoming less invasive or featuring new techniques and particles that more precisely target the tumor and limit the dose to normal tissue. Nevertheless, targeted agents, like conventional chemotherapy, radiotherapy, and surgery, may have off-target effects and deserve long-term follow-up of their safety and efficacy. These include injury to the endocrine, cardiovascular, and immunologic systems. New radiation and surgical techniques that theoretically reduce morbidity and improve long-term quality of life must also be validated with actual patient outcomes. Finally, with advances in genomics, information on host susceptibility to late effects is beginning to emerge. Such knowledge, coupled with improved metrics that better describe the spectrum of potential late effects across the entire lifespan, can lead to the development of decision models that project the potential long-term health outcomes associated with various treatment and follow-up strategies. These developments will help extend the current focus on precision medicine to precision survivorship, where clinicians, patients, and families will have a better grasp of the potential risks, benefits, and tradeoffs associated with the growing number of cancer treatment options.

Lenvatinib for Anaplastic Thyroid Cancer and Lenvatinib-Induced Thyroid Dysfunction

BACKGROUND

Lenvatinib is an oral multitargeted tyrosine kinase inhibitor that has an anticancer action in patients with differentiated thyroid cancer that is refractory to radioiodine. Knowledge of the efficacy and safety of lenvatinib in patients with anaplastic thyroid cancer (ATC) is limited. Tyrosine kinase inhibitors frequently cause hypothyroidism, but the incidence of hypothyroidism with lenvatinib is unclear.

OBJECTIVES

We conducted a retrospective study to investigate the efficacy and safety of lenvatinib in ATC.

METHODS

Five patients with unresectable ATC were enrolled. Lenvatinib 24 mg once daily was administered until disease progression, unmanageable toxicity, withdrawal, or death occurred. We retrospectively analyzed the objective response rate (ORR), time to progression (TTP), overall survival, and safety.

RESULTS

Three of the 5 patients (60%) had a partial response, and 5 (40%) had stable disease. The ORR was 60%. Median TTP was 88 days, and overall survival was 165 days. Hypothyroidism was a common treatment-related adverse effect; 4 patients (80%) had hypothyroidism of any grade. These 4 patients had not undergone total thyroidectomy prior to lenvatinib administration, and the other patient had undergone total thyroidectomy. Treatment-related adverse effects of any grade were hypertension in 80% of patients, diarrhea in 40%, fatigue in 80%, and decreased appetite in 80%.

CONCLUSIONS

Lenvatinib is an effective treatment and may improve the prognosis of unresectable ATC. Four of the 5 patients had hypothyroidism, which may have been associated with treatment-induced injury of the thyroid gland. There were many treatment-related adverse effects, most of which were manageable by dose modification and medical therapy.

Risk Factors for New Hypothyroidism During Tyrosine Kinase Inhibitor Therapy in Advanced Nonthyroidal Cancer Patients

BACKGROUND

Thyroid dysfunction during tyrosine kinase inhibitor (TKI) cancer treatment is common, but predisposing risk factors have not been determined. Recommendations for monitoring patients treated with one or multiple TKI and in conjunction with other relevant cancer therapies could be improved. The study objective was to assess the risk factors for new thyroid dysfunction in TKI-treated previously euthyroid cancer patients.

METHODS

A retrospective cohort study of patients with advanced nonthyroidal cancer treated with TKI from 2000 to 2017, having available thyroid function tests showing initial euthyroid status, excluding patients with preexisting thyroid disease or lack of follow-up thyroid function tests. During TKI treatment, patients were classified as euthyroid (thyrotropin [TSH] normal), subclinical hypothyroidism (TSH 5-10 mIU/L, or higher TSH if free thyroxine normal), or overt hypothyroidism (TSH >10 mIU/L, low free thyroxine, or requiring thyroid hormone replacement). The timing of thyroid dysfunction and TKI used were assessed. Risk factors for incident hypothyroidism were evaluated using multivariate models.

RESULTS

In 538 adult patients included, subclinical hypothyroidism occurred in 71 (13.2%) and overt hypothyroidism occurred in 144 (26.8%) patients with TKI therapy, following a median cumulative TKI exposure of 196 days (interquartile range [IQR] 63.5-518.5 days). The odds of hypothyroidism were greatest during the first six months on a TKI. Median exposure time on the TKI concurrent with thyroid dysfunction in patients treated with only one TKI was 85 days (IQR 38-293.5 days) and was similar to the 74 days (IQR 38-133.3 days) in patients treated previously with other TKI (p = 0.41). Patients who developed hypothyroidism compared to those who remained euthyroid had greater odds of being female (odds ratio = 1.99 [confidence interval 1.35-2.93], p < 0.01), but greater cumulative TKI exposure and greater number of TKI received were not associated with thyroid dysfunction.

CONCLUSIONS

Thyroid dysfunction occurred in 40% of euthyroid patients. Monitoring thyroid function in TKI-treated patients is recommended, with particular attention to female patients and within the first six months of exposure to a new TKI.

Hypothyroidism During Tyrosine Kinase Inhibitor Therapy Is Associated with Longer Survival in Patients with Advanced Nonthyroidal Cancers

BACKGROUND

Tyrosine kinase inhibitor (TKI)-induced thyroid dysfunction is recognized as a common adverse effect of treatment, but the importance of incident hypothyroidism during TKI therapy remains unclear. This study analyzed the prognostic significance of hypothyroidism during TKI therapy in cancer patients.

METHODS

This was a retrospective cohort study of adult patients with advanced nonthyroidal cancer treated with TKI and available thyroid function testing at three affiliated academic hospitals from 2000 to 2017. Patients with preexisting thyroid disease were excluded. Demographic, clinical, and cancer treatment data were collected. Thyroid status with TKI treatment was determined from thyroid function testing and initiation of thyroid medication, and classified as euthyroid (thyrotropin [TSH] normal), subclinical hypothyroidism (SCH; TSH 5-10 mIU/L, or higher TSH if free thyroxine normal), or overt hypothyroidism (OH; TSH >10 mIU/L, low free thyroxine, or requiring replacement). Multivariate models were used to evaluate the effect of TKI-related hypothyroidism on overall survival (OS).

RESULTS

Of 1120 initial patients, 538 remained after exclusion criteria. SCH occurred in 72 (13%) and OH in 144 (27%) patients with TKI therapy. Patients with hypothyroidism had significantly longer OS, with median OS in euthyroid patients of 685 days [confidence interval (CI) 523-851] compared to 1005 days [CI 634-1528] in SCH and 1643 days [CI 1215-1991] in OH patients (p < 0.0001). After adjustment for age, sex, race/ethnicity, cancer type, cancer stage, ECOG performance status, and checkpoint inhibitor therapy, OH remained significantly associated with OS (hazard ratio = 0.561; p < 0.0001), whereas SCH did not (hazard ratio = 0.796; p = 0.165). Analysis of hypothyroid patients (SCH and OH) with TSH >5 and <10 mIU/L stratified by hormone replacement status showed improved survival associated with hormone replacement.

CONCLUSIONS

New hypothyroidism in cancer patients treated with TKI is associated with significantly improved OS, should not necessitate TKI dose reduction or discontinuation, and may provide independent prognostic information.

Structural aspects of thyroid hormone binding to proteins and competitive interactions with natural and synthetic compounds

Thyroid hormones and their metabolites constitute a vast class of related iodothyronine compounds that contribute to the regulation of metabolic activity and cell differentiation. They are in turn transported, transformed and recognized as signaling molecules through binding to a variety of proteins from a wide range of evolutionary unrelated protein families, which renders these proteins and their iodothyronine binding sites an example for extensive convergent evolution. In this review, we will briefly summarize what is known about iodothyronine binding sites in proteins, the modes of protein/iodothyronine interaction, and the ligand conformations. We will then discuss physiological and synthetic compounds, including popular drugs and food components, that can interfere with iodothyronine binding and recognition by these proteins. The discussion also includes compounds persisting in the environment and acting as endocrine disrupting chemicals.

Regorafenib-induced hypothyroidism and cancer-related fatigue: is there a potential link?

OBJECTIVE

Thyroid dysfunction has been reported during Regorafenib (Reg) administration, but no detailed study is presently available.

DESIGN

Prospective, observational cohort study. Patients with documented metastatic colorectal cancer and progression of disease during or within 3 months after the last standard therapy, with no evidence and history of previous thyroid disease were enrolled.

METHODS

Twenty-five consecutive patients were evaluated before and 8-50 weeks after initiating Reg therapy by monthly clinical, ultrasound and laboratory (thyrotropin (TSH), free thyroxine (fT4), antithyroglobulin (TgAb) and antithyroid peroxidase (TPOAb)) evaluation.

RESULTS

Thirteen/25 patients (52%) became hypothyroid (TSH: 12.5 ± 4.01 IU/L, range: 4.6-22.0) within 5 months of therapy. TPOAb became detectable (99-155 IU/mL) in 2/25 (8%) patients. Thyroid volume progressively decreased (from 8.6 ± 2.2 mL to 4.9 ± 2.4 mL after 5 months of Reg therapy, P < 0.0001). The progression-free survival (PFS) was longer in patients developing hypothyroidism (43 weeks) than in those remaining euthyroid (17 weeks, P < 0.01). Fatigue (the most common general serious Reg adverse event) was associated with hypothyroidism severity and reversed after levothyroxine therapy (L-T4).

CONCLUSIONS

Reg rapidly causes hypothyroidism in about 50% of patients and in a minority of them also triggers thyroid autoimmunity. Reg-induced hypothyroidism was strictly related to fatigue, easily reversed by L-T4 administration and associated to longer survival. These results suggest that prompt recognition of hypothyroidism in patients with severe fatigue may prevent unnecessary Reg dose reduction or withdrawal.

Managing tyrosine kinase inhibitors side effects in thyroid cancer

BACKGROUND

Tyrosine kinase inhibitors (TKIs) are a new group of drugs that show the activity against receptors of different growth factors leading to the inhibition of tumor cells growth and proliferation. To date, four different TKIs have been approved for RAI-refractory DTC or MTC: sorafenib, lenvatinib, vandetanib and cabozantinib.

METHODS

This review focuses on treatment toxicity related to above-mentioned TKIs administration in thyroid carcinoma.

RESULTS

TKIs cause a variety of side effects in nearly all treated patients, among them: hypertension, gastrointestinal disturbances (diarrhea, abdominal pain, nausea, vomiting), skin reactions (rashes, acne, hand-foot syndrome), fatigue and weight loss. Most of side effects are mild and moderate and manageable by dose adjustment (dose interruptions and dose reductions) and concomitant therapy. However, some complications although rare may be life-threatening or even fatal. Conclusion​: TKIs shows an acceptable toxicity profile in patients with advanced and progressive RAI refractory DTC and MTC but only in experienced hands familiar with TKIs, particularly with diagnostics and management of treatment-related complications and also with thyroid carcinoma, what is essential to safely care for the patients and keep them on kinase inhibitor therapy as long as the treatment is beneficial without an unfavorable impact on their quality of life.

Organ Atrophy Induced by Sorafenib and Sunitinib - Quantitative Computed Tomography (CT) Evaluation of the Pancreas, Thyroid Gland and Spleen

Background

To evaluate organ atrophy induced by sorafenib and sunitinib, we retrospectively reviewed the CT scans of renal cell carcinoma (RCC) patients receiving molecular targeted therapy (MTT) using sorafenib or sunitinib, and performed volumetric analysis of the pancreas, thyroid gland, and spleen.

Material/Methods

Thirteen RCC patients receiving MTT were assigned as the evaluation cases (MTT group), while thirteen additional RCC patients not receiving MTT were retrieved as the Control group. We evaluated the baseline and follow-up CT studies. The volume of the three organs estimated by CT volumetry was compared between the baseline and follow-up CTs. The atrophic ratio of the organ volume in the follow-up CT to that in the baseline CT was calculated, and compared between the MTT and Control groups.

Results

All measured organs in the MTT group showed statistically significant volume loss, while no significant change was observed in the Control group. Mean atrophic ratio in the MTT group was 0.74, 0.58, and 0.82 for the pancreas, thyroid and spleen, respectively. The differences in atrophic ratios between both groups were all statistically significant (P<0.05).

Conclusions

Single-agent sorafenib or sunitinib therapy induced statistically significant atrophy in the pancreas, thyroid, and spleen.

2016 American Thyroid Association Guidelines for Diagnosis and Management of Hyperthyroidism and Other Causes of Thyrotoxicosis

BACKGROUND

Thyrotoxicosis has multiple etiologies, manifestations, and potential therapies. Appropriate treatment requires an accurate diagnosis and is influenced by coexisting medical conditions and patient preference. This document describes evidence-based clinical guidelines for the management of thyrotoxicosis that would be useful to generalist and subspecialty physicians and others providing care for patients with this condition.

METHODS

The American Thyroid Association (ATA) previously cosponsored guidelines for the management of thyrotoxicosis that were published in 2011. Considerable new literature has been published since then, and the ATA felt updated evidence-based guidelines were needed. The association assembled a task force of expert clinicians who authored this report. They examined relevant literature using a systematic PubMed search supplemented with additional published materials. An evidence-based medicine approach that incorporated the knowledge and experience of the panel was used to update the 2011 text and recommendations. The strength of the recommendations and the quality of evidence supporting them were rated according to the approach recommended by the Grading of Recommendations, Assessment, Development, and Evaluation Group.

RESULTS

Clinical topics addressed include the initial evaluation and management of thyrotoxicosis; management of Graves' hyperthyroidism using radioactive iodine, antithyroid drugs, or surgery; management of toxic multinodular goiter or toxic adenoma using radioactive iodine or surgery; Graves' disease in children, adolescents, or pregnant patients; subclinical hyperthyroidism; hyperthyroidism in patients with Graves' orbitopathy; and management of other miscellaneous causes of thyrotoxicosis. New paradigms since publication of the 2011 guidelines are presented for the evaluation of the etiology of thyrotoxicosis, the management of Graves' hyperthyroidism with antithyroid drugs, the management of pregnant hyperthyroid patients, and the preparation of patients for thyroid surgery. The sections on less common causes of thyrotoxicosis have been expanded.

CONCLUSIONS

One hundred twenty-four evidence-based recommendations were developed to aid in the care of patients with thyrotoxicosis and to share what the task force believes is current, rational, and optimal medical practice.

Update on the treatment of hypothyroidism

PURPOSE OF REVIEW

Differentiated thyroid cancer is a malignancy that is rapidly increasing in frequency. As thyroidectomy plays a central role in the treatment of thyroid cancer, it is incumbent on physicians treating this patient group to be well versed in the intricacies of treating hypothyroidism.

RECENT FINDINGS

Treatment of hypothyroidism may be refined by careful attention to dose selection, monitoring of therapy and achievement of thyrotropin goals that are specific to the individual patient's overall clinical situation. These goals are common not only to patients with a sole diagnosis of hypothyroidism, as discussed in the recent American Thyroid Association Guidelines, but also to patients with hypothyroidism in the setting of thyroid cancer. Several recent studies have illuminated our understanding of the benefits and risks of thyrotropin suppression therapy in patients with differentiated thyroid cancer. Multiple studies of combination therapy with levothyroxine and liothyronine for treating hypothyroidism have not led to a clear conclusion about its benefits over levothyroxine monotherapy. Animal studies have advanced our understanding of the altered serum and tissue milieu that characterizes levothyroxine monotherapy. Crossing the bridge from this translational research into clinical research using sustained release triiodothyronine preparations may ultimately enhance the health of our patients.

SUMMARY

Continued refinement of our understanding of thyroid status and our ability to flawlessly implement thyroid hormone replacement is an active area of research.

Silychristin, a Flavonolignan Derived From the Milk Thistle, Is a Potent Inhibitor of the Thyroid Hormone Transporter MCT8

Thyroid hormones (THs) are charged and iodinated amino acid derivatives that need to pass the cell membrane facilitated by thyroid hormone transmembrane transporters (THTT) to exert their biological function. The importance of functional THTT is affirmed by the devastating effects of mutations in the human monocarboxylate transporter (MCT) 8, leading to a severe form of psychomotor retardation. Modulation of THTT function by pharmacological or environmental compounds might disturb TH action on a tissue-specific level. Therefore, it is important to identify compounds with relevant environmental exposure and THTT-modulating activity. Based on a nonradioactive TH uptake assay, we performed a screening of 13 chemicals, suspicious for TH receptor interaction, to test their potential effects on THTT in MCT8-overexpressing MDCK1-cells. We identified silymarin, an extract of the milk thistle, to be a potent inhibitor of T3 uptake by MCT8. Because silymarin is a complex mixture of flavonolignan substances, we further tested its individual components and identified silychristin as the most effective one with an IC50 of approximately 100 nM. The measured IC50 value is at least 1 order of magnitude below those of other known THTT inhibitors. This finding was confirmed by T3 uptake in primary murine astrocytes expressing endogenous Mct8 but not in MCT10-overexpressing MDCK1-cells, indicating a remarkable specificity of the inhibitor toward MCT8. Because silymarin is a frequently used adjuvant therapeutic for hepatitis C infection and chronic liver disease, our observations raise questions regarding its safety with respect to unwanted effects on the TH axis.

Thyroid Hormones as Renal Cell Cancer Regulators

It is known that thyroid hormone is an important regulator of cancer development and metastasis. What is more, changes across the genome, as well as alternative splicing, may affect the activity of the thyroid hormone receptors. Mechanism of action of the thyroid hormone is different in every cancer; therefore in this review thyroid hormone and its receptor are presented as a regulator of renal cell carcinoma.

Effectiveness of chemotherapy in advanced differentiated thyroid cancer: a systematic review

In differentiated thyroid carcinoma refractory to radioactive iodine (CDT-RTI), chemotherapy has been considered for decades to be the only systemic therapy with palliative purpose. Phase II studies assessing the efficacy of different chemotherapy outlines have been published. Nevertheless, phase III studies in these tumours have not been performed. Our objective is to evaluate the effectiveness of chemotherapy in patients with CDT-RTI by a systematic review of published studies. Systematic research of the literature in Medline and Embase databases (among others) was carried out. The full texts of selected references were analysed by two independent reviewers and then assessed for risk of bias in each study. We also extracted data using specifically designed questionnaires. Later, a qualitative synthesis of results was performed and pooled data were calculated. We found that 16 studies with 473 patients published in the last 40 years were included out of 509 identified references in databases. Thirteen studies (176 patients) included data on response to treatment and histology. Four studies included 70 patients only with well-differentiated non-medullary tumours. Response rate (RR) was 22.1% (0-57%) for 13 studies, 25% for the 176 patients and 27.1% for the 70 patients, with 2.5, 3.4 and 2.8% complete responses respectively. Survival times could not be assessed or pooled due to the lack of data and heterogeneity of the studies, and was determined to have a high risk of bias. Although it has not been possible to find solid evidence about the efficacy of chemotherapy, the results shown indicate that it may have some effectiveness, although this should be proven with well-designed studies using modern drugs.

Cabozantinib for the treatment of progressive metastatic medullary thyroid cancer

Cabozantinib (XL-184) is a potent inhibitor of MET, VEGFR 2/KDR, RET and other receptor tyrosine kinases, such as KIT, AXL and FLT3. Its efficacy against MTC has been demonstrated in a prospective, randomized, placebo-controlled study (EXAM). Cabozantinib comparing to placebo significantly prolonged progression free survival both in hereditary and sporadic MTC, 11.2 vs 4.0 months, respectively. Final analysis showed no global differences in overall survival (OS) between cabozantinib and placebo. However, in a subgroup with RET M918T mutation the difference in OS was significant: 44.3 vs 18.9 months, respectively. Among the most frequent cabozantinib-related adverse events (AEs), observed in >30% of patients were diarrhea, palmar-plantar erythrodysesthesia, decreased weight, decreased appetite, nausea, fatigue, dysgeusia, hair color changes and hypertension. Expert Commentary: Cabozantinib constitutes an effective treatment option with acceptable toxicity in MTC patients showing either germinal or sporadic tumor RET M918T mutation as the drug prolonged OS in these subjects.

Thyroid Dysfunction in Patients with Metastatic Carcinoma Treated with Sunitinib: Is Thyroid Autoimmunity Involved?

BACKGROUND

Sunitinib is a tyrosine kinase inhibitor (TKI) inducing thyroid dysfunction, but the precise mechanism(s) involved remains to be explained, including the role of thyroid autoimmunity. The objective of this study was to evaluate thyroid function, parameters of autoimmunity, and thyroid ultrasound findings in patients with metastatic cancer and normal thyroid function/autoimmunity before the initiation of sunitinib therapy. This was a prospective, observational cohort study.

METHODS

Twenty-seven patients with metastatic carcinomas at comparable tumor stages were evaluated over 12-18 months after initiating therapy with sunitinib given at a daily oral dose of 50 mg for four weeks (ON), followed by one to two weeks off therapy (OFF). Serum thyrotropin (TSH), free thyroxine (fT4), free triiodothyronine (fT3), and antithyroglobulin (TgAb), and antithyroid peroxidase (TPOAb) autoantibodies were measured in all cases. Thyroid morphology and volume were evaluated by echo-color Doppler ultrasound.

RESULTS

A total of 16/27 patients (60%) became hypothyroid (TSH range 7-114 mIU/L) within 30-120 days of therapy. The thyroid volume decreased in 24/27 (89%) patients (from M = 14.6 mL, SD = 6.4 mL to M = 3.8 mL, SD = 2.6 mL after 12 months; p < 0.001), together with the appearance of mild to severe hypoechogenicity. TPOAb (40-3000 IU/mL) became detectable in 7/27 (25%) patients, and TPOAb-positive patients displayed a higher degree of hypothyroidism and volume reduction. The progression-free survival (PFS) was significantly longer in patients developing TPOAb (10.8 months) than in the other group of patients (5.8 months).

CONCLUSIONS

These data confirm the thyroid inhibitory effect of sunitinib, in keeping with the key role of kinases in controlling thyroid function and growth. However, the novel appearance of TPOAb in a subgroup of patients with more severe hypothyroidism and longer survival indicates that sunitinib may also trigger/exacerbate thyroid autoimmunity contributing to thyroid failure. The development of TPOAb was associated with a longer PFS.