Clinical characteristics of thyroid abnormalities induced by sunitinib treatment in Japanese patients with renal cell carcinoma

Phase Ib/II dose expansion study of lenvatinib combined with letrozole in post-menopausal women with hormone receptor positive breast cancer

BACKGROUND

RET is an estrogen response gene with preclinical studies demonstrating cross talk between RET and estrogen receptor (ER) pathways. We investigate the role of lenvatinib, a multi-kinase inhibitor with potent activity against RET, in patients with metastatic breast cancer.

PATIENTS AND METHODS

Patients with advanced ER+/HER2- breast cancer were treated with lenvatinib plus letrozole in a phase Ib/II trial. Primary objectives included safety and recommended phase II dose (RP2D) determination in phase Ib, and objective response rates (ORR) in phase II dose expansion.

RESULTS

Sixteen patients were recruited in dose finding, where de-escalating doses of lenvatinib from 20mg to 14mg were investigated. Lenvatinib 14mg plus letrozole 2.5mg daily was determined as RP2D. Thirty-one patients with 5 median lines of prior therapy in the metastatic setting (range 0-11) were recruited in dose expansion. In this cohort, ORR was 23.3% (95% CI 9.9 to 42.3%), with median duration of response (DoR) of 6.9 months (Interquartile range(IQR) 5.9 to 13.1). Clinical benefit rate {greater than or equal to}6 months (CBR) was 50.0% (95% CI 31.3 to 68.7%). Similar efficacy was observed in the subgroup of 25 patients who progressed on prior CDK4/6 inhibitor therapy (ORR 20.0% (95% CI 6.8 to 40.7%), median DoR 6.9 months (IQR 5.9 to 13.1) and CBR 52.0% (95% CI 31.3 to 72.2%). Pharmacodynamic studies showed target modulation, with paired tumor biopsies indicating downregulation of RET/pERK and improved vascular normalisation index.

CONCLUSION

Lenvatinib plus letrozole had manageable toxicity, with target engagement and preliminary antitumor activity observed, supporting further assessment in randomized studies.

Endocrinological Toxicity Secondary to Treatment of Gastroenteropancreatic Neuroendocrine Neoplasms (GEP-NENs)

Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) are increasingly recognized, characterized by prolonged survival even with metastatic disease. Their medical treatment is complex involving various specialties, necessitating awareness of treatment-related adverse effects (AEs). As GEP-NENs express somatostatin receptors (SSTRs), long-acting somatostatin analogs (SSAs) that are used for secretory syndrome and tumor control may lead to altered glucose metabolism. Everolimus and sunitinib are molecular targeted agents that affect glucose and lipid metabolism and may induce hypothyroidism or hypocalcemia, respectively. Chemotherapeutic drugs can affect the reproductive system and water homeostasis, whereas immunotherapeutic agents can cause hypophysitis and thyroiditis or other immune-mediated disorders. Treatment with radiopeptides may temporarily lead to radiation-induced hormone disturbances. As drugs targeting GEP-NENs are increasingly introduced, recognition and management of endocrine-related AEs may improve compliance and the quality of life of these patients.

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.

Current evidence on thyroid related adverse events in patients treated with protein tyrosine kinase inhibitors

Tyrosine kinase inhibitors (TKI) are gaining more ground in oncology, they are widely used in the treatment of multiple types of cancers; still important side effects limit their efficacy. The aim of this study is to evaluate the existing medical literature on TKI induced thyroid dysfunction, to assess the adverse effects of targeted therapy on thyroid function in oncological patients and to evaluate the effects of thyroid dysfunction on disease prognosis. We included in this review 22 original studies published between 2010 and 2019. We used the PubMed database to search for articles upon the development of hypothyroidism and hyperthyroidism in TKI treated patients. After a careful review of the existing literature, we selected the relevant studies and cross-referenced the bibliography of each paper. A number of 1641 patients were included in our review. We found that thyroid dysfunction is not a rare side effect of TKI treatment, approximately 33% of the total number of patients presented clinical hypothyroidism. We also studied the necessity of thyroid hormone substitution treatment, a quarter of evaluated patients needed substitution therapy. Multiple studies showed that there is a link between a patient developing hypothyroidism and progression free survival. Hypothyroidism is a frequent side effect of TKI treatment, which affects the quality of life, sometimes even determines physicians to stop TKI treatment altogether. Our study underlines the necessity of TSH baseline testing and monitoring in patients treated with TKI agents.

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.

Tyrosine kinase inhibitors and immune checkpoint inhibitors-induced thyroid disorders

Recently, tyrosine kinase inhibitors (TKI) and immune checkpoint inhibitors (ICPIs) have emerged as new classes of anticancer therapies. Although generally considered less toxic than cytotoxic chemotherapy, these new drugs can cause significant unanticipated side effects including thyroid dysfunction. This review provides a literature assessment of thyroid dysfunctions induced by TKI and ICPIs. We intend to define for these two classes the frequency of thyroid involvement, the potential mechanisms that result in this toxicity, the clinical-biological impact and the therapeutic management. Detection of thyroid dysfunction requires monitoring of TSH, in combination with free T4 if needed and, depending on the clinical impact and the kinetics of biological abnormalities, starting symptomatic treatment of hyperthyroidism and/or correcting hypothyroidism.

Ιmpact of sunitinib-induced hypothyroidism on survival of patients with metastatic renal cancer

BACKGROUND

Sunitinib plays an important role in managing the metastatic renal cell cancer (mRCC). Sunitinib-induced hypothyroidism is a common side-effect of the drug. There have been attempts to link hypothyroidism with a better clinical outcome in sunitinib-treated (mRCC) patients. Our aim was to relate the impact of hypothyroidism to the survival of these patients.

METHODS

We have evaluated 70 patients with mRCC that received sunitinib as a first line treatment. Thyroid-stimulating hormone (TSH) was measured at baseline, after 15 days of treatment (day-15) and at the end of the second cycle (day-75). Biomarker data and correlations with response were analysed with Microsoft Excel. Comparison results from Student's t-test with a p less than 0.05 were considered statistically significant. Kaplan-Meyer and log-rank tests were performed using GraphPad Prism 5 for Windows.

RESULTS

Regarding the response to treatment, a progression-free survival (PFS) of 9.47 months and an overall survival (OS) of 22.03 months were demonstrated. Our data are consistent with published data by other authors. On day-15 from the beginning of the treatment an important number of patients exhibited a TSH elevation. On day-15 42.86% had a TSH over the upper normal limit and 50.0% at the end of the second cycle (day-75). TSH increased earlier in patients that exhibited an objective response (× 3.33 times the baseline values on day-15) than patients that exhibited disease stabilisation (× 2.18) or disease progression (× 1.59). Early increases in TSH were associated with a longer PFS (11.92 vs. 8.82 months, p = 0.0476) and a longer OS (3.10 vs. 1.08 years, p = 0.0011).

CONCLUSIONS

Early TSH-increase is associated with a clinical benefit. The patients that showed at least a twofold increase of their baseline TSH, responded to therapy by stabilisation or by regression of disease. This is the only study to our knowledge which shows that early increases - 2 weeks from starting the treatment - in TSH levels have a prognostic value. Both PFS and OS of the patients who demonstrated a higher than a twofold rise were significantly longer than the PFS and the OS of the patients that presented a lower or no TSH-increase.

Destructive Thyroiditis Induced by Lenvatinib in Three Patients with Hepatocellular Carcinoma

Hypothyroidism is a frequently occurring complication in patients on lenvatinib treatment. However, little is known about lenvatinib-induced thyrotoxicosis and destructive thyroiditis. We herein report the cases of three patients who developed hyperthyroidism during the course of lenvatinib treatment. All patients had multiple hepatocellular carcinoma of Child-Pugh class A. Two patients required beta blockers for the management of palpitations. One patient developed hyperthyroidism only one week after the initiation of lenvatinib treatment. Thus, the possibility of hyperthyroidism developing within one week after the first administration should be kept in mind, and periodic surveillance of the thyroid function should be performed during the early period of lenvatinib therapy (within the first two weeks or so after the initial administration).

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.

Kinase inhibitors and monoclonal antibodies in oncology: clinical implications

Molecularly targeted cancer therapies, such as small-molecule kinase inhibitors and monoclonal antibodies, constitute a rapidly growing and an important part of the oncology armamentarium. Unlike conventional (cytotoxic) chemotherapeutics, targeted therapies were designed to disrupt cancer cell pathogenesis at specific biological points essential for the development and progression of the tumour. These agents were developed to disrupt specific targets with the aim of minimizing treatment burden compared with conventional chemotherapy. Nevertheless the increasingly common use of targeted therapies has revealed some unanticipated, often clinically significant toxic effects, as well as compromising effective palliative and end-of-life management approaches. Although patients and clinicians welcome improvements in cancer prognosis, these changes can also impact patient quality-of-life. Therefore, as demand for oncology expertise increases, physicians need to apprise themselves of targeted therapies and their clinical implications, including drug-specific side effects, impact on quality of life, and cost issues, especially in relation to end-of-life care. This Review provides a useful summary and guide for professionals treating patients with malignant diseases.

Overall survival and final efficacy and safety results from a Japanese phase II study of axitinib in cytokine-refractory metastatic renal cell carcinoma

In an open-label, multicenter phase II study of Japanese patients with cytokine-refractory metastatic renal cell carcinoma, axitinib showed substantial antitumor activity with an acceptable safety profile. Here, we report overall survival and updated efficacy and safety results. Sixty-four Japanese patients with metastatic renal cell carcinoma following prior therapy with cytokines were treated with axitinib at a starting dose of 5 mg b.i.d. Following median treatment duration of 14.2 months, median overall survival was 37.3 months (95% CI, 28.6-49.9). The objective response rate, the primary endpoint of the study, was 51.6% (95% CI, 38.7-64.2); the median duration of response, 11.1 months (95% CI, 8.2-13.7); and the median progression-free survival was 11.0 months (95% CI, 9.2-12.0), assessed by the independent review committee. Common treatment-related all-grade adverse events were hypertension (88%), hand-foot syndrome (75%), diarrhea (66%), proteinuria (63%), fatigue (55%) and dysphonia (53%). In an exploratory analysis, median overall survival was found to be significantly longer in patients who had greater decreases in plasma levels of soluble vascular endothelial growth factor receptor-2 during the first cycle of treatment. In conclusion, the present study showed axitinib to be effective, and toxicities with long-term treatment were generally controllable with axitinib dose modification and/or standard medications in these Japanese patients. Some frequently reported adverse events warrant close monitoring and management. Changes in the plasma levels of soluble vascular endothelial growth factor receptor-2 may be used as a prognostic factor for overall survival in metastatic renal cell carcinoma following axitinib treatment. This study is registered at ClinicalTrial.gov (identifier NCT00569946).

[Dysthyroidism with anti-VEGF treatment, a class effect? about one case report]

Tyrosine-kinase inhibitors are recent therapy used in different neoplastic diseases. Dysthyroidism seems to be a class effect of these drugs with a potentially cross cumulative effect. We describe here the case of a man who first developed dysthyroidism with sunitinib, then a deep and permanent hypothyroidism when axitinib was introduced.

Cabozantinib-induced thyroid dysfunction: a review of two ongoing trials for metastatic bladder cancer and sarcoma

BACKGROUND

Thyroid dysfunction is a common adverse event associated with tyrosine kinase inhibitors (TKI), but its underlying pathophysiology is unclear. Cabozantinib is a novel TKI currently Food and Drug Administration approved for advanced medullary thyroid cancer and tested in clinical trials on solid tumors including prostate, liver, bladder, breast, and ovarian cancer.

METHODS

We analyzed the thyroid function of patients enrolled in two phase 2 clinical trials using cabozantinib at the National Institutes of Health Clinical Center. Two cases of thyroiditis associated with cabozantinib therapy are presented in detail, and a systematic review of the literature on TKI-associated thyroid dysfunction is also discussed.

RESULTS

Between September 2012 and September 2013, 33 patients were treated with cabozantinib, and follow-up thyroid function tests were available for 31 (20 males, 11 females; age 59±1 years). Thyroid dysfunction was recorded in the majority of patients (93.1%), with a predominance of subclinical hypothyroidism. Two cases showed a biphasic pattern of thyroid dysfunction characterized by a transient thyrotoxicosis followed by hypothyroidism. Color Doppler demonstrated an increase in vascularization during the thyrotoxic phase, but no uptake was visualized on nuclear medicine imaging. A systematic review of the literature resulted in the identification of 40 original manuscripts, of which 13 were case series and 6 were case reports describing TKI-associated thyroid dysfunction.

CONCLUSION

TKI therapy often results in clinically significant thyroid dysfunction. Cabozantinib treatment commonly results in thyroid dysfunction varying from subclinical hypothyroidism to symptomatic thyrotoxicosis. Early detection and characterization of cabozantinib-associated thyroid dysfunction and close follow-up are essential to provide adequate management of this common adverse event.

Thyroid dysfunctions induced by tyrosine kinase inhibitors

INTRODUCTION

Recently, tyrosine kinase inhibitors (TKIs) have emerged as a new class of anticancer therapy. Although generally considered less toxic than cytotoxic chemotherapy, TKIs do cause significant side effects including fatigue and hypertension. In addition, thyroid dysfunction is a well-known adverse effect of TKI.

AREAS COVERED

This review provides a comprehensive assessment of TKI-induced thyroid dysfunctions by sunitinib, sorafenib, pazopanib, imatinib, dasatinib, nilotinib, vandetanib, axitinib, motesanib and tivozanib. Furthermore, the potential mechanisms that result in this toxicity, the clinical impact of thyroid dysfunction in these patients and the controversies regarding treatment with thyroid hormone (TH) therapy are evaluated.

EXPERT OPINION

Detection of TKI-induced thyroid dysfunction requires routine monitoring of thyroid function and may necessitate treatment. Potential benefits in developing thyroid dysfunction and potential harm in treating it necessitate controlled studies. Finally, if treatment is pursued, appropriate dosing and timing of TH replacement will require prospective clinical evaluation.

Clinical response to sunitinib as a multitargeted tyrosine-kinase inhibitor (TKI) in solid cancers: a review of clinical trials

Angiogenesis is an integral process in carcinogenesis, and molecular inhibitors of angiogenic factors are currently being tested as treatments for cancer. Sunitinib is an oral multitargeted tyrosine-kinase inhibitor that blocks activation through the stem cell-factor receptor (Kit) and platelet-derived growth-factor receptor. Sunitinib has shown potent antitumor activity against several solid tumors, including renal cell carcinoma, gastrointestinal stromal tumors, and neuroendocrine tumors in several Phase II/III trials. Recently, sunitinib has been used to treat other solid cancers, such as lung cancer, pancreatic cancer, chondrosarcoma, esophageal cancer, bladder cancer, glioma, and aggressive fibromatosis, and also showed potential efficacy in progression-free survival and overall survival. In this review, we examine the efficacy of sunitinib as a molecular-targeted therapy in patients with different types of solid cancers.

Autoimmune thyroid disease elicited by NY-ESO-1 vaccination

BACKGROUND

Immunotherapies and targeted therapies are frequently associated with thyroid dysfunction, which is in contrast with the rare thyroid abnormalities induced by cytotoxic agents. Immunotherapy with NY-ESO-1, a tumor-associated antigen expressed by a number of malignancies, was reported to trigger hyperthyroidism or hypothyroidism in two HLA-A2 patients with ovarian cancer. We describe now a case of Graves' disease triggered by NY-ESO-1 in a HLA-A2-negative woman.

PATIENT FINDINGS

A 32-year-old woman with a synovial sarcoma received radiotherapy, chemotherapy, and finally NY-ESO-1 vaccine. The patient was found to have HLA A11/A33(19), B13/B56(22), Cw3/-. One month after the beginning of immunotherapy, thyroid dysfunction was clinically suspected and Graves' disease was biochemically confirmed. Fearful of the antithyroid drugs' side effects, the patient was treated with a beta-blocker (propranolol, 80-20 mg/day). As hyperthyroidism progressively worsened, the patient underwent total thyroidectomy. We hypothesized that NY-ESO-1 shared partial homology with thyroid autoantigens (the so-called molecular mimicry mechanism) and that at least one pair of homologous sequences contained amino acid sequence binding motifs to a restricted number of HLA molecules. We used BLAST software to search amino acid sequence homologies between NY-ESO-1 and thyroid autoantigens (thyrotropin receptor [TSH-R], thyroperoxidase, and thyroglobulin), and the HLA ligand/motif database to look for HLA/T-cell receptor binding motifs in the regions of NY-ESO-1 and thyroid autoantigens that were homologous. We found 15 epitopic regions of NY-ESO-1 homologous to 15 regions of thyroid autoantigens, some of which epitopic: 5 of TSH-R, 8 of thyroglobulin, and 2 of thyroperoxidase. These homologous sequences contain binding motifs belonging to several HLA class I antigens, including HLA A2 and the patient's A11 and A33.

SUMMARY

Genetically predisposed patients who receive NY-ESO-1 vaccination are at risk to develop thyroid dysfunction.

CONCLUSIONS

Considering the increasing use of NY-ESO-1, thyroid dysfunctions induced by NY-ESO-1 are expected to increase in cancer patients over the next years.

Tyrosine kinase inhibitors: their on-target toxicities as potential indicators of efficacy

Tyrosine kinase inhibitors (TKIs) have revolutionized the treatment of certain forms of cancers, raising hopes for many patients with otherwise unresponsive tumours. While these agents are generally well tolerated, clinical experience with them has highlighted their unexpected association with serious toxic effects on various organs such as the heart, lungs, liver, kidneys, thyroid, skin, blood coagulation, gastrointestinal tract and nervous system. Many of these toxic effects result from downstream inhibition of vascular endothelial growth factor or epidermal growth factor signalling in cells of normal organs. Many of these undesirable effects such as hypertension, hypothyroidism, skin reactions and possibly proteinuria are on-target effects. Since tyrosine kinases are widely distributed with specific functional roles in different organs, this association is not too surprising. Various studies suggest that the development of these on-target effects indicates clinically desirable and effective inhibition of the corresponding ligand-mediated receptor linked with oncogenesis. This is reflected as improved efficacy in the subgroup of patients who develop these on-target adverse effects compared with those who do not. Inevitably, issues arise with respect to the regulatory assessment of efficacy and risk/benefit of the TKIs as well as the clinical approach to managing patients who develop these effects. Routine subgroup analysis of efficacy data from clinical trials (patients with and without on-target toxicity) may enable more effective clinical use of TKIs since (i) discontinuing or reducing the dose of the TKI has a negative impact if the tumour is TKI-responsive; and (ii) it is usually possible to manage these undesirable on-target effects with conventional clinical approaches. Prospective studies are needed to investigate this proposition further.

Inappropriate elevation of serum thyrotropin levels in patients treated with axitinib

BACKGROUND

Although anticancer treatment with the tyrosine kinase inhibitor (TKI) axitinib frequently causes thyroid dysfunction, the associated mechanism and clinical features have not been elucidated.

METHODS

Six patients were treated with axitinib for metastatic renal cell carcinoma at the Hamamatsu University School of Medicine between 2008 and 2010. We reviewed their thyroid function results and compared them to those of patients treated with two other TKIs, sunitinib or sorafenib, and to those of subjects with normal hypothalamic-pituitary-thyroid (HPT) function.

RESULTS

Axitinib-induced thyroid dysfunction was observed in all patients, and two patterns were observed: increased serum thyrotropin (TSH) levels within one month after administration occurred in five patients and transient thyrotoxicosis due to destructive thyroiditis occurred in five patients within 7 months of treatment. Four patients exhibited both. When the relationship between the serum TSH and thyroid hormones was evaluated using plots of TSH versus both free thyroxine and free triiodothyronine, four patients showed an inappropriate elevation of serum TSH during administration of axitinib. Their values apparently shifted against the regression line compared to data from patients with a normal HPT function. A similar tendency, though weaker, was observed in some patients treated with sunitinib or sorafenib.

CONCLUSION

This is the first study to report an inappropriate elevation of serum TSH levels in patients treated with axitinib.

Extreme hypothyroidism associated with sunitinib treatment for metastatic renal cancer

Although thyroid abnormalities are reported with the use of tyrosine kinase inhibitors, patients rarely require replacement therapy. The initial multicentre studies of sunitinib for metastatic renal cancer did not report hypothyroidism in fatigued patients, and thyroid tests were not routinely monitored. More recent studies, however, suggest that up to 70% of patients develop thyroid test abnormalities during treatment with sunitinib. Despite these concerns, the clinical relevance of sunitinib-induced hypothyroidism is uncertain since thyroid gland recovery is the norm in most patients. We report a case of a patient with metastatic papillary renal cell cancer on combination anti-angiogenic therapy with sunitinib, who developed unusually high thyroid stimulating hormone levels and severe symptoms despite receiving L-thyroxine. Our case also illustrates the complexity of managing sunitinib-associated thyroid dysfunction, which may be accompanied by transient thyroiditis, hyperthyroidism, and profound hypothyroidism.

Erlotinib-associated exacerbation of hypothyroidism with pericardial tamponade

OBJECTIVE

To report a case of erlotinib-associated exacerbation of hypothyroidism complicated by pericardial tamponade.

METHODS

We describe the patient's clinical presentation, biochemical workup, and clinical course.

RESULTS

Non-small cell lung cancer was diagnosed in a 54-year-old woman. After cisplatin and radiation therapy, she was noted to have subclinical hypothyroidism that did not necessitate treatment. The tyrosine kinase inhibitor erlotinib, 150 mg once daily, was prescribed. Three months later, the patient was documented to have severe hypothyroidism. Levothyroxine was prescribed, but she continued to experience shortness of breath, fatigue, and chest and back pain, which resulted in an emergency department visit. Inpatient workup revealed cardiac tamponade with a large pericardial effusion and a right ventricular diastolic collapse. Pericardiocentesis was performed.

CONCLUSIONS

This is the first case report linking erlotinib use and thyroid disease.

A case of acute adrenal insufficiency unmasked during sunitinib treatment for metastatic renal cell carcinoma

Sunitinib has recently become a standard treatment for metastatic renal cell carcinoma. However, various adverse events have been reported. We present the first case of clinically evident adrenal insufficiency during sunitinib therapy. A 72-year-old man began sunitinib therapy for bilateral lung and adrenal metastases of renal cell carcinoma. His adrenocorticotrophic hormone level was 93.6 pg/ml (7.2-63.3 pg/ml) before sunitinib treatment, indicating that subclinical adrenal insufficiency already existed. Fatigue, which is a frequently seen adverse effect of sunitinib treatment, emerged acutely on Day 24 of the second cycle. Adrenocorticotrophic hormone and free T4 were high and thyroid-stimulating hormone was suppressed. Under the clinical diagnosis of acute adrenal insufficiency with thyrotoxicosis, a low dose of steroid was administered. Fatigue was completely ameliorated by the following morning, although free T4 was still high and thyroid-stimulating hormone was still low. Therefore, hypermetabolism due to thyrotoxicosis unmasked adrenal insufficiency in our case. Physicians should be aware of this rare but potentially fatal complication when severe acute fatigue develops in patients with subclinical adrenal insufficiency.