Could thyroid dysfunction influence outcome in sunitinib-treated metastatic renal cell carcinoma?

Discovery of a new potent oxindole multi-kinase inhibitor among a series of designed 3-alkenyl-oxindoles with ancillary carbonic anhydrase inhibitory activity as antiproliferative agents

An optimization strategy was adopted for designing and synthesizing new series of 2-oxindole conjugates. Selected compounds were evaluated for their antiproliferative effect in vitro against NCI-60 cell lines panel, inhibitory effect on carbonic anhydrase (CA) isoforms (hCAI, II, IX and XII), and protein kinases. Compounds 5 and 7 showed promising inhibitory effects on hCA XII, whereas compound 4d was the most potent inhibitor with low nanomolar CA inhibition against all tested isoforms. These results were rationalized by using molecular docking. Despite its lack of CA inhibitory activity, compound 15c was the most active antiproliferative candidate against most of the 60 cell lines with mean growth inhibition 61.83% and with IC₅₀ values of 4.39, 1.06, and 0.34 nM against MCT-7, DU 145, and HCT-116 cell lines, respectively. To uncover the mechanism of action behind its antiproliferative activity, compound 15c was assessed against a panel of protein kinases (RET, KIT, cMet, VEGFR1,2, FGFR1, PDFGR and BRAF) showing % inhibition of 74%, 31%, 62%, 40%, 73%, 74%, 59%, and 69%, respectively, and IC₅₀ of 1.287, 0.117 and 1.185 μM against FGFR1, VEGFR, and RET kinases, respectively. These results were also explained through molecular docking.

Thyroid Dysfunction from Treatments for Solid Organ Cancers

In recent years, cancer care has been transformed by immune-based and targeted treatments. Although these treatments are effective against various solid organ malignancies, multiple adverse effects can occur, including thyroid dysfunction. In this review, the authors consider treatments for solid organ cancers that affect the thyroid, focusing on immune checkpoint inhibitors, kinase inhibitors, and radioactive iodine-conjugated treatments (I-131-metaiodobenzylguanidine). They discuss the mechanisms causing thyroid dysfunction, provide a framework for their diagnosis and management, and explore the association of thyroid dysfunction from these agents with patient survival.

CRISPR-mediated knockout of VEGFR2/KDR inhibits cell growth in a squamous thyroid cancer cell line

Squamous and anaplastic thyroid cancers are the most aggressive and life‐threatening cancer types in humans, with the involvement of lymph nodes in 59% of cases and distant metastases in 26% of cases of all thyroid cancers. The median survival of squamous thyroid cancer patients is < 8 months and therefore is of high clinical concern. Here, we show that both VEGFC and VEGFR2/KDR are overexpressed in thyroid cancers, indicating that VEGF/VEGFR signaling plays a carcinogenic role in thyroid cancer development. Using CRISPR/Cas9, we established a KDR knockout (KO) SW579 squamous thyroid cancer cell line that exhibited dramatically decreased colony formation and invasion abilities (30% and 60% reduction, respectively) when compared to scrambled control cells. To validate the potential of KDR as a therapeutic target for thyroid cancers, we used the KDR RTK inhibitor sunitinib. Protein analysis and live/dead assay were performed to demonstrate that sunitinib significantly inhibited cell growth signal transduction and induced cell apoptosis of SW579 cells. These results suggest that selective targeting of KDR may have potential for development into novel anti‐cancer therapies to suppress VEGF/VEGFR‐mediated cancer development in patients with clinical advanced thyroid cancer.

Sunitinib-Induced Hypothyroidism and Survival in Pancreatic Neuroendocrine Tumors

Sunitinib has been approved for the treatment of pancreatic neuroendocrine tumors, renal-cell carcinoma, and gastrointestinal stromal tumors. The elevation of thyroid-stimulating hormone serum levels is a common side effect. Studies suggest a correlation between sunitinib-induced hypothyroidism and treatment outcome in patients with renal-cell carcinoma and gastrointestinal stromal tumors. This study assessed whether sunitinib-induced hypothyroidism is a predictive marker of the objective response rate, progression-free survival, and overall survival in pancreatic neuroendocrine tumor patients. Twenty-nine patients treated with sunitinib for advanced pancreatic neuroendocrine tumors were included. The incidence of sunitinib-induced hypothyroidism was 33%. The median progression-free survival of patients who developed hypothyroidism was 16 months (95% confidence interval: 6.2-25.8 months) as compared with six months among euthyroid patients (95% confidence interval: 0.1-12.2 months) (p=0.02). The median overall survival was 77 months (95% confidence interval: 31.4-122.6 months) in hypothyroid patients but 12 months (95% confidence interval: 5.9-18.1 months) in subjects with euthyroidism (p=0.001). The median overall survival from the time of initial diagnosis ranged from 247 months in patients with hypothyroidism to 65 months in euthyroid subjects (p=0.015). Elevated thyroid-stimulating hormone levels are a prognostic biomarker of improved outcomes of sunitinib therapy in pancreatic neuroendocrine tumor patients.

Acquired Hypothyroidism in Patients with Metastatic Renal Cell Carcinoma Treated with Tyrosine Kinase Inhibitors

PURPOSE

We analyze a number of studies that describe the relationship between the onset of hypothyroidism and the prognosis of patients with metastatic renal cell carcinoma (mRCC) treated with TKIs.

PATIENTS AND METHODS

Targeted therapies are currently considered as the first-line treatment for patients with mRCC. The occurrence of hypothyroidism in the treatment of mRCC with TKIs is a major side effect. A comprehensive search was performed in Pubmed, Cochrane Library, Institute for Scientific Information, and CKNI. The following keywords and descriptors were used during the search and were combined in a number of sequences in English and Chinese languages: protein kinase inhibitors (including sunitinib, pazopanib, tivozanib, cabozantinib, axitinib, sorafenib), hypothyroidism and renal cell carcinoma.

RESULTS

Scholars have studied the clinical relationship between hypothyroidism and TKI treatment and its molecular biology mechanism. Most studies hold that hypothyroidism occurring during TKI therapy may serve as potential biomarkers of response and efficacy of treatment, but there is no consensus on this point.

CONCLUSION

The mechanism of hypothyroidism occurring is still unclear. Therefore, more studies are needed to clarify whether better outcomes are associated with TKI-induced hypothyroidism in mRCC patients, helping to maximize the treatment outcome of mRCC patients.

Regorafenib-Induced Hypothyroidism as a Predictive Marker for Improved Survival in Metastatic or Unresectable Colorectal Cancer Refractory to Standard Therapies: A Prospective Single-Center Study

BACKGROUND

Tyrosine kinase inhibitor-induced hypothyroidism is associated with favorable survival in patients with various cancers.

OBJECTIVE

We aimed to investigate the incidence of regorafenib-induced hypothyroidism and assess its prognostic value in patients with metastatic or unresectable colorectal cancer (CRC) receiving regorafenib.

PATIENTS AND METHODS

This study included 68 patients treated at Asan Medical Center (Seoul, Republic of Korea) between 2014 and 2016 with metastatic or unresectable CRC refractory to standard therapies. Regorafenib (160 mg/day on days 1-21 followed by a 7-day break) was administered.

RESULTS

The median patient age was 58 (range 26-72) years; 61.8% of patients were male. Among the 68 patients, 50 (73.5%) showed hypothyroidism; 39 (57.4%) had subclinical and 11 (16.2%) had symptomatic hypothyroidism. Overall, the objective response rate (ORR) and disease control rate (DCR) were 7.4% and 70.6%, respectively; both were significantly higher in patients with symptomatic or subclinical hypothyroidism than in euthyroid patients (ORR 27.3% vs. 5.1% vs. 0.0%, P = 0.001; DCR 100% vs. 76.9% vs. 38.9%, P = 0.001). Median progression-free survival (PFS) and overall survival (OS) were longer in patients with symptomatic hypothyroidism than in those with subclinical hypothyroidism (median PFS 9.1 vs. 3.8 months, P = 0.018; median OS: 19.2 vs. 9.4 months, P = 0.012) or with euthyroid status (median PFS 9.1 vs. 1.8 months, P < 0.001; median OS 19.2 vs. 4.7 months, P = 0.001). Symptomatic hypothyroidism was a significant protective factor for PFS (hazard ratio (HR) = 0.37, P = 0.006) and OS (HR = 0.35, P = 0.007); no other adverse events were associated with survival.

CONCLUSIONS

Regorafenib-induced hypothyroidism frequently occurs in patients with metastatic CRC receiving regorafenib and is associated with improved survival. Thyroid function status should be actively monitored in CRC patients receiving regorafenib.

Biomarkers of Prognosis and Efficacy of Anti-angiogenic Therapy in Metastatic Clear Cell Renal Cancer

In the last decades, the prognosis of metastatic renal cell carcinoma (mRCC) has remarkably improved following the advent of the "targeted therapy" era. The expanding knowledge on the prominent role played by angiogenesis in RCC pathogenesis has led to approval of multiple anti-angiogenic agents such as sunitinib, pazopanib, axitinib, cabozantinib, sorafenib, and bevacizumab. These agents can induce radiological responses and delay cancer progression for months or years before onset of resistance, with a clinically meaningful activity. The need for markers of prognosis and efficacy of anti-angiogenic agents has become more compelling as novel systemic immunotherapy agents have also been approved in RCC and can be administered as an alternative to angiogenesis inhibitors. Anti PD-1 monoclonal antibody nivolumab has been approved in the second-line setting after tyrosine kinase inhibitors failure, while combination of nivolumab plus anti CTLA-4 monoclonal antibody ipilimumab has been approved as first-line therapy of RCC patients at intermediate or poor prognosis. In this review article, biomarkers of prognosis and efficacy of antiangiogenic therapies are summarized with a focus on those that have the potential to affect treatment decision-making in RCC. Biomarkers predictive of toxicity of anti-angiogenic agents have also been discussed.

On-target Toxicities Predictive of Survival in Metastatic Renal Cell Carcinoma (mRCC) Treated With Sunitinib: A Multicenter Retrospective Study

BACKGROUND

Preliminary studies suggested that selected drug-related toxicities of sunitinib may correlate with a better prognosis.

PATIENTS AND METHODS

From January 2006 through December 2015, we retrospectively analyzed data of 145 patients with metastatic renal cell carcinoma treated with sunitinib as a first-line therapy in 7 different Italian oncology departments. Hypertension, hypothyroidism, thrombocytopenia, neutropenia, and anemia were evaluated. Overall survival (OS) and progression-free survival (PFS) were calculated. OS and PFS were compared in patients who developed and who did not develop a drug-related toxicity. A multivariate analysis using the Cox regression model was performed.

RESULTS

We evaluated 145 patients (92 males; median age, 70 years); 105 (62.4%) patients experienced at least 1 toxicity: 66 (45.5%) patients developed hypothyroidism, 41 (28.3%) thrombocytopenia, 39 (26.9%) hypertension that required medical therapy, 22 (15.2%) anemia, and 11 (7.6%) neutropenia. The median PFS of patients who developed hypertension was 12 months (95% confidence interval [CI], 9-21 months) versus 9 months (95% CI, 7-12 months) in patients who did not develop toxicity; the median OS was 36 months (95% CI, 22 months to not reached) versus 26 months (95% CI, 18-34 months). For neutropenia, the median PFS was 17.5 months (95% CI, 9-65 months) versus 10 months (95% CI, 8-12 months); the median OS was 23 months (95% CI, 13 months to not reached) versus 28 months (95% CI, 22-35 months). At univariate and multivariate analysis, we observed a protective effect of hypertension and neutropenia on tumor progression (hazard ratio, 0.47; 95% CI, 0.28-0.78 and hazard ratio, 0.26; 95% CI, 0.09-0.76, respectively).

CONCLUSIONS

Many patients developed toxicities during treatment with sunitinib; hypertension and neutropenia were related to longer PFS in our cohort.

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.

Tetrac as an anti-angiogenic agent in cancer

The thyroid hormones T3 and T4 have emerged as pro-angiogenic hormones with important implications for cancer management. Endogenous circulating hormone levels may help stimulate cancer progression and limit the effectiveness of anticancer therapy, though clinical data remain inconclusive. The capacity of thyroid hormones to modulate angiogenesis is mediated through non-canonical mechanisms initiated at the cell surface receptor integrin αvβ3. This integrin is predominantly expressed on tumour cells, proliferating endothelial cells and tumour stroma-associated cells, emphasising its potential relevance in angiogenesis and tumour biology. Thyroid hormone/integrin αvβ3 signalling results in the activation of intracellular pathways that are commonly associated with angiogenesis and are mediated through classical pro-angiogenic molecules such as vascular endothelial growth factor. The naturally occurring T4 analogue tetrac blocks the pro-angiogenic actions of thyroid hormones at the integrin receptor, in addition to agonist-independent anti-angiogenic effects. Tetrac reduces endothelial cell proliferation, migration and tube formation through a reduction in the transcription of vascular growth factors/growth factor receptors, hypoxia-inducible factor-1α, pro-angiogenic cytokines and a number of other pro-angiogenic genes, while at the same time stimulating the expression of endogenous angiogenesis inhibitors. It further modulates vascular growth factor activity by disrupting the crosstalk between integrin αvβ3 and adjacent growth factor receptors. Moreover, tetrac disrupts thyroid hormone-stimulated tumour recruitment, differentiation and the pro-angiogenic signalling of tumour stroma-associated mesenchymal stem cells. Tetrac affects tumour-associated angiogenesis via multiple mechanisms and interferes with other cancer cell survival pathways. In conjunction with its low toxicity and high tissue selectivity, tetrac is a promising candidate for clinical application.

Long-Term Endocrine and Metabolic Consequences of Cancer Treatment: A Systematic Review

The number of patients surviving ≥5 years after initial cancer diagnosis has significantly increased during the last decades due to considerable improvements in the treatment of many cancer entities. A negative consequence of this is that the emergence of long-term sequelae and endocrine disorders account for a high proportion of these. These late effects can occur decades after cancer treatment and affect up to 50% of childhood cancer survivors. Multiple predisposing factors for endocrine late effects have been identified, including radiation, sex, and age at the time of diagnosis. A systematic literature search has been conducted using the PubMed database to offer a detailed overview of the spectrum of late endocrine disorders following oncological treatment. Most data are based on late effects of treatment in former childhood cancer patients for whom specific guidelines and recommendations already exist, whereas current knowledge concerning late effects in adult-onset cancer survivors is much less clear. Endocrine sequelae of cancer therapy include functional alterations in hypothalamic-pituitary, thyroid, parathyroid, adrenal, and gonadal regulation as well as bone and metabolic complications. Surgery, radiotherapy, chemotherapy, and immunotherapy all contribute to these sequelae. Following irradiation, endocrine organs such as the thyroid are also at risk for subsequent malignancies. Although diagnosis and management of functional and neoplastic long-term consequences of cancer therapy are comparable to other causes of endocrine disorders, cancer survivors need individually structured follow-up care in specialized surveillance centers to improve care for this rapidly growing group of patients.

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.

Thyroid hormones induce doxorubicin chemosensitivity through enzymes involved in chemotherapy metabolism in lymphoma T cells

Thyroid hormones (THs) – 3,3′,5-triiodo-L-thyronine (T3) and L-thyroxine (T4) – are important regulators of the metabolism and physiology of most normal tissues. Cytochrome P450 family 3A members are drug metabolizing enzymes involved in the activation and detoxification of several drugs. CYP3A4 is the major enzyme involved in the metabolism of chemotherapeutic drugs. In this work, we demonstrate that THs induce a significant increase in CYP3A4 mRNA levels, protein expression and metabolic activity through the membrane receptor integrin αvβ3 and the activation of signalling pathways through Stat1 and NF-κB. We reasoned that TH-induced CYP3A4 modulation may act as an important regulator in the metabolism of doxorubicin (Doxo). Experiments in vitro demonstrated that in CYP3A4-knocked down cells, no TH-mediated chemosensitivity to Doxo was observed. We also found that THs modulate these functions by activating the membrane receptor integrin αvβ3. In addition, we showed that the thyroid status can modulate CYP450 mRNA levels in tumor and liver tissues, and the tumor volume in response to chemotherapy in vivo. In fact, Doxo treatment in hypothyroid mice was associated with lower tumors, displaying lower levels of CYP enzymes, than euthyroid mice. However, higher mRNA levels of CYP enzymes were found in livers from Doxo treated hypothyroid mice respect to control. These results present a new mechanism by which TH could modulate chemotherapy response. These findings highlight the importance of evaluating thyroid status in patients during application of T-cell lymphoma therapeutic regimens.

Thyroid Hormones and Cancer: A Comprehensive Review of Preclinical and Clinical Studies

Thyroid hormones take major part in normal growth, development and metabolism. Over a century of research has supported a relationship between thyroid hormones and the pathophysiology of various cancer types. In vitro studies as well as research in animal models demonstrated an effect of the thyroid hormones T3 and T4 on cancer proliferation, apoptosis, invasiveness and angiogenesis. Thyroid hormones mediate their effects on the cancer cell through several non-genomic pathways including activation of the plasma membrane receptor integrin αvβ3. Furthermore, cancer development and progression are affected by dysregulation of local bioavailability of thyroid hormones. Case-control and population-based studies provide conflicting results regarding the association between thyroid hormones and cancer. However, a large body of evidence suggests that subclinical and clinical hyperthyroidism increase the risk of several solid malignancies while hypothyroidism may reduce aggressiveness or delay the onset of cancer. Additional support is provided from studies in which dysregulation of the thyroid hormone axis secondary to cancer treatment or thyroid hormone supplementation was shown to affect cancer outcomes. Recent preclinical and clinical studies in various cancer types have further shown promising outcomes following chemical reduction of thyroid hormones or inhibition or their binding to the integrin receptor. This review provides a comprehensive overview of the preclinical and clinical research conducted so far.

Chinese consensus on management of tyrosine kinase inhibitor-associated side effects in gastrointestinal stromal tumors

Tyrosine kinase inhibitors (TKIs) have improved the overall survival of patients with gastrointestinal stromal tumors (GISTs), but their side effects can impact dose intensity and, consequently, the clinical benefit. To date, no guideline or consensus has been published on the TKI-associated adverse reactions. Therefore, the Chinese Society of Surgeons for Gastrointestinal Stromal Tumor of the Chinese Medical Doctor Association organized an expert panel discussion involving representatives from gastrointestinal surgery, medical oncology, cardiology, dermatology, nephrology, endocrinology, and ophthalmology to consider the systemic clinical symptoms, molecular and cellular mechanisms, and treatment recommendations of GISTs. Here, we present the resultant evidence- and experience-based consensus to guide the management of TKI-associated side events in clinical practice.

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.

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.

Assessment of ethnic differences in sunitinib outcome between Caucasian and Asian patients with metastatic renal cell carcinoma: a meta-analysis

BACKGROUND

An increasing number of studies have reported ethnic differences in sunitinib outcome in metastatic renal cell carcinoma (mRCC) patients. However, a comprehensive analysis is still lacking. Therefore, we systematically collected available published data and performed a meta-analysis to compare sunitinib efficacy and toxicity in Asian and Caucasian mRCC patients.

METHODS

Data were extracted from published results from clinical trials, expanded access program and real-world clinical practice. Progression-free survival (or time to tumor progression), overall survival, objective response rate and adverse events were used as endpoints to evaluate the differences of sunitinib outcome between the two ethnicities. For adverse events, we focused the following clinically relevant side effects: diarrhea, fatigue, mucositis/stomatitis, hand-foot syndrome, hypertension, leukopenia, neutropenia and thrombocytopenia.

RESULTS

A total of 33 publications including 9977 patients were available for meta-analysis. The efficacy of sunitinib in Asian patients was similar to that in Caucasian patients. However, Asian patients showed a higher incidence of all grades toxicity of hand-foot syndrome, > grade 2 fatigue, > grade 2 hand-foot syndrome and > grade 2 thrombocytopenia.

CONCLUSION

Ethnic differences in adverse events of sunitinib in mRCC patients existed and dose adjustment in Asian patients may be considered.

Biological toxicities as surrogate markers of efficacy in patients treated with mTOR inhibitors for metastatic renal cell carcinoma

Background

Metabolic toxicities of mTOR inhibitors (mTORi) are well characterized. The purpose of the study was to investigate the relationship between these metabolic toxicities and mTORi efficacy.

Methods

From 2007 to 2011, metabolic toxicities were retrospectively collected in patients treated with an mTORi (everolimus, temsirolimus) for a metastatic renal cell carcinoma (mRCC) in a single institution. Patients were eligible if they have received an mTORi for at least 28 days. Changes in the following parameters were analyzed: lymphocytes, serum creatinine, glycemia, serum phosphate, liver transaminases, cholesterol, and triglycerides. The efficacy was assessed by progression-free survival (PFS) and tumor response.

Results

Data were collected from seventy-five patients (everolimus = 44 patients; temsirolimus = 31 patients). Six patients exhibited a partial response, 42 a stable disease and 15 had a progressive disease (12 missing). After a median follow-up of 12.8 months, the median PFS was 6.7 months (95% confidence interval: 4.0-9.1 months). Patients with CB had a statistically more severe absolute increase of glycemia and absolute decrease in phosphatemia (p = 0.002 and p = 0.02 respectively). The Progression Free Survival was significantly higher with the onset rate of hypophosphatemia (p = 0.03) and hyperglycemia (p = 0.001) and lower with the onset rate of lymphopenia (p = 0.004).

Conclusions

Hyperglycemia, hypophosphatemia and lymphopenia, were significantly associated with tumor response and/or PFS. Those events, as well as their onset rate, should be prospectively monitored as predictors of response to mTORi.

Clinical significance of sunitinib-associated macrocytosis in metastatic renal cell carcinoma

Increases in the mean corpuscular volume (MCV) have been observed in patients with metastatic renal cell carcinoma (mRCC) on tyrosine kinase inhibitor (TKI) treatment; however, its association with progression‐free‐survival (PFS) is unknown. We aimed to characterize TKI‐associated macrocytosis in mRCC and its relationship with PFS. Retrospective review of data on macrocytosis and thyroid dysfunction on mRCC patients treated with sunitinib and/or sorafenib. These results are evaluated in the context of our previous report on the association of hypothyroidism in this setting. We assessed PFS as clinically defined by the treating physician. Seventy‐four patients, 29 of whom received both drugs, were included. A treatment period was defined as time from initiation to discontinuation of either sunitinib or sorafenib; 103 treatment periods [sorafenib (47), sunitinib (56)] were analyzed. Macrocytosis was found in 55 and 8% of sunitinib‐ and sorafenib‐treated patients, respectively, P < 0.001. The median time to developing macrocytosis was 3 months (m, range 1–7). Median PFS in sunitinib‐treated patients was 11 m (95% CI: 6–19). Median PFS was higher among those with macrocytosis compared to normocytosis (21 m [95% CI: 11–25] vs. 4 m [95% CI: 3–8] P = 0.0001). Macrocytosis and hypothyroidism were two significant predictors of PFS. The greatest difference in PFS among all patients was observed in patients with both macrocytosis and hypothyroidism (25 m), compared to the normocytic and euthyroid patients (5 m) (P < 0.0001). Sunitinib‐related macrocytosis was associated with prolonged PFS, and concurrent development of hypothyroidism and macrocytosis further prolonged PFS. Increased MCV may have a role as a predictive biomarker for sunitinib. Prospective studies accounting for other known prognostic factors are needed to confirm this finding.

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.

Thyroid function alters during neoadjuvant chemotherapy in breast cancer patients: results from the NEOZOTAC trial (BOOG 2010-01)

This side study investigated the effect of chemotherapy on thyroid function and the extent to which it can predict pathological complete response (pCR) in patients with early breast cancer taking part in NEOZOTAC phase III trial, randomizing between neoadjuvant chemotherapy with or without additional zoledronic acid. Moreover, we examined the impact of thyroid function on toxicity. Serum samples of 38 patients were available for analyses. Free thyroxin (fT4) and thyroid stimulating hormone (TSH) levels were compared between baseline and before the 6th cycle and between subjects with and without pCR. The relation between toxicity and the variation in fT4 and TSH levels during chemotherapy was tested. Samples at baseline and before the 6th cycle were available for 31 and 21 patients, respectively. The mean baseline fT4 level was 16.0 pmol/L and TSH level 1.11 mU/L, and these did not differ between both arms at each time point. During six cycles of chemotherapy, fT4 levels decreased (p = 0.0001), and TSH levels increased significantly (p = 0.019). Interestingly, the decrease of fT4 was significantly greater in patients without nausea, vomiting, or neuropathy, than in patients with those side effects (p = 0.037, p = 0.043, and p = 0.050, respectively). Baseline TSH levels tended to be higher in patients with pCR (p = 0.035 univariate analysis and p = 0.074 multivariate analysis). Chemotherapy blunts thyroid function, which was associated with less side effects. These data urge further evaluation of the effects of thyroid function on toxicity and outcome of breast cancer therapy.

Acquired Hypothyroidism as a Predictive Marker of Outcome in Patients With Metastatic Renal Cell Carcinoma Treated With Tyrosine Kinase Inhibitors: A Literature-Based Meta-Analysis

Hypothyroidism in patients with metastatic renal cell carcinoma (mRCC) during treatment with the tyrosine kinase inhibitors (TKIs) sunitinib and sorafenib is a well-established side effect. Furthermore, the potential role of hypothyroidism as predictive marker of outcome has been studied but with conflicting results. The aim of the present meta-analysis was to assess the predictive value of hypothyroidism for progression-free (PFS) and overall survival (OS) in patients with mRCC during TKI therapy. We searched PubMed and the electronic abstract databases of the major international congresses' proceedings to identify all eligible studies that reported a correlation between the development of hypothyroidism during TKI treatment and outcome in patients with mRCC. Hazard ratios (HRs) with 95% confidence intervals (CIs) for PFS and OS were obtained from these publications and pooled in a meta-analysis. Eleven studies with a total of 500 patients fulfilled the inclusion criteria. We found no statistical significant difference in PFS between patients who developed hypothyroidism during sunitinib therapy and unaffected patients (HR, 0.82; 95% CI, 0.59-1.13; P = .22; 6 studies; 250 patients). The HR for OS was 0.52 (95% CI, 0.31-0.87; P = .01) for patients who developed hypothyroidism during sunitinib therapy compared with patients who did not (4 studies; 147 patients). The development of hypothyroidism during TKI therapy is not clearly shown to be predictive of efficacy in patients with mRCC. The observed advantage in OS for the patients with acquired hypothyroidism should be interpreted with caution.

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

Tyrosine kinase inhibitors (TKIs) are currently used by most oncologists. Among their side effects, thyroid dysfunctions are nowadays clearly observed. Whereas changes in thyroid function tests have been originally described with sunitinib, we now know that many TKIs can induce hypothyroidism and hyperthyroidism. In this study, the various molecules implicated in thyroid dysfunctions are analysed and the latest data on physiopathological mechanisms are approached in order to propose a strategy of thyroid monitoring of patients on TKI therapy.

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.

Treatment-related fatigue with sorafenib, sunitinib and pazopanib in patients with advanced solid tumors: an up-to-date review and meta-analysis of clinical trials

Fatigue is the most common symptom associated with cancer and cancer treatment. We performed an up-to-date meta-analysis to determine the incidence and relative risk (RR) of fatigue in patients (pts) with cancer treated with sorafenib (SO), sunitinib (SU) and pazopanib (PZ). PubMed databases were searched for articles published till August 2013. Eligible studies were selected according to PRISMA statement. Summary incidence, RR and 95% confidence intervals were calculated using random-effects or fixed-effects models based on the heterogeneity of selected studies. Fifteen studies were included in our analysis. A total of 6,996 pts was enrolled: 2,260 had renal cell carcinomas (RCC), 1,691 non-small cell lung cancers, 1,290 breast cancers, 823 hepatocellular carcinomas, 362 soft tissue sarcomas, 304 gastrointestinal solid tumors, 165 neuroendocrine tumors and 101 melanomas. When stratified by drug, SO registered lower incidence and RR of all and high-grade fatigue when compared to SU, whereas the difference between SO and PZ was significant only for all-grade fatigue (p < 0.001). The difference between SU and PZ was significant for high-grade (p < 0.001) but not for all-grade fatigue (p = 0.52). In RCC pts, PZ showed the lower incidence and RR of all and high-grade fatigue. The differences were significant for SU vs. SO (p < 0.001), SU vs. PZ (p < 0.001) and SO vs. PZ (p < 0.001). Treatment with SO, SU and PZ is associated with an increased incidence of fatigue in pts with cancer. Early and appropriate management is required to avoid unnecessary dose reductions and transitory or definitive treatment discontinuations.

Thyroid dysfunction as an unintended side effect of anticancer drugs

BACKGROUND

Several of the currently used anticancer drugs may variably affect thyroid function, with impairment ranging from modified total but not free concentration of thyroid hormones to overt thyroid disease.

SUMMARY

Cytotoxic agents seem to alter thyroid function in a relatively small proportion of adult patients. Anticancer hormone drugs may mainly alter serum levels of thyroid hormone-binding proteins without clinically relevant thyroid dysfunction. Old immunomodulating drugs, such as interferon-α and interleukin-2, are known to induce variably high incidence of autoimmune thyroid dysfunction. Newer immune checkpoint inhibitors, such as anti-CTLA4 monoclonal antibodies, are responsible for a relatively low incidence of thyroiditis and may induce secondary hypothyroidism resulting from hypophysitis. Central hypothyroidism is a well-recognized side effect of bexarotene. Despite their inherent selectivity, tyrosine kinase inhibitors may cause high rates of thyroid dysfunction. Notably, thyroid toxicity seems to be restricted to tyrosine kinase inhibitors targeting key kinase-receptors in angiogenic pathways, but not other kinase-receptors (e.g., epidermal growth factor receptors family or c-KIT). In addition, a number of these agents may also increase the levothyroxine requirement in thyroidectomized patients.

CONCLUSIONS

The pathophysiology of thyroid toxicity induced by many anticancer agents is not fully clarified and for others it remains speculative. Thyroid dysfunction induced by anticancer agents is generally manageable and dose reduction or discontinuation of these agents is not required. The prognostic relevance of thyroid autoimmunity, overt and subclinical hypothyroidism induced by anticancer drugs, the value of thyroid hormone replacement in individuals with abnormal thyrotropin following anticancer systemic therapy, and the correct timing of replacement therapy in cancer patients need to be defined more accurately in well-powered prospective clinical trials.

Thyroid dysfunction and tyrosine kinase inhibitors in renal cell carcinoma

The most recent World Health Organization classification of renal neoplasms encompassed nearly 50 distinctive renal neoplasms. Different histological subtypes have different clinical outcomes and show different responses to therapy. Overall, the incidence of kidney cancer has increased worldwide in the last years. Although the most common type of kidney cancer is localized renal cell carcinoma (RCC), with a 5-year survival rate of 85%, about one third of patients present advanced or metastatic disease at diagnosis, with a 5-year survival rate of only 10%. Multi-targeted receptor tyrosine kinase inhibitors (TKIs, sunitinib and sorafenib), the anti-VEGF MAB bevacizumab in association with interferon-α, and the mTOR inhibitors are now approved for the treatment of mRCC. Recently, the novel agents pazopanib and axitinib have also demonstrated efficacy in mRCC patients. Several recent retrospective and prospective trials have suggested that some of their adverse events, such as hypertension, hypothyroidism, and hand foot syndrome (HFS) may act as potential biomarkers of response and efficacy of treatment. In this review, we analyzed the studies that have suggested a relationship between hypothyroidism onset and a better outcome of mRCC patients treated with TKIs. The biological mechanisms suggesting and explaining this correlation are not well known and different speculative theories have been considered in order to investigate the clinical link between hypothyroidism occurrence and the prolonged therapy with TKIs in solid tumors. Furthermore, the management of this unexplained side effect is very important to maximize the efficacy of therapy in mRCC patients because there is a clear and consistent relationship between drug dose and efficacy of treatment. Certainly, other studies are needed to clarify whether a better outcome is associated with hypothyroidism induced to TKIs in patients with mRCC.

Clinical biomarkers of response in advanced renal cell carcinoma

There are now a range of effective targeted agents available for the first- and second-line treatment of advanced renal cell carcinoma (RCC). However, patients with advanced RCC have varied responses to therapy; some experience long-term responses while others may not respond, or even progress rapidly. Characteristics or markers that could be used to determine which patients will benefit most from which agent may enable us to select the optimal treatment of each individual patient, thereby improving efficacy and avoiding unnecessary toxic effects. These characteristics may be at the cellular or genetic level. Alternatively, the occurrence of adverse events may act as surrogate markers of a drug's on treatment activity, enabling prediction of outcomes during treatment. Recently, it has been suggested that during some targeted therapy for advanced RCC, the occurrence of specific adverse events, such as hypertension, hypothyroidism, hand-foot syndrome or fatigue/asthenia, may be associated with improved efficacy. This article reviews the evidence supporting clinical biomarkers in patients with advanced RCC receiving targeted agents. We also consider how these clinical biomarkers may affect the future management of patients with advanced RCC.

Dynamic pseudo-observations: a robust approach to dynamic prediction in competing risks

In this article, we propose a new approach to the problem of dynamic prediction of survival data in the presence of competing risks as an extension of the landmark model for ordinary survival data. The key feature of our method is the introduction of dynamic pseudo-observations constructed from the prediction probabilities at different landmark prediction times. They specifically address the issue of estimating covariate effects directly on the cumulative incidence scale in competing risks. A flexible generalized linear model based on these dynamic pseudo-observations and a generalized estimation equations approach to estimate the baseline and covariate effects will result in the desired dynamic predictions and robust standard errors. Our approach has a number of attractive features. It focuses directly on the prediction probabilities of interest, avoiding in this way complex modeling of cause-specific hazards or subdistribution hazards. As a result, it is robust against departures from these omnibus models. From a computational point of view an advantage of our approach is that it can be fitted with existing statistical software and that a variety of link functions and regression models can be considered, once the dynamic pseudo-observations have been estimated. We illustrate our approach on a real data set of chronic myeloid leukemia patients after bone marrow transplantation.

Risk of hypothyroidism in patients with cancer treated with sunitinib: a systematic review and meta-analysis

BACKGROUND

The multitargeted tyrosine kinase inhibitor sunitinib is used in various cancers. Clinical studies have reported a substantial variation in the incidence of hypothyroidism associated with sunitinib, without a systemic attempt to synthesize these data.

METHODS

We searched Medline databases for relevant clinical trials published up to May 2012. Phase II and III trials and expanded access programs of sunitinib in patients with any type of cancer that reported occurrence of hypothyroidism were eligible. The summary incidence, relative risk (RR) and 95% confidence intervals (CIs) were calculated using random- or fixed-effects models based on the heterogeneity of included studies.

RESULTS

Incidence analysis was performed using 6678 sunitinib-treated patients from all 24 eligible trials. The incidence of all- and high-grade hypothyroidism was 9.8% (95% CI 7.3-12.4%) and 0.4% (95% CI 0.3-0.5%), respectively. A meta-analysis of seven randomized trials with 2787 subjects revealed a RR of all- and high-grade hypothyroidism of 13.95 (95% CI 6.91-28.15; p < 0.00001) and 4.78 (95% CI 1.09-20.84; p = 0.04), respectively. Subgroup analysis revealed a significantly higher incidence of all-grade hypothyroidism in patients receiving sunitinib for longer duration than in patients receiving sunitinib for shorter duration (p = 0.02).

CONCLUSIONS

This meta-analysis of data available from clinical trials demonstrates that sunitinib is associated with a significant risk of developing all- and high-grade hypothyroidism. These data provide further evidence to recommend monitoring for hypothyroidism in patients receiving sunitinib.

Thyroid hormone, thyroid hormone receptors, and cancer: a clinical perspective

Thyroid hormones (THs) may play a role in diseases other than hyper- and hypothyroidism. Several lines of evidence suggest tumor-promoting effects of TH and TH receptors. They are possibly mediated by phosphatidylinositol-3-kinase and MAPK and involve among others stimulation of angiogenesis via αvβ3. Thus, an increased risk for colon, lung, prostate, and breast cancer with lower TSH has been demonstrated in epidemiological studies, even suggesting a TH dose effect on cancer occurrence. Furthermore, higher TH levels were associated with an advanced clinical stage of breast and prostate cancer. In rodent models, TH stimulated growth and metastasis of tumor transplants, whereas hypothyroidism had opposite effects. In clinical studies of glioblastoma and head and neck cancer, hypothyroid patients showed longer survival than euthyroid patients. Also, patients with renal cell cancer that were treated with the tyrosine kinase inhibitor sunitinib and developed hypothyroidism in due course showed significantly longer survival than patients that remained euthyroid. Development of hypothyroidism was an independent predictor for survival in two studies. Yet, it is still possible that hypothyroidism is only a surrogate marker for treatment efficacy and does not positively influence treatment outcome by itself. Future cancer treatment studies, especially with substances that can induce hypothyroidism, should therefore be designed in a way that allows for an analysis of thyroid function status and its contribution on treatment outcome.

Tyrosine kinase inhibitor-induced thyroid disorders: a review and hypothesis

BACKGROUND

Thyroid dysfunction is a well-known adverse effect of sunitinib, a drug that targets multiple receptor tyrosine kinases, including vascular endothelial growth factor receptor (VEGFR). As several kinds of tyrosine kinase inhibitors (TKIs) are now available, this has been postulated to be a side effect of the TKIs that target the VEGFR (VEGF-TKIs). However, sunitinib, one of the first-generation TKIs, likely causes thyroid dysfunction more frequently than other TKI classes, leading not only to hypothyroidism, but also to thyrotoxicosis.

SUMMARY

Based on the reports published to date, including our own studies, we have hypothesized that sunitinib may exert these effects, because it targets a broad spectrum of tyrosine kinases. This not only includes VEGFR2, but also VEGFR1 and the platelet-derived growth factor receptor (PDGFR). This, in turn, may suggest that not only VEGFR2 but also the PDGFR and/or the VEGFR1 play an important role during angiogenesis in the thyroid.

CONCLUSIONS

Our current hypothesis may explain the mechanisms that underlie TKI-induced thyroid disorders. By learning how various kinds of TKIs affect thyroid function, we may elucidate how the angiogenesis in thyroid is regulated both physiologically and pathologically.

Thyroid dysfunction in patients treated with sunitinib or sorafenib

INTRODUCTION

Sunitinib and sorafenib are tyrosine kinase inhibitors used in metastatic renal cell carcinoma and are known to cause hypothyroidism in a subset of patients. The goal of this study was to better characterize the development of hypothyroidism in patients and to examine its relationship to progression-free survival.

PATIENTS AND METHODS

A retrospective chart review was performed on patients treated with sunitinib or sorafenib from January 1, 2005, to January 1, 2011. Data pertaining to the treatment course and development of hypothyroidism were extracted. Patients with hypothyroidism at the beginning of treatment were analyzed separately.

RESULTS

A total of 73 treatment periods had sufficient data to analyze. Among patients with normal baseline thyroid function, 15 (44%) of 34 patients treated with sunitinib and 6 (27%) of 22 patients treated with sorafenib developed hypothyroidism. The hazard ratio for the development of hypothyroidism with sorafenib vs. sunitinib treatment was significant, at 0.38 (95% CI, 0.14-0.97). There was a statistically significant difference in the progression-free survival between patients who developed hypothyroidism while receiving treatment compared with those who did not, 18.2 vs. 10.1 months (P = .01).

CONCLUSIONS

This study demonstrated a significant difference in the incidence of hypothyroidism during treatment with sunitinib and sorafenib, with a higher incidence of hypothyroidism in patients treated with sunitinib. The development of hypothyroidism was associated with a longer progression-free survival.

[Targeted therapies: towards a new toxicology?]

Targeted therapies (TT) represent since 10 years, an interesting progress in oncology for many cancers in adjuvant, neoadjuvant or palliative situation. The development of this new class of drugs, with an original mechanism of action, their easy administration, mainly per os, and a particular toxicity profile different from "classical" chemotherapy (CT) leads them entering in the therapeutic arsenal of breast, digestive tract, lung and hematologic cancers, in association with CT. Medical oncologists took rapidly the train of TT, managing a new and original skin, digestive, cardiovascular, endocrine and pulmonary toxicity profile, that remains relatively less important than "classical" CT.

Does sunitinib-induced hypothyroidism play a role in the activity of sunitinib in metastatic renal cell carcinoma?

BACKGROUND

The objective of this study was to evaluate if hypothyroidism developing during sunitib therapy in patients with metastatic renal cell carcinoma (mRCC) is associated with a better outcome.

METHODS

Thirty-one consecutive patients with clear cell mRCC were retrospectively analyzed. Thyroid function was assessed prior to therapy, every 6 weeks during the first 6 months and every 2-4 months thereafter. Hypothyroidism was considered present if thyroid-stimulating hormone (TSH) exceeded the upper normal limit (UNL) with normal triiodothyronine (T3) and thyroxine (T4).

RESULTS

Hypothyroidism occurred in 16 patients (52%) within 3 months (range 0.7-22.9) of treatment initiation. Thyroid replacement corrected TSH below the UNL in 10 patients (63%). The distribution according to Motzer prognostic criteria revealed good prognosis in 16 patients (52%), intermediate in 9 (29%) and poor in 6 (19%). The hypothyroid patients tended to have longer progression-free survival (PFS; median 12.2 vs. 9.4 months; p = 0.234) and longer survival (median 22.4 vs. 13.9 months; p = 0.234) than the euthyroid patients. Clinical benefits were similar in both groups.

CONCLUSIONS

Hypothyroidism that develops in mRCC patients treated with sunitinib is associated with a trend toward prolonged PFS and survival, with a similar clinical benefit rate.

Prevalence of thyroid dysfunction in untreated cancer patients: a cross-sectional study

The relationship between thyroid disease and cancer (and cancer therapies) has been under investigation for years. Factors that increase the risk for thyroid disease include iodine deficiency, autoimmune disorders, old age, and pregnancy. The screening policy for thyroid disease in the healthy population is not precisely defined, and the frequency of thyroid dysfunction in untreated cancer patients has not been investigated in any great detail. This study was designed to compare the prevalence of thyroid dysfunction in 457 untreated cancer patients at the time of initial diagnosis to that of 373 age- and sex-matched subjects who were healthy and cancer-free (control group). Thyroid dysfunction was found in 29.5 % (135/457) of the cancer patients, while only 15.4 % (56/373) of the control group had thyroid dysfunction (p = 0.0001). The most prevalent abnormality was euthyroid sick syndrome (14.0 %, 64/457). Overt and subclinical hyperthyroidism and overt hypothyroidism were observed more frequently in cancer patients than the control group, and these differences were all statistically significant. Thyroid dysfunction was more frequent in patients with poor performance scores and those over the age of 50 years. These data indicate that alterations in thyroid hormone metabolism are twice as common in patients with untreated cancer than in control subjects. Those alterations may lead to delayed diagnosis, suboptimal treatment, and a poorer prognosis. In all, this study suggests that screening with thyroid function tests is strongly recommended in all newly diagnosed cancer patients.

Tyrosine kinase inhibitors in the treatment of advanced renal cell carcinoma: focus on pazopanib

Advances in our understanding of renal cancer biology have led to a new treatment paradigm in renal cancer. Tyrosine kinase inhibitors (TKI), that target the intracellular kinase domain of the VEGF receptor, have become established as the most successful class of agent in this disease. Three TKIs are currently approved for use in patients with advanced disease. Newer, more potent inhibitors have reached phase III clinical testing, meaning others are likely to follow. In 2009, pazopanib became the most recent TKI to receive FDA approval. This review sets out to discuss the key opportunities and challenges associated with TKI use in RCC, focusing particularly on pazopanib. We also review the current place of pazopanib in the management of patients with advanced disease, in what is a rapidly evolving therapeutic landscape.