Recurrent Differentiated Thyroid Cancer

ObjectiveTo discuss the risk of recurrence in patients with differentiated thyroid cancer and emphasize the importance of risk-group stratification.MethodsCommon risk factors associated with recur rent thyroid cancer are outlined, and appropriate manage ment strategies are reviewed.ResultsThe overall prognosis in patients with dif ferentiated thyroid cancer is excellent. Factors associated with recurrent thyroid cancer include extrathyroidal exten sion of the primary tumor, bulky nodal metastatic lesions, macroscopic local invasion, and aggressive histologic subtypes. The locoregional recurrence and mortality are higher in patients with high-risk thyroid cancers. Patients initially presenting with locally aggressive and advanced thyroid cancer have a higher incidence of recurrent disease in the thyroid bed or nodal metastasis. These patients also have a high incidence of distant metastatic lesions. Locally recurrent thyroid cancer may be seen in more than 25% of patients with aggressive differentiated thyroid cancer. Recurrent disease in the thyroid bed can be a difficult prob lem to manage because of the proximity of the tumor to the recurrent laryngeal nerve, visceral structures in the central compartment, and occasional involvement of the trachea or larynx. External beam radiation therapy after surgical treatment may be important for better local control in the thyroid bed region, especially in patients with poorly dif ferentiated histologic features. The role of additional radio iodine therapy remains undefined at this stage.ConclusionManagement of patients with recur rent thyroid cancer necessitates a true multidisciplinary approach. These patients require close follow-up, with cross-sectional imaging and positron emission tomo graphic scanning in selected individuals. (Endocr Pract. 2012;18:600-603)     

A Stepwise Approach to the Evaluation and Treatment of Subclinicalhyperthyroidism

ObjectivesTo review a stepwise approach to the evaluation and treatment of subclinical hyperthyroidism.MethodsEnglish-language articles regarding clinical management of subclinical hyperthyroidism published between 2007 and 2012 were reviewed.ResultsSubclinical hyperthyroidism is encountered on a daily basis in clinical practice. When evaluating patients with a suppressed serum thyrotropin value, it is important to exclude other potential etiologies such as overt triiodothyronine toxicosis, drug effect, nonthyroidal illness, and central hypothyroidism. In younger patients with mild thyrotropin suppression, it is acceptable to perform testing again in 3 to 6 months to assess for persistence before performing further diagnostic testing. In older patients or patients with thyrotropin values less than 0.1 mIU/L, diagnostic testing should proceed without delay. Persistence of thyrotropin suppression is more typical of nodular thyroid autonomy, whereas thyroiditis and mild Graves disease frequently resolve spontaneously. The clinical consequences of subclinical hyperthyroidism, such as atrial dysrhythmia, accelerated bone loss, increased fracture rate, and higher rates of cardiovascular mortality, are dependent on age and severity. The decision to treat subclinical hyperthyroidism is directly tied to an assessment of the potential for clinical consequences in untreated disease. Definitive therapy is generally selected for patients with nodular autonomous function, whereas antithyroid drug therapy is more appropriate for mild, persistent Graves disease.ConclusionThe presented stepwise approach to the care of patients presenting with an isolated suppression of serum thyrotropin focuses on the differential diagnosis, a prediction of the likelihood of persistence, an assessment of potential risks posed to the patient, and, finally, a personalized choice of therapy. (Endocr Pract. 2012;18: 772-780)     

Overview of Molecular Biomarkers for Enhancing the Management of Cytologically Indeterminate Thyroid Nodules and Thyroid Cancer

ObjectiveTo provide information on molecular bio markers that can help assess cytologically indeterminate thyroid nodules.MethodsPublished studies on immunohistologic, somatic mutation, gene expression classifier, microRNA, and thyrotropin receptor messenger RNA biomarkers are reviewed, and commercially available molecular test pan els are described.ResultsThyroid nodules are common, and clinical guidelines delineate an algorithmic approach including serum thyroid-stimulating hormone measurement, diagnostic ultrasound examination, and, when appropriate, fine-needle aspiration (FNA) biopsy for determination of a benign versus malignant status. In clinical practice, approximately 20% of FNA-derived cytology reports are classified as “indeterminate” or follicular nodules that do not fulfill either benign or malignant criteria. In this set ting, the actual risk for malignancy of a cytologically indeterminate nodule ranges from approximately 15% to 34%. Research describing molecular biomarkers from thyroid cancer tissue has been applied to FNA-derived thyroid nodule material. There is also a serum molecular marker that has been reported with goals similar to those for the FNA-derived molecular markers: to enhance the preoperative diagnosis of thyroid cancer and reduce the large number of patients who have a diagnostic surgical procedure for benign thyroid nodules.ConclusionProgress toward the foregoing goals has been made and continues to evolve with the recent appearance of molecular biomarker tests that can be selectively applied for further assessment of cytologically indeterminate thyroid nodules. (Endocr Pract. 2012;18:611-615)     

Incidental Radiologic Finding of an Anterior Superior Mediastinal Mass Masquerading as Metastatic Thyroid Cancer in Patients with Treated Thyroid Cancer

ObjectiveTo demonstrate that an anterior superior mediastinal mass on radiologic imaging may represent an incidental finding and not metastases in patients with a history of treated well-differentiated thyroid cancer.MethodsWe report the clinical presentation and outcomes of 4 patients with a history of thyroid cancer who were incidentally found to have anterior superior mediastinal masses on imaging. We also review the relevant literature.ResultsFour young adults with a history of stage I papillary thyroid cancer treated with total thyroidectomy and radioiodine were incidentally found to have thymic enlargement on imaging studies within a 3-year posttreatment window. In each case, this enlargement was believed to be secondary to thymic hyperplasia and not metastatic disease, and each patient has exhibited a benign clinical course. Review of the literature revealed few reports of an association between thymic hyperplasia and thyroid cancer.ConclusionsThymic hyperplasia may be discovered on posttreatment imaging studies in patients with a history of well-differentiated thyroid cancer, particularly in young adults who have received radioiodine therapy. Recognition of the possible coexistence of this incidental finding in patients with thyroid cancer may help to avoid unnecessary invasive procedures and treatments. (Endocr Pract. 2011;17:65-69)     

Insular Variant of Poorly Differentiated Thyroid Carcinoma

ObjectiveTo present a case of an insular variant of poorly differentiated thyroid carcinoma (PDTC) and to review the literature related to diagnosis, natural history, and treatment of this unusual form of thyroid cancer.MethodsWe present the clinical, laboratory, and pathologic findings of the study patient and review Englishlanguage literature related to PDTC published between 1970 and the present.ResultsPDTC is a controversial and rare epithelial thyroid cancer, intermediate between differentiated thyroid carcinoma and anaplastic thyroid carcinoma that exhibits increased aggressiveness, propensity to local recurrence, distant metastases, and increased mortality. PDTC warrants aggressive management with total thyroidectomy followed by radioactive iodine ablation and potentially additional therapy for residual or recurrent disease. Some carcinomas do not take up radioactive iodine, and dedifferentiated clones of distant metastases may evolve. It is unclear whether chemotherapy is beneficial. Use of additional imaging modalities, including positron emission tomography, 18-fludeoxyglucose positron emission tomography/computed tomography, 18-fludeoxyglucose positron emission tomography/computed tomography/magnetic resonance imaging, ¹²⁴I positron emission tomography/computed tomography, positron emission tomography/magnetic resonance imaging fusion studies, and recombinant human thyrotropin-stimulated radioactive iodine uptake for cancer surveillance are discussed.ConclusionsPDTC is an unusual and aggressive form of thyroid cancer. Fine-needle aspiration cytology may not yield sufficient information to specifically diagnose PDTC. Aggressive management with total thyroidectomy and neck dissection followed by high-dose radioactive iodine remnant ablation is standard. Iodine I 131 whole body scanning is often the initial test for tumor surveillance, with other imaging modalities applied as needed. (Endocr Pract. 2011;17:115-121)     

Evolving Approaches in Managing Radioactive Iodine-Refractory Differentiated Thyroid Cancer

ObjectiveTo discuss the approach to care of patients with advanced differentiated thyroid cancer (DTC), in particular those with radioactive iodine (RAI)-refractory disease, and the transition to systemic treatment.MethodsA PubMed search was conducted using the search terms “radioactive iodine-refractory, differentiated thyroid cancer and treatment” restricted to a 2000-2012 timeframe, English language, and humans. Relevant articles were identified from the bibliographies of selected references. Four patient cases are presented to illustrate the clinical course of RAI-refractory DTC.ResultsThe current standard of care for early stage DTC could include surgery, RAI in some cases, and thyroid hormone suppression. For advanced RAI-refractory DTC, clinical practice guidelines established by the National Comprehensive Cancer Network and the American Thyroid Association recommend, as one option, the use of systemic therapy, including kinase inhibitors. Numerous trials are underway to evaluate the clinical benefit of these targeted therapies.ConclusionPreliminary results are encouraging with respect to the clinical benefit of targeted systemic therapies. However, at present there is no consensus on the criteria that define RAI-refractory disease and the optimal timing for transition to systemic therapy. There remains a need to establish common criteria to enhance patient care and enable better comparison across clinical studies. (Endocr Pract. 2014;20:263-275)     

Autoimmune Thyroid Disease in the Use of Alemtuzumab for Multiple Sclerosis: A Review

ObjectiveThe monoclonal antibody alemtuzumab has been demonstrated to reduce the risks of relapse and accumulation of sustained disability in multiple sclerosis (MS) patients when compared to β-interferon. The development of autoimmune diseases, including thyroid disease, has been reported in the literature with a frequency of 20 to 30%. In this article, we describe 4 cases of alemtuzumab-induced thyroid disease in patients with MS. We also performed a systematic review of the available literature.MethodsFour patients who had received alemtuzumab for MS and subsequently developed thyroid dysfunction are presented. We compared our patients' clinical courses and outcomes to established disease patterns. We also undertook a systematic review of the published literature.ResultsAll 4 patients presented with initial hyperthyroidism associated with elevated thyroid-stimulating hormone (TSH) receptor antibodies (TRAb). In 2 cases, hyperthyroidism did not remit after a total of 24 months of carbimazole therapy, and they subsequently underwent subtotal thyroidectomy. The third case subsequently developed biochemical hypothyroidism and required thyroxine replacement, despite having a markedly raised initial TRAb titer. Autoimmunity following alemtuzumab therapy in MS appears to occur as part of an immune reconstitution syndrome and is more likely in smokers who have a family history of autoimmune disease.ConclusionManagement of alemtuzumab-induced thyroid disease is similar to the management of “wild-type” Graves’ disease. The use of alemtuzumab in this setting will necessitate close monitoring of thyroid function and early intervention when abnormalities are developing. (Endocr Pract. 2013;19:821-828)     

Does Testosterone Therapy Increase the Risk of Prostate Cancer?

ObjectiveTo review factors affecting use of testosterone therapy for hypogonadism including the persistent controversial link between testosterone therapy and prostate cancer.MethodsWe reviewed studies investigating the relationship between testosterone therapy and prostate cancer progression and summarized strategies for hypogonadism management and prostate monitoring.ResultsTrials of up to 36 months in length and longitudinal studies consistently fail to demonstrate an increased prostate cancer risk associated with increased testosterone levels. No evidence of an associated relationship between exogenous testosterone therapy and prostate cancer has emerged from clinical trials or adverse event reports. It does not appear that exogenous testosterone accumulates in the prostate or provokes major biologic change in the prostate gland. In addition, preliminary evidence indicates that low endogenous testosterone may confer an increased risk of prostate cancer.ConclusionsMounting evidence demonstrates that there is a lack of association between testosterone therapy and prostate cancer progression. Testosterone therapy may be prescribed for men for whom it was once not considered. Careful monitoring of patients with hypogonadism who are receiving testosterone therapy is imperative. Well-designed, large-scale prospective clinical trials are necessary to adequately address prostate safety in hypogonadal men receiving testosterone therapy. (Endocr Pract. 2008;14:904-911)     

Management of Low-Risk Differentiated Thyroid Cancer

ObjectiveTo summarize the definitions of and management recommendations for low-risk thyroid cancer made by the American and European Thyroid Associations and synthesize this information with the recent literature, including systematic evaluations of tumor staging systems guiding therapy.MethodsThe American Thyroid Association and European Thyroid Association guidelines were compared and pertinent literature since 2005 was reviewed.ResultsOf papillary thyroid microcarcinomas (PTMC), up to 50% breach the thyroid capsule, 64% have lymph node metastases, up to 43% are multifocal, and as many as 2.8% have distant metastases. Locoregional and distant recurrences are, respectively, as high as 5.9% and 1.5%. As many as 1 in 4 patients with a papillary thyroid carcinoma 1.5 cm or smaller develop persistent disease. Cancer-related mortality rates are usually less than 1%, but are as high as 2% in some reports. Tumor staging systems are too inaccurate to guide therapy.ConclusionIt is unlikely that many patients will forgo treatment after understanding their risk, especially when total thyroidectomy and radioiodine (¹³¹I) therapy can reduce the PTMC recurrence or persistence disease rate to zero. Preoperatively diagnosed PTMC should be treated with total or near-total thyroidectomy, regardless of tumor size. For very low-risk patients with unifocal PTMC smaller than 1 cm that is removed by chance during surgery to treat benign thyroid disease, lobectomy alone without ¹³¹I therapy may be sufficient therapy if there are no concerning histologic features and no tumor extension beyond the thyroid, metastases, history of head and neck irradiation, or positive family history—any of which requires total or near-total thyroidectomy and remnant ablation with 30 mCi. (Endocr Pract. 2007;13:498-512)     

Two Cases of Statin-Induced Myopathy Caused By Induced Hypothyroidism

ObjectiveTo present information regarding the potential danger of performing levothyroxine withdrawal radioiodine scans and treatment in patients with thyroid cancer who are concurrently taking lipid-lowering agents.MethodsWe review the clinical history, serial laboratory data, and radiologic findings in 2 patients with multifocal papillary carcinoma of the thyroid.ResultsBoth study patients had substantial elevations of muscle enzymes or myopathies (or both) when they were withdrawn from levothyroxine therapy, during treatment with lipid-lowering agents, in preparation for radioiodine scanning and treatment.ConclusionExtreme caution should be exercised when levothyroxine therapy is withdrawn from patients taking lipid-lowering agents. Such patients should be monitored very closely or, when appropriate, recombinant human thyroid-stimulating hormone injections should be used rather than levothyroxine withdrawal in this setting. (Endocr Pract. 2008;14:726-731)     

Assessing The Risk of False-Negative Fine-Needle Aspiration Cytology and of Incidental Cancer in Nodular Goiter

ObjectiveIn cases of multinodular goiter with negative cytologic result, reasonable management options include surgical treatment, simple follow-up, or more recently introduced conservative therapies such as laser or radiofrequency ablation, and recombinant human thyroid-stimulating hormone-augmented radioiodine. For patients who are eligible for follow-up or nonsurgical treatments, the possibility that they may have an undiagnosed malignancy (false-negative [FN]-fine-needle aspiration cytology [FNAC] result or incidental thyroid cancer [ITC]) should be considered. The aim of our study was to assess the risk of malignancy in patients known to have presumably benign thyroid disease.MethodsSurgical series of patients who underwent total thyroidectomy for benign disease between 2000 and 2010 at two Italian centers were reviewed. Patients with any preoperative suspicion of malignancy were excluded.ResultsHistologic examination revealed that 84 of 970 (8.6%) thyroidectomized patients had malignancy (5% ITC and 3.6% FN-FNAC), with 89.8% of ITCs having a diameter <10 mm, and 65.7% of FN-FNAC cancers having a diameter >30 mm. Sixty-seven thyroid malignancy patients (79.8%) had stage I disease (American Joint Committee on Cancer criteria). The risk of FN-FNAC increases with increasing size of the nodule, while the risk of ITC increases as nodule size decreases.ResultsThe risk of malignancy in presumably benign thyroid disease cannot be overlooked, but can be minimized through skillfully performed ultrasonography (US) examination and FNAC. Once a patient with multinodular goiter is referred for follow-up or nonsurgical therapy, careful US surveillance is mandatory. (Endocr Pract. 2013;19:444-450)     

Advances in Lipid Testing and Management in Patients with Diabetes Mellitus

ObjectiveTo review the pathophysiologic basis for the classic phenotype associated with diabetic dyslipidemia, discuss recent advances in lipid and lipoprotein testing for risk assessment and lipid therapy monitoring, and summarize a systematic approach to the clinical management of diabetic dyslipidemia.MethodsWe review the pertinent literature, including treatment guidelines and results of major clinical trials, and discuss the effectiveness of various pharmacologic interventions for management of lipid levels in patients with diabetes.ResultsThe incidence and prevalence of type 2 diabetes mellitus continue to escalate globally at alarming rates. Diabetes predisposes to multiple microvascular and macrovascular complications, including cardiovascular disease, the number 1 cause of mortality in the United States. The third report of the National Cholesterol Education Program Adult Treatment Panel in 2001 identified diabetes as a coronary heart disease (CHD) risk equivalent, in light of the evidence that CHD risk in persons with diabetes is similar to that of nondiabetic persons with established CHD. Diabetic dyslipidemia is characterized by a constellation of lipid derangements—hypertriglyceridemia, a low concentration of high-density lipoprotein cholesterol (HDL-C), and a high concentration of small, dense low-density lipoprotein (LDL) particles—that accelerate the progression of atherosclerotic disease and the development of atherothrombotic events.ConclusionStatin trials have demonstrated significant reductions in morbidity and mortality from cardiovascular diseases, including in patients with diabetes. Nevertheless, many patients who achieve their LDL cholesterol (LDL-C) goal still have residual CHD risk. Diabetic dyslipidemia contributes to this residual risk because of the increased concentration of atherogenic apolipoprotein B-containing lipoproteins that can persist despite normalized LDL-C levels and low HDL-C levels. Recent clinical trials emphasize the importance of intensive lipid lowering to achieve recommended goals for LDL-C, non-HDL-C, and apolipoprotein B. (Endocr Pract. 2009;15:641-652)     

The Role of Recombinant Human Thyrotropin for Diagnostic Monitoring of Patients with Differentiated Thyroid Cancer

ObjectiveTo describe the evolving role of recombinant human thyrotropin in the diagnostic evaluation of patients treated for differentiated thyroid carcinoma.MethodsA systematic review was performed of published English language articles appearing in PubMed using terms “recombinant thyrotropin” and “thyroid cancer”. The author selected articles for inclusion based upon potential for clinical impact of the reported findings.ResultsThe addition of recombinant human thyrotropin to diagnostic testing replaced the requirement for thyroid hormone withdrawal and symptomatic hypothyroidism that had been necessary to generate sufficient endogenous thyrotropin for radioiodine scanning and thyroglobulin testing. The high negative predictive value of stimulated thyroglobulin testing removed the need for serial radioiodine scanning for many patients, but repeated stimulated testing rarely appeared to add significantly. The development of highly sensitive second generation thyroglobulin assays may replace the need for stimulated testing in a subset of patients.ConclusionRecombinant human thyrotropin-stimulated testing continues to be a valuable component of follow-up testing in the first year after initial treatment of differentiated thyroid cancer. (Endocr Pract. 2013;19: 157-161)     

Referral Patterns for Patients With High-Risk Thyroid Cancer

ObjectiveKnowledge of referral patterns for specialty cancer care is sparse. Information on both the need and reasons for referral of high-risk, well-differentiated thyroid cancer patients should provide a foundation for eliminating obstacles to appropriate patient referrals and improving patient care.MethodsWe surveyed 370 endocrinologists involved in thyroid cancer management. From information in a clinical vignette, respondents were asked to identify the reasons they would need to refer a high-risk patient to a more specialized facility for care. We performed multivariable analysis controlling for hospital and physician characteristics.ResultsThirty-two percent of respondents reported never referring thyroid cancer patients to another facility. Of those that would refer a high-risk patient to another facility, the opportunity for a patient to enter a clinical trial was the most common reason reported (44%), followed by high-dose radioactive iodine (RAI) with or without dosimetry (33%), lateral neck dissection (24%), and external beam radiation (15%). In multivariable analysis, endocrinologists with a higher percentage of their practice devoted to thyroid cancer care were significantly less likely to refer patients to another facility (P = .003).ConclusionsThe majority of endocrinologists treating thyroid cancer patients report referring a high-risk patient to another facility for some or all of their care. Knowledge of the patterns of physician referrals and the likelihood of need for referral are key to understanding discrepancies in referral rates and obstacles in the referral process. (Endocr Pract. 2013;19:638-643)     

Management of Patients With Low-Risk Papillary Thyroid Carcinoma

ObjectiveTo define a rational, cost-effective, simple approach to managing most patients with papillary thyroid cancer (PTC) who are at low-risk of either cause-specific mortality or tumor recurrence.MethodsTaking advantage of the collective experience of a cohort of 2512 patients with PTC who had initial definitive treatment at the Mayo Clinic in Rochester, Minnesota, between 1940 and 2000, a 5-step approach to the management of low-risk PTC has been devised. This program is based on appropriate preoperative ultrasound localization of neck disease and potentially curative surgery consisting of near-total or total thyroidectomy, with appropriate neck nodal exploration and resection.ResultsThe emphasis of the present program is on the extent of initial surgery, where optimal care is ascribed to a near-total thyroidectomy with curative intent and appropriate neck nodal resection as predicated by appropriate preoperative ultrasonography evaluation of regional lymph nodes. Radioiodine remnant ablation (RRA) is not applicable to patients with PTC who are defined on the day of definitive initial surgery to be at low risk as defined by a metastasis, age, completeness of resection, invasion, and size (MACIS) score of less than 6.ConclusionThe outlook for patients with low-risk PTC is very optimistic, with rates at 30 postoperative years of only 1% for cause-specific mortality and less than 15% for tumor recurrence at any site. The long-term results obtained by potentially curative bilateral resection, appropriate regional lymph nodal excision, and selective use of RRA are excellent. Realistically improving these acceptably low rates for cause-specific mortality and tumor recurrence may be difficult. (Endocr Pract. 2007;13:521-533)     

Development and Internal Validation of a Predictive Model for Individual Cancer Risk Assessment for Thyroid Nodules

Objective: The objective of this study was to develop and validate a predictive model for the assessment of the individual risk of malignancy of thyroid nodules based on clinical, ultrasound, and analytic variables.Methods: A retrospective case-control study was carried out with 542 patients whose thyroid nodules were analyzed at our endocrinology department between 2013 and 2018 while undergoing treatment for thyroidectomy. Starting with a multivariate logistic regression analysis, which included clinical, analytic, and ultrasound variables, a predictive model for thyroid cancer (TC) risk was devised. This was then subjected to a cross-validation process, using resampling techniques.Results: In the final model, the independent predictors of the risk of malignancy were: being male, age of the extremes, family history of TC, thyroid-stimulating hormone level >4.7 μU/L, presence of autoimmune thyroiditis, solid consistency, hypoechogenicity, irregular or microlobed borders, nodules that are taller than they are wide, microcalcifications, and suspicious adenopathy. With a cut-off point of 50% probability of thyroid cancer, the predictive model had an area under the receiver operating characteristic curve of 0.925 (95% confidence interval 0.898 to 0.952). Finally, using the 10-fold cross-validation method, the accuracy of the model was found to be 88.46%, with a kappa correlation coefficient of 0.62.Conclusion: A predictive model for the individual risk of malignancy of thyroid nodules was developed and validated using clinical, analytic, and ultrasound variables. An online calculator was developed from this model to be used by clinicians to improve decision-making in patients with thyroid nodules.     

Clinical Profile of Ectopic Thyroid in Asian Indians: a Single-Center Experience

ObjectiveTo assess clinical characteristics of patients with ectopic thyroid seen at a single tertiary care center in India.MethodsIn this case series, we retrospectively reviewed the data of patients who presented with ectopic thyroid between January 1995 and March 2008. Clinical presentation, nuclear imaging findings, endocrine profile, and clinical management were analyzed.ResultsRecords of 22 female patients and 14 male patients were reviewed. Ectopic thyroid was more common in female patients. Mean age of presentation was 14.3 years (median, 14 years; range, 5 months to 40 years). Seventeen patients (47%) presented with lingual thyroid, detected incidentally or because of dysphagia and bleeding while eating, and 19 patients (53%) had sublingual thyroid, which mainly presented as an anterior neck swelling. Thirty patients (83%) had hypothyroidism (overt or subclinical). In 29 patients (81%), ectopic thyroid either in the neck or in the lingual area was the only functional thyroid tissue. Thirty-one patients (86%) were treated medically, and surgery was performed in only 5 patients (14%) who had either recurrent bleeding or dysphagia.ConclusionsEctopic thyroid should be considered during the evaluation of a midline neck mass or hypothyroidism. Careful clinical examination, thyroid function tests, and radionuclide imaging help establish the diagnosis and localize ectopic thyroid. Appropriate treatment should be decided on an individual basis. (Endocr Pract. 2009;15:322-325)     

Risk Factors for Nonremission and Progression-Free Survival after I-131 Therapy in Patients with Lung Metastasis from Differentiated Thyroid Cancer: A Single-Institute,Retrospective Analysis in Southern China

Objective: Prognostic factors related to progression-free survival (PFS) have not received much attention in the literature regarding iodine-131 (¹³¹I) therapy for patients with differentiated thyroid cancer and lung metastases. We sought to explore the factors associated with PFS and nonremission in a group of patients with differentiated thyroid cancer and pulmonary metastases at initial diagnosis and to investigate the impact of ¹³¹I therapy on pulmonary function and peripheral blood counts in the same cohort of patients.Methods: The medical records of 1,050 patients with differentiated thyroid cancer treated at the Zhujiang Hospital of Southern Medical University from January 2006 to January 2015 were retrospectively reviewed. Among them, 107 patients fulfilled the inclusion criteria.Results: Multivariate Cox regression analysis indicated that age ≥45 years and ¹³¹I nonavidity were independent risk factors for disease progression. Multivariate logistic regression analysis revealed that pulmonary nodule size ≥1 cm and ¹³¹I nonavidity were the strongest risk factors predicting nonremission. Varying cumulative ¹³¹I dosage had no association with posttreatment pulmonary function or peripheral blood cell counts.Conclusion: Similar to earlier studies, our results confirm that ¹³¹I nonavidity was associated with an increased risk of disease progression and greater odds of nonremission. In addition, patients with differentiated thyroid cancer and lung metastases with pulmonary nodules ≥1 cm had a reduced likelihood of achieving remission. Furthermore, special attention is needed when monitoring patients over 45 years at a higher risk of disease progression.Abbreviations:CI = confidence intervalDTC = differentiated thyroid cancer¹⁸F-FDG = fluoro-18 fluorodeoxyglucoseFEF = forced expiratory flowFTC = follicular thyroid cancerFVC = forced vital capacityGR = granulocytesHb = hemoglobinHR = hazard ratio¹³¹I = iodine-131LN = lymph nodeOR = odds ratioOS = overall survivalPET/CT = positive positron emission tomography/computed tomographyPFS = progression-free survivalPT = partial thyroidectomyPTC = papillary thyroid cancerRAI = radioactive iodineRBC = red blood cellTg = thyroglobulinTgAb = thyroglobulin antibodyTSH = thyroid-stimulating hormoneTT = total thyroidectomyWBC = white blood cellsWBS = whole body scan     

Determinants of Long-Term Outcome after Radioiodine Therapy for Solitary Autonomous Thyroid Nodules

ObjectiveTo determine the incidence and clinical predictors of hypothyroidism in one institution after radioiodine treatment of solitary toxic nodules.MethodsWe retrospectively analyzed the outcome of radioiodine therapy in 105 patients with solitary autonomous thyroid nodules treated at our institution during a 10-year period (January 1996 to December 2005; mean duration of follow-up, 53 ± 34 months). Patients were monitored until the development of hypothyroidism, death, or the end of the study period. The cumulative incidence of hypothyroidism was determined by Kaplan-Meier life-table analysis, and predictors of hypothyroidism were determined by using a Cox regression model.ResultsThe cumulative incidence of hypothyroidism was 11% at 1 year, 33% at 5 years, and 49% at 10 years. The development of hypothyroidism was not associated with age, sex, radioiodine dose, radioiodine uptake, or degree of suppression of extranodal tissue on scintiscans. The predictors of occurrence of hypothyroidism were pretreatment with antithyroid medications (P = .004; relative risk = 1.94) and positive thyroid antibody status (P = .008; relative risk = 1.84). Antibody-positive patients showed an earlier progression toward hypothyroidism than did antibody-negative patients.ConclusionHypothyroidism is a common outcome of radioiodine treatment for autonomous thyroid nodules. In this study, coexistent thyroid autoimmunity and pretreatment with antithyroid medications were significant risk factors for the development of hypothyroidism. (Endocr Pract. 2008;14:543-549)     

Concordance of Pre-Operative Clinical Stage With Pathologic Stage In Patients ≥45 Years Old With Well-Differentiated Thyroid Cancer

Objective: Clinical stage (cStage) in thyroid cancer determines extent of surgical therapy and completeness of resection. Pathologic stage (pStage) is an important determinant of outcome. The rate of discordance between clinical and pathologic stage in thyroid cancer is unknown.Methods: The National Cancer Data Base was queried to identify 27,473 patients ≥45 years old with cStage I through IV differentiated thyroid cancer undergoing surgery from 2008–2012.Results: There were 16,286 (59.3%) cStage I patients; 4,825 (17.6%) cStage II; 4,329 (15.8%) cStage III; and 2,013 (7.3%) cStage IV patients. The upstage rate was 15.1%, and the downstage rate was 4.6%. For cStage II, there was a 25.5% upstage rate. The change in cStage was a result of inaccurate T-category in 40.8%, N-category in 36.3%, and both in 22.9%. On multivariate analysis, the patients more likely to be upstaged had papillary histology, tumors 2.1 to 4 cm, total thyroidectomy, nodal surgery, positive margins, or multifocal disease. Upstaged patients received radioiodine more frequently (75.3% vs. 48.1%; P<.001).Conclusion: Approximately 20% of cStage is discordant to pStage. Certain populations are at risk for inaccurate staging, including cT2 and cN0 patients. Upstaged patients are more likely to receive radioactive iodine therapy.Abbreviations: CI = confidence interval; cStage = clinical stage; DTC = differentiated thyroid cancer; NCDB = National Cancer Data Base; OR = odds ratio; pStage = pathologic stage; RAI = radioactive iodine