Metastatic differentiated thyroid carcinoma: clinical management and outcome of disease in patients with initial and late distant metastases

Rare Presentations of Differentiated Thyroid Cancer Exposing Dr Jekyll and Mr Hyde Nature of an Otherwise Indolent Disease: Case Series

ABSTRACT

Differentiated thyroid carcinoma (DTC) usually manifests as an indolent cancer with good prognosis. However, rarely uncommon sites of metastatic involvement can worsen the prognosis and require aggressive therapeutic approach. Here in, we describe 5 patients (3 women and 2 men) harboring rare sites of metastatic involvement from DTC including the adrenals, colon, kidneys, urinary bladder, brachial plexus, and superior vena cava with contiguous right atrial involvement. The awareness of such rare sites of involvement from DTC is imperative for treating clinicians to plan individualistic approach in management including multiprong therapies for better patient care.

Clinicopathological Characteristics and Treatment Outcome of Patients with Metastatic Differentiated Thyroid Cancer

BACKGROUND AND OBJECTIVE

Differentiated thyroid carcinoma (DTC) is a slow-growing tumour with 20% of the cases having distant metastasis. Its prognosis can vary by its histological characteristics, extension and spread. The data on metastatic DTC patients in Pakistan is scarce; therefore, the purpose of our study was to assess the clinicopathological characteristics and treatment outcomes of metastatic DTC in our population.

METHODS

This retrospective, single-centre study was carried out on 117 patients with metastatic DTC with their age at diagnosis, gender, tumour size and extent and spread of the tumour, and its histologic characteristic recorded. The treatment they received and the outcome in terms of status, at last, follow-up were also recorded.

RESULTS

The mean age of diagnosis was found to be 46.6 ± 17.2 years with an almost equal male to female ratio. The most common site of metastasis was the lung followed by bone. Papillary carcinoma was the most common subtype with 89.7% of the cases followed by follicular carcinoma occurring in 7.7%. The overall survival in years was found to be 5.6 ± 2.6 years. Ninety-six per cent had complete surgical resection followed by radioactive iodine (RAI) in 91.5%.

CONCLUSION

Our study shows that the most significant factors in predicting the outcome in metastatic DTC are age, an extrathyroidal extension of the primary tumour and distant metastasis. However, further multicentric studies done on a much larger population will be needed to further support and strengthen our results.

Differentiated Thyroid Carcinoma: Distant Metastasis as an Unusual Sole Initial Manifestation

Objective:

The objective of this study was to identify the characteristic features of patients with distant metastasis as the only manifestation of well-differentiated thyroid cancers and to analyze the treatment outcomes

Methods:

A retrospective review of all patients with well-differentiated thyroid cancers and distant metastasis as the sole initial presentation was carried out. Data regarding age, gender, tumor histology, site, symptoms, and treatment outcomes were collected.

Results:

There were 10 patients who presented with distant metastasis as the only presentation. The mean age was 56.1 years. Eight (80%) patients had osseous metastasis, one (10%) had pulmonary and one (10%) had both. Follicular thyroid carcinoma was more common and seen in six (60%) patients. Seven (77.8%) out of nine patients had demised within five years of initial presentation.

Conclusion:

Distant metastases without a neck lump as the initial presentation of well-differentiated thyroid cancers are extremely rare. No specific guidelines are available to manage such patients due to lack of relevant data in the literature.

Late-onset distant metastases confer poor prognosis in patients with well-differentiated thyroid cancer

Background

Distant metastases from well-differentiated thyroid carcinoma (WDTC) occasionally occur over a wide range of time intervals after primary thyroid surgery. The prognostic impact of the timing of distant metastasis onset remains unclear.

Methods

We retrospectively reviewed the clinicopathologic features and clinical outcomes of 57 patients with WDTC and distant metastases, and evaluated the mutational profiles of BRAF, RAS, and TERT promoter genes. All patients underwent thyroidectomy and radioactive iodine (RAI) ablation using the same treatment protocol. Synchronous distant metastases were defined as those detected within 12 months of the primary WDTC diagnosis. Metachronous metastases were considered early- and late-onset diseases if detected 1-5 and ≥5 years after the primary diagnosis, respectively.

Results

In all patients, the 5- and 10-year cancer-specific survival (CSS) rates after the diagnosis of distant metastasis were 86% and 57%, respectively. Late-onset (≥5 years) metachronous distant metastasis was associated with age of ≥55 years (P=0.043) and patients refractory to RAI therapy (P=0.026). TERT promoter mutations were associated with RAI refractivity (P=0.026). BRAF V600E and RAS mutations had no prognostic significance. Bone metastasis (P=0.002) and the onset time of distant metastasis (P=0.004) were associated with poor CSS. There was no significant difference in CSS between patients with synchronous distant metastases and those with early-onset (1-5 years) metachronous distant metastases. In the multivariate analysis, bone metastasis [hazard ratio (HR) =10.24; 95% confidence interval (CI): 1.25-83.74; P=0.030] and late-onset (≥5 years) metachronous distant metastasis (HR =5.20; 95% CI: 1.01-26.63; P=0.048) were independent predictors for worse CSS.

Conclusions

The prognosis of patients with WDTC was poorer for late metachronously detected metastases than for synchronous or early metachronous metastases. Patients with distant metastasis occurring 5 years later after primary thyroid diagnosis should, therefore, be more carefully treated.

Unusual metastases from differentiated thyroid carcinoma: analysis of 36 cases

PURPOSE

Metastases of differentiated thyroid cancer (DTC) in sites different from lungs and bone are unusual (UM); their impact in management and prognosis remains unknown. Our aim was to evaluate the prevalence of UM, to describe their characteristics and to analyze their impact in disease outcome and mortality.

METHODS

We retrospectively reviewed the file records from 8 different centers. Those patients with DTC and UM were included. UM were diagnosed by: (i) biopsy/cytology and/or (ii) radioiodine (RAI) uptake associated to elevated thyroglobulin (Tg) levels and/or c) presence of one or more structural lesion/s with 18-FDG uptake in the PET/CT scan and elevated Tg levels.

RESULTS

Thirty-six (0.9%) out of a total of 3982 DTC patients were diagnosed with UM; 75% had papillary histology. The most frequent localization was central nervous system (CNS, 31%). UM were metachronous in 75%, symptomatic in 55.6% and fulfilled RAI-refractoriness criteria in 77.8% of cases. Metastatic lesions in lung/bone and/or locoregional disease were present in 34 cases (94.4%). Diagnosis of UM changed the therapeutic approach in 72.2% of patients. After a median follow up of 13 months, 21 (58.3%) patients died from DTC related causes. In 8 of them CNS progression was the immediate cause of death.

CONCLUSIONS

Prevalence of UM was low; they were frequently metachronic and RAI-refractory. Although UM were found in patients with widespread disease, their diagnosis usually led to changes in therapy. UM were associated with poor prognosis and high frequency of disease-specific mortality.

Clinical and prognostic role of detection timing of distant metastases in patients with differentiated thyroid cancer

PURPOSE

Distant metastases (DM) from DTC occur in 5-25% of cases and are correlated to lower survival; the prognostic significance of the temporal onset of DM is unclear. Our aim was to retrospectively analyze the prevalence of DM and to assess the prognostic role of the timing of manifestation of DM regarding the outcome.

MATERIALS AND METHODS

We included 174 patients (mean age 64 years). According to the time of manifestation, DM were divided in two groups: synchronous DM (SDM, n = 108) defined as metastases present at initial diagnosis and metachronous DM (MDM, n = 66) as diagnosed during follow-up. SDM were further sub grouped in pre-RAIT when diagnosed during pre-surgery work-up (n = 35) and baseline-RAIT when detected by first whole body scan after RAIT (n = 73). Disease-specific survival (DSS) was analyzed using the Kaplan-Meier method.

RESULTS

Total RAI activities and number of treatments were significantly higher in MDM, also loss of RAI avidity was more frequent in MDM. Forty-four patients died during follow-up, of which 41 were DTC-related deaths, 5-year and 10-year DSS were 80% and 56%. On univariate analysis MDM had significantly shorter DSS; also histotype and RAI avidity were significant risk factors of impaired survival. On multivariate analysis, only loss of RAI avidity remained as independent negative predictor (p = 0.043). Considering SDM, DSS was significantly shorter in pre-RAIT group than baseline-RAIT (p = 0.004). Instead there was no significant difference between pre-RAIT-SDM and MDM in survival outcome (p = 0.875).

CONCLUSIONS

In DTC with DM, loss of RAI uptake has an important role in survival. No significant difference in survival outcome was discovered between SDM and MDM; but, among SDM, pre-RAIT had significant shorter DSS than baseline-RAIT.

Primary Thyroid Carcinoma with Low-Risk Histology and Distant Metastases: Clinicopathologic and Molecular Characteristics

BACKGROUND

Distant metastases (DM) are a rare occurrence in well-differentiated thyroid carcinoma. The aim of this study was to analyze the clinical, pathologic, and molecular features of primary thyroid carcinoma with low-risk histology that develop DM.

METHODS

A detailed clinicopathologic review and targeted next-generation sequencing were performed on a cohort of well-differentiated thyroid carcinoma lacking gross extrathyroidal extension, extensive vascular invasion, or significant lymph node metastases but exhibiting DM.

RESULTS

Primary well-differentiated thyroid carcinoma with low-risk histologic features and DM was a rare occurrence, accounting for only 3% of metastatic non-anaplastic thyroid carcinoma. All 15 cases meeting the inclusion criteria harbored DM at presentation. The majority (11/15) of these tumors were follicular variant of papillary thyroid carcinoma (PTC), especially the encapsulated form (n = 8). The remaining patients harbored encapsulated Hürthle cell carcinoma (n = 2), encapsulated follicular carcinoma (n = 1), and an encapsulated papillary carcinoma classical variant (n = 1). Of the 12 encapsulated carcinomas, 10 had capsular invasion only and no vascular invasion. Ninety-two percent of the tumors exhibited extensive intra-tumoral fibrosis. Among the eight tumors that were subjected to next-generation sequencing analysis, a RAS mutation was the main driver (5/8), and TERT promoter mutation was highly prevalent (6/8). In four cases, TERT promoter mutations were associated with RAS or BRAF mutations. BRAF-mutated classical variant of papillary carcinoma also presented with DM but was less common (1/8). In 11/15 cases, the clinician was able to diagnose distant disease based on the clinical presentation. In 3/4 incidental cases that were genotyped, TERT promoter mutations were found.

CONCLUSIONS

When DM occur in primary thyroid carcinoma with low-risk histology, they are almost always found at presentation. The majority are encapsulated follicular variant of PTC with capsular invasion only. TERT promoter mutations occur at a higher rate than that seen in PTC in general and may help explain the aggressive behavior of these histologically deceptive primary carcinomas.

Patterns of metastasis in follicular thyroid carcinoma and the difference between early and delayed presentation

Introduction Follicular thyroid cancer (FTC) has a good prognosis if treated early. The aim of this study was to look at the difference in outcomes in those who presented with metastasis early or late in their disease. Methods A retrospective cohort study was conducted of patients diagnosed with FTC (n=91) treated between 2000 and 2013. Demographic, laboratory, pathological and survival data were collected and analysed. Results Metastatic FTC was diagnosed in 20 cases (22%). The median age at diagnosis was 65 years (range: 17-86 years) and 65% of the patients were female. Twelve patients (60%) were diagnosed with metastatic disease at presentation, with the bones being the most common site (75%). In the remaining eight cases (40%), metastasis developed at a median of 4.5 years (range: 2-8 years) after initial thyroid surgery, lungs being the most common site (50%). Eighteen patients (90%) underwent surgical intervention for the primary disease. Sixteen patients (80%) received adjuvant radioactive iodine and eight (40%) received external beam radiotherapy. Widely invasive follicular cancer was the predominant histological diagnosis (90%). No prognostic association was observed with any of the parameters studied. The overall disease specific mortality rate was 40%. There was no significant difference in mortality between those who presented with metastatic disease and those who developed metastasis during the follow-up period (33% vs 50%, p=0.61). Conclusions The clinical outcome and prognosis for cases with metastatic disease is generally poor. Despite this, almost half of the patients in our study were still alive at a median follow-up of 5.5 years, regardless of whether they were diagnosed with metastatic disease on initial presentation or whether they developed metastasis after initial thyroid surgery.

Prognostic implications of radioiodine avidity and serum thyroglobulin in differentiated thyroid carcinoma with distant metastasis

BACKGROUND

Although differentiated thyroid carcinoma (DTC) rarely develops distant metastases, the present study was performed to evaluate factors that affect the survival of patients with DTC who present with distant metastasis.

METHODS

Among 4,989 patients who underwent thyroid surgery for DTC, 82 presenting with distant metastasis were analyzed. Based on radioiodine ((131)I) avidity and the thyroid-stimulating hormone-stimulated serum thyroglobulin (sTg) level at the time of metastasis, patients were divided into three groups: group 1 ((131)I uptake + sTg ≤ 215 ng/mL, n = 46), group 2 ((131)I uptake + sTg > 215 ng/mL, n = 24), group 3 (no (131)I uptake, n = 12). Disease-specific survival (DSS) was estimated using the Kaplan-Meier method. Factors predicting the outcome were evaluated using Cox proportional hazard regression analysis.

RESULTS

The age of patients (p = 0.04), frequency of follicular thyroid carcinoma (p = 0.002), tumor size (p < 0.001), and number of multiple metastatic sites (p = 0.004) differed significantly among the groups. With a median follow-up after surgery of 72 months, the 5- and 10-year DSSs for all patients were 84 and 69 %, respectively. The predictors of survival were age (p = 0.004), symptoms at the time of presentation (p = 0.045), histology (p = 0.01), sites of metastasis (p = 0.03), and (131)I avidity and sTg level at the time of metastasis (p = 0.002). In the multivariate analysis, age, histology, and (131)I avidity and sTg level at the time of metastasis remained significant factors for survival.

CONCLUSIONS

Certain DTC patients with distant metastasis demonstrate favorable outcomes dependent on age, histology, and (131)I avidity and sTg level at the time of metastasis.

The impact of distant metastases at presentation on prognosis in patients with differentiated carcinoma of the thyroid gland

BACKGROUND

Distant metastases at presentation are rare in well-differentiated thyroid cancer (WDTC). The objective of this study was to report outcomes for patients presenting with distant metastases managed by thyroidectomy and radioactive iodine (RAI) therapy.

METHODS

Fifty-two patients with distant metastases from thyroid cancer diagnosed before thyroid surgery (n=32) or on a postoperative RAI scan after thyroid surgery (n=20) were identified from a database of patients with WDTC treated between 1985 and 2005. The median age was 58 years (range 12-83 years), with a male-to-female ratio of 3:2. Forty-seven patients (90%) had total thyroidectomy and two (4%) had thyroid lobectomy, and three patients (6%) were found to be unresectable. Distant metastases were classified into pulmonary and extrapulmonary. Overall survival (OS), disease-specific survival (DSS), and locoregional recurrence-free survival were calculated by the Kaplan-Meier method. Factors predictive of the outcome were determined by univariate and multivariate analyses.

RESULTS

Thirty-nine patients (75%) were diagnosed with pulmonary metastases alone and 13 (25%) with extrapulmonary metastases. The sites of extrapulmonary metastases were bone in nine, mediastinum in one, pyriform sinus in one and skin in one, and one patient had synchronous lung, bone, and intracerebral metastases. After thyroid surgery, 47 patients (90%) were treated with RAI alone, and 2 patients had external beam radiation in addition to RAI. With a median follow-up after surgery of 78.5 months, the 5-year OS and DSS were 65% and 68%, respectively. Twenty-nine patients (56%) died during follow-up, of whom 24 (46%) died of thyroid cancer. Six patients (12%) developed recurrent disease in the lateral neck, and three patients (6%) developed recurrence in the thyroid bed. Over 45 years, follicular pathology and extrapulmonary metastases were predictive of lower 5-year DSS (56% vs. 100%, p<0.001; 50% vs. 70%, p=0.004; and 46% vs. 75%, p=0.013, respectively).

CONCLUSION

Approximately half of patients with WDTC presenting with distant metastases die of disease within 5 years of initial diagnosis despite thyroid surgery and RAI. Age over 45 years, extrapulmonary metastases, and follicular pathology were significant predictors of the poor outcome.

Lovastatin inhibits proliferation of anaplastic thyroid cancer cells through up-regulation of p27 by interfering with the Rho/ROCK-mediated pathway

Previously, we demonstrated that lovastatin, a HMG-CoA reductase inhibitor, induced apoptosis, differentiation, and inhibition of invasiveness of human anaplastic thyroid carcinoma cells (ATCs). Here, we further examined the effect of lovastatin on the growth of ARO cells. Lovastatin (0-20μM) concentration-dependently decreased cell number in cultured ATC and arrested the cell at the G0/G1 phase of the cell cycle. Western blot analysis revealed that lovastatin caused an increase of the protein level of p27 and cyclin-dependent kinase (CDK)4 and a decrease of the protein level of cyclin A2, cyclin D3, and phosphorylated Rb (pRb), but did not significantly change the protein levels of p21, cyclins D1 and E, and CDK2, in ARO cells. The formation of the CDK2-p27 complex was increased and the CDK2 activity was decreased in the lovastatin-treated ARO cells. Pretreatment of ARO cells with a p27, but not p21, antisense oligonucleotide prevented the lovastatin-induced G0/G1 arrest in ARO cells. The lovastatin-induced growth inhibition and translocation of RhoA and Rac1 in ARO cells were completely prevented by mevalonate and partially by geranylgeranyl pyrophosphate. Treatment of ARO cells with Y27632, an inhibitor of Rho-associated kinase, abolished the GGPP-mediated prevention of lovastatin-induced anti-proliferation and up-regulation and prolonged degradation of p27. Taken together, these data suggest that lovastatin treatment caused a reduction of Rho geranylgeranylation, which in turn increased the expression and stability of p27, and then inhibited ARO cell proliferation. These data suggest that lovastatin merits further investigation as multipotent therapy for treatment ATC.

Standard and emerging therapies for metastatic differentiated thyroid cancer

Differentiated thyroid cancer accounts for >90% of cases of thyroid cancer, with most patients having an excellent prognosis. Distant metastases occur in 10%-15% of patients, decreasing the overall 10-year survival rate in this group to 40%. Radioactive iodine has been the mainstay of treatment for distant metastases, with good results when lesions retain the ability to take up iodine. For patients with metastatic disease resistant to radioactive iodine, treatment options are few and survival is poor. Chemotherapy and external beam radiotherapy have been used in these patients, but with disappointing results. In recent years, our understanding of the molecular pathways involved in thyroid cancer has increased and a number of molecular targets have been identified. These targets include the proto-oncogenes BRAF and RET, known to be common mutations in thyroid cancer; vascular endothelial growth factor receptor and platelet-derived growth factor receptor, associated with angiogenesis; and the sodium-iodide symporter, with the aim of restoring its expression and hence radioactive iodine uptake. There are now multiple trials of tyrosine kinase inhibitors, angiogenesis inhibitors, and other novel agents available to patients with metastatic thyroid cancer. This review discusses both traditional and novel treatments for metastatic differentiated thyroid cancer with a particular focus on emerging treatments for patients with radioactive iodine-refractory disease.