Recurrence of differentiated thyroid cancer in the elderly

Impact of microscopic extrathyroidal extension on differentiated thyroid cancer post-surgical risk of recurrence: a retrospective analysis

PURPOSE

In the last edition of the American Joint Committee on Cancer (AJCC) staging system, differentiated thyroid cancers (DTC) showing microscopic extrathyroidal extension (mETE) are considered comparable to intrathyroidal cancers for their clinical behavior and prognosis. The aim of the study is to evaluate the impact of this updated assessment of T, when applied to the postoperative recurrence risk stratification, according to the American Thyroid Association Guidelines (ATA-RR).

METHODS

One-hundred DTC patients who underwent total thyroidectomy were retrospectively evaluated. The downstaging of mETE was introduced in the definition of T, and the updated classification defined as modified ATA-RR (ATAm-RR). For each patient, post-surgical basal and stimulated thyroglobulin (Tg) levels, neck ultrasound (US) and post-ablative 131-I whole body scan (WBS) reports were considered. The predictive performance (PP) of disease recurrence was calculated both for each single parameter, as well as for all of them.

RESULTS

According to ATAm-RR classification, 19/100 patients (19%) were downstaged. ATA-RR proved a significant PP for disease recurrence (DR) (sensitivity 75.0%, specificity 63.0%, p = 0.023). However, ATAm-RR performed slightly better due to an increased specificity (sensitivity 75.0%, specificity 83.7%, p < 0.001). For both classifications, the PP was optimal when all the above-mentioned predictive parameters were considered.

CONCLUSION

Our results suggest that the new assessment of T considering mETE resulted in a downgrading of ATA-RR class in a significant number of patients. This provides a better PP for disease recurrence, and the best PP was obtained when considering the whole predictive variables together.

Consumption of health resources in older people with differentiated thyroid carcinoma: a multicenter analysis

OBJECTIVE

There is hardly any information on the consumption of healthcare resources by older people with differentiated thyroid cancer (DTC). We analyzed these consumptions in older patients with DTC and compared patients 75 years and older with subjects aged 60-74 years.

METHODS

A multicenter, retrospective analysis was designed. We recorded three groups of health resources consumption (visits, diagnostic procedures, and therapeutic procedures) and identified a subgroup of patients with high consumption of resources. We compared patients aged between 60-74 years (group 1) with patients aged 75 and over (group 2).

RESULTS

We included 1654 patients (women, 74.4%), of whom 1388 (83.9%) belonged to group 1 and 266 (16.1%) to group 2. In group 2, we found a higher proportion of patients requiring emergency department visits (7.9 vs. 4.3%, P = 0.019) and imaging studies (24.1 vs. 17.3%; P = 0.012) compared to group 1. However, we did not find any significant difference between both groups in the consumption of other visits, diagnostic procedures, or therapeutic procedures. Overall, 340 patients (20.6%) were identified as high consumers of health resources, 270 (19.5%) in group 1 and 70 (26.3%) in group 2 (P = 0.013). Multivariate logistic regression analysis showed that the risk of recurrence and mortality, radioiodine treatment, tumor size, and vascular invasion were significantly related to the high global consumption of resources. However, the age was not significantly related to it.

CONCLUSION

In patients with DTC over 60 years of age, advanced age is not an independent determining factor in the consumption of health resources.

Immune profiling identifies CD8+ T-cell subset signatures as prognostic markers for recurrence in papillary thyroid cancer

Background

Thyroid tissue has a special immune microenvironment that is not well characterized. Whether immune cells have a prognostic value in the recurrence of papillary thyroid cancer (PTC) needs further investigation.

Methods

Multinodular non-toxic goiter (MNG) was taken as normal tissue for the difficulty in obtaining completely normal thyroid tissue (normal thyroid function, no thyroiditis, and no nodules). We compared the composition of mononuclear cells (MNCs) in peripheral blood and thyroid tissues from MNG and PTC patients by high-dimensional flow cytometry profiling and verified the results by multiplex immunohistochemistry. The recurrence rates of PTC patients with different CD8⁺T cell subset signatures were compared using TCGA database.

Results

We observed that the immune cell composition of MNG was different from that in peripheral blood. Thyroid tissue contains higher percentages of T cells and NK cells. Moreover, the percentages of memory T cells and Treg cells were higher in thyroid than in peripheral blood and increased in PTC tumors. We further focused on the antitumoral CD8⁺T cells and found that the expression patterns of PD-1, CD39, and CD103 on CD8⁺T cells were different between MNG and PTC. Importantly, we found higher percentages of PD-1⁺CD39⁺CD103⁺CD8⁺T and PD-1⁺CD39⁺CD103^-CD8⁺T cells in PTC tumor tissues from recurrent patients than non-recurrent patients. By analyzing PTC data from TCGA database, we found that the expression patterns of these molecules were associated with different pathologic types and genders among PTC patients. Moreover, patients with PD-1^hiCD39^loCD103^hiCD8^hi, PD-1^hiCD39^hiCD103^loCD8^hi, and PD-1^loCD39^hiCD103^hiCD8^hi expression patterns have a higher 10-year recurrence-free survival.

Conclusion

The immune microenvironment in MNG tissue is distinct from that in peripheral blood and paratumor tissue. More memory CD8⁺T cells were detected in PTC, and expression patterns of PD-1, CD39, and CD103 on CD8⁺T cells were significantly different in physiology and gender and associated with the recurrence rate of PTC. These observations indicate that CD8⁺T cell signatures may be useful prognostic markers for PTC recurrence.

Extrathyroidal extension and cervical node infiltration are associated with recurrences and shorter recurrence-free survival in differentiated thyroid cancer: a cohort study

Background

Differentiated thyroid cancer has excellent overall survival. However, around 20% of patients experience recurrent diseases after a certain time of follow-up. Therefore, identification of risk factors for recurrence is necessary to adjust treatment and surveillance planning.

Methods

A retrospective study was conducted of 312 patients with differentiated thyroid cancer who received surgery with and without adjuvant treatment. Clinical and pathological risk factors were analyzed for recurrences.

Results

After median follow-up of 57 months, 109 of 312 patients (34.9%) developed recurrences. Extrathyroidal extension and positive cervical nodes were significantly associated with recurrences (OR = 2.449, 95%CI:1.260–4.760, P = 0.008 and OR = 3.511, 95%CI:1.860–6.626, P < 0.001; respectively). Lympho-vascular invasion (LVI) and tumor multifocality were also associated with increased risk of recurrence (OR = 2.577, 95%CI:1.380–4.812, P = 0.003 and OR = 1.602, 95%CI:1.001–2.495, P = 0.050; respectively). Using multivariable regression, only older age and tumor infiltration to the lymph nodes were significantly associated with recurrences (OR = 2.227, 95%CI:1.037–4.782, P = 0.040 and OR = 2.966, 95%CI:1.470–5.986, P = 0.002; respectively). In addition, T4, cervical lymph node infiltration, older age, and LVI were associated with shorter recurrence-free survival.

Conclusion

Recurrence rates in our study population are relatively high. Extrathyroidal extension, positive neck lymph node, and older age were associated with recurrence risks of well differentiated thyroid cancers.

Differentiated thyroid carcinoma in the elderly: influence of age on disease-free and overall survival

PURPOSE

We investigated whether age at diagnosis of differentiated thyroid carcinoma (DTC) may be a risk factor for structural disease and mortality after primary treatment in aging patients.

METHODS

A multicenter, retrospective analysis including patients older than 60 years at DCT diagnosis was designed. All subjects were treated by surgery with or without radioiodine adjuvant therapy and had a minimum follow-up of one year. We compared elderly patients (group 1, 60-74 years) with very old patients (group 2, ≥75 years).

RESULTS

The study involved 1668 patients (74.3% women, median age 67 years, 87.6% papillary thyroid cancer, 73.3% treated with radioiodine), including 1397 in group 1 and 271 in group 2. Patients in group 2 had larger tumor size (1.8 [0.8-3.0] vs 1.5 [0.7-2.8] cm; P = 0.005), higher proportions of tumors with vascular invasion (23.8 vs 16.4%; P = 0.006), and lower proportion of lymphocytic thyroiditis (18.6 vs 24.9%; P = 0.013) than subjects in group 1. Kaplan-Meier survival analysis showed that patients in group 2 had significantly lower structural disease-free survival (DFS) and overall survival (OS) than patients in group 1 (P = 0.035 and <0.001, respectively). In multivariate Cox regression analysis, age was a risk factor significantly associated with OS. However, age was significantly associated with DFS in unadjusted analysis and in analysis adjusted by gender and risk classification variables, but not when pathological and therapy-related variables were introduced in the model. On the other hand, patients who received radioiodine had worse DFS (P < 0.001) compared to those who did not.

CONCLUSION

Although age is a conditioning factor for OS, very old patients do not have a greater risk of developing structural disease throughout the follow-up than elderly patients with DTC.

Histopathological Characteristics of N1b Papillary Thyroid Carcinoma are Associated with Risk of Recurrence

BACKGROUND

The presence of cervical lymph node (LN) metastasis at the initial presentation of papillary thyroid carcinoma (PTC) constitutes an independent risk factor for disease recurrence, increases the risk for mortality, and impacts overall outcome. The 2016 American Joint Committee on Cancer raised the age cutoff for PTC staging from 45 to 55 years for better prediction of overall survival. Age > 55 years is considered a significant risk factor for a more aggressive and advanced disease with worse outcomes. We identified histopathological factors for disease recurrence in PTC patients younger and older than 55 years of age.

METHODS

Data on all patients who underwent thyroid surgery due to PTC between 2006 and 2018 in the Tel Aviv Sourasky Medical Center were retrieved for this retrospective cohort study. Patients with lymph node (LN) metastases were further investigated for preoperative presentation, pathological characteristics, and recurrence. A multivariate analysis was used to detect predictors for recurrence and patient outcome for each age-group.

RESULTS

Twenty-two of the 183 patients (12%) with PTC who met the inclusion criteria and had sufficient follow-up period sustained recurrence. The predictors of recurrence varied between the two age-groups. The size of thyroid lesions (p = 0.003) was identified as a risk factor in the older group, while the number of metastatic cervical LNs (p = 0.001) and the ratio of metastatic-to-total dissected cervical LNs (p = 0.027) were the main predictors of recurrence for the younger group.

CONCLUSION

The histopathological factors predictive for disease recurrence differed among PTC patients younger and older than 55 years of age.

Evaluation of thyroid nodules by shear wave elastography: a review of current knowledge

PURPOSE

Shear wave elastography (SWE), as a tool for diagnosing thyroid malignancy, has gathered considerable attention during the past decade. Diverging results exist regarding the diagnostic performance of thyroid SWE.

METHODS

A comprehensive literature review of thyroid SWE was conducted using the terms "Thyroid" and "shear wave elastography" in PubMed.

RESULTS

The majority of studies found SWE promising for differentiating malignant and benign thyroid nodules on a group level, whereas results are less convincing on the individual level due to huge overlap in elasticity indices. Further, there is lack of consensus on the optimum outcome reflecting nodule elasticity and the cut-off point predicting thyroid malignancy. While heterogeneity between studies hinders a clinically meaningful meta-analysis, the results are discussed in a clinical perspective with regard to applicability in clinical practice as well as methodological advantages and pitfalls of this technology.

CONCLUSION

Technological as well as biological hindrances seem to exist for SWE to be clinically reliable in assessing benign and malignant thyroid nodules. Structural heterogeneity of thyroid nodules in combination with operator-dependent factors such as pre-compression and selection of scanning plane are likely explanations for these findings. Standardization and consensus on the SWE acquisition process applied in future studies are needed for SWE to be considered a clinically reliable diagnostic tool for detection of thyroid cancer.

Highly sensitive electrochemical immunosensor using a protein-polyvinylidene fluoride nanocomposite for human thyroglobulin

The highly sensitive detection of serum thyroglobulin (Tg) is essential in the post-treatment follow-up of patients with differentiated thyroid cancer undergoing total or partial thyroidectomy and radioactive iodine ablation and requires sensitive, accurate and stable methods. This work proposes an electrochemical immunosensor for the detection of serum Tg antigen, making use of innovative nanocomposites including polyvinylidene fluoride (PVDF) microparticles coated with streptavidin (MP) and gold nanoparticles (AuNPs). The functionalized polymer matrices were characterized by UV-Vis, FTIR, XPS, SEM, dynamic light scattering, and free surface energy. Immobilization of biotin-labeled anti-thyroglobulin monoclonal antibodies was achieved by binding these to the polymer nanocomposite via streptavidin proteins. The analytical response was measured in quintuplicate and had a linear profile from 2.0 to 10.0 ng/mL Tg, with r² of 0.985. The limits of detection and quantification were excellent, equal to 0.015 and 0.047 ng/mL, respectively. In addition, the recovery factor was equal to 95.4% (1.0 ng/mL Tg). Overall, the innovative polymer-based nanocomposite used herein enabled the production of an electrochemical-based immunosensor with excellent sensitivity, selectivity, and reproducibility. It evidenced the remarkable potential of determining low levels of Tg in in vitro assays, thereby suggesting that it may be considered for the analyzes of serum patients.

LPAR5 promotes thyroid carcinoma cell proliferation and migration by activating class IA PI3K catalytic subunit p110β

Lysophosphatidic acid receptor 5 (LPAR5) is involved in mediating thyroid cancer progression, but the underlying mechanism needs to be further revealed. In this study, we confirmed that LPAR5 is upregulated in papillary thyroid carcinoma (PTC), especially in BRAF‐like PTC, by analyzing The Cancer Genome Atlas (TCGA) database and performing immunohistochemistry assay in human thyroid cancer tissues. LPAR5‐specific antagonist TC LPA5 4 treatment inhibited CGTH‐W3, TPC‐1, B‐CPAP, and BHT‐101 cell proliferation, CGTH‐W3 and TPC‐1 cell migration significantly. In vivo, TC LPA5 4 treatment could delay CGTH‐W3 xenograft growth in nude mice. We also found that LPAR5‐specific antagonist TC LPA5 4, PI3K inhibitor wortmannin, or mTOR inhibitor rapamycin pretreatment abrogated phosphorylation of Akt and p70S6K1 stimulated by LPA in CGTH‐W3 and TPC‐1 cells. Stimulating CGTH‐W3 cells transfected with pEGFPC1‐Grp1‐PH fusion protein with LPA resulted in the generation of phosphatidylinositol (3,4,5)‐triphosphate, which indicates that PI3K was activated by LPA directly. The p110β‐siRNA instead of p110α‐siRNA transfection abrogated the increase of levels of phosphorylated Akt and S6K1 stimulated by LPA. Furthermore, immunoprecipitation assay confirmed an interaction between LPAR5 and p110β. Overall, we provide new insights that the downregulation of LPAR5 decreased the proliferation and migration phenotype via the PI3K/Akt pathway. Inhibition of LPAR5 or the PI3K/Akt signal may be a novel therapeutic strategy for treating thyroid cancer.

Incidental versus clinically diagnosed differentiated thyroid cancer in both adult and elderly subjects: histological characteristics and follow-up in a retrospective analysis from a single institution

PURPOSE

Most thyroid cancer are incidentally diagnosed. However, little is known on the different modalities of incidental diagnosis in adult versus older patients.

METHODS

We retrospectively analyzed data from 440 patients consecutively diagnosed with differentiated thyroid cancer (DTC) in a single institution. Modalities of diagnosis were categorized as follows: (A) clinically diagnosed, nonincidental cases; (B) incidental during carotid power-duplex (CPD); (C) incidental during neck imaging other than carotid power-duplex; (D) incidental during imaging workup of thyroid dysfunction or at histological examination after thyroidectomy for benign lesions. Demographics, histology and follow-up were compared between adult (<65 years) and older (≥65 years) patients according to the different modalities of diagnosis.

RESULTS

A total of 363 and 67 cases were recorded in adult and older patients, respectively with incidental proportions of 79% and 85%, respectively. A P < 0.001 significant difference in the modality of diagnosis was found between adult and older subjects, the latter presenting with a higher prevalence of Group B. In the nonincidental group, papillary histotype, larger size, and extrathyroidal invasion were more frequently observed in older subjects. Disease-free survival was comparable between adult and older subjects in the incidental cases, whereas it was reduced, though not significantly, in older subjects.

CONCLUSION

Incidental cases of DTC are more frequently diagnosed in the old subjects and are mainly due to CPD. Disease-free survival is comparable between adult and older subjects in both incidental and nonincidental cases, although it may be slightly reduced in nonincidentally diagnosed older patients.

Microscopic Positive Tumor Margin Increases Risk for Disease Persistence but Not Recurrence in Patients with Stage T1-T2 Differentiated Thyroid Cancer

Introduction

Differentiated thyroid cancer (DTC) has an overall excellent prognosis. Patients who develop recurrent disease have a more unfavorable disease course than those with no recurrence. Higher recurrence rates are seen with incomplete surgical resection and gross positive margins. It is unclear whether microscopic positive margin affects disease recurrence rates as much as grossly positive margin. Aim of the Study. To assess whether microscopic positive margin is an independent predictor of disease recurrence in patients with overall low-risk DTC. Patients and Methods. We conducted a retrospective single-center institutional review of 1,583 consecutive patients' charts from 1995–2013 using the Canadian Thyroid Cancer Consortium Registry. We included adult patients with nonmetastasizing T1 and T2 DTC with a minimum of three years follow-up. Univariate and multivariate analyses were used to study factors that may influence the risk of persistent/recurrent disease. Strict definitions of persistent versus recurrent disease were applied.

Results

963 patients (152 men and 811 women) were included in the study with a mean age of 46 years. Microscopic positive margins were present in 12% of the specimens and were associated with an increased rate of persistent disease (8% versus 2% in the controls) but not with an increased risk of recurrent disease (1% in both groups). T2 tumors had a significantly higher incidence of positive margins than T1 tumors (48% versus 36%) and significantly higher nodal staging.

Conclusions

Microscopic positive margin in the histopathology report in patients with low-risk DTC was associated with a higher rate of persistent disease but did not increase the risk of disease recurrence. A close follow-up of biomarkers and occult residual cancerous lesions is needed, especially in the first year. Further studies are needed to determine whether additional therapeutic measures to prevent recurrence are indicated in T1 and T2 DTC with positive microscopic surgical margins.

Low-Risk Thyroid Cancer in Elderly: Total Thyroidectomy/RAI Predominates but Lacks Survival Advantage

BACKGROUND

Papillary thyroid cancer (PTC) is the fastest increasing cancer in the United States; incidence increases with age. It generally has a favorable prognosis but may behave more aggressively in older patients. This study aims to describe national treatment patterns for low-risk PTC in older adults.

MATERIALS AND METHODS

The Surveillance, Epidemiology, and End Results-Medicare database was used to identify patients ≥66 y treated for clinical T1N0M0 PTC between 1996 and 2011. Multivariable logistic regression was used to identify factors associated with extent of surgery (total thyroidectomy versus lobectomy) and radioactive iodine (RAI) administration. Cox proportional hazards modeling was used to estimate the effect of treatment type on disease-specific survival (DSS).

RESULTS

Three thousand two hundred and fourteen patients met inclusion criteria; 77.6% were women, median age was 72 y, and mean tumor size was 0.7 cm. 42.7% had preoperatively diagnosed PTC (versus incidental). 65.4% underwent total thyroidectomy, 29.0% lobectomy, and 5.6% lobectomy followed by completion thyroidectomy; 33.4% received postoperative RAI. Five- and 10-year DSS were 98.9% and 98.3%, respectively. After adjustment, larger tumor size (1.1-2 cm), multifocality, and a preoperative PTC diagnosis were associated with greater odds of undergoing more extensive surgery and receiving RAI (P < 0.0001). DSS was not associated with extent of surgery or RAI administration (P > 0.05).

CONCLUSIONS

Most older adults with PTC underwent total thyroidectomy and a third received RAI; neither treatment improved DSS. In the growing elderly population, less extensive interventions for PTC may reduce morbidity and improve quality of life while preserving an excellent prognosis.

Assessment of risk based on variant pathways and establishment of an artificial neural network model of thyroid cancer

BACKGROUND

This study aimed to establish an artificial neural network (ANN) model based on variant pathways to predict the risk of thyroid cancer.

METHODS

The RNASeq data of 482 thyroid cancer samples were downloaded from the TCGA database. The samples were divided into low-risk and high-risk groups, followed by identification of differentially expressed genes (DEGs). Co-expression analysis and pathway enrichment analysis were then performed. The variant pathways were screened according to the functional deviation score of each pathway, and an ANN model was established. Finally, the efficiency of the ANN model for risk assessment was validated by survival analysis and analysis of an independent microarray dataset (GSE34289) for thyroid cancer.

RESULTS

In total, 190 DEGs (85 up-regulated and 105 down-regulated) were identified between the low-risk and high-risk groups. Ten risk-related variant pathways were identified between the low-risk and high-risk groups, which were related to inflammatory and immune responses. Based on these variant pathways, an ANN model was built, consisting of an input layer, two hidden layers, and an output layer, corresponding to 15, 8, 5, and 1 neuron, respectively. Survival analysis showed that this model could effectively distinguish the samples with different risks. Analysis of microarray dataset GSE34289 showed that the accuracy of this model for predicating low-risk and high-risk samples was 77.5 and 86.0%, respectively.

CONCLUSIONS

This study suggests that the ANN model based on variant pathways can be used for effectively evaluating the risk of thyroid cancer.

Bone-Marrow Suppression in Elderly Patients Following Empiric Radioiodine Therapy: Real-Life Data

Background: Elderly patients with differentiated thyroid cancer (DTC) tend to have more advanced disease at presentation, for which high activities of radioiodine (RAI) are often recommended. However, the 2015 American Thyroid Association guidelines recommend that empirically administered activities of RAI >150 mCi should be avoided in patients >70 years of age, based on calculated bone-marrow exposure according to two dosimetry-based studies. This study aimed to evaluate the effect of RAI treatment on bone-marrow function in elderly DTC patients. Methods: DTC patients ≥70 years of age who received RAI treatment and on whom a complete blood count was performed before and after treatment were included. Blood counts within one year before RAI and one year following treatment were compared in order to assess for marrow suppression. The impact of demographic, clinical, and laboratory variables on complete blood count were assessed. Results: One hundred fifty-three treatments in 122 patients met inclusion criteria, with a mean patient age of 76 ± 4.3 years, and 75% were women. High-risk features at presentation included T4 disease in 17%, lymph node metastases in 34%, and distant metastases in 14%. Mean RAI activity was 136.8 ± 48 mCi (82% ≥ 100 mCi, 66% ≥ 150 mCi). Of 153 RAI treatments analyzed, 114 (74%) were first treatments, 28 (18%) second treatments, seven (5%) third treatments, and four (3%) fourth treatments. At 0-3 months after RAI treatment, there was a statistically significant decrease in platelets (238 ± 66 vs. 216 ± 69 × 10⁹/L, 10% decrease; p < 0.001), white blood cells (WBC; 6.9 ± 2 vs. 6.1 ± 1.9 × 10⁹/L, 13% decrease; p < 0.001), and hemoglobin (Hb) in women (12.8 ± 1.1 vs. 12.4 ± 1.1 g/dL, 3% decrease; p = 0.01). Mean platelets, WBC, Hb in women, and lymphocytes remained decreased (but within the reference range) one year after treatment. Subgroup analysis demonstrated platelet suppression only with activities ≥100 mCi, and WBC and Hb suppression only with activities ≥150 mCi, with mean values within the reference ranges. There were no clinically significant cytopenia events during follow-up. Conclusions: Empiric RAI treatment in elderly patients causes mild bone-marrow suppression, with little clinical significance. Activities of 150-200 mCi can be safely used when indicated.

The role of prophylactic central compartment lymph node dissection in elderly patients with differentiated thyroid cancer: a multicentric study

BACKGROUND

Prophylactic central neck lymph-nodes dissection is still a topic of major debate in Literature. There is a lack of randomized controlled trials proving advantages in its application in terms of overall survival and local recurrence. Due to the recent rapid increase of elderly population, differentiated tumor carcinoma diagnosis increased in patients over 65 years old. The aim of this study was to compare recurrence rate, complications rate and histological features of tumors in elderly population.

METHODS

A retrospective study was carried out collecting data from 371 patients with differentiated thyroid cancer without clinical evidence of lymph-nodes involvement in three Italian referral centers from 2005 to 2015. All patients were aged ≥ 65 years and were divided in two groups based on the performed surgery (total thyroidectomy alone or associated with central lymph-nodes dissection). Moreover, patients were stratified according to the age between 65 and 74 years old and over 75 years old.

RESULTS

Total thyroidectomy alone was performed in 184 patients (group A) and total thyroidectomy with prophylactic central neck dissection was performed in 187 cases (group B). There was a statistically significant difference in complications between the groups in terms of neck hematoma (0.5% group A vs 3.7% group B), temporary hypoparathyroidism (11.4% group A vs 21.4% group B), and temporary unilateral recurrent nerve injury (1.5% group A vs 6.4% group B). Lymph nodes recurrence rate was 9.2% in group A and 8.5% in group B, with no statistically significant difference. There was a statistically significant difference in patients over 75 years old in terms of temporary hypoparathyroidism (24% group A vs 11% group B), permanent hypoparathyroidism (2,7% group A vs 0,3% group B) and recurrent nerve injury (9,5% group A vs 2% group B).

CONCLUSIONS

The role of prophylactic central neck dissection is still controversial, especially in elderly patients, and an aggressive surgical approach should be carefully evaluated. The Authors reported a similar low recurrence rate between total thyroidectomy and total thyroidectomy associated with prophylactic central neck dissection, with increased postoperative complications in the lymphadenectomy group and in patients over 75 years old, advocating a tailored surgical approach in elderly population.

Clinicopathological characteristics and recurrence risk of papillary thyroid microcarcinoma in the elderly

Background: The optimal management for elderly patients with papillary thyroid microcarcinoma (PTMC) is not well established. The aim of the present study is to describe the clinicopathological characteristics and identify predictors of recurrence in the elderly PTMC patients.

Methods: We conducted a retrospective study of PTMC patients who underwent thyroidectomy. The clinicopathological characteristics were compared between patients with age ≥65 years and <65 years. The independent predictors of recurrence were identified by multivariate Cox regression analysis.

Results: The patients in elderly group were more likely to exhibit bilaterality (P<0.050), extrathyroidal extension (P < 0.001), and central compartment lymph node metastasis (CLNM) (P<0.010), especially the ratio of CLNM >0.5 (P<0.010), than the patients with age <65 years. The elderly patients had poorer recurrence-free survival (RFS) than those with younger ages (P=0.002). Multivariate analysis indicated tumor size >5 mm (P=0.009) and CLNM ratio >0.5 (P=0.002) were independent risk factors for recurrence of the elderly patients with PTMC.

Conclusions: The elderly PTMC patients have more aggressive biological characteristics and higher recurrence rate. More aggressive treatment and rigorous follow-up could be considered for elderly patients with tumor diameter >5 mm and CLNM ratio >0.5.

Thyroidectomy for thyroid cancer in the elderly: A meta-analysis

Thyroid cancer, the most common endocrine malignancy, has patients who generally have excellent prognosis. It has been shown that elderly patients are more likely to undergo sub-therapeutic management, despite having more aggressive disease, resulting in increased mortality and morbidity. The present study aimed to quantitatively investigate the risks of elderly patients who underwent thyroidectomy for thyroid cancer regarding mortality/survival, recurrence of disease, and complications arising from thyroidectomy. A systematic search and meta-analysis was carried out using the electronic databases PubMed and Medline. We searched for articles containing epidemiological evidence of mortality and recurrence of disease in patients above the age of 60, who are treated for operatively thyroid cancer and data involving complications following total thyroidectomy. The meta-analysis consisted of a total of 16 studies meeting the inclusion and exclusion criteria. The current study confirmed that patients have increased risk of recurrence (HR 4.84; 95% CI = 22.2-10.52; I² = 0.00; P = 0.98) including increased risk of lymph node recurrence and distant metastases. Additionally these patients had an increased risk of complications (OR 1.82; 95% CI = 0.88-3.77; I² = 77.01; P = 0.005) following thyroidectomy compared to patients in the younger cohort. The current study also qualitatively compared survival data between the different age cohorts, and identified a reduced overall survival and disease free survival for elderly patients. The current study suggests that elderly patients should be classified as higher risk following total thyroidectomy for thyroid cancer and puts an emphasis is early detection and intervention.

Should Age at Diagnosis Be Included as an Additional Variable in the Risk of Recurrence Classification System in Patients with Differentiated Thyroid Cancer

OBJECTIVE

To evaluate the influence of age at diagnosis on the frequency of structural incomplete response (SIR) according to the modified risk of recurrence (RR) staging system from the American Thyroid Association guidelines.

PATIENTS AND METHODS

We performed a retrospective analysis of 268 patients with differentiated thyroid cancer (DTC) followed up for at least 3 years after initial treatment (total thyroidectomy and remnant ablation). The median follow-up in the whole cohort was 74.3 months (range: 36.1-317.9) and the median age at diagnosis was 45.9 years (range: 18-87). The association between age at diagnosis and the initial and final response to treatment was assessed with analysis of variance (ANOVA). Patients were also divided into several groups considering age younger and older than 40, 50, and 60 years.

RESULTS

Age at diagnosis was not associated with either an initial or final statistically significant different SIR to treatment (p = 0.14 and p = 0.58, respectively). Additionally, we did not find any statistically significant differences when the percentages of SIR considering the classification of RR were compared between different groups of patients by using several age cutoffs.

CONCLUSIONS

When patients are correctly risk stratified, it seems that age at diagnosis is not involved in the frequency of having a SIR at the initial evaluation or at the final follow-up, so it should not be included as an additional variable to be considered in the RR classifications.

Clinical features of recently diagnosed papillary thyroid carcinoma in elderly patients aged 65 and older based on 10 years of sonographic experience at a single institution in Korea

Purpose

The aim of this study was to assess the characteristics of papillary thyroid carcinoma (PTC) in patients aged 65 and older in order to predict postoperative recurrence based on the results of ultrasonographic surveillance.

Methods

Among 1,494 patients (200 male and 1,294 female; mean age, 46.6±11.3 years) who underwent surgery for thyroid cancer at our institution between 2006 and 2015, we retrospectively enrolled 150 PTC patients (29 male and 121 female; mean age, 69.4±4.2 years). To identify the risk factors for recurrence, we analyzed age, gender, multiplicity, size, number, extrathyroidal extension (ETE) of the tumor, lymph node metastasis (LNM), type of surgery, and the dose of radioactive ablation using a Cox regression model to identify hazard ratios (HRs).

Results

Among the 115 asymptomatic patients with PTCs detected by screening ultrasonography (n=86), other cross-sectional imaging modalities (computed tomography or positron emission tomography-computed tomography, n=13), or incidentally through a surgical specimen (n=16), 78 patients were confirmed to have papillary thyroid microcarcinomas (PTMCs). The other 35 patients presented with palpable neck masses (n=25), vocal cord palsy (n=9) or blood-tinged sputum (n=1). During the follow-up period (mean, 43.6 months), 17 patients (12.5%) experienced recurrence in the neck. None of the patients died due to PTC-related recurrence or distant metastasis during the follow-up period. Cox regression analysis demonstrated that tumor size (HR, 2.12; P<0.001) and LNM (central LNM: HR, 9.08; P=0.004; lateral LNM: HR, 14.71; P=0.002; both central and lateral LNM: HR, 58.41; P<0.001) significantly increased the recurrence rate. ETE, LNM, and recurrence were significantly less frequent in PTMCs than in non-PTMC (all P<0.001).

Conclusion

PTCs of small size and absent LNM showed significantly better prognoses in patients 65 years and older.

Comparative clinicopathological and outcome analysis of differentiated thyroid cancer in Saudi patients aged below 60 years and above 60 years

INTRODUCTION

The aim of this study was to evaluate the treatment outcomes of differentiated thyroid cancer in Saudi patients aged above 60 years.

MATERIALS AND METHODS

Comparative analysis was performed in 252 patients aged 46-60 years (Group A) and 118 patients aged above 60 years (Group B), who had thyroidectomy, radioactive iodine-131, and thyroid-stimulating hormone suppression therapy between July 2000 and December 2012. Different clinicopathological features, treatment, complications, disease-free survival, and overall survival rates were compared.

RESULTS

Mean age of patients in Group A was 51.9 years (range: 46-60), and mean age of those in Group B was 68.6 years (range: 62-97). Group B patients had higher positive lymph nodes (43.2%), P=0.011. The frequency of extrathyroidal extension, multifocality, and lymphovascular space invasion was seen more in Group B than in Group A. Postsurgical complications (permanent hypoparathyroidism, bleeding, and wound infections) were also seen more in Group B (P=0.043, P=0.011, and P=0.021, respectively). Group B patients experienced more locoregional recurrences (11.0%, P=0.025); similarly, more distant metastases were observed in Group B (15.3%, P=0.003). The 10-year disease-free survival rates were 87.6% in Group A and 70.8% in Group B (P<0.0001).

CONCLUSION

Differentiated thyroid cancer in patients aged above 60 years are more aggressive biologically and associated with a worse prognosis, and the morbidity is significantly high as compared to patients aged below 60 years.

Use of imaging tests after primary treatment of thyroid cancer in the United States: population based retrospective cohort study evaluating death and recurrence

OBJECTIVE

 To determine whether the use of imaging tests after primary treatment of differentiated thyroid cancer is associated with more treatment for recurrence and fewer deaths from the disease.

DESIGN

 Population based retrospective cohort study.

SETTING

 Surveillance Epidemiology and End Results-Medicare database in the United States.

PARTICIPANTS

 28 220 patients diagnosed with differentiated thyroid cancer between 1998 and 2011. The study cohort was followed up to 2013, with a median follow-up of 69 months.

MAIN OUTCOME MEASURES

 Treatment for recurrence of differentiated thyroid cancer (additional neck surgery, additional radioactive iodine treatment, or radiotherapy), and deaths due to differentiated thyroid cancer. We conducted propensity score analyses to assess the relation between imaging (neck ultrasound, radioiodine scanning, or positron emission tomography (PET) scanning) and treatment for recurrence (logistic model) and death (Cox proportional hazards model).

RESULTS

 From 1998 until 2011, we saw an increase in incident cancer (rate ratio 1.05, 95% confidence interval 1.05 to 1.06), imaging (1.13, 1.12 to 1.13), and treatment for recurrence (1.01, 1.01 to 1.02); the change in death rate was not significant. In multivariable analysis, use of neck ultrasounds increased the likelihood of additional surgery (odds ratio 2.30, 95% confidence interval 2.05 to 2.58) and additional radioactive iodine treatment (1.45, 1.26 to 1.69). Radioiodine scans were associated with additional surgery (odds ratio 3.39, 95% confidence interval 3.06 to 3.76), additional radioactive iodine treatment (17.83, 14.49 to 22.16), and radiotherapy (1.89, 1.71 to 2.10). Use of PET scans was associated with additional surgery (odds ratio 2.31, 95% confidence interval 2.09 to 2.55), additional radioactive iodine treatment (2.13, 1.89 to 2.40), and radiotherapy (4.98, 4.52 to 5.49). Use of neck ultrasounds or PET scans did not significantly affect disease specific survival (hazard ratio 1.14, 95% confidence interval 0.98 to 1.27, and 0.91, 0.77 to 1.07, respectively). However, radioiodine scans were associated with an improved disease specific survival (hazard ratio 0.70, 95% confidence interval 0.60 to 0.82).

CONCLUSIONS

 The marked rise in use of imaging tests after primary treatment of differentiated thyroid cancer has been associated with an increased treatment for recurrence. However, with the exception of radioiodine scans in presumed iodine avid disease, this association has shown no clear improvement in disease specific survival. These findings emphasize the importance of curbing unnecessary imaging and tailoring imaging after primary treatment to patient risk.

IL-12 immunotherapy of Braf(V600E)-induced papillary thyroid cancer in a mouse model

Papillary thyroid carcinoma (PTC) accounts for >80% thyroid malignancies, and BRAF(V600E) mutation is frequently found in >40% PTC. Interleukin-12 (IL-12) is a proinflammatory heterodimeric cytokine with strong antitumor activity. It is not known whether IL-12 immunotherapy is effective against Braf(V600E)-induced PTC. In the present study, we investigated the effectiveness of IL-12 immunotherapy against Braf(V600E)-induced PTC in LSL-Braf(V600E)/TPO-Cre mice. LSL-Braf(V600E)/TPO-Cre mice were created for thyroid-specific expression of Braf(V600E) under the endogenous Braf promoter, and spontaneous PTC developed at about 5 weeks of age. The mice were subjected to two treatment regimens: (1) weekly intramuscular injection of 50 μg plasmid DNA expressing a single-chain IL-12 fusion protein (scIL-12/CMVpDNA), (2) daily intraperitoneal injection of mouse recombinant IL-12 protein (mrIL-12, 100 ng per day). The role of T cells, natural killer (NK) cells, and transforming growth factor-β (TGF-β) in IL-12-mediated antitumor effects was determined by a (51)Cr-release cytotoxicity assay. Tumor size and weight were significantly reduced by either weekly intramuscular injection of scIL-12/CMVpDNA or daily intraperitoneal injection of mrIL-12, and tumor became more localized. Survival was significantly increased when treatment started at 1 week of age as compared with that at the 6 weeks of age. Both NK and CD8(+) T cells were involved in the cytotoxicity against tumor cells and their antitumor activity was significantly reduced in tumor-bearing mice. TGF-β also inhibited the antitumor activity of NK and CD8(+) T cells. The immune suppression was completely reversed by IL-12 treatment and partially recovered by anti-TGF-β antibody. We conclude that both IL-12 gene therapy and recombinant protein therapy are effective against PTC. Given that the immune response is significantly suppressed in tumor-bearing mice and can be restored by IL-12, the current study raises a possibility of the application of IL-12 as an adjuvant therapy for thyroid cancer.

TSH overcomes Braf(V600E)-induced senescence to promote tumor progression via downregulation of p53 expression in papillary thyroid cancer

The BRAF(V600E) mutation is found in approximately 40% of papillary thyroid cancers (PTC). Mice with thyroid-specific expression of Braf(V600E) (TPO-Braf(V600E)) develop PTC rapidly with high levels of serum thyroid-stimulating hormone (TSH). It is unclear to what extent the elevated TSH contributes to tumor progression. To investigate the progression of Braf(V600E)-induced PTC (BVE-PTC) under normal TSH, we transplanted BVE-PTC tumors subcutaneously into nude and TPO-Braf(WT) mice. Regression of the transplanted tumors was observed in both nude and TPO-Braf(WT) mice. They were surrounded by heavy lymphocyte infiltration and oncogene-induced senescence (OIS) was demonstrated by strong β-gal staining and absence of Ki-67 expression. In contrast, BVE-PTC transplants continued to grow when transplanted into TPO-Braf(V600E) mice. The expression of Trp53 was increased in tumor transplants undergoing OIS. Trp53 inactivation reversed OIS and enabled tumor transplants to grow in nude mice with characteristic cell morphology of anaplastic thyroid cancer (ATC). PTC-to-ATC transformation was also observed in primary BVE-PTC tumors. ATC cells derived from Trp53 knockout tumors had increased PI3K/AKT signaling and became resistant to Braf(V600E) inhibitor PLX4720, which could be overcome by combined treatment of PI3K inhibitor LY294002 and PLX4720. In conclusion, BVE-PTC progression could be contained via p53-dependent OIS and TSH is a major disruptor of this balance. Simultaneous targeting of both MAPK and PI3K/AKT pathways offer a better therapeutic outcome against ATC. The current study reinforces the importance of rigorous control of serum TSH in PTC patients.

Recurrence of differentiated thyroid carcinoma during full TSH suppression: is the tumor now thyroid hormone dependent?

Well-standardized primary treatment and long-term management of differentiated thyroid carcinoma (DTC) include lowering or suppression of host thyrotropin (TSH) with exogenous L-thyroxine (T₄). This treatment recognizes the trophic action of TSH on DTC cells. Suppression of endogenous TSH with T₄ is continued in recurrent disease. However, T₄ can induce proliferation of follicular and papillary thyroid carcinoma cell lines and of other human carcinoma cells. The proliferative mechanism is initiated at a cell surface receptor for T₄ on integrin αvβ3, a receptor by which the hormone also inhibits p53-dependent apoptosis in tumor cells. In recurrent DTC with satisfactory suppression of endogenous TSH, we discuss here the possibility that the tumor is no longer TSH dependent and that T₄ has become a critical growth factor for the cancer.

Differentiated thyroid cancer in patients over 60 years of age at presentation: a retrospective study of 438 patients

OBJECTIVES

The aim of this study is to identify the prognostic factors predicting remission and subsequent disease relapse in patients with differentiated thyroid cancer (DTC) greater than 60years of age.

MATERIALS AND METHODS

The institute thyroid cancer database had 4370 patients with DTC, of which 447 (10%) were aged>60. However, 9 patients were excluded due to follow-up less than 1year. The prognostic factors in the remaining 438 patients were studied.

RESULTS

Among the 438 patients, 311 (71%) had only loco-regional disease (M0) and 127 (29%) had distant metastases (M1) at the time of initial presentation. The host factors predictive of distant metastases at presentation were female gender, primary tumor size (>4cm), follicular histology, and extra-thyroidal extension. Among Mo patients, 195 (63%) achieved complete remission while only 12 (9%) M1 patients did so. Average number of radioactive iodine ((131)I) doses administered to achieve complete remission was 2.3 (range, 1-6) and the mean cumulative dose was 3404MBq (range, 925-46,250MBq). In multivariate logistic regression among M0 patients, follicular histology, nodal metastases, and surgical treatment lesser than total/near-total thyroidectomy and among M1 patients, site of distant metastases (skeletal and multiple sites) were independent factors predicting non-remission. Among the patients (both M0 and M1) who achieved remission, factors associated with disease recurrence were primary tumor size (>4cm), nodal metastases, pulmonary metastases, and non-remission after first dose of radioactive iodine and were associated with greater chances of disease relapse.

CONCLUSION

This study highlights that DTC in older patients behaves more aggressively than in adults age<60years, and identifies several prognostic factors for remission and subsequent relapse.

Tree-based model for thyroid cancer prognostication

BACKGROUND

Death is uncommon in thyroid cancer patients, and the factors important in predicting survival remain inadequately studied. The objective of this study was to assess prognostic effects of patient, tumor, and treatment factors and to determine prognostic groups for thyroid cancer survival.

METHODS

Using data from the Surveillance, Epidemiology, and End Results Program (SEER), we evaluated overall and disease-specific survival (DSS) in 43 392 well-differentiated thyroid cancer patients diagnosed from 1998 through 2005. Multivariable analyses were performed using Cox proportional hazards regression, survival trees, and random survival forest. Similar analyses were performed using National Cancer Data Base data, with overall survival (OS) evaluated in 131 484 thyroid cancer patients diagnosed from 1998 through 2005. Relative importance of factors important to survival was assessed based on the random survival forest analyses.

RESULTS

Using survival tree analyses, we identified 4 distinct prognostic groups based on DSS (P < .0001). The 5-year DSS of these prognostic groups was 100%, 98%, 91%, 64%, whereas the 10-year survival was 100%, 96%, 85%, and 50%. Based on random survival forest analyses, the most important factors for DSS were SEER stage and age at diagnosis. For OS, important prognostic factors were similar, except age at diagnosis demonstrated marked importance relative to SEER stage. Similar results for OS were found using National Cancer Data Base data.

CONCLUSION

This study identifies distinct prognostic groups for thyroid cancer and illustrates the importance of patient age to both disease-specific and OS. These findings have implications for patient education and thyroid cancer treatment.

Differentiated thyroid cancer in the elderly: our experience

INTRODUCTION

The objective of this retrospective study was to investigate clinical and pathologic characteristics of differentiated thyroid cancer in elderly patients and to evaluate the results of surgical treatment in this age group.

METHODS

The clinical records of patients who underwent total thyroidectomy between 2002 and 2012 with histopathological diagnosis of differentiated thyroid cancer were analyzed. Patients were divided into two groups: those 65 years old or older were included in group A (101), those younger in group B (354).

RESULTS

The mean surgical time was 100.9 ± 30.5 min in group A and 100.7 ± 27.6 in B. Postoperative stay was significantly longer in group A (2.8 ± 1.5 days vs 2.4 ± 0.7; p < 0.01). Classic papillary carcinoma was more frequent in group B, whereas follicular variant of papillary carcinoma and tall cell carcinoma in A. In group B node metastases were nearly twice. In Group A transient hypoparathyroidism occurred in 25 patients (24.8%), permanent hypoparathyroidism in 4 (4%), hematoma in 6 (5.9%), recurrent nerve palsy in 2 (2%), and wound infection in 2 (2%). In group B transient and permanent hypoparathyroidism occurred in 48 and 7 patients respectively (13.6% and 2%), hematoma in 4 (1.1%), recurrent nerve palsy in 5 (1.4%), and wound infection in 1 (0.3%).

CONCLUSIONS

Differentiated thyroid carcinoma is more aggressive in elderly patients for biological causes connected to age and to histotype but also for the diagnostic delay. Thyroid surgery in elderly patients is safe when the procedure is carried out by experienced staff. Total thyroidectomy is the surgical operation of choice.