The Impact of Metastatic Lymph Nodes on Risk Stratification in Differentiated Thyroid Cancer: Have We Reached a Higher Level of Understanding?

Guiding the postoperative radioactive iodine-131 therapy for patients with papillary thyroid carcinoma according to the prognostic risk groups: a SEER-based study

PURPOSE

The effectiveness of iodine-131(131I) therapy in patients with papillary thyroid cancer (PTC) of various stage is controversial. This study aimed to use prognostic risk groups to guide 131I therapy in patients with PTC after radical thyroidectomy.

METHODS

Data of 53,484 patients with PTC after radical thyroidectomy were collected from the Epidemiology and End Results (SEER) database. Patients were divided into subgroups according to MACIS system and regional lymph node involvement. The prognostic role of 131I therapy was investigated by comparing Kaplan-Meier survival analysis and Cox proportional hazard models in different subgroups.

RESULTS

Sex, age, tumor size, invasion, regional lymph node involvement, and distant metastasis was related to the survival of patients with PTC. If MACIS < 7, 131I treatment didn't affect the cancer-specific survival (CSS) rate. If MACIS ≥ 7, 131I therapy didn't work on CSS rate for patients with N0 or N1a < 5 status; 131I therapy had improved CSS rate for patients in the N1a ≥ 5 or N1b status. If patients with distant metastasis, invasion, or large tumor, 131I therapy didn't improve CSS rate for patients in N0 or N1a < 5 stage.

CONCLUSION

After radical thyroidectomy, if MACIS < 7, patients with PTC could avoid 131I therapy. If MACIS ≥ 7, patients in the N0 or N1a < 5 could avoid 131I therapy; those in the N1a ≥ 5 or N1b stage should be given 131I therapy. Among them, all patients with distant metastasis should be given 131I therapy.

Lymph node ratio independently associated with postoperative thyroglobulin levels in papillary thyroid cancer

OBJECTIVES

To investigate the impact of the lymph node ratio (LNR) on postoperative thyroglobulin (Tg) levels in patients with papillary thyroid carcinoma (PTC).

PATIENTS AND METHODS

This was a retrospective, cohort study. The association between clinicopathological variables and postoperative unstimulated Tg (uTg) levels, preablative-stimulated Tg (sTg) levels, and postablative unstimulated Tg levels was analysed.

RESULTS

A total of 300 patients with PTC were identified. Multivariate logistic analysis showed that M classification (odds ratio [OR], 2.33; 95% confidence interval [CI], 1.62-3.34), and postoperative thyroid-stimulating hormone levels (OR, 1.01; 95% CI, 1.01-1.02) were independently associated with postoperative uTg levels. One hundred and sixteen patients underwent radioactive iodine (RAI) therapy. Multivariate analysis showed that LNR in the central neck (OR, 1.24; 95% CI, 1.02-1.51), LNR in the lateral neck (OR, 1.73; 95% CI, 1.09-2.77), RAI dose (OR, 1.43; 95% CI, 1.21-1.69), and M classification (OR, 1.79; 95% CI, 1.22-2.61) were independently associated with preablative sTg levels. Tumour size (OR, 1.01; 95% CI, 1.00-1.01), LNR in the central neck (OR, 1.28; 95% CI, 1.08-1.51), LNR in the lateral neck (OR, 1.66; 95% CI, 1.10-2.49), RAI dose (OR, 1.54; 95% CI, 1.34-1.79), and M classification (OR, 1.56; 95% CI, 1.12-2.19) were also independently associated with postablative uTg levels.

CONCLUSION

LNR was independently associated with postoperative Tg levels in patients with PTC. Patients with high LNR were more likely to have incomplete biochemical responses after surgery.

Recurrence Risk Evaluation in Patients with Papillary Thyroid Carcinoma: Multicenter Machine Learning Evaluation of Lymph Node Variables

Background: Lymph node (LN)-related risk factors have been updated to predict long-term outcomes in patients with papillary thyroid carcinoma (PTC). However, those factors’ analytic appropriateness and general applicability must be validated. This study aimed to assess LN-related risk factors, and suggest new LN-related risk categories. Methods: This multicenter observational cohort study included 1232 patients with PTC with N1 disease treated with a total thyroidectomy and neck dissection followed by radioactive iodine remnant ablation. Results: The median follow-up duration was 117 months. In the follow-up period, structural recurrence occurred in 225 patients (18.3%). Among LN-related variables, the presence of extranodal extension (p < 0.001), the maximal diameter of metastatic LN foci (p = 0.029), the number of retrieved LNs (p = 0.003), the number of metastatic LNs (p = 0.003), and the metastatic LN ratio (p < 0.001) were independent risk factors for structural recurrence. Since these factors showed a nonlinear association with the hazard ratio of recurrence-free survival (RFS) rates, we calculated their optimal cutoff values using the K-means clustering algorithm, selecting 0.2 cm and 1.1 cm for the maximal diameter of metastatic LN foci, 4 and 13 for the number of metastatic LN, and 0.28 and 0.58 for the metastatic LN ratio. The RFS curves of each subgroup classified by these newly determined cutoff values showed significant differences (p < 0.001). Each LN risk group also showed significantly different RFS rates from the others (p < 0.001). Conclusions: In PTC patients with an N1 classification, our novel LN-related risk estimates may help predict long-term outcomes and design postoperative management and follow-up strategies. After further validation studies based on independent datasets, these risk categories might be considered when redefining risk stratification or staging systems.

American Head and Neck Society Endocrine Surgery Section and International Thyroid Oncology Group consensus statement on mutational testing in thyroid cancer: Defining advanced thyroid cancer and its targeted treatment

BACKGROUND

The development of systemic treatment options leveraging the molecular landscape of advanced thyroid cancer is a burgeoning field. This is a multidisciplinary evidence-based statement on the definition of advanced thyroid cancer and its targeted systemic treatment.

METHODS

An expert panel was assembled, a literature review was conducted, and best practice statements were developed. The modified Delphi method was applied to assess the degree of consensus for the statements developed by the author panel.

RESULTS

A review of the current understanding of thyroid oncogenesis at a molecular level is presented and characteristics of advanced thyroid cancer are defined. Twenty statements in topics including the multidisciplinary management, molecular evaluation, and targeted systemic treatment of advanced thyroid cancer are provided.

CONCLUSIONS

With the growth in targeted treatment options for thyroid cancer, a consensus definition of advanced disease and statements regarding the utility of molecular testing and available targeted systemic therapy is warranted.

Macroscopic extranodal extension is an independent predictor of lung metastasis in papillary thyroid cancer

PURPOSE

Lymph node metastasis is common in patients with papillary thyroid cancer (PTC). Some metastatic lymph nodes may present extranodal extension (ENE). The clinical role of ENE in PTC has yet to be clearly identified. We evaluated macroscopic ENE as a potential prognostic indicator of lung metastasis in PTC.

PATIENTS AND METHODS

We identified 1140 consecutive patients who had PTC initially resected at our cancer center. Clinical data and pathological results were reviewed. Univariate and multivariate logistic regression analyses were used to figure out the association between clinicopathological variables and lung metastasis.

RESULTS

In this cohort, 51.7% of PTC patients had lymph node metastasis; 10.4% had macroscopic ENE positive nodes; 2.3% had lung metastasis. In patients with lymph node metastasis, the average number of positive nodes was 5.10 ± 4.91. Multivariable analysis of clinicopathological factors revealed that extrathyroidal extension (odds ratio [OR], 3.57; 95% CI, 1.41-9.04), macroscopic ENE (OR, 7.08; 95% CI, 2.54-19.74), and number of positive nodes were significantly associated with lung metastasis. Compared with 0-3 positive nodes, 7-9 positive nodes denoted a moderate risk of lung metastasis (OR, 4.53; 95% CI, 1.03-19.85). And 10 positive nodes or more indicated a high risk of lung metastasis (OR, 9.63; 95% CI, 2.65-35.02).

CONCLUSION

Macroscopic ENE could serve as a strong independent prognostic factor of lungmetastasis in PTC. More attention should be paid to patients with ENE positive nodes duringfollow-up.

Nodal metastatic load in papillary thyroid carcinoma. Morphological and molecular analysis with one-step nucleic acid amplification on more than 550 lymph nodes

BACKGROUND AND OBJECTIVE

The risk of recurrence in papillary thyroid carcinoma (PTC) is likely related to the amount of tumour in the metastatic lymph node (LN). Therefore, the current TNM classification (N0/N1) make it necessary to find a method to quantify the LN metastasis (LNM). We propose that the quantitative molecular assay One-Step Nucleic-Acid Amplification (OSNA), which measures the number of cytokeratin-19 (CK-19) mRNA copies as a marker of LNM, could play this role. Our objective was to describe the characteristics of the LNs from PTC, and to compare the morphological characteristics that have been claimed as criteria for metastatic burden with OSNA.

PATIENTS AND METHOD

Prospective study of LNs from 42 patients. All of the LNs were measured, weighed and analysed by OSNA and also by imprint cytology.

RESULTS

A total of 573 LNs were included, 187 (32.6%) of them were OSNA-positives. The global consistency between cytology and OSNA was 87.4%. Significant differences were observed in the CK-19 copy number between the LNMs<0.2cm and those >3cm, as well as between those from 0.2 to 3cm with respect to those >3cm, but not between those <0.2cm and those between 0.2 and 3cm. The total tumour load per neck dissection showed no differences based on whether there were ≤5 or >5 LNMs.

CONCLUSIONS

In our series the LNMs >3cm show an increased tumour load, but it is unclear if it is necessary to sub-classify the smaller ones as well as the relevance of the number of metastatic nodes according to the cut-off of 5 nodes. We consider that the OSNA analysis avoids the bias of nodal histology and allows for a greater understanding of its real oncological potential.

Predictive Value of Gross Extranodal Extension for Differentiated Thyroid Carcinoma Persistence/Recurrence

OBJECTIVE

We systematically investigated the predictive value of gross extranodal extension (gENE) for differentiated thyroid carcinoma persistence/recurrence.

STUDY DESIGN

Retrospective study.

SETTING

A tertiary care hospital.

METHODS

This study was divided into 2 groups according to gENE status: the gENE group and non-gENE group. We compared the disease persistence/recurrence rates of these 2 groups in the entire cohort and by individual risk group (intermediate/high risk), analyzed whether gENE was an independent risk factor for disease persistence/recurrence, and explored the impact of gENE-specific features on disease persistence/recurrence.

RESULTS

There were 989 patients who satisfied the inclusion criteria: 57 patients in the gENE group and 932 in the non-gENE group. The disease persistence/recurrence rate of the gENE group was higher than that of the non-gENE group in the entire cohort and by individual risk group (P < .05 for each). Unexpectedly, the outcomes of the gENE group with intermediate risk were similar to those of the non-gENE group with high risk (P = .72). For the entire cohort, gENE was an independent predictor for disease persistence/recurrence (odds ratio, 2.89; 95% CI, 1.39-6.00; P = .005). Specific features of gENE (P > .05 for each) were not related to disease persistence/recurrence.

CONCLUSION

Patients with gENE and intermediate risk might be regraded as high risk. Specific features of gENE have no impact on disease persistence/recurrence.

Management of the Neck in Well-Differentiated Thyroid Cancer

PURPOSE OF REVIEW

In this narrative review, we discuss the indications for elective and therapeutic neck dissections and the postoperative surveillance and treatment options for recurrent nodal disease in patients with well-differentiated thyroid cancer.

RECENT FINDINGS

Increased availability of advanced imaging modalities has led to an increased detection rate of previously occult nodal disease in thyroid cancer. Nodal metastases are more common in young patients, large primary tumors, specific genotypes, and certain histological types. While clinically evident nodal disease in the lateral neck compartments has a significant oncological impact, particularly in the older age group, microscopic metastases to the central or the lateral neck in well-differentiated thyroid cancer do not significantly affect outcome. As patients with clinically evident nodal disease are associated with worse outcomes, they should be treated surgically in order to reduce rates of regional recurrence and improve survival. The benefit of elective neck dissection remains unverified as the impact of microscopic disease on outcomes is not significant.

Nodal metastatic load in papillary thyroid carcinoma. Morphological and molecular analysis with one-step nucleic acid amplification on more than 550 lymph nodes

BACKGROUND AND OBJECTIVE

The risk of recurrence in papillary thyroid carcinoma (PTC) is likely related to the amount of tumour in the metastatic lymph node (LN). Therefore, the current TNM classification (N0/N1) make it necessary to find a method to quantify the LN metastasis (LNM). We propose that the quantitative molecular assay One-Step Nucleic-Acid Amplification (OSNA), which measures the number of cytokeratin-19 (CK-19) mRNA copies as a marker of LNM, could play this role. Our objective was to describe the characteristics of the LNs from PTC, and to compare the morphological characteristics that have been claimed as criteria for metastatic burden with OSNA.

PATIENTS AND METHOD

Prospective study of LNs from 42 patients. All of the LNs were measured, weighed and analysed by OSNA and also by imprint cytology.

RESULTS

A total of 573 LNs were included, 187 (32.6%) of them were OSNA-positives. The global consistency between cytology and OSNA was 87.4%. Significant differences were observed in the CK-19 copy number between the LNMs<0.2cm and those >3cm, as well as between those from 0.2 to 3cm with respect to those >3cm, but not between those <0.2cm and those between 0.2 and 3cm. The total tumour load per neck dissection showed no differences based on whether there were ≤5 or >5 LNMs.

CONCLUSIONS

In our series the LNMs >3cm show an increased tumour load, but it is unclear if it is necessary to sub-classify the smaller ones as well as the relevance of the number of metastatic nodes according to the cut-off of 5 nodes. We consider that the OSNA analysis avoids the bias of nodal histology and allows for a greater understanding of its real oncological potential.

Is a Prophylactic Central Compartment Neck Dissection Required in Papillary Thyroid Carcinoma Patients with Clinically Involved Lateral Compartment Lymph Nodes?

BACKGROUND

The 2015 American Thyroid Association guidelines state that a prophylactic central compartment neck dissection (PCND) should be considered for patients with papillary thyroid carcinoma (PTC) and clinically involved lateral neck lymph nodes (cN1b). The purpose of our study was to determine the rate of central neck recurrence in select cN1b patients, with no evidence of clinically involved central compartment lymph nodes, treated without a PCND.

METHODS

After institutional review board approval, adult PTC patients with cN1b disease who were treated with a total thyroidectomy and lateral neck dissection were identified from an institutional database of 6259 patients who underwent initial surgery for well-differentiated thyroid carcinoma from 1986 to 2015. Patients with gross extrathyroidal extension, distant metastases, or no preoperative imaging were excluded. Patients with evidence of clinically involved central compartment lymph nodes, on preoperative imaging or intraoperative evaluation, also were excluded. A total of 152 cN1b patients were included and categorized into non-PCND and PCND groups. Central neck recurrence-free probability (CNRFP) was calculated using the Kaplan-Meier method and log-rank tests.

RESULTS

One hundred three patients (67.8%) did not have a PCND. With a median follow-up of 65 months, the 5- and 10-year CNRFP was 98.4% in the non-PCND group and 93.6% in the PCND group (p = 0.133).

CONCLUSIONS

Select PTC patients with cN1b disease but no evidence of clinically involved central compartment lymph nodes, on preoperative imaging and intraoperative evaluation, appear to have a low rate of central neck recurrence. These patients may not require or benefit from a PCND.

Unusual locations for differentiated thyroid cancer nodal metastasis

Lymph node metastasis is common in differentiated thyroid cancer especially papillary thyroid cancer. Presence of lymph node metastasis does not have an impact on survival in younger patients. Therapeutic central and lateral neck dissection in the presence of clinically or radiologically evident lymph nodes has resulted in good overall survival. However, disease persistence in the lymph node/early recurrences may be seen in patients owing to lymph nodes that may be missed during the initial neck dissection. These observed locations are retropharyngeal and parapharyngeal nodal location, retro carotid location, sublingual, axillary, and intraparotid locations, supraclavicular and superficial to the sternothyroid muscle. We aim to highlight these locations with the goal to minimize persistence or early recurrence of disease at these locations.

Modern surgery for advanced thyroid cancer: a tailored approach

Surgical treatment of advanced thyroid malignancy can be morbid, compromising normal functions of the upper aerodigestive tract. There is a paucity of guidelines dedicated to the management of advanced disease. In fact, there is not even a uniform definition for advanced thyroid cancer currently. The presence of local invasion, bulky cervical nodes, distant metastases or recurrent disease should prompt careful preoperative evaluation and planning. Surgical strategy should evolve from multidisciplinary discussion that integrates individual disease characteristics and patient preference. Intraoperative neuromonitoring has important applications in surgery for advanced disease and should be used to guide surgical strategy and intraoperative decision-making. Recent paradigm shifts, including staged surgery and use of neoadjuvant targeted therapy hold potential for decreasing surgical morbidity and improving clinical outcomes. Modern surgical planning provides optimal treatment for each patient through a tailored approach based on exact extent and type of disease as well as incorporating appreciation of surgical complications, patient preferences and intraoperative findings.

The extent of lymph node yield in central neck dissection can be affected by preoperative and intraoperative assessment and alter the prognosis of papillary thyroid carcinoma

Background

Lymph node yield (LNY) was implemented in the stratification of papillary thyroid cancer (PTC) patients. The effect of LNY may be related to the extent of surgery. This study aims to identify influencing factors for LNY in central compartment neck dissection (CND).

Methods

Data of 13 712 consecutive PTC patients were analyzed retrospectively. Risk factors for LNY in CND and distribution characteristics of LNY were evaluated. Its relationship with prognosis was studied in another cohort of 136 cases.

Results

LNY in therapeutic CND was significantly higher than prophylactic CND (Unilateral: 5.55 ± 3.79 vs 3.41 ± 2.77; Bilateral: 8.90 ± 5.10 vs 6.47 ± 4.17, P < .001). Other independent factors included extranodal extension (ETE), tumor size, and concurrent Hashimoto's thyroiditis. The inconsistency distribution of LNY in bilateral CND was associated with preoperative and intraoperative assessment. Patients with significant difference between major and minor LNY suffered from poorer prognosis (10y‐RFS: 58.3% vs 92.0%; HR = 6.719, 95%, P < .0001).

Conclusions

CND surgical procedure, ETE, and Hashimoto's thyroiditis were independent factors of LNY. Inconsistent distribution of LNY was associated with prognosis of bilateral PTC patients. The impact of preoperative and intraoperative assessment on the actual extent of CND can be used to explain the relationship between LNY and PTC prognosis.

Impact of Extranodal Extension on Risk Stratification in Papillary Thyroid Carcinoma

Background: The current American Thyroid Association risk-stratification system for papillary thyroid carcinoma (PTC) incorporates the number and size of positive lymph nodes (LNs) but places less weight on extranodal extension (ENE). This study investigated how to incorporate ENE into the current system to predict recurrence better in PTC N1 patients. Methods: A total of 369 N1 PTC patients without distant metastasis were enrolled. The combination of number of positive LNs and LNs with ENE that had the highest C-index were identified with multivariable Cox proportional hazards models. ENE number was incorporated into the current system considering the recurrence rate and unadjusted and adjusted hazard ratios (HRs) of the subgroups. Kaplan-Meier curves for recurrence based on current and alternative systems were compared by log-rank test. Results: The recurrence rate for the subgroup with five or fewer positive LNs and one to three ENEs (7/61; 11.5%) was higher than that of the subgroup with five or fewer positive LNs without ENE (5/129; 3.9%; adjusted HR = 3.42 [confidence interval (CI) 0.99-11.75]; p = 0.050). In contrast, adjusted HRs of the subgroup with more than five positive LNs and one to three ENEs (2.33 [CI 0.52-10.35]) or with four or more ENEs (3.86 [CI 1.05-14.17]) were not higher than those of the subgroup with more than five LNs without ENE (4.47 [1.16-17.19]). Incorporating ENE into the current system as an intermediate-risk group yielded a lower log-rank p-value (0.05 vs. 0.01) than the current system. Conclusions: The presence of ENE in low volume LN metastasis confers an intermediate risk of recurrence. Incorporating ENE into the current system allows more accurate decisions regarding further management of PTC N1 patients.

Influence of Body Mass Index on the Clinicopathologic Features of Papillary Thyroid Carcinoma

BACKGROUND

Epidemiologic studies have demonstrated an increased risk for papillary thyroid carcinoma (PTC) with increasing body mass index (BMI). However, the relationships between excess weight and the behavior of PTC are inconsistent. The aim of this study was to evaluate the impact of excess weight on clinicopathologic features of PTC and on patient outcomes.

METHODS

Data from 417 patients with PTC who underwent total thyroidectomy with cervical lymph node dissection were retrospectively analyzed. On the basis of World Health Organization standardized categories of BMI, patients were divided into 4 groups: underweight, normal weight, overweight, and obese. Histopathologic tumor features, stage at diagnosis, and disease status were determined by chart review. Logistic regression models were used to define associations between BMI and clinicopathologic features of PTC. Cox proportional-hazards models were used to assess associations between BMI and locoregional recurrence.

RESULTS

Overweight (odds ratio [OR], 3.90; P = .040) and obesity (OR, 9.19; P = .012) were independent predictors of vascular invasion. Furthermore, obesity (OR, 6.14; P = .004) was an independent predictor of extrathyroidal invasion. During follow-up (median, 29 months; range, 5-87 months), 48 patients (11.5%) experienced locoregional recurrence. There were no significant differences in locoregional recurrence of PTC among BMI groups. When adjusted for other confounding factors, extrathyroidal invasion (OR, 8.35; P < .001), vascular invasion (OR, 3.57; P < .001), cervical lymph node metastasis (OR, 3.71; P = .009), and advanced tumor-node-metastasis stage (OR, 3.81; P < .001) were identified as independent factors for locoregional recurrence.

CONCLUSIONS

Higher BMI was associated with extrathyroidal invasion and vascular invasion in patients with PTC, which suggests that excess weight is associated with aggressive clinicopathologic features of PTC. But patients with higher BMI did not have an increased risk for developing postoperative complications and locoregional recurrence.

The Prevalence of Extranodal Extension in Papillary Thyroid Cancer Based on the Size of the Metastatic Node: Adverse Histologic Features Are Not Limited to Larger Lymph Nodes

Extranodal extension (ENE) is a prognostic indicator of aggressiveness for papillary thyroid cancer (PTC). The association between the size of metastatic nodes and the prevalence of ENE has not been previously explored. However, there is a common belief that small lymph nodes with metastatic disease do not significantly impact patient outcome. This study investigates the relationship between the prevalence of ENE and the size of a positive lymph node. Linear dimensions and malignant histological characteristics of 979 metastatic lymph nodes from 152 thyroid cancer patients were retrospectively analyzed. Data was analyzed using chi-square tests and multilevel logistic regression modeling. ENE was present in 144 of 979 lymph nodes; the sizes of the involved lymph nodes ranged from 0.9 to 44 mm. ENE was identified in 7.8% of lymph nodes measuring ≤ 5 mm, 18.9% between 6 and 10 mm, 23.1% between 11 and 15 mm, 25.0% between 16 and 20 mm, and 14.0% between 21 and 25 mm in size. The association between node size and ENE status was significant (odds ratio (OR) = 1.07, confidence interval (CI) = [1.04, 1.11]). The size of the metastatic focus directly correlated with ENE (OR = 1.07, 95% CI = [1.07, 1.14], p value < 0.001). Increasing lymph node size increases the likelihood of ENE for metastatic PTC. Importantly, small positive lymph nodes can also harbor ENE to a significant extent. Further studies are required to determine the clinical and prognostic significance of lymph node size and the presence of ENE.

Dynamic risk stratification in the follow-up of thyroid cancer: what is still to be discovered in 2017?

The adequate risk stratification in thyroid carcinoma is crucial to avoid on one hand the overtreatment of low-risk and on the other hand the undertreatment of high-risk patients. The question how to properly assess the risk of relapse has been discussed during recent years and resulted in a substantial change in our approach to risk stratification in differentiated thyroid cancer, proposed by the newest ATA guidelines. First initial risk stratification, based on histopathological data is carried out just after primary surgery. It should be emphasized, that a high quality of histopathological report is crucial for proper risk stratification. Next, during the follow-up, patients are restratified considering their response to treatment applied and classified to one of the following categories: excellent response, biochemical incomplete response, structural incomplete or indeterminate response. This new approach is called dynamic risk stratification as, in contrary to the previous rigid evaluation performed at diagnosis, reflects a real-time prognosis and thereby substantially influences and personalizes disease management. In this review, we raise some unresolved questions, among them the lack of prospective studies, fulfilling evidence-based criteria, necessary to validate this model of risk stratification. We also provided some data concerning the use of dynamic risk stratification in medullary thyroid cancer, not yet reflected in ATA guidelines. In conclusion, dynamic risk stratification allows for better prediction of the risk of recurrence in thyroid carcinoma, what has been demonstrated in numerous retrospective analyses. However, the validation of this approach in prospective studies seems to be our task for near future.

Prognostic markers in well differentiated papillary and follicular thyroid cancer (WDTC)

OBJECTIVES

WDTC (papillary and follicular thyroid cancer) make up around 90% of all thyroid tumours. Overall, the prognosis in patients with WDTC is excellent. However, there are small cohorts of patients who experience a more aggressive form of disease which is often associated with certain poor prognostic factors. Identifying these patients at an early stage is imperative for guiding treatment decisions. With recent developments in this area we plan to discuss the current evidence surrounding prognostic markers.

METHODS

The literature regarding prognostic factors in WDTC was reviewed using an electronic database Medline - Pubmed. Using the MeSH search engine specific prognostic factors including age, size, grade, lymph node involvement, distant metastasis, extension/invasion, ethnic background, radioactive iodine avidity, and thyroglobulin level and their association with WDTC were evaluated. A broader search of prognostic markers in thyroid cancer was also carried out to avoid missing other pertinent markers.

RESULTS

Multiple clinical and pathologic variables have been shown to be poor prognostic factors in WDTC with statistical significance. Extensive extrathyroidal extension and age may be the most important factors when predicting clinical outcomes in WDTC, although the age threshold may be increased from 45 to 55 years in due course.

CONCLUSIONS

Management of WDTC has changed considerably over the last two years as reflected in evolving British and American Thyroid Guidelines. In all cases a combined multi-disciplinary approach, with consideration of the available guidelines and stratification systems should be utilised when planning an individualised treatment program to offer the best contemporary care to WDTC patients.

[Taste dysfunction (dysgeusia) and radioiodine therapy of thyroid cancer - be aware of side effects by antidepressants and sedatives. Vorschädigung durch Antidepressiva und Sedativa beachten]

In addition to xerostomia, taste dysfunction (hypo-, dysgeusia) is an independent side effect of radioiodine therapy of thyroid cancer. Hypogeusia results from damage of the small mucous salivary glands in the vicinity of the taste buds. Particularly in those patients, who are treated with drugs such as antidepressants or sedatives, taste dysfunction becomes frequently clinically symptomatic. If feasible, therapy regimens bearing a potential risk for taste dysfunction should be switched. Additional damage to taste function should be minimalized, including cessation of smoking, change of agents for dental hygiene, and change of toothpaste. If the medical indication for ablative radioiodine therapy is based on the patient's decision, the patient should be informed about alternative strategies. Potential clinical consequences of the sialadenitis (xerostomia, alteration in taste, risk of caries and tooth extraction, lacrimal gland dysfunction, tearing and need of dacryocystorhinostomy) should be revealed completely. Adapted to the initial risk of relapse, the ¹³¹I-activity for ablation should be reduced to the latest standard of care. Clinical data are currently too heterogeneous to decide whether rhTSH might reduce the rate of dysgeusia. The specialist in nuclear medicine should be aware of the multifactorial causes of taste dysfunction, in particular if the patient seeks medical advice after radioiodine therapy.

Differentiated and Medullary Thyroid Cancer: Surgical Management of Cervical Lymph Nodes

Thyroid cancer metastasises to the central and lateral compartments of the neck frequently and early. The impact of nodal metastases on outcome is affected by the histological subtype of the primary tumour and the patient's age, as well as the size, number and location of those metastases. The impact of extranodal extension has recently been highlighted as an important prognosticating factor. Although clinically evident nodal disease in the lateral neck compartments has a significant impact on both survival and recurrence, microscopic metastases to the central or the lateral neck in well-differentiated thyroid cancer do not significantly affect outcome. Here we discuss the surgical management of neck metastases in well-differentiated and medullary thyroid carcinoma.

Genome-Wide Expression Screening Discloses Long Noncoding RNAs Involved in Thyroid Carcinogenesis

CONTEXT

Long noncoding RNAs (lncRNAs) regulate pathological processes, yet their potential roles in papillary thyroid carcinoma (PTC) are poorly understood.

OBJECTIVE

To profile transcriptionally dysregulated lncRNAs in PTC and identify lncRNAs associated with clinicopathological characteristics.

DESIGN

We performed RNA sequencing of 12 paired PTC tumors and matched noncancerous tissues and correlated the expression of lncRNAs with clinical parameters. The 2 most significantly dysregulated lncRNAs were studied in an Ohio PTC cohort (n = 109) and in PTC data (n = 497) from The Cancer Genome Atlas.

SETTING

A combination of laboratory-based studies and computational analysis using clinical data and samples and a publically available database.

MAIN OUTCOME MEASURES

Correlation between expression values and clinical parameters.

RESULTS

We identified 218 lncRNAs showing differential expression in PTC (fold change ≥ 2.0, P < .01). Significant correlation was observed between the expression of 2 lncRNAs (XLOC_051122 and XLOC_006074) and 1) lymph node metastasis (N stage) and 2) BRAF(V600E) mutation. Among patients with wild-type BRAF, the expression of these 2 lncRNAs showed significantly higher levels in the patients with lymph node metastasis. In silico analysis of these lncRNAs pinpointed cell movement and cellular growth and proliferation as targeted functions.

CONCLUSIONS

Comprehensive expression screening identified 2 novel lncRNAs associated with risk factors of adverse prognosis in PTC patients. These lncRNAs may be novel players in PTC carcinogenesis.