Surgical management of primary thyroid tumours

Pathological findings of the retrospective diagnosis of NIFTP (non-invasive follicular thyroid neoplasm with papillary-like nuclear features) in 84 cases from Turkey and systematic review

AIM

The terminology of "noninvasive follicular thyroid neoplasm with papillary-like nuclear features" (NIFTP) was introduced in 2016; and estimated to cause significant effects in the clinical management of thyroid nodules. The aim of our study is to review our cases that were previously diagnosed as non-invasive encapsulated follicular variant PTC (NI/E-FVPTC) which are compatible with NIFTP and to correlate their follow-up.

METHOD

All thyroidectomy cases evaluated in the last 15 years were screened, and possible NIFTP cases were determined among patients with NI/E-FVPTC and they were re-examined microscopically. Revised histopathological criteria were used for the retrospective diagnosis of NIFTP. Histopathological findings were correlated to follow up information.

RESULTS

Totally 2138 cases had been previously diagnosed with PTC; 481 (22.5%) of them were FVPTC. After microscopic reevaluation of potential NIFTP cases, 84 cases (3.9%) received final diagnosis of NIFTP. 78.6% of NIFTP patients were female (F/M: 66/18); mean age was 49.0, tumor diameter was 22.7 mm and follow-up time was 66.4 months. 17.9% of NIFTP cases were multifocal and 13.1% were bilateral. No recurrence, lymph node involvement or distant metastasis was detected in any of the patients who were followed up. The mean age of the patients who had total thyroidectomy and received RAI was significantly higher than those who did not.

CONCLUSION

Although conservative treatment of NIFTP with lobectomy is recommended, age of the patients has been continuing to be the most important determinant for the clinicians to decide on total thyroidectomy and RAI ablation therapy at our institution.

Identifying Thyroid Carcinoma-Related Genes by Integrating GWAS and eQTL Data

Thyroid carcinoma (TC) is the most common endocrine malignancy. The incidence rate of thyroid cancer has increased rapidly in recent years. The occurrence and development of thyroid cancers are highly related to the massive genetic and epigenetic changes. Therefore, it is essential to explore the mechanism of thyroid cancer pathogenesis. Genome-Wide Association Studies (GWAS) have been widely used in various diseases. Researchers have found multiple single nucleotide polymorphisms (SNPs) are significantly related to TC. However, the biological mechanism of these SNPs is still unknown. In this paper, we used one GWAS dataset and two eQTL datasets, and integrated GWAS with expression quantitative trait loci (eQTL) in both thyroid and blood to explore the mechanism of mutations and causal genes of thyroid cancer. Finally, we found rs1912998 regulates the expression of IGFALS (P = 1.70E-06) and HAGH (P = 5.08E-07) in thyroid, which is significantly related to thyroid cancer. In addition, KEGG shows that these genes participate in multiple thyroid cancer-related pathways.

The Impact of the Extent of Surgery on the Long-Term Outcomes of Patients with Low-Risk Differentiated Non-Medullary Thyroid Cancer: A Systematic Meta-Analysis

Recently, the management of patients with low-risk differentiated non-medullary thyroid cancer (DTC), including papillary and follicular thyroid carcinoma subtypes, has been critically appraised, questioning whether these patients might be overtreated without a clear clinical benefit. The American Thyroid Association (ATA) guideline suggests that thyroid lobectomy (TL) could be a safe alternative for total thyroidectomy (TT) in patients with DTC up to 4 cm limited to the thyroid, without metastases. We conducted a meta-analysis to assess the clinical outcomes in patients with low-risk DTC based on the extent of surgery. The risk ratio (RR) of recurrence rate, overall survival (OS), disease-free survival (DFS) and disease specific survival (DSS) were estimated. In total 16 studies with 175,430 patients met the inclusion criteria. Overall, low recurrence rates were observed for both TL and TT groups (7 vs. 7%, RR 1.10, 95% CI 0.61-1.96, I² = 72%), and no statistically significant differences for OS (TL 94.1 vs. TT 94.4%, RR 0.99, CI 0.99-1.00, I² = 53%), DFS (TL 87 vs. TT 91%, RR 0.96, CI 0.89-1.03, I² = 85%), and DSS (TL 97.2 vs. TT 95.4%, RR 1.01, CI 1.00-1.01, I² = 74%). The high degree of heterogeneity of the studies is a notable limitation. Conservative management and appropriate follow-up instead of bilateral surgery would be justifiable in selected patients. These findings highlight the importance of shared-decision making in the management of patients with small, low-risk DTC.

Differentiated Thyroid Cancer: How Do Current Practice Guidelines Affect Management?

BACKGROUND

International best-practice guidelines recommend completion thyroidectomy and radioiodine remnant ablation (RRA) for patients with differentiated thyroid cancer (DTC) > 4 cm or with specific risk factors. Patients with DTC < 1 cm without risk factors are recommended for lobectomy alone. Indications for aggressive surgery and RRA are less clearly defined for tumours measuring 1-4 cm. A personalised approach to decision-making is recommended.

OBJECTIVES

This study assesses therapeutic approaches to DTC as compared to the current British Thyroid Association (BTA) clinical practice guidelines. We ascertained the effect of equivocal guidance in the 1-4 cm tumour cohort on contemporary practice patterns.

METHODS

Data were obtained from a prospectively maintained thyroid cancer database of patients treated for DTC in a tertiary referral centre at the University Hospital Galway. Consecutive patients attending a dedicated thyroid cancer clinic between August 2014 and August 2017 were included. Clinicopathological characteristics and management strategies were assessed.

RESULTS

Ninety-four percent (n = 168/178) of patients were surgically managed in adherence with guidelines. A minority (n = 10) received surgery not aligned with guidelines. Ninety-seven percent (n = 172/178) of RRA treatment decisions were in accordance with guidelines. The BTA guidelines recommended a personalised decision-making approach for 18.0% (n = 32) and 44.9% (n = 80) of surgery and RRA treatment decisions, respectively. The more aggressive, treatment-driven approach was typically favoured by the multidisciplinary team, with 97% (n = 31/32) undergoing completion thyroidectomy and 100% (n = 80) proceeding to RRA.

CONCLUSIONS

Management of DTC at our institution closely adheres to contemporary clinical practice guidelines. The finding of more aggressive management in those requiring a personalised decision-making approach highlights the requirement for improved risk stratification in this cohort to ratio-nalise management strategies.

Surgical management for follicular variant of papillary thyroid carcinoma

Background and Aims

For most patients with follicular variant of papillary thyroid carcinoma (FVPTC), surgery is required, while the surgical management remains controversial. We aim to further understanding of treatment of FVPTC and to determine whether specific features could be identified for the decision of surgical strategy.

Materials and Methods

Data were obtained from the Surveillance, Epidemiology, and End Results (SEER) Program database during 2003 and 2013. 26700 patients were eligible and stratified by tumor size or extension. Survival rates were compared using multivariate Cox proportional hazard regressions.

Results

Of the total death of 1041, 136 patients died from thyroid cancer. Most patients (79.1%) underwent total thyroidectomy while only a little part of patients (8.2%) underwent lobectomy. Patients receiving radioisotopes had significantly better overall survival (OS) (HR = 0.659, P < 0.001), but showed no differences on disease-specific survival (DSS). No statistical difference was found between total thyroidectomy and lobectomy in multivariate analysis when controlling for tumor size. While for tumor > 2 cm with extrathyroidal extension, lobectomy had significantly worse OS (aHR = 3.364, P = 0.010) and DSS (aHR = 5.494, P = 0.032) compared to total thyroidectomy. Multivariate analysis demonstrated that advanced age, male, higher grade, extrathyroidal extension, lymph nodes metastases and distant metastases had negative effects on OS and DSS controlling for the remaining variables (each P < 0.05).

Conclusions

The results of our study revealed total thyroidectomy could benefit the survival for patients whose tumors > 2 cm with extrathyroidal extension, total thyroidectomy should be recommended for those patients. Lots of factors should be taken into consideration on the decision of surgical treatment.

Sympathetic Nerve Injury in Thyroid Cancer

The double innervation of the thyroid comes from the sympathetic and parasympathetic nervous system. Injury rates during surgery are at 30% but can be minimized by upwardly preparing the thyroid vessels at the level of thyroid capsule. Several factors have been accused of increasing the risk of injury including age and tumor size. Our aim was to investigate of there is indeed any possible correlations between these factors and a possible increase in injury rates following thyroidectomy. Seven studies were included in the meta-analysis. Statistical correlation was observed for a positive relationship between injury of the sympathetic nerve and thyroid malignancy surgery (p 2 = 74%) No statistical correlations were observed for a negative or positive relationship between injury of the sympathetic nerve and tumor size. There was also no statistically significant value observed for the correlation of the patients' age with the risk of sympathetic nerve injury (p = 0.388). Lack of significant correlation reported could be due to the small number of studies and great heterogeneity between them.