Intraoperative Pathologic Examination in the Era of Molecular Testing for Differentiated Thyroid Cancer

Thyroid nodules of indeterminate cytology in Hispanic/Latinx patients

BACKGROUND

Behavior of differentiated thyroid cancer (DTC) varies among ethnic groups. Recommended management of thyroid nodules with indeterminate cytology (TN-IC) is based on molecular analysis from predominantly non-Hispanic white patients. We hypothesized that TN-IC in Hispanic/Latinx patients would have different features, management, and outcomes and that molecular testing might perform differently in Hispanic/Latinx patients.

METHODS

Retrospective chart review was performed on 127 TN-IC analyzed with Afirma. Patient characteristics were compared using linear model ANOVA and Fisher's exact test.

RESULTS

Out of 127 TN-IC, 71 (56%) were Hispanic/Latinx. Hispanic/Latinx had a greater prevalence of diabetes, but Afirma results (benign or suspicious) were similar between ethnic groups. Fourteen patients had malignant pathology. Their management and outcomes were similar across groups. The negative predictive value for our cohort (97.9%) was similar to published data.

CONCLUSIONS

Data from our predominantly-Hispanic/Latinx cohort suggest that Afirma performs similarly in Hispanic/Latinx and non-Hispanic white patients with TN-IC.

Utility of intraoperative frozen sections of thyroid tissue in the age of molecular testing

OBJECTIVES

Our study aims to examine the correlation between preoperative ultrasound-guided fine-needle aspiration and intraoperative frozen section and examine the clinical benefit of frozen section in the context of the latest national guidelines on the management of differentiated thyroid cancer.

STUDY DESIGN

A retrospective review of thyroid frozen section from 2012 to2017 at one institution.

SETTING

Tertiary care centre.

PARTICIPANTS/MAIN OUTCOME

Patient demographics, fine-needle aspiration results, molecular testing results, frozen section diagnosis (classified as benign, indeterminate, or malignant), final pathologic diagnosis, initial planned surgery, actual surgery performed, need for additional surgery and complications were recorded. Complications included hematoma formation, hypocalcaemia (requiring readmission, symptomatic, or >24-hour stay post op) and recurrent or superior laryngeal nerve damage.

RESULTS

728 total patients had an intraoperative frozen section performed. A Thy 4/Bethesda V USGFNA diagnosis (n = 55) significantly correlated with a clinically important intraoperative frozen section (n = 17, P < .01). Intraoperative management was changed by the frozen section 53 times (7.2%). Molecular testing was sent on 92 USGFNA specimens, 80 of which were deemed "suspicious." Of the 49 patients whose management was upstaged intraoperatively, 29 (59%) would not necessitate a completion thyroidectomy under the latest UK and ATA guidelines based on final pathology.

CONCLUSION

Intraoperative frozen sections rarely alter the pre-surgical plan and indeed may result in expanded surgery that could have been avoided based on latest UK and US guidelines. Molecular testing of indeterminate fine-needle aspiration results does not appear to predict meaningful intraoperative frozen section results.

Molecular testing for cytologically suspicious and malignant (Bethesda V and VI) thyroid nodules to optimize the extent of surgical intervention: a retrospective chart review

Background

Molecular testing has been used for cytologically indeterminate thyroid nodules (Bethesda III and IV), where the risk of malignancy is 10–40%. However, to date, the role of molecular testing in cytologically suspicious or positive for malignancy (Bethesda V and VI) thyroid nodules has been controversial. The aim of this study was to determine whether patients who had molecular testing in Bethesda V and VI thyroid nodules had the optimal extent of surgery performed more often than patients who did not have molecular testing performed.

Methods

A retrospective chart review of 122 cases was performed: 101 patients from the McGill University teaching hospitals and 21 patients from the Hillel Yaffe Medical center, Technion University. Patients included in the study were those with Bethesda V or VI thyroid nodules who underwent molecular testing (ThyGenext® or ThyroseqV3®) (McGill n = 72, Hillel Yaffe n = 14). Patients with Bethesda V or VI thyroid nodules who did not undergo molecular testing were used as controls (McGill n = 29, Hillel Yaffe n = 7). Each case was reviewed in order to determine whether the patient had optimal surgery. This was defined as total thyroidectomy in the presence of either a positive lymph node, extrathyroidal extension, or an aggressive pathological variant of papillary thyroid carcinoma (tall cell, hobnail, columnar cell, diffuse sclerosing, and solid/trabecular) documented on the final pathology report. In all other cases, a lobectomy/hemi/subtotal thyroidectomy was considered as optimal surgery. Chi-squared testing was performed to compare groups.

Results

When molecular testing was done, 91.86% (79/86) of surgeries in the molecular testing group were optimal, compared to 61.11% (22/36) in the control group. At McGill University teaching hospitals and at Hillel Yaffe, 91.67% (66/72) and 92.86% (13/14) of surgeries in the intervention group were considered as optimal, respectively. This compares to 58.62% (17/29) at McGill and 71.43% (5/7) at Hillel Yaffe when molecular testing was not performed (p = .001, p = .186).

Conclusions

In this study, molecular testing in Bethesda V and VI thyroid tumors significantly improved the likelihood of optimal surgery. Therefore, molecular testing may have an important role in optimizing surgical procedures performed in the setting of Bethesda V and VI thyroid nodules. Prospective studies with larger sample sizes are required to further investigate this finding.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s40463-021-00500-6.

Decision Making in Indeterminate Thyroid Nodules and the Role of Molecular Testing

Cytologically indeterminate thyroid nodules are associated with a broad range (5%-75%) of malignant risk and accurately informing definitive management poses a challenge. Advancements in molecular testing of fine-needle aspiration biopsies have improved preoperative diagnostic accuracy and prognostication. For indeterminate nodules, such testing ideally will reduce the need for surgery for benign nodules and potentially guide appropriate extent of initial surgery for malignancy.

The contemporary utility of intraoperative frozen sections in thyroid surgery

PURPOSE

To determine the accuracy of intraoperative frozen section analysis on thyroidectomy specimens stratified by the Bethesda classification scheme and its utility for intraoperative decision-making.

STUDY DESIGN

Retrospective chart review.

METHODS

A retrospective review was performed on all patients who underwent thyroidectomy or thyroid lobectomy with intraoperative frozen sections at a tertiary care academic center from 2009 to 2015.

RESULTS

There were 74 total patients who underwent partial or total thyroidectomy with intraoperative frozen section analysis of a thyroid nodule whom had previously undergone a thyroid fine needle aspiration of the nodule. The sensitivity, specificity, positive predictive value, and negative predictive value for a thyroid frozen section with respect to its prediction for malignancy was 81%, 95%, 98%, and 66%, respectively, with a diagnostic accuracy of 85%. For 37 patients with an indeterminate cytologic diagnosis on fine needle aspiration (Bethesda categories III-V), the sensitivity, specificity, positive predictive value, and negative predictive value for a thyroid frozen section was 81%, 91%, 95%, and 67%, respectively, with a diagnostic accuracy of 84%. False positives and false negatives resulted in 1 completion thyroidectomy for benign pathology and 3 reoperations for malignancy not discovered on frozen section.

CONCLUSION

While intraoperative frozen sections on thyroid specimens may be helpful if positive, the false negative rate remains high. There appears to be limited value in routine frozen sections to guide clinical management and decision-making in the era of the Bethesda system.

Cost-effectiveness of Gene Expression Classifier Testing of Indeterminate Thyroid Nodules Utilizing a Real Cohort Comparator

Objective

To predict the cost-effectiveness of implementing routine gene expression classifier testing for thyroid nodules with indeterminate fine-needle aspiration cytology, by utilizing a real cohort of patients as a comparator.

Study Design

Cost-effectiveness analysis of a retrospective cohort compared with a simulated cohort.

Setting

Tertiary academic medical center.

Subjects and Methods

We reviewed the records of all patients who underwent ultrasound-guided fine-needle aspiration from 2010 to 2014 at a tertiary academic medical center. All patients with Bethesda class III or IV cytopathology had the details of their management catalogued over the subsequent 2 years of care. These patients were assigned to the standard-of-care arm of the study. We compared the third-party payer costs of care and the proportion of patients who underwent surgery with a simulated cohort who underwent gene expression classifier testing after an initial indeterminate fine-needle aspiration (molecular test arm).

Results

The cost of managing 1 nodule over 2 years was $2399 higher (range, $397-$4399) for the molecular test group than the standard of care group. The molecular test group had a 13.1% decrease (base parameters; range, 0.73%-45.09%) in the number of patients undergoing surgery.

Conclusion

When applied to a real cohort of patients, routine gene expression classifier is predicted to reduce the number of patients undergoing surgery but will increase cost of care. Cost-effectiveness is heavily dependent on prevalence of malignancy and gene expression classifier specificity.

[Thyroid cancers: from epidemiology to molecular biology]

Experts increasingly recognize the hypothesis of "over-diagnosis" as the main factor of the raising incidence of thyroid cancers (TC). The detection of multiple microtumors, mainly of a papillary type, at a sub-clinical stage, with the use of sensitive detection methods supports this hypothesis. However, the intensive management and monitoring of these cancers failed to reduce mortality. Environmental and other risk factors cannot provide a sufficient explanation, as previously thought. In this context, the use of improved tools is needed, and the most promising perspective lies in molecular biology applied to thyroid cancer for diagnosis, evaluation of prognosis and treatment. The next generation sequencing (NGS) has demonstrated its diagnostic performances in recent clinical trials. Its interest in cases with indeterminate cytology is demonstrated and should help better targeting surgical indications. Its promising prognostic and therapeutic applications must be confirmed by additional studies. The integration of NGS in current practice should have a real medical, economic and scientific impact. Indeed, the exponential increase in our knowledge of molecular mechanisms of thyroid tumorigenesis strengthens the will to "reclassify" these cancers into molecular rather than histological subtypes, in order to offer patients more specific and targeted treatment.

2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer: The American Thyroid Association Guidelines Task Force on Thyroid Nodules and Differentiated Thyroid Cancer

BACKGROUND

Thyroid nodules are a common clinical problem, and differentiated thyroid cancer is becoming increasingly prevalent. Since the American Thyroid Association's (ATA's) guidelines for the management of these disorders were revised in 2009, significant scientific advances have occurred in the field. The aim of these guidelines is to inform clinicians, patients, researchers, and health policy makers on published evidence relating to the diagnosis and management of thyroid nodules and differentiated thyroid cancer.

METHODS

The specific clinical questions addressed in these guidelines were based on prior versions of the guidelines, stakeholder input, and input of task force members. Task force panel members were educated on knowledge synthesis methods, including electronic database searching, review and selection of relevant citations, and critical appraisal of selected studies. Published English language articles on adults were eligible for inclusion. The American College of Physicians Guideline Grading System was used for critical appraisal of evidence and grading strength of recommendations for therapeutic interventions. We developed a similarly formatted system to appraise the quality of such studies and resultant recommendations. The guideline panel had complete editorial independence from the ATA. Competing interests of guideline task force members were regularly updated, managed, and communicated to the ATA and task force members.

RESULTS

The revised guidelines for the management of thyroid nodules include recommendations regarding initial evaluation, clinical and ultrasound criteria for fine-needle aspiration biopsy, interpretation of fine-needle aspiration biopsy results, use of molecular markers, and management of benign thyroid nodules. Recommendations regarding the initial management of thyroid cancer include those relating to screening for thyroid cancer, staging and risk assessment, surgical management, radioiodine remnant ablation and therapy, and thyrotropin suppression therapy using levothyroxine. Recommendations related to long-term management of differentiated thyroid cancer include those related to surveillance for recurrent disease using imaging and serum thyroglobulin, thyroid hormone therapy, management of recurrent and metastatic disease, consideration for clinical trials and targeted therapy, as well as directions for future research.

CONCLUSIONS

We have developed evidence-based recommendations to inform clinical decision-making in the management of thyroid nodules and differentiated thyroid cancer. They represent, in our opinion, contemporary optimal care for patients with these disorders.

American Thyroid Association Statement on Surgical Application of Molecular Profiling for Thyroid Nodules: Current Impact on Perioperative Decision Making

BACKGROUND

Recent advances in research on thyroid carcinogenesis have yielded applications of diagnostic molecular biomarkers and profiling panels in the management of thyroid nodules. The specific utility of these novel, clinically available molecular tests is becoming widely appreciated, especially in perioperative decision making by the surgeon regarding the need for surgery and the extent of initial resection.

METHODS

A task force was convened by the Surgical Affairs Committee of the American Thyroid Association and was charged with writing this article.

RESULTS/CONCLUSIONS

This review covers the clinical scenarios by cytologic category for which the thyroid surgeon may find molecular profiling results useful, particularly for cases with indeterminate fine-needle aspiration cytology. Distinct strengths of each ancillary test are highlighted to convey the current status of this evolving field, which has already demonstrated the potential to streamline decision making and reduce unnecessary surgery, with the accompanying benefits. However, the performance of any diagnostic test, that is, its positive predictive value and negative predictive value, are exquisitely influenced by the prevalence of cancer in that cytologic category, which is known to vary widely at different medical centers. Thus, it is crucial for the clinician to know the prevalence of malignancy within each indeterminate cytologic category, at one's own institution. Without this information, the performance of the diagnostic tests discussed below may vary substantially.

Translational research in endocrine surgery

This article reviews translational research in endocrine surgery, with a focus on disorders of the thyroid, parathyroids, adrenals, and endocrine pancreas. Discovery of genes responsible for heritable endocrine cancer syndromes has increased knowledge of the causes and mechanisms of endocrine cancer and has refined surgical treatment options. Knowledge of mutations in sporadic cancer has led to rapid progress in small-molecule kinase inhibitor strategies. These breakthroughs and their influence on current therapy are discussed to provide surgeons with an overview of the basic science research currently creating new clinical treatments and improving patient care.