Which papillary thyroid microcarcinoma should be treated as "true cancer" and which as "precancer"?

Preferred labels and language to discuss low-risk lesions that may be cancer precursors: A review

OBJECTIVES

Patients diagnosed with low-risk lesions are confused about whether they have cancer, and experience similar anxiety to those with invasive cancer, which affects quality of life. Current labels for low-risk lesions were chosen by clinicians and lack meaning to patients.

METHODS

We reviewed published research on preferred labels and language for low-risk lesions, and the rationale for those preferences.

RESULTS

Of 6569 titles screened, we included 13 studies. Among healthy adults with cervix or prostate lesions, use of the term "cancer" rather than "nodule" or "lesion" resulted in greater anxiety, higher perceived disease severity, and selection of more invasive treatment. Physicians asked about removing "carcinoma" from thyroid lesion labels to reduce patient anxiety and discourage over-treatment did not support this change, instead preferring a term that included "neoplasm".

CONCLUSIONS

This review revealed a startling paucity of research on preferences for low-risk lesion labels and language, and associated rationale. Future research is needed to understand how to improve communication about low-risk lesions.

PRACTICE IMPLICATIONS

To reduce anxiety and improve the overall well-being of patients, it is crucial to gain a deeper understanding of how to improve patient-provider conversations regarding screen-detected lesions with a low risk of developing into invasive cancer.

The overtreatment of papillary thyroid microcarcinoma in the community

INTRODUCTION

Total thyroidectomy is the traditional primary approach for papillary thyroid cancer. However, recent evidence supports conservative management for low-risk tumors like papillary thyroid microcarcinomas (PTMCs). This study explores the adoption of these practices in our community, using a cancer database to analyze treatment strategies.

METHODS

A retrospective review of a 1433-patient institutional database identified 258 ​PTMC cases. Outcomes, including 30-day mortality, reoperation rate, postoperative hypocalcemia, and recurrent laryngeal nerve (RLN) injury, were assessed.

RESULTS

Of PTMC patients, 63.4% underwent total thyroidectomy, with higher rates of RLN injury (8.8% vs. 2.3%) and hypocalcemia (12.4% vs. 0.0%) compared to lobectomy. Non-endocrine surgeons had higher postoperative radioactive iodine administration rates (28.6% vs. 6.1%). Subgroup analysis revealed a shift in total thyroidectomy rates based on tumor size and surgery period.

CONCLUSION

Our community favors total thyroidectomy for PTMC, despite associated complications. Enhanced awareness and adherence to PTMC best practice guidelines are warranted.

Survival benefits of extensive surgery in patients with papillary thyroid microcarcinoma

BACKGROUND

Despite the guidelines recommending thyroid lobectomy, many papillary thyroid microcarcinoma (PTMC) patients still undergo total thyroidectomy. PTMC's optimal treatment remains unclear. We aimed to determine whether total thyroidectomy improves outcomes compared to less extensive surgery.

METHODS

We analyzed 6064 PTMC adult patients from the Surveillance, Epidemiology, and End Results (SEER) database (2000-2019) who underwent either total thyroidectomy (n ​= ​3652) or less extensive surgery (n ​= ​2412). Endpoints were overall survival, cancer-specific survival, and recurrence.

RESULTS

Total thyroidectomy patients had a 5.2 ​% mortality rate versus 8.1 ​% with less extensive surgery. Recurrence occurred in 1 (0.03 ​%) total thyroidectomy patient compared to 24 (1.0 ​%) less extensive surgery patients (HR 0.07, p ​= ​0.01). Median survival was 8.1 years for total thyroidectomy versus 8.8 years for less extensive surgery. Overall survival favored total thyroidectomy (p ​= ​0.001) but cancer-specific survival did not differ.

CONCLUSION

Although total thyroidectomy may not improve cancer-specific survival, it lowers recurrence risk and confers an overall survival advantage for PTMC patients. These findings may help guide surgical decisions.

The Incidence Trend and Management of Thyroid Cancer-What Has Changed in the Past Years: Own Experience and Literature Review

Because of ambiguous and widely debated observations concerning the incidence, trend, and management of TC, we performed this analysis. We drew attention to some events, such as "cancer screening activity", introduction of noninvasive follicular neoplasm with papillary-like nuclear features (NIFTP) to TC types, possibility of papillary thyroid microcarcinoma (PTMC) active surveillance (AS), occurrence of personalized medicine in TC management, and, finally, COVID-19 pandemic time. Because of the opinion that all changes have been made mostly by PTC, we compared it to the remaining types of TC in terms of incidence, clinical and pathological characteristics, and treatment. We analyzed patients treated in a single surgical center in eastern Europe (Poland). The prevalence of TC significantly increased from 5.15% in 2008 to 13.84% in 2015, and then significantly decreased to 1.33% in 2022 when the COVID-19 pandemic lasted (p < 0.0001). A similar trend was observed for PTC, when the incidence significantly increased to 13.99% in 2015 and then decreased to 1.38% in 2022 (p < 0.0001). At that time, the NIFTP category was introduced, and observation of PTMC began. The prevalence of FTC and MTC also increased until 2015 and then decreased. Significant differences in age, types of surgery, necessity of reoperation, and pTNM between PTCs and other types of TCs were observed. The average age was significantly lower in PTC patients than in patients with the remaining types of TC (p < 0.0001). Four milestones, including NIFTP introduction, the possibility of PTMC AS, personalized cancer medicine, and the COVID-19 pandemic, may have influenced the general statistics of TC.

Cellular Adaptation Takes Advantage of Atavistic Regression Programs during Carcinogenesis

Adaptation of cancer cells to extreme microenvironmental conditions (i.e., hypoxia, high acidity, and reduced nutrient availability) contributes to cancer resilience. Furthermore, neoplastic transformation can be envisioned as an extreme adaptive response to tissue damage or chronic injury. The recent Systemic-Evolutionary Theory of the Origin of Cancer (SETOC) hypothesizes that cancer cells "revert" to "primitive" characteristics either ontogenically (embryo-like) or phylogenetically (single-celled organisms). This regression may confer robustness and maintain the disordered state of the tissue, which is a hallmark of malignancy. Changes in cancer cell metabolism during adaptation may also be the consequence of altered microenvironmental conditions, often resulting in a shift toward lactic acid fermentation. However, the mechanisms underlying the robust adaptive capacity of cancer cells remain largely unknown. In recent years, cancer cells' metabolic flexibility has received increasing attention among researchers. Here, we focus on how changes in the microenvironment can affect cancer cell energy production and drug sensitivity. Indeed, changes in the cellular microenvironment may lead to a "shift" toward "atavistic" biologic features, such as the switch from oxidative phosphorylation (OXPHOS) to lactic acid fermentation, which can also sustain drug resistance. Finally, we point out new integrative metabolism-based pharmacological approaches and potential biomarkers for early detection.

Risk factors of cervical lymph node metastasis in multifocal papillary thyroid cancer

Introduction

Identifying risk variables for cervical lymph node metastases in multifocality papillary thyroid cancer (MPTC) could assist surgeons in determining whether cervical lymph node dissection would be an appropriate surgical option.

Methods

A retrospective cohort of 2006 patients with papillary thyroid cancer were selected. MPTC (N = 460) was defined as the presence of two or more foci of PTC. The risk factors for central lymph node metastasis (CLNM) and lateral lymph node metastasis (LLNM) in MPTC were investigated by univariate and multivariate analyses, including the following items: age at diagnosis, gender, Hashimoto's thyroiditis, extrathyroidal extension (ETE), maximal axial diameter (MAD) and the sum of axial diameters (SAD) of tumor. In addition, CLNM was used to evaluate LLNM.

Results

The incidence of CLNM and LLNM was 44.57% and 17.17%, respectively. The multivariate analysis demonstrated that gender, extrathyroidal extension (ETE), age, maximal axial diameter (MAD), and the sum of axial diameters (SAD) were related to increased risk for CLNM in MPTC (p < 0.05). The area under the receiver operating characteristic (ROC) curve (AUC) for age at diagnosis of CLNM was 0.647, the cut-off value was 50 years old. Additionally, by multivariate analysis, CLNM, ETE, MAD, and SAD were independent risk factors for LLNM in MPTC (p < 0.05). ROC curve analysis demonstrates that AUC for MAD and SAD diagnosis of LLNM were 0.639 and 0.757, and the cut-off values were 16 and 26 mm, respectively.

Conclusions

MPTC patients who have risk factors for CLNM were advised to perform prophylactic central lymph node dissection (CLND). Additionally, the presence of risk factors for LLNM should be individually evaluated and analyzed for the necessity of lateral lymph node dissection.

RADIOMICS BASED ON TWO-DIMENSIONAL AND THREE-DIMENSIONAL ULTRASOUND FOR EXTRATHYROIDAL EXTENSION FEATURE PREDICTION IN PAPILLARY THYROID CARCINOMA

Aim

To evaluate the diagnostic performance of radiomics features of two-dimensional (2D) and three-dimensional (3D) ultrasound (US) in predicting extrathyroidal extension (ETE) status in papillary thyroid carcinoma (PTC).

Patients and Methods

2D and 3D thyroid ultrasound images of 72 PTC patients confirmed by pathology were retrospectively analyzed. The patients were assigned to ETE and non-ETE. The regions of interest (ROIs) were obtained manually. From these images, a larger number of radiomic features were automatically extracted. Lastly, the diagnostic abilities of the radiomics models and a radiologist were evaluated using receiver operating characteristic (ROC) analysis. We extracted 1693 texture features firstly.

Results

The area under the ROC curve (AUC) of the radiologist was 0.65. For 2D US, the mean AUC of the three classifiers separately were: 0.744 for logistic regression (LR), 0.694 for multilayer perceptron (MLP), 0.733 for support vector machines (SVM). For 3D US they were 0.876 for LR, 0.825 for MLP, 0.867 for SVM. The diagnostic efficiency of the radiomics was better than radiologist. The LR model had favorable discriminate performance with higher area under the curve.

Conclusion

Radiomics based on US image had the potential to preoperatively predict ETE. Radiomics based on 3D US images presented more advantages over radiomics based on 2D US images and radiologist.

Prognostic factors for incomplete response in thyroid microcarcinoma: an analysis of initial response to therapy in 517 patients

OBJECTIVE

Although thyroid microcarcinoma (TMC) usually has a favorable prognosis, some patients present a higher risk of disease recurrence or persistence. Thus, we aimed at identifying possible risk factors associated with an incomplete response to therapy in TMC.

METHODS

This was a retrospective study of 517 patients with TMC treated with total thyroidectomy, with or without radioactive iodine (RAI) therapy, reclassified after 1.1 ± 0.4 years according to the response to treatment into "favourable" (excellent/indeterminate) or "unfavorable" (biochemical/structural incomplete) responses. We evaluated participants' age, sex, tumor size, histological variants, multifocality, presence of vascular/lymphatic/perineural invasion, extrathyroidal extension, metastatic lymph nodes (LN), and distant metastasis. The effect of RAI therapy on the response range was analyzed in a given subgroup.

RESULTS

The mean age observed was 46.4 ± 12.0 years, and 89.7% were female. We noted 97.5% with papillary carcinoma, 27.8% with multifocality and 11.2% with LN metastasis. Although the majority of patients had a low risk of recurrence/persistence (78%), 75% were submitted to RAI therapy. Incomplete response (20.7%) was associated with multifocality (p=0.041; OR=1.619) and metastatic LN (p=0.041; OR=1.868). These variables were strongly correlated (p=0.000; OR=3.283). No cut-off of tumor size was identified as a predictor of incomplete response by the receiver operating curve analysis. RAI treatment did not influence the response of patients with multifocality or LN metastasis.

CONCLUSION

Multifocality and LN metastasis are independent risk factors for incomplete response in TMC patients and are strongly correlated. Additional RAI therapy was not associated with a more favorable response in these subgroups.

Bilateral multifocality, a marker for aggressive disease, is not an independent prognostic factor for papillary thyroid microcarcinoma: A propensity score matching analysis

CONTEXT

Multifocality and bilaterality are common in patients with papillary thyroid microcarcinoma (PTMC). However, their clinical behaviours and prognostic implications remain controversial.

OBJECTIVE

To investigate the relationship between multifocality and classically aggressive characteristics and outcomes in patients with PTMC.

METHODS

Clinical data of 3005 patients with PTMC were retrospectively reviewed at a tertiary medical centre. The role of unilateral and bilateral multifocality in aggressive characteristics and clinical outcomes of PTMC was evaluated using propensity score matching (PSM).

RESULTS

A total of 573 patients had bilateral multifocal disease (B-MFD), 272 had unilateral multifocal disease (U-MFD), and 2160 had unifocal disease (UFD). Univariate analysis showed that patients in the multifocal disease (MFD) groups showed significantly different characteristics compared to patients in the UFD group in terms of age, chronic lymphocytic thyroiditis (CLT), follicular variant PTMC, tumour diameter, aggressive growth, including extrathyroidal extension (ETE), central lymph node metastasis (CLNM) and lateral lymph node metastasis (LLNM), and TNM stage, and underwent radioactive iodine (RAI) therapy. Further stratified analysis revealed that patients in the B-MFD group reflected the differences between the MFD and UFD groups. However, those in the U-MFD group showed slight differences only in sex, CLT and cell subtypes, compared to the UFD group. In addition, PSM indicated differences in ETE, CLNM and LLNM between the B-MFD and UFD groups (p < .001), while only ETE differed between the U-MFD and UFD groups (p < .001). After a median follow-up period of 60 months, no difference was observed in recurrence-free survival between the UFD and B-MFD (p = .294) or U-MFD (p = .603) groups using PSM.

CONCLUSION

This propensity score matching analysis provides strong evidence that bilateral multifocality, rather than unilateral multifocality, should be considered as an aggressive marker at presentation, and neither is an independent prognostic factor for clinical outcome in PTMC.

Oncosuppressor-Mutated Cell-Based Diagnostic Platform for Liquid Biopsy Diagnoses Benign Head and Neck Masses and Predicts Malignancy in Thyroid Nodules: Results from a Consecutive Cohort of Patients

BACKGROUND

We reported that a novel oncosuppressor-mutated cell (OMC)-based platform has the potential for early cancer detection in healthy individuals and for identification of cancer patients at risk of developing metachronous metastases.

OBJECTIVE

Herein, we sought to determine the diagnostic accuracy of this novel OMC-based platform in a consecutive cohort of patients operated for suspicious head and neck masses.

METHODS

OMCs (BRCA1-deficient fibroblasts) were exposed to blood serum from patients with head and neck nodules before surgical removal. These cells were analyzed for their proliferation and survival. Treated OMCs were inoculated subcutaneously in NOD/SCID mice, and tumor growth was monitored over time.

RESULTS

OMCs exposed to serum from patients with malignant lesions displayed increased proliferation compared to those exposed to serum from patients with benign lesions. Only OMCs exposed to serum from patients diagnosed with malignant thyroid neoplasia generated a cancerous mass. The sensitivity of the test was 92%, with only 1 false negative out of 34 patients. Immunohistochemical staining showed that the cancerous masses were poorly differentiated adenocarcinomas with high proliferative index.

CONCLUSIONS

These data show that liquid biopsy combined with an OMC-based in vivo platform has the potential to diagnose benign head and neck masses and predict whether a thyroid nodule is malignant. These results strengthen the concept that OMCs can be used to detect circulating malignant factors in cancer patients.

Fine needle aspiration and the Bethesda system: Correlation with histopathology in 1,228 surgical patients

BACKGROUND

Fine-needle aspiration combined with the Bethesda System for Reporting Thyroid Cytopathology is indispensable in the diagnostic evaluation of thyroid nodules. Their increased detection over the last few decades mandates the determination of which thyroid nodules require surgical management for malignancy. This study examines the correlation of fine-needle aspiration to final histopathology of dominant thyroid nodules in a large series of surgical patients undergoing thyroidectomy at a single academic institution.

METHODS

A retrospective review of prospectively collected data of 1,228 patients who underwent fine-needle aspiration for a dominant thyroid nodule and thyroidectomy from a single institution between 2010 and 2019 was performed. The cases were stratified into all 6 Bethesda categories. Fine-needle aspiration results were compared to index thyroid nodule malignancy on final histopathology.

RESULTS

Of 1,228 patients who underwent thyroidectomy, the overall malignancy rate was 53%. When fine-needle aspiration was stratified by the Bethesda System for Reporting Thyroid Cytopathology, malignancy rate was 29% for nondiagnostic; 11% for benign; 51% for atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS); 47% for follicular neoplasm/suspicious for follicular neoplasm (FN/SFN); 84% for suspicious for malignancy (SFM); and 98% for malignant results on final histopathology. There was a false positive rate of 1% and false negative rate ranging from 7 to 11%.

CONCLUSION

Fine-needle aspiration of a dominant thyroid nodule in patients who underwent thyroidectomy had an overall malignancy rate of 53%. False negative and false positive rates are within the reported range in surgical patient populations. The majority of patients with AUS/FLUS, FN/SFN and SFM results with underlying malignancy received the appropriate surgical resection.

Obesity and Overweight Are Associated with Minimal Extrathyroidal Extension, Multifocality and Bilaterality of Papillary Thyroid Cancer

Epidemiological studies have shown a strong association between high body mass index (BMI) and papillary thyroid cancer (PTC). We assessed the clinical and histopathological features of PTC in patients with a higher BMI and compared them to analogous parameters in PTC patients with a normal BMI. We retrospectively analyzed 5021 medical records of patients admitted and surgically treated for thyroid tumors in one center between 2008 and 2018. Finally, we extracted data from 523 adult patients with PTC and stratified patients into two groups according to BMI: Group 1 with BMI < 25 kg/m² and Group 2 with BMI ≥ 25 kg/m². Data stratification was performed to estimate the association of overweight and obesity with clinical and histopathological features of PTC in both univariable and multivariable binary logistic regression analyses. Overall, compared to patients with a normal BMI, overweight and obese patients had a greater risk of minimal extrathyroidal extension (minimal ETE), multifocality and bilaterality of PTC (p < 0.001 for all). Analysis did not show that BMI was significantly associated with the more advanced tumor-node-metastasis (TNM) stage (p = 0.894). Obesity and overweight were significantly associated with higher aggressiveness of PTC. When considering various management options for PTC patients, these findings regarding overweight and obesity should be taken into consideration during the decision-making process.

Risk factors of papillary thyroid microcarcinoma that predispose patients to local recurrence

BACKGROUND

Currently, less aggressive treatment or even active surveillance of papillary thyroid microcarcinoma (PTMC) is widely accepted and recommended as a therapeutic management option. However, there are some concerns about these approaches. We investigated whether there are any demographic, clinical and ultrasound characteristics of PTMC patients that are easy to obtain and clinically available before surgery to help clinicians make proper therapeutic decisions.

METHODS

We performed a retrospective chart review of 5,021 patients with thyroid tumors surgically treated in one center in 2008-2018. Finally, 182 (3.62%) PTMC patients were selected (158 (86.8%) females and 24 (13.2%) males, mean age 48.8±15.4 years). We analyzed the disease-free survival (DFS) time of the PTMC patients according to demographic and histopathological parameters. Univariate and multivariate logistic regression analyses were used to assess the relationships of demographic, clinical and ultrasound characteristics with aggressive histopathological features.

RESULTS

Age ≥55 years, hypoechogenicity, microcalcifications, irregular tumor shape, smooth margins and high vascularity significantly increased the risk for minimal extrathyroidal extension (minETE), lymph node metastasis (LNM), and capsular and vascular invasion (p<0.0001). Multivariate logistic regression analysis demonstrated a statistically significant risk of LNM (OR = 5.98, 95% CI: 2.32-15.38, p = 0.0002) and trends toward significantly higher rates of minETE and capsular and vascular invasion (OR = 2.24, 95% CI: 0.97-5.19, p = 0.056) in patients ≥55 years than in their younger counterparts. The DFS time was significantly shorter in patients ≥55 years (p = 0.015), patients with minETE and capsular and vascular invasion (p = 0.001 for all), patients with tumor size >5 mm (p = 0.021), and patients with LNM (p = 0.002).

CONCLUSIONS

The absence of microcalcifications, irregular tumor shape, blunt margins, hypoechogenicity and high vascularity in PTMC patients below 55 years and with tumor diameters below 5 mm may allow clinicians to select individuals with a low risk of local recurrence so that they can receive less aggressive management.

Effect of optical energy modulation on the thermal response of biological tissue: computational and experimental validations

This study develops an energy modulation technique to attain a constant interstitial tissue temperature and to induce the predetermined thermal coagulation without carbonization in tissue. An optical diffuser was employed to deliver 1064 nm light to the biological tissue. The combined mode maintained the interstitial temperature at 70 °C for longer durations compared to the continuous wave mode. Coagulation volumes increased linearly with the time and met the predetermined treatment volume range (0.32-0.52 cm³) after the combined treatment for 100 s. The combined modulation can be a feasible modality to induce the predetermined extent of thermal coagulation for treating papillary thyroid microcarcinoma.

Cancer screening activity results in overdiagnosis and overtreatment of papillary thyroid cancer: A 10-year experience at a single institution

Background

It is estimated that one of the potential cause of the increasing prevalence of thyroid cancer (TC) is the easier and widespread access to diagnostic tools. If an individual evaluates the thyroid gland due to a mentioned mechanism without considering TC risk factors or symptoms, we can describe this phenomenon as cancer screening activity (CSA).

Aim of the study

We 1) estimated what types of TC were diagnosed due to CSA, 2) analyzed what clinicopathological features were characteristic of TCs diagnosed by CSA, 3) determined if these features were characteristic of indolent cases, and finally we 4) assessed whether CSA could have resulted in the increasing incidence of potentially indolent papillary thyroid cancer (PTC).

Materials and methods

A retrospective review of 4,701 medical records of patients admitted and surgically treated at one surgical center between 2008 and 2017 was performed. Among the enrolled patients, 569 (12.1%) had thyroid malignancy, and 514 (10.9%) were diagnosed with PTC. We divided these patients into two groups: 1) patients in whom TC diagnostics were performed without considering any TC risk factors or symptoms (CSA-yes) and 2) those in whom TC was diagnosed due to TC risk factors or symptoms (CSA-no). We then compared the clinicopathological features of these two groups.

Results

The most common type of TC diagnosed in the CSA-group was PTC (p = 0.024). CSA-yes patients showed a significantly lower degree of Tumor-Node-Metastasis (TNM) staging and demonstrated a significantly lower rate of multifocality, but not of bilaterality (p<0.0001 and p = 0.198, respectively). In the CSA-yes group, the number of TC foci was significantly lower than that in the CSA-no group (p<0.0001). All clinicopathological features characteristic of aggressive cases of TC were absent in CSA-yes patients (p<0.0001), while all features observed in CSA-yes patients were characteristic of indolent cases (p<0.0001).

Conclusions

The use of CSA results in the diagnosis of indolent cases of PTC and may be one of the potential causes of overdiagnosis and overtreatment of this malignancy.

Preoperative and Postoperative Risk Stratification of Thyroid Papillary Microcarcinoma: A Comparative Study Between Kuma Criteria and 2015 American Thyroid Association Guidelines Risk Stratification

Background: The incidence of micropapillary thyroid carcinoma (mPTC) has increased in the last decade. Active surveillance (AS) has been proposed as an alternative management for low-risk mPTC based on preoperative Kuma criteria. Controversy still exists on how to appropriately manage this group of patients, as some low-risk mPTC may harbor some postoperative features associated with disease recurrence as described in the 2015 American Thyroid Association (ATA) guidelines. Methods: We retrospectively reviewed 108 patients with histopathologic diagnosis of mPTC after surgery at a third level hospital in Mexico City from 2000 to 2018. Demographic and clinicopathologic data were analyzed as predictors for disease recurrence and/or metastatic disease (lymph node or distant). Comparison between group stratification based on preoperative Kuma criteria and postoperative 2015 ATA guidelines risk criteria for disease recurrence was performed. Measures of diagnostic accuracy were obtained for preoperative risk features according to the Kuma criteria. Results: Of 108 patients, 79 (73%) were classified as preoperative high-risk mPTC and 29 (27%) as low risk based on the Kuma criteria. Of these 79 high-risk patients, 38 (48%) were reclassified as low risk for disease recurrence, 12 (15%) as intermediate risk, and 29 (37%) remained as high risk based on the 2015 ATA risk criteria. Of the 29 preoperative low-risk patients, 19 (65.5%) remained as postoperative low risk for disease recurrence, 2 (7%) as intermediate risk, and 8 (27.5%) as high risk. Higher accuracy of preoperative risk features was obtained for lymph node and distant metastases, 84.2% and 97.2%, respectively. After multivariate analysis, age <40 years and microscopic extrathyroidal extension (ETE) were associated with higher risk for metastatic disease (lymph node or distant) in our cohort. Conclusions: Patients with mPTC under 40 years old and microscopic ETE are more prone to develop metastatic disease (lymph node or distant). One-third of our patients stratified as low-risk mPTC according to the Kuma criteria for AS had histopathologic features associated with a more aggressive clinical behavior or structural recurrence. In addition, lymph node and distant metastases are the preoperative risk features with the highest diagnostic accuracy for preoperative risk stratification.

Diagnostic accuracy and ability to reduce unnecessary FNAC: A comparison between four Thyroid Imaging Reporting Data System (TI-RADS) versions

BACKGROUND

Thyroid Imaging Reporting Data System (TI-RADS) is used to characterize thyroid nodules while reducing unnecessary FNAC. Over the years, several versions of TI-RADS have been developed but there is no consensus on which TI-RADS is the best system. This study aimed to compare the diagnostic accuracy and ability of ACR TI-RADS, EU TI-RADS, K TI-RADS, AI TI-RADS to eliminate unnecessary FNAC.

METHODS

In this prospective study, thyroid nodules were characterized by using the four TI-RADS systems and US-guided FNAC was done for nodule with the highest ACR TI-RADS score. Correlation between TI-RADS and FNAC results were analyzed.

RESULTS

Out of 244 thyroid nodules, 100 nodules with either size <1 cm (43 nodules) non-diagnostic or inconclusive FNAC results (57 nodules) were excluded. Seven nodules (4.9%) were confirmed to be malignant on FNAC. K TI-RADS showed 100% sensitivity and NPV but the lowest specificity (40.2%). EU TI-RADS had the highest specificity (83.2%) but the lowest sensitivity (57.1%) and NPV (97.4%). ACR TI-RADS had an average sensitivity (85.7%) and NPV (98.6%). The specificity of ACR TI-RADS (51.1%) was lower than EU TI-RADS but higher than K TI-RADS. AI TI-RADS showed higher specificity (61.8% vs 51.1%, p < 0.05) but comparable NPV and sensitivity to ACR TI-RADS. AI TI-RADS was able to avoid the highest number of unnecessary FNAC (62.5%) followed by ACR TI-RADS(54.2%), EU TI-RADS(37.5%) and K TI-RADS(11.8%).

CONCLUSION

AI TI-RADS is a more simple scoring system with better overall diagnostic performance and ability to exclude unnecessary FNAC with high NPV.

ADVANCES IN KNOWLEDGE

Highest number of unnecessary FNAC thyroid could be prevented by applying AI TI-RADS.