Papillary thyroid microcarcinoma: characteristics at presentation, and evaluation of clinical and histological features associated with a worse prognosis in a Latin American cohort

Influence of Tumor Laterality and Focality on Clinical Implications and Tumor Advancement in Well-Differentiated Thyroid Cancer

BACKGROUND

The accurate preoperative diagnosis of TC plays a very important role in the selection of an appropriate treatment strategy. In addition to the hypoechogenicity of thyroid lesions on ultrasound and the presence of microcalcifications or high cell atypia on FNAB, highlighting the features of laterality and focality and ascertaining their influence (alone or combined) on TC staging and appropriate treatment are crucial.

MATERIALS AND METHODS

A retrospective analysis of the clinical data of 697 patients admitted to the study center between 2008 and 2023 was conducted. Preoperative data (age, sex, type of surgery, ultrasound, and FNAB data) and postoperative histopathological data indicating TC advancement (pTNM, extrathyroidal extension, vascular invasion) were collected and analyzed. Patients presenting well-differentiated TCs (papillary TC and follicular TC) were isolated for better clinical evaluation. Finally, patients were divided into four groups according to their laterality and focality features, and the influences of combinations of these features on TC advancement were analyzed.

RESULTS

The largest group included patients with unilateral and solitary TC (n = 461). This group had the lowest rate of negative prognostic features: extrathyroidal extension, lymph node invasion, distant metastases, and vascular invasion (25.81%, 19.96%, 3.69%, and 26.46%, respectively). In contrast, the group with bilateral and multifocal TC (n = 40) presented the highest percentages of the mentioned features (82.50%, 82.50%, 7.50%, and 77.50%, respectively). All the results were statistically significant (p < 0.0001).

CONCLUSIONS

Laterality and focality features may be important parameters in the management of TC and should be accurately determined. These features should be combined and a more aggressive treatment method should be selected to reduce the reoperation rate.

Study on diagnosing thyroid nodules of ACR TI-RADS 4-5 with multimodal ultrasound radiomics technology

BACKGROUND

Explore the feasibility of using the multimodal ultrasound (US) radiomics technology to diagnose American College of Radiology (ACR) Thyroid Imaging Reporting and Data System (TI-RADS) 4-5 thyroid nodules.

METHOD

This study prospectively collected the clinical characteristics, conventional, and US elastography images of 100 patients diagnosed with ACR TI-RADS 4-5 nodules from May 2022 to 2023. Independent risk factors for malignant thyroid nodules were extracted and screened using methods such as the least absolute shrinkage and selection operator (LASSO) logistic regression (LR) model, and a multimodal US radiomics combined diagnostic model was established. Using a multifactorial LR analysis and a Rad-score rating, the predictive performance was validated and evaluated, and the final threshold range was determined to assess the clinical net benefit of the model.

RESULTS

In the training set, the US radiomics combined predictive model area under curve (AUC = 0.928) had higher diagnostic performance compared with clinical characteristics (AUC = 0.779), conventional US (AUC = 0.794), and US elastography model (AUC = 0.852). In the validation set, the multimodal US radiomics combined diagnostic model (AUC = 0.829) also had higher diagnostic performance compared with clinical characteristics (AUC = 0.799), conventional US (AUC = 0.802), and US elastography model (AUC = 0.718).

CONCLUSION

Multi-modal US radiomics technology can effectively diagnose thyroid nodules of ACR TI-RADS 4-5, and the combination of radiomics signature and conventional US features can further improve the diagnostic performance.

The impact of lymph node ratio on disease recurrence in papillary thyroid microcarcinoma

INTRODUCTION

Lymph node (LN) metastases in papillary thyroid microcarcinomas (microPTCs) are common. The lymph node ratio (LNR) has been proposed as a risk factor for recurrence in papillary thyroid cancer. However, its relevance in microPTC is undetermined.

METHODS

Patients who underwent resection of their microPTC with concomitant LN clearance between 2005 and 2018 were identified. The LNR was calculated as the ratio of positive LNs to the total number of LNs.

RESULTS

Data on 50 patients (36 female [72%]; median age 47 years [range: 19-84]) who underwent LN clearance (28 central [56%] vs 22 central + lateral [44%]) were analysed. Positive LNs were found in over two-thirds of the patients (n = 34; 68%). After a median follow-up of 61 months, 14 patients (28%) had developed recurrence. Positive LNs were not found to impact recurrence-free survival; extranodal extension and an LNR ≥ 0.26 were found to significantly increase the risk of recurrence on unadjusted analyses (p < 0.05).

CONCLUSIONS

LN metastases are frequent among patients with microPTC. A higher LNR seems to be associated with recurrence. Additional studies are needed to further clarify these findings and to assess the possible role of LNR in treatment and surveillance.

Incidentally discovered papillary thyroid microcarcinoma in patients undergoing thyroid surgery for benign disease

INTRODUCTION

The incidence of thyroid carcinoma has grown significantly over the last few decades. A possible explanation is the increased diagnosis of small thyroid microcarcinoma (TMc). TMc reach a maximum diameter of ≤1 cm, identified during histopathology examination following a thyroidectomy performed for reasons not pertaining to malignancy. This study aims to investigate the prevalence of papillary thyroid microcarcinoma (PTMc) according to the benign pathology that refers patients to surgery and its trend evolution.

METHODS

Retrospective cohort analysis of 1815 patients who underwent total thyroidectomy for non-malignant diseases in the 2005-2020 period.

RESULTS

The mean age of the subjects was 53.5 years, with a higher proportion of women (1481, 82.1%). A total of 167 PTMc (9.3%) were incidentally discovered. A multivariate logistic regression analysis was performed, showing no differences in prevalence according to sex or age in patients with PTMc compared to final benign histology. Multinodular goiter increases the risk of PTMc with an odds ratio of 2.2 (p = 0.001) compared to Hashimoto's thyroiditis and Graves' disease (GD). There is a statistically significant increase in the incidence of PTMc in the group operated in the 2017-2020 vs. 2005-2008 period (p = 0.005).

CONCLUSION

The overall prevalence of PTMc in patients who underwent thyroid surgery for the benign disease was 9.3%. Thyroid nodular hyperplasia was the most frequent benign pathology associated with PTMc compared to Hashimoto's or GD. Gender and age were not correlated with the prevalence of TMc. Over the years, surgical findings of PTMc have grown, particularly in the 2017-2020 period.

Clinical characteristics and prognosis of familial nonmedullary thyroid carcinoma

INTRODUCTION

Familial non-medullary thyroid carcinoma (FNMTC) is defined by the presence of 2 or more first-degree family members with differentiated thyroid carcinoma (DTC). The aim of this study is to compare clinicopathological features and prognosis of FNMTC and sporadic carcinoma (SC).

MATERIALS AND METHODS

Retrospective study of DTC included in the hospital database during the period 1990-2018.

RESULTS

A total of 927 patients were analyzed, 61 of them were FNMTC, with a mean follow-up of 9.7 ± 6.5 years. The prevalence of FNMTC was 6.6%, with a lower TNM staging presentation (P = 0.003) consequence of a higher proportion of tumors smaller than 2 cm (P = 0.003), combined with a greater multifocality (P = 0.034) and papillary histologic subtype (P = 0.022) compared to SC. No significant differences in age at diagnosis (P = 0.347), gender (P = 0.406), neither in other aggressiveness markers (bilaterality, extrathyroidal extension, lymph node involvement and metástasis) were detected. Rate of persistence/recurrence (P = 0.656), disease-free survival (P = 0.929) and mortality caused by the tumor itself (P = 0.666) were comparable. Families with ≥3 affected relatives, had smaller tumors (P = 0.005), more multifocality (P = 0.040) and bilaterality (P = 0.002), as well as a higher proportion of males (P = 0.020). Second generation patients present earlier FNMTC compared to those of the first generation (P = 0.001).

CONCLUSION

In our study FNMTC presents a lower TNM staging, higher multifocality and papillary variant, with similar aggressiveness and prognosis compared to SC.

Clinical characteristics and prognosis of familial nonmedullary thyroid carcinoma

INTRODUCTION

Familial non-medullary thyroid carcinoma (FNMTC) is defined by the presence of 2or more first-degree family members with differentiated thyroid carcinoma (DTC). The aim of this study is to compare clinicopathological features and prognosis of FNMTC and sporadic carcinoma (SC).

MATERIALS AND METHODS

Retrospective study of DTC included in the hospital database during the period 1990-2018.

RESULTS

A total of 927 patients were analyzed, 61 of them were FNMTC, with a mean follow-up of 9.7±6.5 years. The prevalence of FNMTC was 6.6%, with a lower TNM staging presentation (P=.003) consequence of a higher proportion of tumors smaller than 2 centimeters (P=.003), combined with a greater multifocality (P=.034) and papillary histologic subtype (P=.022) compared to SC. No significant differences in age at diagnosis (P=.347), gender (P=.406), neither in other aggressiveness markers (bilaterality, extrathyroidal extension, lymph node involvement and metástasis) were detected. Rate of persistence/recurrence (P=.656), disease-free survival (P=.929) and mortality caused by the tumor itself (P=.666) were comparable. Families with ≥3 affected relatives, had smaller tumors (P=.005), more multifocality (P=.040) and bilaterality (P=.002), as well as a higher proportion of males (P=.020). Second generation patients present earlier FNMTC compared to those of the first generation (P=.001).

CONCLUSION

In our study FNMTC presents a lower TNM staging, higher multifocality and papillary variant, with similar aggressiveness and prognosis compared to SC.

Position paper from the Japan Thyroid Association task force on the management of low-risk papillary thyroid microcarcinoma (T1aN0M0) in adults

The incidence of thyroid carcinoma has been increasing worldwide. This is interpreted as an increase in the incidental detection of papillary thyroid microcarcinomas (PTMCs). However, mortality has not changed, suggesting overdiagnosis and overtreatment. Prospective clinical trials of active surveillance for low-risk PTMC (T1aN0M0) have been conducted in two Japanese institutions since the 1990s. Based on the favorable outcomes of these trials, active surveillance has been gradually adopted worldwide. A task force on the management of PTMC in adults organized by the Japan Thyroid Association therefore conducted a systematic review and has produced the present position paper based on the scientific evidence concerning active surveillance. This paper indicates evidence for the increased incidence of PTMC, favorable surgical outcomes for low-risk PTMC, recommended criteria for diagnosis using fine needle aspiration cytology, and evaluation of lymph node metastasis (LNM), extrathyroidal extension (ETE) and distant metastasis. Active surveillance has also been reported with a low incidence of disease progression and no subsequent recurrence or adverse events on survival if conversion surgery was performed at a slightly advanced stage. Active surveillance is a safe and valid strategy for PTMC, because it might preserve physical quality of life and reduce 10-year medical costs. However, some points should be noted when performing active surveillance. Immediate surgery is needed for PTMC showing high-risk features, such as clinical LNM, ETE or distant metastasis. Active surveillance should be performed under an appropriate medical team and should be continued for life.

A Radiomic Nomogram for the Ultrasound-Based Evaluation of Extrathyroidal Extension in Papillary Thyroid Carcinoma

Purpose

To construct a sequence diagram based on radiological and clinical factors for the evaluation of extrathyroidal extension (ETE) in patients with papillary thyroid carcinoma (PTC).

Materials and Methods

Between January 2016 and January 2020, 161 patients with PTC who underwent preoperative ultrasound examination in the Affiliated People’s Hospital of Jiangsu University were enrolled in this retrospective study. According to the pathology results, the enrolled patients were divided into a non-ETE group and an ETE group. All patients were randomly divided into a training cohort (n = 97) and a validation cohort (n = 64). A total of 479 image features of lesion areas in ultrasonic images were extracted. The radiomic signature was developed using least absolute shrinkage and selection operator algorithms after feature selection using the minimum redundancy maximum relevance method. The radiomic nomogram model was established by multivariable logistic regression analysis based on the radiomic signature and clinical risk factors. The discrimination, calibration, and clinical usefulness of the nomogram model were evaluated in the training and validation cohorts.

Results

The radiomic signature consisted of six radiomic features determined in ultrasound images. The radiomic nomogram included the parameters tumor location, radiological ETE diagnosis, and the radiomic signature. Area under the curve (AUC) values confirmed good discrimination of this nomogram in the training cohort [AUC, 0.837; 95% confidence interval (CI), 0.756–0.919] and the validation cohort (AUC, 0.824; 95% CI, 0.723–0.925). The decision curve analysis showed that the radiomic nomogram has good clinical application value.

Conclusion

The newly developed radiomic nomogram model is a noninvasive and reliable tool with high accuracy to predict ETE in patients with PTC.

Analysis of Curative Effect and Influencing Factors of N1 Stage Papillary Thyroid Micro-Carcinoma and Papillary Thyroid Non-Micro Carcinoma After Initial Radioactive Iodine Ablation Therapy

Objective

To compare the efficacy and influencing factors of initial radioactive iodine (RAI) ablation therapy for postoperative N1 stage papillary thyroid micro-carcinoma (PTMC) and papillary thyroid non-micro carcinoma (PTC), and to explore the necessity of RAI for N1 stage PTMC.

Methods

A retrospective analysis of patients with N1 stage papillary thyroid cancer who underwent RAI in our department from January 2018 to June 2019. According to the tumor diameter, papillary thyroid carcinoma was divided into PTMC group (≤ 1.0cm) with 129 patients and PTC group (> 1.0 cm) with 214 patients. According to the 2015 ATA guidelines, the patient’s treatment response was evaluated 6–8 months after discharge from the hospital: excellent response (ER), indeterminate response (IDR), biochemical incomplete response (BIR), and structural incomplete response (SIR). IDR, BIR, and SIR were classified into NER group. Chi-squared test, independent sample t-test, Mann–Whitney U test, and binary logistic regression analysis were used to compare the differences between PTMC and PTC patients.

Results

The ps-Tg of the PTMC group was significantly lower than that of the PTC group (P = 0.001), and the ER ratio of the PTMC group was higher (χ² = 5.445, P < 0.05). The ER ratio of PTMC patients in the N1a group was significantly higher than that of PTC patients (80%, 66.7%, χ² = 4.076, P < 0.05), while the ER ratio of PTMC in the N1b group was not significantly different from that of PTC. Gender, N stage, and ps-Tg were found to be independent factors of RAI treatment response.

Conclusion

The efficacy of the initial RAI of PTMC patients was significantly better than that of PTC patients. There was no significant difference in the efficacy of RAI between males with PTMC, N1b stage, ps-Tg ≥ 5.87ng/mL and PTC patients, which suggested that RAI is necessary for these patients.

Evaluation of surgical risk and prognosis between thyroid nodules of size <1 and ≥1 cm

Background

The objective of this study was to evaluate the surgical risk and prognosis between thyroid nodules of size <1 and ≥1 cm and to explore whether it is reasonable generally to ignore the diagnosis and treatment of thyroid nodules and thyroid carcinoma <1 cm in wide areas of China.

Methods

A retrospective observational study included all first-time thyroid surgery patients between January 2005 and December 2016 of the First Affiliated Hospital of Harbin Medical University. All patients were divided into two groups (group A: <1 cm, group B: ≥1 cm) according to the maximum diameter of the nodules and demographics, surgery procedure, pathology, postoperative complications, morbidity, and mortality were analyzed.

Results

A total of 6,317 patients were reviewed and 3,424 (54.20%) of them were malignant; 2,128 patients in group A and 4,189 in group B. Patients in group A had better pathological diagnosis, inferior extent of lymph node metastasis, less surgical complexity, fewer postoperative complications, and longer disease-free survival (DFS).

Conclusions

Thyroid operations were safer and involved fewer postoperative complications when thyroid nodules were <1 cm and patients who were diagnosed with malignant thyroid disease had superior prognoses. Underdeveloped regions of China should diagnose and treat thyroid nodules <1 cm early.

Radioiodine remnant ablation in papillary thyroid microcarcinoma: a meta-analysis

BACKGROUND

The incidence of papillary thyroid microcarcinoma (PTMC) has been increasing sharply, the current statement about whether PTMC patients should undergo radioactive iodine (RAI) remnant ablation is still controversial, mainly because it is uncertain whether RAI treatment can reduce the recurrence rate.

OBJECTIVE

To evaluate the effectiveness of RAI remnant ablation for thyroid cancer-related outcomes of PTMC patients.

METHODS

We comprehensively searched PubMed, Cochrane Library, Scopus and Science Direct for studies that compared the effectiveness after total-thyroidectomy or near total-thyroidectomy, with or without RAI remnant ablation treatment. Random and fixed-effects meta-analytical models were used where indicated, and between-study heterogeneity was assessed.

RESULTS

Twenty-two studies, which included 8724 patients, met our search criteria and were assessed. For PTMC patients treated by total thyroidectomy or near-total thyroidectomy, the locoregional recurrence rates were 1.92 and 7.36% [risk ratio (RR)=0.45; 95% confidence interval (CI)=0.18-1.11; P=0.08] for patients with or without RAI treatment respectively, the distant metastasis rates were 1.39 and 2.46% (RR=0.64; 95% CI=0.28-1.48; P=0.30), and the thyroid cancer-related mortality rates were 0.98 and 1.76% (RR=0.68; 95% CI=0.22-2.09; P=0.50).

CONCLUSION

For PTMC patients who have already treated by total thyroidectomy or near-total thyroidectomy, incremental RAI remnant ablation may significantly improve thyroid cancer-related outcomes.

Computed Tomography Radiomic Nomogram for Preoperative Prediction of Extrathyroidal Extension in Papillary Thyroid Carcinoma

Objectives: Determining the presence of extrathyroidal extension (ETE) is important for patients with papillary thyroid carcinoma (PTC) in selecting the proper surgical approaches. This study aimed to explore a radiomic model for preoperative prediction of ETE in patients with PTC. Methods: The study included 624 PTC patients (without ETE, n = 448; with minimal ETE, n = 52; with gross ETE, n = 124) whom were divided randomly into training (n = 437) and validation (n = 187) cohorts; all data were gathered between January 2016 and November 2017. Radiomic features were extracted from computed tomography (CT) images of PTCs. Key radiomic features were identified and incorporated into a radiomic signature. Combining the radiomic signature with clinical risk factors, a radiomic nomogram was constructed using multivariable logistic regression. Delong test was used to compare different receiver operating characteristic curves. Results: Five key radiomic features were incorporated into the radiomic signature, which were significantly associated with ETE (p < 0.001 for both cohorts) and slightly better than clinical model integrating significant clinical risk factors in the training cohort (area under the receiver operating characteristic curve (AUC), 0.791 vs. 0.778; F₁ score, 0.729 vs. 0.714) and validation cohort (AUC, 0.772 vs. 0.756; F₁ score, 0.710 vs. 0.692). The radiomic nomogram significantly improved predictive value in the training cohort (AUC, 0.837, p < 0.001; F₁ score, 0.766) and validation cohort (AUC, 0.812, p = 0.024; F₁ score, 0.732). Conclusions: The radiomic nomogram significantly improved the preoperative prediction of ETE in PTC patients. It indicated that radiomics could be a valuable method in PTC research.