Clinical outcomes of multifocal papillary thyroid cancer: A systematic review and meta-analysis

Multifocality of papillary thyroid carcinoma with low risk of recurrence: Prevalence, predictive markers, prognostic significance and initial surgical treatment

BACKGROUND AND OBJECTIVE

The impact of multifocality on the prognosis of patients with papillary thyroid cancer is relevant when considering the choice of initial surgical treatment by hemithyroidectomy or total thyroidectomy. The aim of the study is to determine the prevalence of multifocality in our setting, its predictive markers and the rates of persistence, recurrence and mortality associated with papillary thyroid cancer with a low risk of recurrence in order to infer the most appropriate initial surgical treatment.

PATIENTS AND METHOD

Retrospective observational cross-sectional study of 85 total thyroidectomies.

RESULTS

Prevalences: unifocal carcinoma: 68.2%; multifocal: 31.8%. Predictive markers of multifocality: multinodular ultrasound pattern (OR:17.069, 95% CI:2.989-97.454) and non-incidental finding (OR:7.569, 95% CI:2.363-24.242). In 66.6% of multifocal cases there was bilateral involvement, all of them had a bilateral multinodular ultrasound pattern. Multifocal cases received postoperative radioiodine more frequently (p < 0.001). During the follow-up of 95.5 ± 32.2 months there was one case of persistence and one of recurrence, both in the multifocal group (p:ns), at 12 and 71 months of follow-up. There was no mortality.

CONCLUSIONS

This is the first study in our country to estimate the prevalence of multifocality in papillary carcinoma with a low risk of recurrence and to show an excellent prognosis, with no differences compared to unifocal cases, considering that all cases have been treated with total thyroidectomy, but multifocal cases with radioiodine more frequently. Hemithyroidectomy could offer a similar prognosis to total thyroidectomy in cases with an ultrasound pattern of a single or unilateral multinodular nodule, but not in cases of bilateral multinodular thyroid.

Multigene Detection Analysis of Multifocal Papillary Thyroid Carcinoma

OBJECTIVE

To analyze the relationship between clinical characteristics and pathogenic gene mutations in multifocal papillary thyroid carcinoma (MPTC) and to investigate the proportion of independent primary tumors (IP) versus intrathyroidal metastases (ITM) in MPTC. Additionally, to explore the correlation between specific gene mutations and clinical features such as multifocality, tumor size, and lymph node metastasis.

METHODS

Patients with multifocal thyroid tumor meeting inclusion criteria were consecutively enrolled. Two lesions per case were selected for preoperative ultrasound-guided fine-needle aspiration biopsy (FNAB). All lesions were pathologically confirmed as papillary thyroid carcinoma postoperatively. FNAB samples were subjected to multi-gene panel testing and classified into three groups based on mutational profiles of 26 thyroid-related genes: (1) identical mutations in both lesions (intrathyroidal metastasis), (2) completely discordant mutations (independent primary tumors), and (3) shared mutations with an additional mutation in one lesion (uncertain origin).

RESULTS

Among 58 initially enrolled MPTC patients, 8 were excluded due to noncompliant specimens. The final cohort included 50 patients (37 females, 13 males) with a mean age of 42.64 ± 11.12 years. The median tumor diameter was 12.5 (IQR: 7.6, 20.0) mm, with 38.0% (19/50) classified as papillary thyroid microcarcinoma. A total of 128 mutations, 4 gene fusions, and 3 gene amplifications were detected across 100 qualified FNAB samples. BRAF V600E was the most prevalent mutation (84.0%, 84/100), followed by DICER1 (7.0%), PTEN (6.0%), and RET (4.0%). Identical mutational profiles (intrathyroidal metastasis) were observed in 64.0% (32/50) of cases, while 18.0% (9/50) exhibited completely discordant mutations (independent primary tumor). The remaining 18.0% (9/50) showed shared mutations with an additional mutation, predominantly in smaller lesions. The incidence of completely different mutations in ipsilateral lesions and bilateral lesions was different (p = 0.030). No significant correlation between BRAF V600E and clinical characteristics such as tumor size, multifocality, capsular invasion or lymph node metastasis (p > 0.05).

CONCLUSION

Multi-gene panel testing of preoperative FNAB samples effectively discriminates clonal relationships in MPTC, revealing distinct molecular profiles between ITM and IP. The high prevalence of BRAF V600E mutations and frequent clonal homogeneity underscore the necessity of comprehensive genetic profiling to guide personalized management. Routine multi-lesion sampling is advocated for optimizing risk stratification and surgical decision-making.

Preoperative circulating tumor cells level is associated with lymph node metastasis in patients with unifocal papillary thyroid carcinoma

OBJECTIVE

Unifocal papillary thyroid carcinoma (PTC) refers to thyroid cancer that has only one isolated lesion, it has also the possibility of lymph node metastasis (LNM). Circulating tumor cell (CTC) has been used to assist in the assessment of tumor progression, but the relationship between CTCs levels and LNM in unifocal PTC patients is unclear.

METHODS

The clinical records (age, gender, Hashimoto's thyroiditis, thyroid function, tumor size, invaded capsule (thyroid cancer penetrating the capsule), clinical stage, and LNM) of unifocal PTC patients in Meizhou People's Hospital were analyzed retrospectively. Receiver operating characteristic (ROC) curve analysis was used to determine the cutoff value of CTCs levels to distinguish LNM. The relationship between CTCs level and clinical features was analyzed. Logistic regression analysis was used to evaluate the relationship between CTCs and LNM.

RESULTS

A total of 507 unifocal PTC patients were included, and 198(39.1%) patients with LNM. The critical value of CTCs was 9.25 FU/3mL by ROC analysis, and 288(56.8%) unifocal PTC patients with preoperative CTC-positive(≥ 9.25 FU/3mL). The patients with positive CTCs had higher proportions of normal thyroid function (91.3% vs. 84.5%, p = 0.018), and LNM (44.1% vs. 32.4%, p = 0.008) than patients with negative. High preoperative CTCs level (≥ 9.25/<9.25 FU/3mL, odds ratio(OR): 1.653, 95% confidence interval(CI): 1.115-2.451, p = 0.012), tumor size > 1 cm (OR: 3.189, 95% CI: 2.069-4.913, p < 0.001), and invaded capsule (OR: 1.521, 95% CI: 1.005-2.302, p = 0.047) were associated with LNM among unifocal PTC in multivariate logistic regression analysis.

CONCLUSIONS

High preoperative CTCs level (≥ 9.25 FU/3mL), tumor size > 1 cm, and invaded capsule were associated with LNM among unifocal PTC.

Multifocal Papillary Thyroid Carcinomas With Discordant Molecular Drivers: Emphasizing the Morphology and Collision Tumors

Multifocal papillary thyroid carcinomas (PTCs) are common and the majority of the tumors harbor mutual BRAF p.V600E mutation. This study aimed to investigate a contemporary series of multifocal PTCs with discordant molecular drivers. Consecutive thyroidectomies diagnosed with multifocal PTCs ≥0.5 cm between 2019 and 2023 were reviewed. Immunohistochemistry (IHC) for BRAF VE1 was performed for all tumors. Cases with discordant BRAF IHC results or morphologic discrepancy were identified, and BRAF IHC-negative tumors were subjected to RAS Q61R IHC and/or targeted RNA next-generation sequencing. A total of 770 patients with a main PTC ≥0.5 cm were identified; 255 (33.1%) had multifocal disease, and 142 (18.4%) had at least another PTC ≥0.5 cm. Among them, 13 cases (9.2%, 13/142) had discordant molecular drivers. Twelve cases had one or more BRAF -positive PTCs accompanied by a BRAF -negative PTC (3 with CCDC6::RET fusion, 1 with NCOA4::RET fusion, 1 with ACBD5::RET fusion, 2 with ETV6::NTRK3 fusion, 1 with TG::FGFR1 fusion, 1 with LMTK2::BRAF fusion, 1 with AGK::BRAF fusion and RAS p.Q61R mutation, 1 with RAS p.Q61R mutation, and 1 without detectable molecular drivers). The last case had tumors with discordant fusion drivers ( VIM::NTRK3 and TNS1::BRAF ). Most cases showed tumors that were morphologically distinct (92.3%, 12/13) and occurred in the contralateral lobes (76.9%, 10/13). Notably, we identified 4 cases (30.8%) that presented as collision tumors and 6 cases (46.2%) that showed lymph node metastases, including 2 with simultaneous involvement by tumors with discordant molecular drivers, as novel findings. In summary, a subset (9.2%) of multifocal PTCs had discordant molecular drivers and 84.6% of them were a combination of BRAF -positive and kinase gene fusion-associated PTCs, most with distinct morphologies. Almost half of the cases had nodal metastasis and a third of them showed simultaneous involvement by tumors with discordant molecular drivers. The results highlight the clinical importance of identifying such cases, given the potentially different treatments.

Analysis of the clonal origin and differences in the biological behavior of multifocal papillary thyroid carcinoma

Papillary thyroid carcinoma (PTC) exhibits a trend of multifocal growth. However, the clonal origin of multiple cancer foci in the thyroid gland remains an issue of ongoing debate. In order to investigate the clonal origin and biological behavior differences of multifocal PTC (MPTC) from a unique perspective, a combination of dual gene and dual protein detection methods was used. The present study included 52 patients with MPTC. Immunohistochemical staining was used to assess the expression of v-raf murine sarcoma viral oncogene homolog B1 (BRAF) and telomerase reverse transcriptase (TERT) proteins, while quantitative PCR and Sanger sequencing were used to identify BRAF and TERT gene mutations. Based on the results, MPTC cases were classified into two clonal origins, namely intraglandular metastatic (71.2%) and independent multicentric origin (28.8%). BRAF protein expression and BRAF gene mutation were significantly higher in the intraglandular metastasis group than in the multicentric cancer group. However, no significant differences in TERT protein expression and TERT gene mutation were observed between the two groups. Sex, central lymph node metastasis rate, Hashimoto's thyroiditis and tumor distribution laterality were not found to differ significantly between the two groups. However, significant differences were detected in age at initial diagnosis, lateral cervical lymph node metastasis rate, tumor capsule invasion rate and maximum tumor diameter. The study found that MPTC predominantly occurs due to intraglandular metastasis, which is associated with stronger tumor invasiveness than cancer foci with multiple independent origins, as it is more likely to exhibit pathogenic gene mutations and abnormal protein expression, cervical lymph node metastasis and capsule invasion. Therefore, it is recommended that the surgical approaches and follow-up strategies for intraglandular metastatic MPTC should be aggressive and individualized.

FBXO2 promotes the progression of papillary thyroid carcinoma through the p53 pathway

Emerging evidence have demonstrated that F-box only protein 2 (FBXO2) is intimately associated with malignant tumor development and occurrence. However, neither the functions nor the molecular mechanisms underlying FBXO2 have been determined in the papillary thyroid carcinoma (PTC). The quantitative real-time PCR (qRT-PCR), western blotting and immunohistochemistry were carried out to detect the FBXO2 expression in PTC tissues. CCK-8 assay, EdU assay and flow cytometry were used to assess cell proliferation, cell cycle and apoptosis. The trans-well assay was conducted to determine the cell invasiveness. The effect of FBXO2 on PTC cell proliferation in vivo was observed through a subcutaneous tumor formation experiment in nude mice. Immunoprecipitation were conducted to detect the interaction between FBXO2 and p53. The ubiquitination assays were conducted to assess the regulation of p53 ubiquitination by FBXO2. FBXO2 was overexpressed in both PTC tissues and cell lines. FBXO2 expression positively correlated with PTC tumor size, lymphatic metastasis, and extramembranous invasion. Furthermore, silencing FBXO2 inhibited PTC cell proliferation and promoted apoptosis. The overexpression of FBXO2 significantly promotes PTC cell proliferation. Mechanistic studies revealed that FBXO2 could directly bind to p53 and promote its ubiquitination degradation. Knockdown of p53 partially reversed the progression arrest induced by FBXO2 Knockdown in PTC cells. FBXO2 knockdown inhibited PTC cell proliferation and promoted apoptosis by targeting p53 for ubiquitination and degradation. This process represents a research foundation for its diagnostic and therapeutic applications.

Incomplete ablation of thyroid cancer: Achilles' Heel?

BACKGROUND

In recent years, the incidence of thyroid nodules has increased significantly. There are various ways to treat thyroid nodules, and ablation therapy is one of the important ways to treat thyroid nodules. However, there are many complications and deficiencies in the current ablation treatment of thyroid nodules, especially the incomplete ablation of thyroid cancer nodules, which limits the further application of ablation technology. In this paper, we report two cases of incomplete ablation of thyroid nodules, one of which underwent surgical treatment due to anxiety after ablation, and the postoperative pathology confirmed that there was still residual papillary thyroid carcinoma, and the other patient underwent an operation after ablation, but visited our medical institution again due to cervical lymph node metastasis in a short period of time, and after radical cervical lymph node dissection, pathology confirmed multiple cervical lymph node metastasis. Radionuclide therapy was performed after surgery, and two patients are currently receiving endocrine suppression therapy, and their condition is stable with no signs of recurrence.

CONCLUSION

The incomplete ablation of thyroid cancer nodules limits the development of ablation therapy, making ablation treatment a double-edged sword. Guidelines and expert consensus can guide their development, but they need to evolve with the times, and a multidisciplinary diagnostic team can help screen the most suitable patients. Only by using this technology more standardly, using the most appropriate technology, and treating the most suitable patients, can benefit more and more patients.

Multi-UniFocality (MUF), in contrast to multifocality, in thyroid lesions: Relation to lymphocytic thyroiditis

Whereas multifocality typically concerns papillary thyroid carcinoma (PTC) without specification of intrathyroidal metastatic or independent nature of tumor foci, the designation of the latter as Multi-UniFocal (MUF) may be relevant for select cases. A case series involving multifocal thyroid lesions with divergent histopathological morphology and/or molecular profile, with molecular evaluation of multiple individual tumor foci per patient based on a next-generation sequencing approach, was retrospectively reviewed. Twenty-five patient cases with multifocal thyroid lesions suggestive of MUF, with 2-6 (median 3) tumor foci per patient, were described. Tumor lesions comprised diverse histopathology, including PTC, (E)FVPTC, NIFTP, FA, FTC, and oncocytic. Morphologically similar and/or diverse tumor foci harbored different molecular alterations (suggestive of non-shared clonality); with(out) coexistent similar foci harboring identical molecular alterations; or (partly) shared molecular alterations. MUF was associated with chronic lymphocytic thyroiditis in almost half of the cases. The recognition of MUF may justify the independent clinical consideration per individual tumor focus; as separate lesions albeit within a multifocal context. The potential clinical relevance and prognostic value of MUF remain to be further established.

Total thyroidectomy versus unilateral lobectomy for unilateral multifocal papillary thyroid carcinoma: systematic review and meta‑analysis

The optimal surgical procedure(s) for unilateral multifocal papillary thyroid carcinomas is currently controversial. As such, the present study aimed to compare the efficacies of total thyroidectomy and lobectomy in patients with unilateral multifocal papillary thyroid carcinoma. A literature search of the PubMed/Medline, Embase, Web of Science, Cochrane Library, Wan Fang, and Zhi Wang databases for relevant studies, published from inception to October 31, 2022, was performed. Two researchers independently extracted data from the included studies. Lymph node metastasis, vocal fold paralysis, parathyroid injury, postoperative recurrence, and disease-free survival were evaluated. The meta-analysis included 7 studies comprising 1540 patients, of whom 496 and 1044 underwent lobectomy and total thyroidectomy, respectively. Compared with lobectomy, total thyroidectomy resulted in more vocal cord paralysis (odds ratio [OR] 0.35 [95% confidence interval (CI) 0.13 to 0.96]; P = 0.04) and parathyroid injury (OR 0.11 [95% CI 0.03-0.39]; P = 0.001) but with better disease-free survival (OR 0.21 [95% CI 0.09-0.49]; P = 0.000), although vocal cord paralysis and parathyroid injury, in large part, resolved within 1 year after surgery. In addition, there was no difference in postoperative lymph nodes metastasis (OR 0.74 [95% CI 0.13-4.21]; P = 0.737) and postoperative recurrence (OR 2.37 [95% CI 0.42-13.38]; P = 0.33). Excluding studies that deviated from the general trend, total thyroidectomy was beneficial in reducing recurrence. Compared with lobectomy, total thyroidectomy was beneficial in reducing recurrence and disease-free survival and may be considered a more optimal approach for unilateral multifocal papillary thyroid carcinoma.

Bilaterality, not multifocality, is an independent risk factor for recurrence in low-risk papillary thyroid cancer

BACKGROUND

The impact of multifocality and bilaterality on recurrence in patients with low-risk papillary thyroid cancer (PTC) is relevant when considering patients for a de-escalated treatment strategy: hemithyroidectomy instead of total thyroidectomy followed with or without radioactive iodine. This study aims to analyze contralateral tumor probability in patients treated for low-risk PTC and assess multifocality and bilaterality as possible predictors for recurrence.

METHODS

Patients with low-risk PTC treated with total thyroidectomy followed with or without radioactive iodine in the Netherlands between 2005 and 2015 were included in this study. Patients were identified from the Netherlands Comprehensive Cancer Organization (IKNL) and linked with the nationwide network and registry of Pathology in the Netherlands (PALGA). Contralateral tumor probability and recurrence were assessed.

RESULTS

Of 791 included patients, 41.8% (331 of 791) had multifocal disease, with 68.9% (228 of 331) of those patients having bilateral disease. The contralateral tumor probability after hemithyroidectomy was 24.6% (150 of 610) for patients with unifocal disease and 43.1% (78 of 181) for patients with multifocal disease. We found a higher trend of recurrence in patients with bilateral disease, regardless of multifocality: in patients with contralateral disease after precompletion diagnosed unifocal disease 7.3% (11 of 150) had recurrent disease, and patients without contralateral disease after precompletion diagnosed multifocal disease 1.9% (2 per 103) had recurrence. Cox regression analysis showed that bilaterality (hazard ratio = 3.621, 95% confidence interval = 1.548 to 8.471) was the sole statistically significant risk factor for recurrence.

CONCLUSION

Low recurrence rates are found in patients with either multifocal or bilateral disease with low-risk PTC. Bilaterality should be taken into account when considering these patients for de-escalated treatment strategy.

Association between thyroid stimulating hormone levels and papillary thyroid cancer risk: A meta-analysis

High thyroid stimulating hormone (TSH) levels may stimulate papillary thyroid cancer (PTC) cell proliferation; however, the relationship between TSH levels and PTC risk remains controversial. We aim to ascertain the association through a meta-analysis. Literature searches were conducted in PubMed, Embase, and Web of Science databases. After literature screening, the methodological quality was assessed using the Newcastle-Ottawa Scale and Agency for Healthcare Research and Quality methods. Cochran's Q and I 2 tests were used to evaluate heterogeneity in the meta-analysis. Egger's test was applied to assess publication bias. A total of 12 eligible studies were included in this meta-analysis; all were of moderate and high methodological quality. The pooled results suggested that increased TSH levels were significantly associated with PTC risk; however, the included studies were significantly heterogeneous. Stratification analysis indicated that the heterogeneity might be from the area or type of control. Although significant publication bias existed among the studies, the trim-and-fill method and sensitivity analysis revealed that the combined results were stable and robust. TSH levels are significantly associated with the PTC risk; however, more high-quality studies in large sample sizes are recommended to verify the extrapolation of these findings.