Recurrence following hemithyroidectomy in patients with low- and intermediate-risk papillary thyroid carcinoma

Analysis of preoperative computed tomography radiomics and clinical factors for predicting postsurgical recurrence of papillary thyroid carcinoma

BACKGROUND

Postsurgical recurrence is of great concern for papillary thyroid carcinoma (PTC). We aim to investigate the value of computed tomography (CT)-based radiomics features and conventional clinical factors in predicting the recurrence of PTC.

METHODS

Two-hundred and eighty patients with PTC were retrospectively enrolled and divided into training and validation cohorts at a 6:4 ratio. Recurrence was defined as cytology/pathology-proven disease or morphological evidence of lesions on imaging examinations within 5 years after surgery. Radiomics features were extracted from manually segmented tumor on CT images and were then selected using four different feature selection methods sequentially. Multivariate logistic regression analysis was conducted to identify clinical features associated with recurrence. Radiomics, clinical, and combined models were constructed separately using logistic regression (LR), support vector machine (SVM), k-nearest neighbor (KNN), and neural network (NN), respectively. Receiver operating characteristic analysis was performed to evaluate the model performance in predicting recurrence. A nomogram was established based on all relevant features, with its reliability and reproducibility verified using calibration curves and decision curve analysis (DCA).

RESULTS

Eighty-nine patients with PTC experienced recurrence. A total of 1218 radiomics features were extracted from each segmentation. Five radiomics and six clinical features were related to recurrence. Among the 4 radiomics models, the LR-based and SVM-based radiomics models outperformed the NN-based radiomics model (P = 0.032 and 0.026, respectively). Among the 4 clinical models, only the difference between the area under the curve (AUC) of the LR-based and NN-based clinical model was statistically significant (P = 0.035). The combined models had higher AUCs than the corresponding radiomics and clinical models based on the same classifier, although most differences were not statistically significant. In the validation cohort, the combined models based on the LR, SVM, KNN, and NN classifiers had AUCs of 0.746, 0.754, 0.669, and 0.711, respectively. However, the AUCs of these combined models had no significant differences (all P > 0.05). Calibration curves and DCA indicated that the nomogram have potential clinical utility.

CONCLUSIONS

The combined model may have potential for better prediction of PTC recurrence than radiomics and clinical models alone. Further testing with larger cohort may help reach statistical significance.

The American Thyroid Association risk stratification and long-term outcomes of differentiated thyroid cancer: a 20-year follow-up of patients in Saudi Arabia

Background

Studies have reported differing factors associated with poor outcomes in patients with differentiated thyroid cancer (DTC). We aimed to describe our 20 years of experience in the management of thyroid cancer (TC) and identify predictors of treatment outcomes.

Methods

We conducted a retrospective review of medical records of patients with TC seen in the Thyroid Center at King Saud University Medical City (KSUMC) in Riyadh, Saudi Arabia, between the years 2000 and 2020. Demographic and clinical data including pathological characteristics were collected. The American Thyroid Association (ATA) risk stratification was determined for all patients at the postoperative period as well as the response to therapy at the final follow-up visit.

Results

A total of 674 patients (mean age: 47.21 years) with TC, 571 (84.7%) of which were women, were included. There were 404 (60.0%) patients with ATA low risk, 127 (18.8%) with intermediate risk, and 143 (21.2%) with high-risk histology. Overall, 461 patients (68.4%) had an excellent response to treatment, 65 (9.6%) had an indeterminate response, 83 (12.3%) had a biochemical incomplete response, and 65 (9.6%) had a structural incomplete response. Patients who had an excellent response were mostly ATA low risk (n = 318 of 431, 68.1%), whereas 40 of 65 patients (61.5%) of those with ATA high-risk histology had a structural incomplete response to treatment. There were significantly more women who had an excellent response compared with men. Obesity, lymphovascular invasion, and size of the tumor were significant predictors of worse outcomes to therapy.

Conclusion

Tumor size, lymphovascular invasion, and obesity are strong predictors of a worse response to therapy among patients with TC. Patients with obesity should be carefully followed up regardless of their risk stratification in light of the recent compelling evidence associating obesity with thyroid cancer and its higher risk of a worse disease outcome. ATA risk stratification is well correlated with patient long-term outcomes.

Impact of microscopic extrathyroidal extension on differentiated thyroid cancer post-surgical risk of recurrence: a retrospective analysis

PURPOSE

In the last edition of the American Joint Committee on Cancer (AJCC) staging system, differentiated thyroid cancers (DTC) showing microscopic extrathyroidal extension (mETE) are considered comparable to intrathyroidal cancers for their clinical behavior and prognosis. The aim of the study is to evaluate the impact of this updated assessment of T, when applied to the postoperative recurrence risk stratification, according to the American Thyroid Association Guidelines (ATA-RR).

METHODS

One-hundred DTC patients who underwent total thyroidectomy were retrospectively evaluated. The downstaging of mETE was introduced in the definition of T, and the updated classification defined as modified ATA-RR (ATAm-RR). For each patient, post-surgical basal and stimulated thyroglobulin (Tg) levels, neck ultrasound (US) and post-ablative 131-I whole body scan (WBS) reports were considered. The predictive performance (PP) of disease recurrence was calculated both for each single parameter, as well as for all of them.

RESULTS

According to ATAm-RR classification, 19/100 patients (19%) were downstaged. ATA-RR proved a significant PP for disease recurrence (DR) (sensitivity 75.0%, specificity 63.0%, p = 0.023). However, ATAm-RR performed slightly better due to an increased specificity (sensitivity 75.0%, specificity 83.7%, p < 0.001). For both classifications, the PP was optimal when all the above-mentioned predictive parameters were considered.

CONCLUSION

Our results suggest that the new assessment of T considering mETE resulted in a downgrading of ATA-RR class in a significant number of patients. This provides a better PP for disease recurrence, and the best PP was obtained when considering the whole predictive variables together.

Clinical significance and diagnostic value of QPCT, SCEL and TNFRSF12A in papillary thyroid cancer

PURPOSE

To identify specific novel genes that could be used as diagnostic and prognostic factors in papillary thyroid carcinoma (PTC).

METHODS

Screening of differential genes by RNA sequencing (RNA-Seq) in normal thyroid, Hashimoto's thyroiditis, PTC combined with Hashimoto's thyroiditis and PTC tissues. The genes QPCT, SCEL and TNFRSF12A were selected by qRT-PCR and immunohistochemical pre-experiments. The GEPIA2 database, qRT-PCR, and immunohistochemical studies were used to confirm the target genes QPCT, SCEL, and TNFRSF12A. ROC curves were used to assess the diagnostic usefulness of these 3 genes for PTC in more detail.

RESULTS

Functional enrichment analysis showed that QPCT, SCEL and TNFRSF12A were enriched in the pathways for peptidyl-pyroglutamic acid biosynthesis, keratinocyte differentiation, WNT signaling, apoptosis. GEPIA2 database analysis revealed that QPCT, SCEL and TNFRSF12A were high in thyroid cancer, and TC patients with lower TNFRSF12A levels had short survival. QPCT, SCEL and TNFRSF12A were elevated in PTC and thyroid adenoma. The mRNA diagnostic values were as follows: for QPCT, AUROC = 0.891, 95% CI, 0.835-0.947; for SCEL, AUROC = 0.921, 95% CI, 0.869-0.974; for TNFRSF12A, AUROC = 0.884, 95% CI, 0.809-0.958. Immunohistochemical results showed that QPCT, SCEL, and TNFRSF12A differed to varying degrees between subgroups of thyroid tissue. SCEL was associated with BRAF V600E mutation status and stratification of recurrence risk, while TNFRSF12A was associated with Cyclin D1. The protein diagnostic values were as follows: for QPCT, AUROC = 0.752, 95% CI, 0.685-0.819; for SCEL, AUROC = 0.715, 95% CI, 0.645-0.784; for TNFRSF12A, AUROC = 0.660, 95% CI, 0.587-0.734.

CONCLUSION

QPCT, SCEL and TNFRSF12A are expected to be diagnostic markers for PTC.

A retrospective study of papillary thyroid carcinoma: Hashimoto's thyroiditis as a protective biomarker for lymph node metastasis

PURPOSE

There is approximately 10%-50% of papillary thyroid carcinoma (PTC) patients with Hashimoto's thyroiditis (HT). In this research, we sought to better understand the role of HT in PTC progression as well as lymph node metastasis.

METHODS

It is a retrospective and cross-sectional study, and 4131 PTC patients who underwent thyroidectomy were finally enrolled. Chi-square test, univariate and multivariate logistic regression analyses were employed to evaluate both the risk factors and the critical roles of HT during PTC metastasis.

RESULT

In this cohort, 1555 patients (37.6%) were diagnosed with HT. According to multivariate analysis, male sex, high levels of TG and TPOAb, tumor extrathyroidal extension, maximum diameter >1 cm, and multifocality were independent risk factors for both central lymph node metastasis (CLNM) and lateral lymph node metastasis (LLNM). In addition, age <55 years and smoking were risk factors for CLNM, while CLNM was one of the risk factors for LLNM. Furthermore, HT was suggested a valuable protective factor for both CLNM and LLNM. In patients with HT, the total number of central lymph nodes was higher, while the positive rate was lower. Compared with those without HT, age and sex did not predict CLNM and LLNM in patients with HT.

CONCLUSION

HT is considered a protective factor for both CLNM and LLNM in PTC. For patients with HT, surgeons should pay more attention to the preservation of parathyroid gland and the protection of recurrent laryngeal nerve due to less lymph node metastasis. Otherwise, radical operation is highly recommended.

Endoscopic hemithyroidectomy plus prophylactic central neck dissection via breast approach versus gasless transaxillary approach in treating low-risk papillary thyroid cancer: a retrospective series

Hemithyroidectomy plus prophylactic central neck dissection (pCND) has been adopted as a de-escalating surgical strategy for low-risk papillary thyroid cancer (PTC). This study aimed to evaluate and compare the outcomes of these two different endoscopic approaches in the treatment of PTC with hemithyroidectomy plus pCND. This retrospective study reviewed medical records of 545 patients receiving breast approach (ETBA) (n = 263) or gasless transaxillary approach (ETGTA) (n = 282) in treating PTC. Demographics and outcomes were compared between the two groups. Preoperatively, the two groups were similar in demographics. Regarding surgical outcomes, no differences were found in terms of intraoperative bleeding, total amount of drainage, duration of drainage, postoperative pain, hospital stay, vocal cord palsy, hypoparathyroidism, hemorrhage, wound infection, chyle leakage, or subcutaneous ecchymosis. Conversely, ETBA recorded fewer skin paresthesia (1.5% vs. 5.0%, respectively) but longer operative times (138.1 ± 27.0 vs. 130.9 ± 30.8 min,) and more swallowing disturbances (3.4% vs. 0.7%) compared to ETGTA (p < 0.05). No difference in scar cosmetic results, but ETBA had lower neck assessment score than ETGTA (2.6 ± 1.2 vs. 3.2 ± 2.0, p < 0.05). For low-risk PTC, endoscopic hemithyroidectomy plus pCND using either ETBA or ETGTA is both feasible and safe. Although the two approaches are comparable in terms of most surgical and oncological outcomes, ETBA is superior to ETGTA in terms of neck cosmetic results and skin paresthesia but is associated with more swallowing disturbances and requires a longer operative time.

Activated partial thromboplastin time maybe associated with the prognosis of papillary thyroid carcinoma

Objective

Hemostasis markers associated with tumors have been widely studied. However, the associations between the coagulation factors and papillary thyroid carcinoma (PTC) prognosis remain unclear. The aim of the present study was to investigate these associations.

Patients and methods

PTC patients treated at Shengjing Hospital between 2013 and 2019 were retrospectively analyzed and divided into three groups. Clinical, ultrasound, and pathological patient characteristics were recorded. The blood routine, coagulation factors, and thyroid function data were compared.

Results

A total of 50 patients were selected and divided into Group 1 [complicated with second primary malignancies (SPMs)], Group 2 (with postoperative cervical lymph node metastasis), and Group 3 (control group). The ages of patients in Group 2 were significantly higher than those in the control group. The neutrophil ratio (%) in Group 1 was significantly higher than that in Groups 2 and 3, while its lymphocyte ratio (%) was significantly lower. The coagulation factor activated partial thromboplastin time (APTT) in the first and second groups was statistically significantly lower than that in the control group. There were no statistical differences in APTT between the first and second groups. Shorter APTT was associated with SPM and postoperative cervical lymph node metastasis.

Conclusions

Coagulation indicators, especially APTT, may be a new biomarker for predicting PTC prognosis and may provide a new molecular target, especially in combination with SPM and postoperative cervical lymph node metastasis.

Assessment of age as different variable types for determining survival in differentiated thyroid cancer

PURPOSE

The current tumor, node, metastasis (TNM) system uses an age of 55 years as a threshold for differentiated thyroid cancer (DTC). The aim of our study was to explore the concept of using age as a continuous variable.

METHODS

A total of 36,559 patients with DTC in the Surveillance, Epidemiology, and End Results (SEER) database and 7491 patients in our centers were enrolled. Overall survival (OS) and cancer-specific survival (CSS) were compared. Furthermore, the different statistical model performance of the 6th edition TNM system and age cutoffs for papillary (PTC) and follicular thyroid cancer (FTC) were assessed. Then, a nomogram was built and validated to evaluate the efficacy of age as a continuous variable for predicting survival.

RESULTS

The OS and CSS of patients with DTC were significantly increased in patients <55 years compared with those aged ≥55 years. However, no significant differences in prognosis were observed in certain groups as patients between 50 and 60 years were stratified by 1-year increments. Furthermore, the highest concordance index (C-index) was observed in the TNM staging without an age cutoff in SEER database (0.895), our two centers (0.877) and receiver operating characteristic (ROC) curves showed different age cutoffs for PTC and FTC. More importantly, the nomogram incorporating age as a continuous variable showed a favorable area under the ROC curve and calibration for training and validation groups.

CONCLUSIONS

The utilization of age as a continuous variable is a rational approach for predicting outcome in DTC patients.

Clinicopathological and ultrasound features as risk stratification predictors of clinical and pathological nodal status in papillary thyroid carcinoma: a study of 748 patients

Background

Papillary thyroid carcinoma (PTC) is the most common histological type of thyroid malignancy that tends to metastasize to cervical lymph nodes. In the present study, we aimed to investigate which clinicopathologic and ultrasound features of PTC are associated with clinical lymph node metastasis (LNM) and numbers of pathological LNM.

Methods

From January 2016 to December 2018, we identified a cohort of patients with PTC who underwent cervical ultrasonography and were diagnosed through operation and pathology. Clinical N1(cN1) and > 5 pathologic N1(pN1) were considered in the postoperative stratification to have an intermediate risk according to the 2015 ATA guidelines. Clinicopathological and ultrasound features in PTC patients were performed in accordance with the independent risk factors of cN1 and > 5pN1 respectively by using the univariate and multivariate analyses.

Results

We collected 748 PTC patients in the final inclusion criteria. There were 688 cN0 cases and 60 cN1 cases. From the analyses, primary tumor size > 2 cm, capsule contact, extrathyroidal extensions (ETE) and central LNM remained independent risk factors for cN1 in PTC patients. In the 748 PTC patients, 707 cases had ≤ 5 pN1, and 41 cases had > 5 pN1. Multifocality, primary tumor size > 2 cm, capsule contact and ETE are significant independent risk factors for > 5 pN1.

Conclusions

We concluded that multifocality, primary tumor size > 2 cm, capsule contact, ETE and central LNM were independent risk factors for the intermediate risk stratification in patients with PTC. Ultrasonography is a good technique for the preoperative lymph node staging of PTC and is helpful for detecting LNM.

Clinicopathological Findings Associated With Cervical Lymph Node Metastasis in Papillary Thyroid Microcarcinoma: A Retrospective Study in China

Objective

The incidence of papillary thyroid microcarcinoma (PTMC) has increased sharply during the past decades. Yet, whether or not nodal dissection should be performed remains controversial. This article aims to assess the high-risk factors associated with cervical lymph node metastasis (LNM) in patients with PTMC, which may potentially guide clinical management decision-making.

Methods

Medical records of 449 PTMC patients who underwent thyroidectomy in our hospital from August 2016 to July 2017 were retrospectively reviewed. Clinical and pathological factors of the patients were anonymously extracted from the charts and analyzed.

Result

The patients were classified into two subgroups according to maximum tumor size measured through post-surgical pathology: smaller PTMC group (≤5 mm) and larger PTMC group (>5 mm). Larger tumor size was found to be associated with a higher rate of LNM (P = .001), particularly central lymph node metastasis (CLNM) (P = .001). Tumor size was also associated with extrathyroidal tumor extension (ETE) (P < .001), bilateral lesions (P = .015), and BRAF^v600e mutation (P = .004). LNM was found to be more common in older patients (>55 y) (P = .030), and those with multifocal cancer (P < .001). In PTMC patients with unilateral lesions without ETE, tumor size was not significantly associated with LNM (P = .121).

Conclusions

For the PTMC population, tumor size was an independent risk factor for LNM, particularly for patients of old age (>55 y), and multifocality. However, in PTMC patients with unilateral lesions without extrathyroidal extension, tumor size was not related to the risk of LNM. These findings may potentially guide clinical decision-making in terms of cervical nodal dissection.

Restratification of Patients with Intermediate-Risk Papillary Thyroid Carcinoma

BACKGROUND

Long-term management and follow-up strategies in patients with intermediate-risk papillary thyroid carcinoma (PTC) according to the American Thyroid Association (ATA) are still controversial due to the paucity of data on unique risk factors or a risk stratification system predictive of long-term outcomes.

PATIENTS AND METHODS

This study included 649 patients with PTC who underwent an initial surgical treatment. Retrospectively enrolled patients were categorized according to the ATA risk stratification system. Intermediate-risk patients were further categorized into subgroups by the number of ATA intermediate risk factors. The recurrence-free survival (RFS) rates of these subgroups were compared with those of low- and high-risk patient groups. Additionally, the patients were classified according to their response to the initial therapy using the dynamic risk stratification (DRS) system, and the percentages of patients in each category were compared among the subgroups.

RESULTS

The median follow-up period was 102 months. Structural recurrence occurred in 9.2% of all enrolled patients (60/649) and in 13.0% of intermediate-risk patients (40/308). Patients with two or more current intermediate risk factors had a poorer RFS than patients with only one risk factor (p < 0.001) and showed a comparable RFS to high-risk patients (p > 0.050). The percentages of patients with an excellent response category for DRS significantly decreased with an increase in the number of intermediate risk factors.

CONCLUSION

Subclassification according to the number of intermediate risk factors may be useful to better predict the RFS and the response to initial therapy in patients with intermediate-risk PTC.

Serum Linkage-Specific Sialylation Changes Are Potential Biomarkers for Monitoring and Predicting the Recurrence of Papillary Thyroid Cancer Following Thyroidectomy

BACKGROUND

Although papillary thyroid cancer (PTC) could remain indolent, the recurrence rates after thyroidectomy are approximately 20%. There are currently no accurate serum biomarkers that can monitor and predict recurrence of PTC after thyroidectomy. This study aimed to explore novel serum biomarkers that are relevant to the monitoring and prediction of recurrence in PTC using N-glycomics.

METHODS

A high-throughput quantitative strategy based on matrix-assisted laser desorption/ionization time-of-flight mass spectrometry was used to obtain serum protein N-glycomes of well-differentiated PTC, postoperative surveillance (PS), postoperative recurrence (PR), and matched healthy controls (HC) including linkage-specific sialylation information.

RESULTS

Serum N-glycan traits were found to differ among PTC, PS, PR, and HC. The differentially expressed N-glycan traits consisting of sixteen directly detected glycan traits and seven derived glycan traits indicated the response to surgical resection therapy and the potential for monitoring the PTC. Two glycan traits representing the levels of linkage-specific sialylation (H4N3F1L1 and H4N6F1E1) which were down-regulated in PS and up-regulated in PR showed high potential as biomarkers for predicting the recurrence after thyroidectomy.

CONCLUSIONS

To the best of our knowledge, this study provides comprehensive evaluations of the serum N-glycomic changes in patients with PS or PR for the first time. Several candidate serum N-glycan biomarkers including the linkage-specific sialylation have been determined, some of which have potential in the prediction of recurrence in PTC, and others of which can help to explore and monitor the response to initial surgical resection therapy. The findings enhanced the comprehension of PTC.

A critical analysis of the current TNM classification for differentiated thyroid carcinoma in young patients: Time for a change?

BACKGROUND

The current TNM classification that simply classifies differentiated thyroid carcinoma (DTC) patients younger than 55 years into stage I and stage II based on the presence or absence of distant metastases has been questioned. In this study, we reexamined the impact of T status and N status on prognosis and then developed a new prediction model to improve the predictability of cancer-specific survival (CSS) in young patients.

MATERIALS AND METHODS

Kaplan-Meier method was applied to calculate the CSS. Multivariable Cox proportional hazards models were used to assess the impact of T status and N status on CSS after adjustment for known covariates. The area under the receiver operating characteristic curve (AUC), C-index, Bayesian information criterion (BIC), and Akaike information criterion (AIC) were calculated to compare model performance.

RESULTS

A total of 9,242 DTC patients younger than 55 years were enrolled in the study. After adjusting for gender, age at diagnosis, race, pathology subtype, N stage, and M stage, T3 disease [hazard ratio (HR): 3.78, P = 0.006] and T4 disease (HR: 7.96, P < 0.001) remain independent predictors of CSS. Similarly, the 10-year CSS rate of N1b disease (HR: 3.78, P < 0.001) was significantly higher than that of N0 disease after adjustment. Moreover, Kaplan-Meier survival analysis showed that the 10-year CSS of stage II disease in younger patients with DTC showed a sharp decrease compared with that in older patients with DTC (74.47% vs. 98.43%, P < 0.001). Furthermore, a modified TNM staging system based on significantly prognostic T stage and N stage was established, which showed better performance than the current TNM staging system (P < 0.05). The new prediction model is also applicable to papillary thyroid carcinoma patients and follicular thyroid carcinoma patients.

CONCLUSIONS

This is the first study to question the rationality of the current TNM staging system for patients younger than 55 years and successfully develop a new prognostic model, which improves prognostic stratification and guides individualized management.

Association of Multifocality With Prognosis of Papillary Thyroid Carcinoma: A Systematic Review and Meta-analysis

Importance

Multifocality is common in papillary thyroid carcinoma (PTC), but it is unclear whether multifocal tumors are associated with tumor recurrence or cancer-specific survival.

Objective

To compare tumor recurrence rates in patients with multifocal vs unifocal PTCs.

Data Sources

We searched PubMed, SCOPUS, Web of Science Core Collection, and Cochrane Database of Systematic Reviews for pertinent studies published in English from inception to June 30, 2020.

Study Selection

The search strategy yielded 26 studies that compared tumor recurrence in patients with multifocal vs unifocal PTC.

Data Extraction and Synthesis

Data was extracted in accordance with the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-analyses guideline. Characteristics of study populations and hazard ratio (HR) of multifocality were independently extracted by 2 investigators.

Main Outcomes and Measures

The primary outcome was tumor recurrence and the secondary outcome was cancer-specific survival. Subgroup analysis of the primary outcome was based on primary tumor size, number of tumor foci, and patient age.

Results

Among 26 studies with a total of 33 976 patients, recurrence rates were significantly higher in patients with multifocal PTC than in those with unifocal PTC (pooled HR, 1.81; 95% CI, 1.52-2.14). Cancer-specific survival was comparable between the groups (HR, 1.19; 95% CI, 0.85-1.68). In subgroup analyses, the HRs of multifocality for recurrence were associated with primary tumor size (HRs for PTC ≤1 cm and >1 cm were 1.81 and 1.90, respectively), number of tumor foci (HRs for 2 foci and ≥3 foci were 1.45 and 1.95, respectively), and patient age (HRs for pediatric and adult patients were 3.19 and 1.89, respectively).

Conclusions and Relevance

This systematic review with meta-analysis found that multifocality was significantly associated with an increased risk of recurrence in patients with PTC, while cancer-specific survival showed no difference. Differences in tumor size, number of tumor foci, and patient age should be considered when interpreting the multifocality and the risk of recurrence.

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.

Tumor Mutation Burden Predicts Relapse in Papillary Thyroid Carcinoma With Changes in Genes and Immune Microenvironment

BACKGROUND

The risk factors of papillary thyroid carcinoma (PTC) recurrence are meaningful for patients and clinicians. Tumor mutation burden (TMB) has been a biomarker for the effectiveness of immune checkpoint inhibitor (ICI) and prognosis in cancer. However, the role of TMB and its latent significance with immune cell infiltration in PTC are still unclear. Herein, we aimed to explore the effect of TMB on PTC prognosis.

MATERIAL AND METHODS

RNA-seq and DNA-seq datasets of PTC patients were downloaded from The Cancer Genome Atlas (TCGA) database. The Gene Ontology (GO) and gene set enrichment analysis (GSEA 4.0.1) were applied further to explore potential differences in PTC patients' biological functions. The differentially expressed genes (DEGs) and immune microenvironment between the high and low TMB groups were determined.

RESULTS

TMB had the highest AUC score than other clinical indicators in ROC analysis on recurrence-free survival, and a higher TMB score was related to a worse prognosis. Further, GSEA showed a higher level of oxidative phosphorylation (OXPHOS) in the high TMB group, and four genes correlated with recurrence-free survival rate were identified. The abundance of CD8⁺ T cells and M1 macrophages in the high TMB group was significantly lower than that in the low TMB group.

CONCLUSIONS

Our study found that TMB was a better predictor variable at evaluating the risk of PTC recurrence. Moreover, TMB-related genes conferred dramatically correlated prognosis, which was worth exploring in guiding postoperative follow-up and predicting recurrence for PTC patients.

Clinical Relevance and Management of Recurrent Laryngeal Nerve Inlet Zone Lymph Nodes Metastasis in Papillary Thyroid Cancer

BACKGROUND

Recurrent nodal disease often occurs in recurrent laryngeal nerve inlet zone (RLNIZ), leading to difficult surgical management.

METHODS

Medical records of 947 patients with PTC and 33 patients with recurrent PTC were retrospectively reviewed. Totally 169 sides of RLNIZ dissection in 152 patients (17 cases were bilateral and 135 cases were unilateral) with primary surgery and 4 patients with structural recurrent disease were included for the analysis.

RESULTS

The rate of lymph node metastasis in RLNIZ was 31.3% (47/150). The incidence of transient hypoparathyroidism was 5.9% and no RLN injury and permanent hypoparathyroidism occurred. RLNIZ lymph nodes metastasis (LNM) was significantly associated with age <45 years, larger tumor size, number of CNLNM, and lateral node metastasis. CNLNM and lateral node metastasis were independent risk factors for RLNIZ LNM. Recurrent nodal disease in RLNIZ was identified in four of 33 patients and permanent recurrent laryngeal nerve (RLN) injury was observed in one of four patients.

CONCLUSION

Lymph nodes in RLNIZ are usually involved in patients with heavy tumor burden and can be removed safely at initial surgery. Once central or lateral LNM was confirmed preoperatively or intraoperatively, RLNIZ lymph node dissection should be carefully performed to reduce the rate of structural recurrence in the central compartment.

A Case Report on Challenging Management of Multiple Neoplasms in Elderly

Multiple primary malignancies especially in the head and neck region is no longer a rare occurrence and the prevalence is increasing. They were described as synchronous when the malignancies present within 6 months of another or metachronous tumors if the subsequent malignancy presents 6 months later. Many etiologies had been hypothesised including similar carcinogens exposure, genetic susceptibility and mutation, immunodeficiency or treatment of the index tumor. Among the hypotheses, the most accepted theory was field cancerisation in which the occurrence of multiple primaries in the aerodigestive tract was due to persistent exposure of similar carcinogens through inhalation or oral intake . However the co-incidence of thyroid and aerodigestive malignancies is relatively low. Hereby we would like to report a case of a 74 years old lady with known esophageal squamous cell carcinoma presented with metachronous laryngeal squamous cell carcinoma and papillary micro carcinoma of thyroid.