The new AJCC/TNM Staging System (VIII ed.) in papillary thyroid cancer: clinical and molecular impact on overall and recurrence free survival

Autoimmune Thyroid Disease and Differentiated Thyroid Carcinoma: A Review of the Mechanisms That Explain an Intriguing and Exciting Relationship

Autoimmune thyroid disease is a complex and highly frequent disease, where a wide variety of genetic, epigenetic and environmental factors (among others) come together and interact, and is characterized by the presence of two clinical outcomes: hypothyroidism (in Hashimoto's thyroiditis) and hyperthyroidism (in Graves-Basedow disease). For its part, differentiated thyroid carcinoma (mainly papillary carcinoma) is the most common type of cancer affecting the thyroid (and one of the most prevalent worldwide). An important co-occurrence between autoimmune thyroid disease and differentiated thyroid carcinoma has been documented. In this article, studies that have evaluated possible associations and relationships between autoimmune thyroid disease and differentiated thyroid cancer are systematically described and summarized. To date, the underlying mechanism that explains this association is inflammation; however, the characteristics and designs of the studies evaluated do not yet allow a causal relationship between the two entities to be established. These aspects have made it difficult to establish "causality" in the continuum of the pathogenesis between both conditions.

Survival outcomes of low-risk papillary thyroid carcinoma at different risk levels: a corollary for active surveillance

Background

This study aims to compare the outcomes of active surveillance (AS) in low-risk papillary thyroid carcinoma (PTC) patients with different tumor sizes and lymph node metastasis status, in order to establish appropriate management strategies. By analyzing these results, this study provides valuable insights for the effective management of such patients, addressing the issues and challenges associated with AS in practical clinical practice.

Methods

The study utilized the SEER database supported by the National Cancer Institute of the United States, extracting data of PTC diagnosed between 2000 and 2015. Statistical analyses were conducted using inverse probability weighting (IPTW) and propensity score matching (PSM), including Kaplan-Meier survival curves and Cox regression models, to evaluate the impact of different tumor sizes and lymph node metastasis status on thyroid cancer-specific survival (TCSS).

Results

A total of 57,000 PTC patients were included, with most covariates having standardized mean differences below 10% after IPTW and PSM adjustments. The TCSS of PTC with a diameter smaller than 13mm is significantly better than that of tumors with a diameter larger than 13mm, regardless of the presence of lymph node metastasis. Among PTC cases with a diameter smaller than 13mm, the TCSS of patients is similar, regardless of the presence of lymph node metastasis. However, in PTC cases with a diameter larger than 13mm, the presence of lateral neck lymph node metastasis (N1b stage) significantly impacts the TCSS, although the absolute impact on TCSS rate is minimal.

Conclusion

The treatment strategy of AS is safe for patients with T1a stage papillary thyroid microcarcinoma (PTMC). However, for patients with T1b stage, if the tumor diameter exceeds 13mm or there is lymph node metastasis in the lateral neck region, the TCSS will be significantly affected. Nevertheless, the absolute impact on survival is relatively small.

The Relationship between Oxidative Status and Radioiodine Treatment Qualification among Papillary Thyroid Cancer Patients

Total oxidative status (TOS), total antioxidant capacity (TAC), tumor protein 53 (p53), nuclear factor kappa B (NF-κB), forkhead box protein O1 (FOXO), and sirtuin 1 (SIRT1) play crucial roles in oxidative homeostasis and the progression of papillary thyroid cancer (PTC), as previously demonstrated in the literature. Therefore, profiling these markers among PTC patients may be useful in determining their eligibility for radioiodine (RAI) treatment. Since treatment indications are based on multiple and dynamic recommendations, additional criteria for adjuvant RAI therapy are still needed. In our study, we evaluated the TOS, TAC, and serum concentrations of p53, NF-κB, FOXO, and SIRT1 to analyze the relationship between oxidative status and qualification for RAI treatment. For the purpose of this study, we enrolled 60 patients with PTC allocated for RAI treatment as the study group and 25 very low-risk PTC patients not allocated for RAI treatment as a reference group. The serum TOS and SIRT1 concentrations were significantly higher in the study group compared to the reference group (both p < 0.001), whereas the TAC and p53, NK-κB, and FOXO concentrations were significantly lower (all p < 0.05). We also demonstrated the diagnostic utility of TAC (AUC = 0.987), FOXO (AUC = 0.648), TOS (AUC = 0.664), SIRT1 (AUC = 0.709), p53 (AUC = 0.664), and NF-κB (AUC = 0.651) measurements as indications for RAI treatment based on American Thyroid Association recommendations. Our study revealed that oxidative status-related markers may become additional criteria for RAI treatment in PTC patients.

Construction of a Tumor Immune Microenvironment-Related Prognostic Model in BRAF-Mutated Papillary Thyroid Cancer

BRAF mutation is a representative oncogenic mutation, with a frequency of 60% in papillary thyroid carcinoma (PTC), but the reasons for the poor prognosis and more aggressive course of BRAF-mutated PTC are controversial. Tumor immune microenvironment (TIME) is an essential factor permitting the development and progression of malignancy, but whether TIME participates in the prognosis of BRAF-mutated PTC has not yet been reported. The primary goal of the present study was to provide a comprehensive TIME-related prognostic model to increase the predictive accuracy of progression-free survival (PFS) in patients with BRAF-mutated PTC. In this study, we analyzed the mRNA-seq data and corresponding clinical data of PTC patients obtained from the TCGA database. By calculating the TIME scores (immune score, stromal score and ESTIMATE score), the BRAF mutation group (n=237) was dichotomized into the high- and low-score groups. By functional analysis of differentially expressed genes (DEGs) in different high/low score groups, we identified 2 key TIME-related genes, HTR3A and NIPAL4, which affected PFS in BRAF-mutated PTC. A risk scoring system was developed by multivariate Cox analysis based on the abovementioned 2 TIME-related genes. Then, the BRAF-mutated cohort was divided into the high- and low-risk groups using the median risk score as a cutoff. A high risk score correlated positively with a higher HTR3A/NIPAL4 expression level but negatively with PFS in BRAF-mutated PTC. Ultimately, a nomogram was constructed by combining risk score with clinical parameter (Tumor stage), and the areas under the ROC curve (AUCs) of the nomogram for predicting 1-, 3- and 5-year PFS were then calculated and found to be 0.694, 0.707 and 0.738, respectively, indicating the improved accuracy and clinical utility of the nomogram versus the risk score model in the BRAF-mutated PTC cohort. Moreover, we determined the associations between prognostic genes or risk score and immune cell infiltration by two-way ANOVA. In the high-risk score, high HTR3A expression, and high NIPAL4 expression groups, higher infiltration of immune cells was found. Collectively, these findings confirm that the nomogram is effective in predicting the outcome of BRAF-mutated PTC and will add a spatial dimension to the developing risk stratification system.