Metastatic medullary thyroid carcinoma (MTC): disease course, treatment modalities and factors predisposing for drug resistance

Photosensitizing metal-organic framework nanoparticles combined with tumor-sensitization strategies can enhance the phototherapeutic effect upon medullary thyroid carcinoma

Photodynamic therapy (PDT) utilizing metal-organic frameworks (MOFs) has developed as a new and efficacious treatment for malignant tumors located on the surface of the human body. In order to achieve more effective PDT treatment outcomes, the traditional method has been to increase the intensity of the laser irradiation, but this approach can easily lead to tissue burns. In this study, we developed a new type of nanoparticle, F68-PKI@PCN224, aims to achieve effective PDT upon medullary thyroid carcinoma (MTC) which is an uncommon form of thyroid cancer that originates in the parafollicular cells of the thyroid and the therapeutic outlook for patients with MTC remains unsatisfactory. F68-PKI@PCN224 combines the antitumor features of PDT with mammalian target of rapamycin (mTOR) inhibitor PKI-587 (PKI). The tumor sensitization, slow release, and pH response features of F68-PKI@PCN224 was demonstrated by a series of in vitro and in vivo experiments / assays. F68-PKI@PCN224 achieved the long-term activation and slow releasing of PKI and TCPP in MTC tumor tissues. During the process of generating PDT effects, F68-PKI@PCN224 enhanced the tumor's sensitivity to PDT, direct laser irradiation of MTC cells or subcutaneous tumor tissues. As a result, low-dose phototherapy achieves a higher anti-tumor effect upon F68-PKI@PCN224 compared with TCPP. This study reveals the synergistic effect between tumor sensitization by mTOR inhibitor and PDT and initially unveils the mechanism of action of these nanoparticles.

Use of Neoadjuvant Vandetanib in Aggressive Pediatric Medullary Thyroid Carcinoma

Novel use of vandetanib in a child with aggressive MTC with prolonged response to treatment.

Molecular Basis and Natural History of Medullary Thyroid Cancer: It is (Almost) All in the RET

Medullary thyroid cancer (MTC) is a rare disease, which can be either sporadic (roughly 75% of cases) or genetically determined (multiple endocrine neoplasia type 2, due to REarranged during Transfection RET germline mutations, 25% of cases). Interestingly, RET pathogenic variants (mainly M918T) have also been reported in aggressive forms of sporadic MTC, suggesting the importance of RET signalling pathways in the pathogenesis of MTC. The initial theory of RET codon-related MTC aggressiveness has been recently questioned by studies suggesting that this would only define the age at disease onset rather than the aggressiveness of MTC. Other factors might however impact the natural history of the disease, such as RET polymorphisms, epigenetic factors, environmental factors, MET (mesenchymal-epithelial transition) alterations, or even other genetic alterations such as RAS family (HRAS, KRAS, NRAS) genetic alterations. This review will detail the molecular bases of MTC, focusing on RET pathways, and the potential mechanisms that explain the phenotypic intra- and interfamilial heterogeneity.

Evaluation of Neutrophil-to-Lymphocyte Ratio (NLR), Platelet-to-Lymphocyte Ratio (PLR) and Systemic Immune-Inflammation Index (SII) as Potential Biomarkers in Patients with Sporadic Medullary Thyroid Cancer (MTC)

Medullary thyroid cancer (MTC) is a rare neuroendocrine neoplasm, and calcitonin is its main biomarker. An elevated neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR) and systemic immune-inflammation index (SII) have been considered as negative prognostic factors in several neoplasms. The aim of this study is to evaluate the potential role of NLR, PLR and SII as biomarkers in MTC. Clinical data and tumor histological characteristics of patients with sporadic MTC, referred to the NET Unit of Federico II University of Naples (ENETS CoE) from 2012 to 2022, were retrospectively evaluated by analyzing preoperative and postoperative calcitonin, NLR, PLR and SII. We included 35 MTC patients undergoing total thyroidectomy. The mean preoperative NLR was 2.70 (±1.41, 0.93-7.98), the PLR was 121.05 (±41.9, 40.98-227.23) and SII was 597.92 (±345.58, 186.59-1628). We identified a statistically significant difference between pre- and post-thyroidectomy NLR (p = 0.02), SII (p = 0.02) and calcitonin (p = 0.0) values. No association with prognosis or tumor characteristics emerged. Elevated preoperative NLR and SII suggest a possible disease-associated inflammatory response, and their reduction after surgery may be related to debulking effects. Further studies are needed to define the role of NLR, PLR and SII as prognostic markers in MTC.

Transcriptomic Analysis Reveals Dysregulation of the Mycobiome and Archaeome and Distinct Oncogenic Characteristics according to Subtype and Gender in Papillary Thyroid Carcinoma

Papillary Thyroid Carcinoma (PTC) is characterized by unique tumor morphology, treatment response, and patient outcomes according to subtype and gender. While previous studies have implicated the intratumor bacterial microbiome in the incidence and progression of PTC, few studies have investigated the potential role of fungal and archaeal species in oncogenesis. In this study, we aimed to characterize the intratumor mycobiome and archaeometry in PTC with respect to its three primary subtypes: Classical (CPTC), Follicular Variant (FVPTC), and Tall Cell (TCPTC), and also with respect to gender. RNA-sequencing data were downloaded from The Cancer Genome Atlas (TCGA), including 453 primary tumor tissue samples and 54 adjacent solid tissue normal samples. The PathoScope 2.0 framework was used to extract fungal and archaeal microbial read counts from raw RNA-sequencing data. Overall, we found that the intratumor mycobiome and archaeometry share significant similarities in CPTC, FVPTC, and TCPTC, although most dysregulated species in CPTC are underabundant compared to normal. Furthermore, differences between the mycobiome and archaeometry were more significant between males and females, with a disproportionate number of fungal species overabundant in female tumor samples. Additionally, the expression of oncogenic PTC pathways was distinct across CPTC, FVPTC, and TCPTC, indicating that these microbes may uniquely contribute to PTC pathogenesis in each subtype. Furthermore, differences in the expression of these pathways were observed between males and females. Finally, we found a specific panel of fungi to be dysregulated in BRAF V600E-positive tumors. This study demonstrates the potential importance of microbial species to PTC incidence and oncogenesis.