Does every classical type of well-differentiated thyroid cancer have excellent prognosis? A case series and literature review

The Incidence Trend and Management of Thyroid Cancer-What Has Changed in the Past Years: Own Experience and Literature Review

Because of ambiguous and widely debated observations concerning the incidence, trend, and management of TC, we performed this analysis. We drew attention to some events, such as "cancer screening activity", introduction of noninvasive follicular neoplasm with papillary-like nuclear features (NIFTP) to TC types, possibility of papillary thyroid microcarcinoma (PTMC) active surveillance (AS), occurrence of personalized medicine in TC management, and, finally, COVID-19 pandemic time. Because of the opinion that all changes have been made mostly by PTC, we compared it to the remaining types of TC in terms of incidence, clinical and pathological characteristics, and treatment. We analyzed patients treated in a single surgical center in eastern Europe (Poland). The prevalence of TC significantly increased from 5.15% in 2008 to 13.84% in 2015, and then significantly decreased to 1.33% in 2022 when the COVID-19 pandemic lasted (p < 0.0001). A similar trend was observed for PTC, when the incidence significantly increased to 13.99% in 2015 and then decreased to 1.38% in 2022 (p < 0.0001). At that time, the NIFTP category was introduced, and observation of PTMC began. The prevalence of FTC and MTC also increased until 2015 and then decreased. Significant differences in age, types of surgery, necessity of reoperation, and pTNM between PTCs and other types of TCs were observed. The average age was significantly lower in PTC patients than in patients with the remaining types of TC (p < 0.0001). Four milestones, including NIFTP introduction, the possibility of PTMC AS, personalized cancer medicine, and the COVID-19 pandemic, may have influenced the general statistics of TC.

Fine-needle aspiration cytology of metastatic carcinomas with papillary architecture: a systemic assessment of clinical, cytologic and immunohistochemical parameters

BACKGROUND

Papillary structures are frequently encountered in metastatic carcinomas from various organs and tumors of different histotypes. This study aims to investigate the predictive value of fine-needle aspiration cytology (FNAC), immunohistochemistry (IHC) and clinical parameters in assessment of primary sites of metastatic carcinomas with papillary architecture.

METHODS

FNAC of metastatic carcinomas with papillary architecture were evaluated for overall cellularity, epithelial cohesion, background features, architecture of papillae, cytology and IHC. The corresponding clinical information were also reviewed.

RESULTS

Totally 130 cases were included. The most common primaries were thyroid (38.5%), lung (30.8%) and gynecological organs (22.3%) with the remainders being pancreaticobiliary, urothelial, colorectal, and esophageal. Age (p=.039), biopsy site (p<.001) and laterality (p=.006) correlated with primary site. Papillary structures were confirmed on biopsy/excision of most cases (n=85/87, 97.7%). Thyroid primaries demonstrated broad papillary stalks, thin lining epithelium, fewer epithelial polymorphs, and presence of background giant cells and histiocytes (p=.021-<.001). Low-grade cytologic features, nuclear grooves and inclusions (p<.001) were seen in thyroid primaries. High-grade features (p<.001-0.49), multinucleated tumor cells, apoptotic bodies and mitoses (p<.001-0.49) were more common in lung/gynecological primaries. Multivariate analysis identified nuclear/cytoplasmic ratio, chromatin character, presence of nuclear groove and mitosis as independent features (p=0.001-.024). TTF1/TGB/PAX8 panel demonstrated good agreement with cytologic assessment and primary site.

CONCLUSION

Papillary structures and cytologic features are reproducible in FNACs of metastases and corresponding primaries. Cytologic features, IHC and clinical information are invaluable in determining the primary site.

Cancer screening activity results in overdiagnosis and overtreatment of papillary thyroid cancer: A 10-year experience at a single institution

Background

It is estimated that one of the potential cause of the increasing prevalence of thyroid cancer (TC) is the easier and widespread access to diagnostic tools. If an individual evaluates the thyroid gland due to a mentioned mechanism without considering TC risk factors or symptoms, we can describe this phenomenon as cancer screening activity (CSA).

Aim of the study

We 1) estimated what types of TC were diagnosed due to CSA, 2) analyzed what clinicopathological features were characteristic of TCs diagnosed by CSA, 3) determined if these features were characteristic of indolent cases, and finally we 4) assessed whether CSA could have resulted in the increasing incidence of potentially indolent papillary thyroid cancer (PTC).

Materials and methods

A retrospective review of 4,701 medical records of patients admitted and surgically treated at one surgical center between 2008 and 2017 was performed. Among the enrolled patients, 569 (12.1%) had thyroid malignancy, and 514 (10.9%) were diagnosed with PTC. We divided these patients into two groups: 1) patients in whom TC diagnostics were performed without considering any TC risk factors or symptoms (CSA-yes) and 2) those in whom TC was diagnosed due to TC risk factors or symptoms (CSA-no). We then compared the clinicopathological features of these two groups.

Results

The most common type of TC diagnosed in the CSA-group was PTC (p = 0.024). CSA-yes patients showed a significantly lower degree of Tumor-Node-Metastasis (TNM) staging and demonstrated a significantly lower rate of multifocality, but not of bilaterality (p<0.0001 and p = 0.198, respectively). In the CSA-yes group, the number of TC foci was significantly lower than that in the CSA-no group (p<0.0001). All clinicopathological features characteristic of aggressive cases of TC were absent in CSA-yes patients (p<0.0001), while all features observed in CSA-yes patients were characteristic of indolent cases (p<0.0001).

Conclusions

The use of CSA results in the diagnosis of indolent cases of PTC and may be one of the potential causes of overdiagnosis and overtreatment of this malignancy.

Inflammation suppression prevents tumor cell proliferation in a mouse model of thyroid cancer

The incidence of thyroid cancer, the most frequent endocrine neoplasia, is rapidly increasing. Significant progress has recently been made in the identification of genetic lesions in thyroid cancer; however, whether inflammation contributes to thyroid cancer progression remains unknown. Using a mouse model of aggressive follicular thyroid cancer (FTC; Thrb^PV/PVPten^+/- mice), we aimed to elucidate a cause-effect relationship at the molecular level. The Thrb^PV/PVPten^+/- mouse expresses a dominantly negative thyroid hormone receptor β (denoted as PV) and a deletion of a single allele of the Pten gene. These two oncogenic signaling pathways synergistically activate PI3K-AKT signaling to drive cancer progression as in human FTC. At the age of 5-7 weeks, thyroids of Thrb^PV/PVPten^+/- mice exhibited extensive hyperplasia accompanied by 77.5-fold infiltration of inflammatory monocytes as compared with normal thyroids. Global gene expression profiling identified altered expression of 2387 genes, among which 1353 were upregulated and 1034 were down-regulated. Further analysis identified markedly elevated expression of inflammation mediators and cytokines such as, Csf1r, Csf1, SPP1, Aif1, IL6, Ccl9, Ccl3, Ccl12, and Ccr2 genes and decreased expression of Kit, Ephx2, Cd163, IL15, Ccl11, and Cxcl13 genes. These changes elicited the inflammatory responses in the hyperplastic thyroid of Thrb^PV/PVPten^+/- mice, reflecting early events in thyroid carcinogenesis. We next tested whether attenuating the inflammatory responses could mitigate thyroid cancer progression. We treated the mice with an inhibitor of colony-stimulating factor 1 receptor (CSF1R), pexidartinib (PLX-3397; PLX). CSF1R mediates the activity of the cytokine, colony stimulating factor 1 (CSF1), in the production, differentiation, and functions of monocytes and macrophages. Treatment with PLX decreased 94% and 62% of inflammatory monocytes in the thyroid and bone marrow, respectively, versus controls. Further, PLX suppressed the expression of critical cytokine and inflammation-regulating genes such as Csf1r, SPP1 (OPN), Aif1, IL6, Ccl9, Ccl3, Ccl12, and Ccr2 (25%-80%), resulting in inhibition of 89% tumor cell proliferation, evidenced by Ki-67 immunostaining. These preclinical findings suggest that inflammation occurs in the early stage of thyroid carcinogenesis and plays a critical in cancer progression. Importantly, attenuation of inflammation by inhibitors such as PLX would be beneficial in preventing thyroid cancer.

LRRC52-AS1 is associated with clinical progression and regulates cell migration and invasion in papillary thyroid cancer

The incidence of thyroid cancer has increased in recent decades. The potential molecular mechanisms of papillary thyroid cancer (PTC) are still to be uncovered. In recent years, a number of studies reported that LRRC super family members are up-regulated in cancer cells. Cancer cells can experience a feature change from an epithelial to a mesenchymal phenotype, which is called epithelial-mesenchymal transition (EMT) during cancer progression. We found that LRRC52-AS1 is highly expressed in PTC cell lines rather than normal tissues and this observation was consistent with The Cancer Genome Atlas (TCGA) cohort. In a word, LRRC52-AS1 is associated with clinical progression in papillary thyroid cancer. In vitro experiments showed that knocking down LRRC52-AS1 significantly decreased the migration and invasion of the PTC cell lines (BCPAP and TPC). Meanwhile, LRRC52-AS1 may influence the progress of papillary thyroid cancer via mesenchymal markers N-cadherin, vimentin and TAZ. The LRRC52-AS1 gene is up-regulated in papillary thyroid cancer, and knockdown of LRRC52-AS1 could restrain cellular migration, and invasion in vitro. This study indicated that LRRC52-AS1 is a gene associated with PTC and might become a potential therapeutic target in PTC.