Chronic Lymphocytic Thyroiditis with Oncocytic Metaplasia Influences PD-L1 Expression in Papillary Thyroid Carcinoma.

BACKGROUND: Despite the increasing recognition of PD-L1 as predictor of immunotherapeutic response in various malignancies, its role and prognostic significance in thyroid cancer remain underexplored and subject to debate. This study begins to address this gap by comprehensively analyzing PD-L1 expression in papillary thyroid carcinoma (PTC) and investigating its correlation with key clinicopathological variables. METHODS: We conducted immunohistochemistry (IHC) to assess PD-L1 expression in whole-tissue sections from 121 primary papillary thyroid carcinoma (PTC) cases. We then analyzed the correlations between PD-L1 expression and various clinicopathological variables. RESULTS: PD-L1 expression was detected in 33.1% of papillary thyroid carcinomas (PTCs), predominantly exhibiting weak to moderate intensity. Notably, this study found no significant correlation between PD-L1 expression and various clinicopathological variables. The lack of association with traditional factors such as age, sex, histological subtype, and tumor size suggests the complex and multifaceted nature of PD-L1 regulation in PTC. Multivariate logistic regression analysis identified chronic lymphocytic thyroiditis with oncocytic metaplasia as the sole independent predictor of PD-L1 expression (P = 0.014), underlining the potential influence of the tumor microenvironment on immune checkpoint expression in PTC. CONCLUSIONS: Our study underscores the intricate interplay between chronic lymphocytic thyroiditis with oncocytic metaplasia and PD-L1 expression in papillary thyroid carcinoma. The observed link suggests a potential avenue for therapeutic intervention using anti-PD-1/PD-L1 therapies in surgery-refractory PTC. Understanding the dynamics of immune checkpoint regulation in the context of the tumor microenvironment is crucial for devising effective treatment strategies. Future research endeavors should delve deeper into the molecular mechanisms underlying this interaction and explore its implications for patient outcomes. As the field of immunotherapy continues to evolve, our findings contribute valuable insights into the complex immunological landscape of thyroid cancer.

Cytogenetic abnormalities in exfoliated oral mucosal cells and their association with oral cancer.

OBJECTIVE: To assess cytogenetic abnormalities through quantification of micronuclei, broken eggs, and karyorrhexis, in cells from normal oral mucosa of individuals exposed to carcinogens (alcohol and tobacco) and adjacent to leukoplakias and squamous cell carcinomas. STUDY DESIGN: The sample was composed of 40 subjects aged > 30 years, divided into four groups: control, alcohol/tobacco, leukoplakia, and squamous cell carcinoma. For control and alcohol/tobacco groups, cells were collected from lower lip, tongue border, and floor of the mouth. For leukoplakia and squamous cell carcinoma groups, mucosa contralateral and adjacent to the lesions were analyzed. Cytologic smears were stained with the Feulgen reaction. A blind observer analyzed 1,000 cells per slide to quantify micronuclei, broken eggs, and karyorrhexis. RESULTS: The leukoplakia group showed an increased number of micronuclei compared to controls (p = 0.0016) and the alcohol/tobacco group (p = 0.0048) and also increased broken eggs compared to the alcohol/tobacco group (p = 0.0172). Similarly, the carcinoma group presented more micronuclei compared to controls (p = 0.0462) and more broken eggs compared to the alcohol/tobacco group (p = 0.0104). CONCLUSION: The assessment of cytogenetic abnormalities micronuclei and broken eggs may be useful for monitoring individuals exposed to risk factors for developing oral cancer.

Teste dos micronúcleos: um biomarcador de dano genotóxico em células descamadas da mucosa bucal / Micronucleus assay: a biomarker of genotoxic damage in exfoliated oral mucosa cells

O objetivo deste trabalho é fazer uma revisão de literatura a respeito do ensaio dos micronúcleos, explicando o seu significado e sua aplicação em células esfoliadas da mucosa bucal. Micronúcleo (MN) é um núcleo acessório, originado a partir de fragmentos de cromossomo ou de cromossomos inteiros que não são incluídos no núcleo principal durante a mitose. MNs surgem por alterações genéticas espontâneas ou são induzidos por agentes genotóxicos. A análise dos micronúcleos tem sido utilizada como uma ferramenta importante de biomonitoramento de populações. Estudos demonstram que consumidores de fumo e álcool, assim como grupos expostos a determinados agentes em função de sua ocupação ou estilo de vida apresentam um elevado número de MNs nas células bucais esfoliadas.

The aim of this study is to summarise the literature on micronucleus assay, explaining its meaning and its application in exfoliated oral mucosal cells. Micronuclei (MN) is an extra nuclei, originated from chromosome fragments or whole chromosomes that are not included in the main nuclei during mitosis. MNs arise from spontaneous genetic damage or are induced by genotoxic agents. MN analysis has been used as an important tool to biomonitore populations exposed to life-style agents. Studies demonstrate that tobacco and alcohol users, as well as occupationally exposed groups present increased number of MNs in exfoliated oral mucosa cells. Despite the fact that the role of MN frequency has not yet been fully understood, the MNs assay is considered to be an effective biomarker of oral squamous cell carcinoma risk factors effects.