Biological role of the bidirectional interaction between epithelial-mesenchymal transition and PD-L1 expression in head and neck squamous cell carcinomas: A systematic review.

BACKGROUND: Squamous cell carcinoma (SCC) is the most common head and neck malignant neoplasm. Despite progress in antineoplastic treatment for SCC, there are still high morbidity and mortality rates. Over the years, several tumor biomarkers have been suggested to predict the prognosis of patients with oral SCC. Studies point to a bidirectional association between the epithelial-mesenchymal transition (EMT) and the expression of PD-L1 with the aggressive biological behavior of the neoplastic cell. Thus, this systematic review aimed to explore the biological roles and mechanisms underlying the interaction between EMT and PD-L1 expression in head and neck SCC-derived cell lines. MATERIAL AND METHODS: An electronic search was performed in the PubMed/Medline, Web of Science, Science Direct, Scopus, Embase, and Cochrane Collaboration Library databases. Articles evaluating the in vitro relationship between EMT/PD-L1 interaction and the biological behavior of head and neck SCC cell lines were selected for this systematic review. The quality of evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) criteria. RESULTS: After applying the previously established inclusion/exclusion criteria, 9 articles were included in the qualitative synthesis. The present systematic review suggests the existence of a bidirectional interaction between EMT and PD-L1 expression, which is related to alterations in the cell cycle, proliferation, apoptosis, and cell survival, affecting the migration and invasion ability of tumor cells. CONCLUSIONS: Combined targeting of the two pathways may be potentially effective for immunotherapy in head and neck SCC.

Prognostic and clinicopathological significance of tumor-stroma ratio in head and neck squamous cell carcinoma: A systematic review.

BACKGROUND: Analysis of the tumor microenvironment has been proposed as a strategy for the treatment and prognosis of different neoplastic processes. A grading system based on the tumor-stroma ratio (TSR), which evaluates the proportion of stroma in relation to neoplastic parenchyma at the invasion front, has shown a strong prognostic value in different neoplastic processes. The aim of the present systematic review was to understand the role of the TSR in head and neck squamous cell carcinoma (HNSCC), evaluating its correlation with clinical and prognostic parameters. MATERIAL AND METHODS: An electronic search was performed in PubMed/Medline, Web of Science, Science Direct, Scopus, Embase, and the Cochrane Collaboration Library. Publications assessing the relationship between TSR and prognosis in cases of HNSCC were eligible. The quality of the studies was assessed independently by four evaluators using the Newcastle-Ottawa scale. RESULTS: After application of the previously es+lished inclusion/exclusion criteria, nine articles were included in the qualitative synthesis. With regards to quality on the Newcastle-Ottawa scale, an overall value of 4.55 was obtained. This systematic review demonstrated a strong association between TSR and prognosis in esophageal and oral squamous cell carcinomas. CONCLUSIONS: Histopathological analysis of the TSR can optimize the analysis of the prognosis of cases diagnosed with HNSSC. In addition, the TSR is a reliable and simple parameter that can be evaluated in hematoxylin/eosin-stained slides during routine laboratory examinations, showing high inter- and intraobserver agreement.

Dermoid and epidermoid cysts of the oral cavity: a 48-year retrospective study with focus on clinical and morphological features and review of main topics.

BACKGROUND: Dermoid and epidermoid cysts are slow-growing, benign developmental cysts that arise from ectodermal tissue and can occur anywhere in the body. Less than 7% of these cysts involve the head and neck region, with only 1.6% of cases presenting in the oral cavity. To evaluate the clinical and histopathological features of dermoid (DCs) and epidermoid (ECs) cysts stored in the archives of a referred Oral Pathology Service over a 48-year-period, and to review current concepts about these cysts. MATERIAL AND METHODS: All DCs and ECs were reviewed, and clinical data were obtained from the patient records. Fourteen cases of DCs and thirteen cases of ECs were re-evaluated microscopically by 2 oral pathologists. RESULTS: Among 15.387 cases, 14 (0.09%) had a histopathological diagnosis of DCs and 13 (0.08%) of ECs. For DCs, ten (71.4%) patients were women, with the mean age of 37.2 years. All DCs were lined by a stratified squamous epithelium (100%), with gut and respiratory epithelium observed in 1 (7.1%) and 2 (14.3%) cases, respectively. Chronic inflammatory cells, melanin, multinucleated giant cell reaction, and Pacini bodies were also observed. For ECs, eight (61.5%) cases were in women, and the mean age was 38.2 years. All ECs were lined by a stratified squamous epithelium (100%). Chronic inflammatory cells, melanin pigmentation, and adipose tissue were observed in the fibrous capsule. CONCLUSION: Our results suggest that stratified squamous epithelium is the predominant epithelial lining of these cystic lesions. Also, we may find some unusual findings in DCs, such as Pacini bodies.

Prognostic value of the immunohistochemical detection of epithelial-mesenchymal transition biomarkers in oral epithelial dysplasia: A systematic review.

BACKGROUND: Oral potentially malignant disorders (OPMDs) comprise a range of clinical-pathological alterations that are frequently characterized as architectural and cytological derangements upon histological analysis. Epithelial-mesenchymal transition (EMT) has been proposed as a critical mechanism for the acquisition of the malignant phenotype in neoplastic epithelial processes. This study aims to systematically review the current findings on the immunohistochemical expression of epithelial-mesenchymal transition markers in oral potentially malignant disorders and to evaluate their possible application as biomarkers associated with the progression of oral epithelial dysplasias. MATERIAL AND METHODS: A systematic search was performed in the following databases: PubMed, EMBASE, Chinese BioMedical Literature Database, and Cochrane Library. Articles that evaluated the relationship between the expression of EMT markers and the degree of oral epithelial dysplasia were selected for the systematic review. The quality of each eligible study was evaluated by independent reviewers that used operationalized prognostic biomarker reporting guidelines (REMARK). RESULTS: Seventeen articles met all inclusion criteria and were selected. The EMT markers analyzed exhibited an important association with the prognosis of the cases evaluated. The results showed a progressive increase in the expression of nuclear transcription factors and markers of mesenchymal differentiation, as well as negative regulation of epithelial and cell adhesion markers, according to the stage of oral epithelial dysplasia. CONCLUSIONS: The dysregulation of expression of important EMT components in oral dysplastic epithelium is a potential prognostic marker in OPMDs.