ABSTRACT
Malignant neoplasms may be composed of several cell groups, including cancer stem cells (CSC). These cells have been related with the capacity of metastasis, relapse and resistance to multiple drugs during chemotherapy. This study aims to identify CSC biomarkers and their expression pattern in human head and neck carcinomas. This study was conducted following the PRISMA checklist. The search for articles was carried out in five databases (PubMed, Scopus, Web of Science, Lilacs and Scielo). The articles found were selected in two phases: 1) reading the titles and / or abstract and 2) reading the full text. At the end, the selected articles were evaluated by QUADAS-2. Most studies evaluated oral neoplastic tissues and, as a control, samples of normal local mucosa. All studies performed immunohistochemistry as a method of immunolocalization and some also applied immunofluorescence. The most commonly used biomarker was CD44. However, other such as Sox2, Oct4, Nestin, Nanog, BMI1, ALDH1, CD133 and CD166 were also found. Several biomarkers were (ALDH1, Sox2, Oct4, ABCB5, AGR2 and TAZ) correlated with clinical characteristics of the tumor, such as staging, tumor size and lymph node metastasis. These data reinforce the CSC theory and favor the use of these biomarkers as possible determinants of prognosis.
Subject(s)
Biomarkers, Tumor/biosynthesis , Head and Neck Neoplasms , Neoplastic Stem Cells , Head and Neck Neoplasms/diagnosis , Head and Neck Neoplasms/metabolism , Head and Neck Neoplasms/pathology , Humans , Lymphatic Metastasis , Neoplasm Staging , Neoplastic Stem Cells/metabolism , Neoplastic Stem Cells/pathology , PrognosisABSTRACT
BACKGROUND: The aim of this systematic review and meta-analysis was to assess the prevalence of clinical signs of temporomandibular joint (TMJ) disorders in children and adolescents. TYPE OF STUDIES REVIEWED: The authors selected only studies in which the investigators' primary objective was to evaluate the prevalence of signs of TMJ disorders according to the international Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) in children and adolescents. The authors performed electronic searches without language restriction in 5 databases. The authors also assessed quality. RESULTS: In this review and meta-analysis, the authors included 11 articles that described studies in which 17,051 participants had been enrolled. The overall prevalence of clinical signs of intra-articular joint disorders was 16% (95% confidence interval [CI], 11.59-19.94; n = 17,051). The prevalence of TMJ sounds (click and crepitation) was 14% (95% CI, 9.67-19.79; n = 11,316). The most prevalent sign was clicking (10.0%; 95% CI, 7.97-12.28; n = 9,665) followed by jaw locking (2.3%; 95% CI, 0.56-5.22; n = 5,735). CONCLUSIONS AND PRACTICAL IMPLICATIONS: One in 6 children and adolescents have clinical signs of TMJ disorders. The results of this systematic research study can alert dentists about the importance of looking for signs of TMD in children and adolescents.
