E-cadherin levels in premalignant and malignant oral lesions: a systematic review

Oral squamous cell carcinoma (OSCC) is the most common type of cancer found in the oral cavity and ranks as the eighth most frequently diagnosed cancer globally. Management still relies heavily on classic parameters such as TNM staging and tumor grading, highlighting the need for novel biomarkers to enable earlier detection and survival improvement. Epithelial cadherin (E-cadherin) is a calcium-dependent protein that has a crucial role in cellular adhesion. It also serves as an invasion suppressor and is a classical tumor suppressor gene. The loss of its function accelerates cancer progression by enhancing cell proliferation, invasion, and metastasis. This study aimed to systematically review E-cadherin levels in both premalignant and malignant oral lesions. Inclusion criteria included case‒control, cohort, comparative descriptive, and cross-sectional studies, published in English. A systematic search was performed in PubMed, Scopus, Web of Science, EMBASE and Google Scholar until April 2023. Study selection was performed according to PRISMA guidelines. The risk of bias was evaluated by the JBI checklist for case‒control studies. Results and characteristics of extracted studies were extracted by two reviewers. Eight studies comprising 346 patients with premalignant lesions and 353 patients with malignant lesions were considered in this review. With the exception of one study, findings indicated that E-cadherin levels were significantly lower in malignant lesions compared to premalignant ones. However, due to the variation among the studies, a meta-analysis could not be conducted. It seems that as premalignant lesions develop malignant changes, there appears to be a decline in E-cadherin levels. Additional research is necessary to assess whether this marker could aid in diagnosing malignancy and enhancing patient prognosis.