Assessment of Correlation of miRNA-21 with Overall Survival in Patients with Oral Squamous Cell Carcinoma: An Observational Study.

INTRODUCTION

Cervical lymph node metastasis is a well-established determinant of reduced overall survival in patients with Oral Squamous Cell Carcinoma (OSCC). MicroRNA-21 (miR-21), a key oncogenic regulator, has been implicated in tumor progression and metastasis. Given the reported association between miR-21 expression and lymph node involvement, this study aimed to evaluate the relationship between miR-21 expression, lymph node metastasis, and overall survival in OSCC patients.

METHODOLOGY: This observational follow-up study included 60 patients with OSCC who had undergone surgical treatment. Expression levels of miR-21 were quantified in both salivary and tumor tissue samples, and histopathologically confirmed lymph node metastasis was recorded as a predictor variable. Patients were followed up through in-person clinical examinations or telephonic communication. Overall survival, measured in months post-surgery, was the primary outcome. Potential confounders, including age, sex, histological grade, and TNM stage, were considered. Kaplan-Meier survival analysis and Hazard Ratio (HR) estimation were performed to evaluate associations.

RESULTS

Kaplan-Meier analysis demonstrated a significant reduction in overall survival among patients with positive lymph node metastasis (P ≤ 0.005). Although differences in survival by miR-21 expression were not statistically significant, elevated miR-21 levels were associated with an increased risk of mortality. Hazard ratios ranged from 1.3 to 1.6 for tumor tissue and 1.19 to 1.63 for salivary samples, indicating a higher risk of adverse outcomes in patients with expression levels above the defined cutoff.

DISCUSSION: Elevated miR-21 expression was associated with reduced overall survival, although statistical significance was not achieved in survival curve analysis. However, hazard ratio estimates suggest a clinically meaningful increase in mortality risk. The relationship between miR-21 expression and survival appears to be influenced by the presence of cervical lymph node metastasis.

CONCLUSION

High miR-21 expression is associated with an increased risk of mortality in OSCC patients, particularly in the presence of lymph node metastasis. These findings support the potential role of miR-21 as a prognostic biomarker in OSCC.