miR-21 and miR-145 as Prognostic Biomarkers for Radiotherapy Responses in Cervical Cancer Patients: A Preliminary Study

Radioresistance poses a significant challenge in the effective treatment of cervical cancer, often leading to poor patient outcomes. MicroRNA-21 (miR-21) and MicroRNA-145 (miR-145) are oncogenic micro-RNAs associated with various cancers, including cervical cancer, but their potential as predictive biomarkers for radioresistance remains underexplored. This study aimed to investigate the association between miR-21 and miR-145 expressions and the response to radiation therapy in cervical cancer patients. An analytical cross-sectional study was conducted on 140 subjects with cervical cancer stages IIIB and IVA who received definitive radiotherapy. miR-21 and miR-145 expressions were measured using real-time reverse transcriptase–polymerase chain reaction (RT-qPCR). A total of 102 subjects (72.9%) were classified as having stage III cervical cancer, and 38 subjects (27.1%) were classified as having stage IV cervical cancer. Disease progression occurred in 60.7% of subjects. The cut-off value for miR-21 expression was 0.00088 nmol/(mg/mL) (AUC 0.676, sensitivity 70.8%, specificity 50.8%), and a higher expression was significantly associated with radioresistance (p = 0.010). miR-145, with a cut-off of 0.0239 nmol/(mg/mL) (AUC 0.612, sensitivity 67.5%, specificity 45.5%), showed no significant association with treatment response (p = 0.132). Combining miR-21 and miR-145 (AUC 0.639, sensitivity 68.6%, specificity 46.9%, p = 0.063) did not significantly improve the predictive accuracy. This study suggests that an elevated miR-21 expression is significantly associated with radioresistance in cervical cancer patients, while miR-145 expression shows no significant correlation with treatment response. Additionally, combining miR-21 and miR-145 does not enhance the predictive power.