Abstract: Objective : To investigate the expression level of serum annexin A2 in oral squamous cell carcinoma (OSCC) and its relationship with radiosensitivity. Methods: From 2015 to 2018, 77 cases of middle and advanced oral squamous cell carcinoma treated in our hospital were collected in the case group and 50 healthy persons were collected in the control group. Three-dimensional conformal radiation therapy before operation was applied in the case group. The level of serum annexin A2 was detected in the two groups, respectively. The difference of serum annexin A2 in patients with different radiosensitivity was analyzed. Receiver operating characteristic curve (ROC) was used to analyze the predictive value of serum annexin A2 level before radiotherapy in patients with oral squamous cell carcinoma. Results: In 77 cases of oral squamous cell carcinoma patients after the radiotherapy, 29 cases were completely relieved, 41 cases were partial remission, 7 cases were ineffective, and the total effective rate of radiotherapy was 90.91%. The serum annexin A2 level in case group before and after treatment was significantly higher than that in control group (P<0.05); the level of serum annexin A2 before treatment in the complete remission group was significantly lower than that in the partial remission group and the ineffective group (P<0.05); the serum annexin A2 level in the partial remission group was significantly lower than the ineffective group before the treatment (P<0.05); the serum annexin A2 level in the complete remission group and the partial remission group was significantly decreased (P<0.05); the serum annexin A2 level in the ineffective group was not statistically significant compared with that before treatment (P>0.05); serum membrane lipoprotein A2 was associated with tumor size and lymph node metastasis in oral squamous cell carcinoma (P<0.05); the area of ROC curve (AUC) was 0.755; the sensitivity was 71.40%; and the specificity was 75.70% for the prediction of radiosensitivity in patients with oral squamous cell carcinoma before radiotherapy. Conclusion: Serum annexin A2 is closely related to radiosensitivity in patients with oral squamous cell carcinoma, and can be used as a biomarker to predict the sensitivity of radiotherapy for patients. It has important guiding significance for the development of clinical treatment plan for oral squamous cell carcinoma.

Key words: Oral squamous cell carcinoma, Annexin A2, Radiosensitivity, ROC curve