A prospective phase II randomized clinical study of folic acid in the intervention of radiation esophagitis induced by concurrent chemoradiotherapy in lung cancer.

e20004 Background: To investigate the efficacy and safety of folic acid intervention in lung cancer patients with radiation esophagitis caused by concurrent chemoradiotherapy. Methods: It was a randomized, controlled, single-center clinical trial of 82 patients with stage N2~N3 lung cancer including SCLC and NSCLC were prospectively included. All patients were randomly divided into experimental and control group according to 1:1, and patients were required to receive radiation therapy for lung lesions and mediastinal metastatic lymph nodes (More than 2 cycles of chemotherapy were completed during the same period of radiotherapy or take targeted drugs at the same time, the cumulative radiation dose of chest lesions should exceed 40Gy). The experimental group took folic acid tablets 30mg/day orally at the beginning of radiotherapy until the end of radiotherapy, while the control group did not receive any drug intervention.When two groups appeared radiation esophagitis, the grading criteria for RTOG should be evaluated first, then according to the guidelines of symptomatic treatment.Esophageal toxicity was evaluated during radiotherapy, and improved RTOG and NCI-CTC ratings were performed weekly at the onset of radiation esophagitis and thereafter until 1 week after the end of radiotherapy. Results: The incidence of radiation esophagitis in the experimental group was low during the observation period, and the occurrence time of radiation esophagitis could be delayed in the experimental group, but there was no statistical significance between the two groups ( P=0.456). After folic acid intervention, the symptoms of pain and dysphagia of radiation esophagitis in the experimental group were significantly decreased, especially the RTOG grade and NCI-CTC improvement grade decreased significantly 2 weeks after the occurrence of radiation esophagitis( P=0.007, P=0.009). In the experimental group, it was found that the greater the change of hemoglobin before and after radiotherapy, the occurrence time of radiation esophagitis was about delayed, which was statistically significant(r=0.348, P=0.040).The correlation analysis of the control group showed that the change of body mass index was positively correlated with the onset time of radiation esophagitis(r=0.372, P=0.020);The lower the hemoglobin content after radiotherapy and the larger the hemoglobin difference before and after radiotherapy, the higher the highest incidence of radiation esophagitis(r= -0.454, P=0.004;r= -0.343, P=0.032). Conclusions: Oral folic acid can delay the onset of radiation esophagitis due to concurrent chemoradiotherapy and promote the recovery of radiation esophagitis to a certain extent,but can not interfere with the occurrence of radiation esophagitis.This trial is registered in Clinical Trials(NCT0529636). Clinical trial information: NCT0529636 .