Can Radiation-Induced Esophagitis Predict The Response Of Esophageal Squamous Cell Carcinoma To Radiotherapy

Objective:The purpose of this investigation was to evaluate the association of the grade of acute radiation-induced esophagitis with the response of esophageal esophageal squamous cell carcinoma to radiotherapy.Materials and Methods:A total of 32 patients with esophageal squamous cell carcinoma stages T1-2NOMO who received radical radiotherapy between 1 August 2007 and 1 May 2008 at Qilu Hospital of Shandong University in Jinan (China) were included in the prospective study.Radiotherapy was delivered using three-dimensional conformal plans.The treatment was administered by a high energy,linear accelerator(10 MV photons) and irradiation was delivered using a standard irradiation(2 Gy/day for five days/week).The total dose was 64 Gy at our institution.Patients were compared between two groups according to the presented worst esophagitis grade:one group with absent or mild radiation-induced esophagitis(grades 0—1) and the other group with moderate or severe esophagitis(grades 2—4).The tumor response rates between the two groups were compared using Pearson's chi-squared analysis.Results:There were no grade 4 or 5 esophageal toxicities.Grades 0-1 and grades 2-3 radiation-induced esophagitis were observed in 18(56.3%) and 14 (43.8%) patients,respectively.There were no differences between the two groups in the distribution of any clinicopathologic features.The patients were divided into two groups based on tumor response:a complete response(CR) group(n=17) and a non-CR group(n=15).The rates of complete response in patients with grades 0-1 and grades 2-3 esophagitis were 33.3%(6/18) versus 78.6%(11/14)(p=0.011).The clinicopathologic characteristics between the patients with complete response of tumor mass(n=17) and that without complete response(n=15) were also analyzed.All the parameters were not significantly different between the two groups.Conclusions:We found a better tumor response in patients with severe radiation-induced esophagitis,and thus suggested a correlation of the radiosensitivity between esophageal mucosa and esophageal cancer cells. Radiation-induced esophagitis may be a marker to individualize the total dose of radiotherapy for esophageal cancer.