Study On The Relationship Between The Changes Of Circulating Tumor DNA And Curative Effect In Patients With Esophageal Squamous Cell Carcinoma Before And After Concurrent Chemoradiotherapy

Background and objectiveLocal recurrence and distant metastasis are two major causes of treatment failure in esophageal cancer.Early detection of these signs could help clinicians to intervene as early as possible,and by which,to improve the survival of esophageal cancer.It has been found that circulating tumor DNA(ct DNA)is superior to other imaging methods on monitoring of treatment response as well as detection of minimal residual disease and recurrence.And its level may be used as an important indicator for clinical diagnosis,treatment,prognosis judgment and so on.The aim of this study is to explore the clinical value of ct DNA in esophageal squamous cell carcinoma(ESCC)by means of analyzing the correlation between the changes of ct DNA and the efficacy following concurrent chemoradiotherapy(CCRT)for patients with stage Ⅲ-ⅣA ESCC.MethodsA total of 30 stage Ⅲ-ⅣA ESCC patients prior to treatment with CCRT were selected for this study.Venous blood samples were obtained 1 week before treatment,2 weeks before the end of CCRT,and 1-3 months after the end of treatment.Four kinds of gene mutations were involved in this experiment.Real-time fluorescence quantitative polymerase chain reaction(PCR)was used to quantitatively detect the changes of ct DNA before and after the treatment.Patients were divided into disease progression group(PD)and non-disease progression group(CR + PR + SD)in term of their response according to RECIST criteria.One-way repeated measures analysis of variance was used to analyze pre-,during-and post-treatment ct DNA differences,t test was used to compare differences between groups.Results1.The average ct DNA concentrations of pre-,during-,and post-treatment are0.690ng/μl,0.758ng/μl and 0.448ng/μl,respectively.The ct DNA concentrations of pre-,during-,and post-treatment for patients with stage Ⅲ esophageal cancer are 0.553ng/μl,0.621ng/μl and 0.329ng/μl.The ct DNA concentrations of pre-,during-,and posttreatment for patients with stage ⅣA esophageal cancer are 0.895ng/μl,0.964ng/μl and0.626ng/μl.2.The average ct DNA concentrations of pre-,during-,and post-treatment of CR patients are 0.480ng/μl,0.570ng/μl and 0.355ng/μl.The average ct DNA concentrations of pre-,during-,and post-treatment of PR patients are 0.729ng/μl,0.777ng/μl and0.362ng/μl.The average ct DNA concentrations of pre-,during-,and post-treatment of SD patients are 0.526ng/μl,0.544ng/μl and 0.304ng/μl.The average ct DNA concentrations of pre-,during-,and post-treatment of PD patients are 0.940ng/μl,1.138ng/μl and 1.083ng/μl.3.The ct DNA concentrations of pre-,during-,and post-treatment for non progress group are 0.652ng/μl,0.700ng/μl and 0.350ng/μl.The ct DNA concentrations of pre-,during-,and post-treatment for progress group are 0.940ng/μl,1.138ng/μl and1.083ng/μl.The ct DNA concentration for predicting disease progression is 0.840ng/ μl.4.TP53 mutations were the most frequently(63.33%)identified in plasma samples among the four genes.Significant differences were observed of ct DNA levels in pre-treatment and post-treatment(all P<0.05).Conclusion1.ct DNA concentrations of patients with stage Ⅲ esophageal cancer were significantly lower than those in stage Ⅳ patients.The ct DNA concentration decreased significantly after concurrent chemoradiotherapy2.The ct DNA concentrations of during-,and post-treatment are for CR,PR and SD patients are lower than PD patients significantly.The ct DNA concentration of non progress group is significantly lower than progress group.3.TP53 mutation level decreased significantly after concurrent chemoradiotherapy.