Correlation Between Plasma Circulating Tumor DNA(ctDNA)and Clinicopathological Features Of Endometrial Carcinoma

Objective:To evaluate the correlation between ctDNA test results and clinical data and pathological characteristics of endometrial cancer by detecting the ctDNA results of patients with initial treatment of endometrial cancer before and 2 weeks after surgery,so as to investigate the application of ctDNA in the diagnosis andtreatment of endometrial cancer.Materials and methods:40 patients with initial treatment of endometrial cancer diagnosed by biopsy pathology who visited QingDao municipal hospital from September 2016 to October 2018 were selected.Peripheral blood samples were collected before and 2 weeks after surgery,and ctDNA was detected by second-generation sequencing(NGS)technology.The clinical and pathological characteristics of each case were collected,so as to analyze the correlation between the ctDNA results and clinical and pathological characteristics before and after surgery.Results:In the initially treated 40 endometrial cancer patients,42.5%(17/40)had positive ctDNA test results in their blood before surgery.Early endometrial carcinoma(IⅡ)ctDNA positive rate was 45.2%,the patients with Ⅲ stage endometrial cancer ctDNA positive rate was 33.3%(3/9).The overall ctDNA negative conversion rate was 82.4%two weeks after surgery.The positive rate of ctDNA before and after surgery was significantly different(P<0.05).The ctDNA negative conversion rate(92.9%)in patients with early endometrial cancer was higher than that in patients with advanced endometrial cancer(33.3%).Two weeks after surgery,ctDNA results were positive in three endometrial cancer,with ctDNA results are positive before the operation,and all the cases are type Ⅱ endometrial carcinoma.All type I ctDNA of postoperatively endometrial cancer patients detection results turned negative.Among the 40 endometrial cancer patients,l patient relapsed six months after surgery,and the ctDNA test result was positive.Statistical analysis of the relationship between ctDNA test results and clinical data and pathological characteristics of endometrial cancer showed that the correlation between preoperative ctDNA test results and endometrial cancer grading was statistically significant(P=0.012).The correlation between postoperative ctDNA test results and endometrial cancer typing was statistically significant(P=0.006).Conclusion1.The positive rate of ctDNA detection in early endometrial cancer is’nt high enough,and the detection of ctDNA is insufficient as a screening method for endometrial cancer,but it can be used as a reference for early diagnosis of endometrial cancer;2.ctDNA test results before surgery are correlated with the grade of endometrial cancer to a certain extent,which may reflect the invasive ability of endometrial cancer.Patients with positive ctDNA before surgery may have a higher degree of tumor malignancy.3.After the operation,examination revealed ctDNA continuous positive and endometrial cancer classification has a certain relevance,and relations with Ⅱ type endometrial cancer are obvious,which predict that postoperative ctDNA positive patients likely to be poor;4.Patients with recurrence of endometrial cancer after surgery are accompanied by positive ctDNA test results,which can be used as a monitoring method for treatment.