Prognostic Value Of Circulating Tumor Cells In Colorectal Cancer:a Meta Analysis

Study AimColorectal Cancer(CRC)is one of the most common malignant tumors with high morbidity and mortality in the world.Some studies have shown that circulating tumor cells(CTCs)have prognosis value for colorectal cancer,but some studies show that it has no prognostic value.In this study,we assessed the relationship between CTCs and the prognosis of patients with colorectal cancer by meta analysis.MethodsThrough searching PubMed,Medline and ISI Web of Science database(until February 2017),inclusion and exclusion criteria were defined for the eligible studies.All statistical analysis was done in Review Manager 5.3 and Stata 14.0 software.The data were analyzed by calculating the pooled hazard ratios(HRs)of overall survival(OS)and progression free survival(PFS),the corresponding 95%confidence interval(CI),odds ratio(OR)about metastasis,and risk ratio(RR)about therapeutic response among studies.Results23 studies including 6371 cases of colorectal cancer were enrolled in the meta analysis.Compared with the overall survival of CTCs negative patients,the overall survival of CTCs positive patients(OS:HR = 2.22,95%CI[1.76,2.82],P<0.01,I2 ?58%)and disease-free survival(PFS:HR = 1.80,95%CI[1.52,2.14],P =0.04,I2 =48%))were shortened,which were statistically different.The positive rate of CTCs was significantly higher in metastasis positive group(OR = 4.13,CI =[1.78,9.57],P<0.01,I2 = 0%).In patients with liver metastases,the detection rate of CTCs was significantly higher than that of patients without liver metastases(OR = 2.12,CI[1.90,3.89],P<0.01,I2 = 0%).With 3 studies included meta analysis of the therapeutic response rate,there was no significant difference between CTCs positive group and CTCs negative group(RR = 0.78,95%CI[0.78,1.02],P = 0.067,I2 = 28.8%).With 3 studies included meta analysis of the disease control rate,a higher disease control rate in patients with CTCs negative in patients with colorectal cancer(RR = 0.89,CI =[0.82,0.97]=,P =0.008,I2 =96.2%).ConclusionThe meta analysis indicates that CTCs in the peripheral blood of patients with colorectal cancer has prognostic value,and prognosis in CTCs positive colorectal cancer is worse than CTCs negative colorectal cancer.In addition,CTCs negative indicate higher disease control rate in patients with colorectal cancer,may provide additional prognostic information for imaging evaluation of cancer patient and may serve as a surrogate marker for chemotherapy response.