The Value Of Tumor Size Change After Treatment In Predicting Survival For Metastatic Colorectal Cancer

Objective: To investigate whether ETS,DPR,and TBTS have predictive value for survival.To explore whether there are differences in the prediction of survival for patients with metastatic colorectal cancer using different treatment schemes according to subgroup analysis.To explore the relationship between ETS,DPR,TBTS and RECIST.Methods: This study was a retrospective study.Data were collected from patients with advanced colorectal cancer who had been treated in the Department of Oncology at the First Hospital of China Medical University from January 2013 to July 2018 and had received two cycles or more of chemotherapy.We collected CT examination information of patients before and after chemotherapy,and calculated the patient's tumor size at baseline and each evaluation of efficacy.ETS(Early Tumor Shrinkage)is defined as the tumor shrink more than 20% at the first evaluation.DPR(Depth of Response)is defined as the maximum tumor shrinkage observed in a patient.TBTS(Timing of Best Tumor Shrinkage)is defined as the time to reach DPR.Patients' clinical characteristics,such as gender,age,primary tumor site,the number of first metastases,and other relevant clinical data,as well as survival information were recorded.Survival analysis was performed using Kaplan-Meier curve and Log-rank test to compare the efficacy of the two groups,using Cox Ratio Risk model for univariate analysis and multivariate survival analysis to explore prognostic factors affecting survival in patients with m CRC.Results: A total of 410 patients were enrolled in the study.106 patients achieved ETS,and the median of TBTS is 8.14 weeks,and the median of DPR is 0.19.In univariate analysis,pathological type(p=0.029),chemotherapy regimen(p=0.026),combined with targeted therapy(p=0.098),ETS(p=0.000),DPR(p=0.000),TBTS(p=0.000)was associated with PFS in patients with advanced first-line colorectal cancer.Number of first metastases(p=0.005),presence of liver metastases(p=0.174),pathological type(p=0.115),ETS(p=0.000),DPR(p=0.000),TBTS(p=0.076)was associated with OS in patients with advanced first-line colorectal cancer.Multi-factor analysis showed that ETS(HR=0.478,95% CI: 0.369-0.619,P=0.000),DPR(HR=0.477,95%CI:0.373-0.609,P=0.000)and TBTS(HR=0.602,95%CI:0.475-0.762,P=0.000)are the independent factor affecting PFS.ETS(HR=0.566,95%CI:0.433-0.740,P=0.000)and DPR(HR=0.541,95%CI:0.423-0.691,P=0.000)are the independent factor affecting OS.Conclusions: The results of this study show that for patients with advanced first-line metastatic colorectal cancer,ETS is an independent predictor of PFS and OS,DPR is an independent predictor of PFS and OS,and TBTS is an independent predictor of PFS.Subgroup analysis shows that ETS,DPR,and TBTS have predictive value for survival,whether or not they are combined with targeted therapy.ETS,TBTS,DPR have a certain predictive value for the survival of patients with advanced first-line colorectal cancer.Although their predictive value is not as good as RECIST,they are the complementary to RECIST.Combining RECIST with ETS,DPR,and TBTS is the best predictor of survival.