Survival Outcome Of Palliative Primary Tumor Resection For Advanced Colorectal Cancer

Objective:There is a great matter of controversies whether some of these unresectable synchronous metastatic colorectal cancer patients can benefit from palliative primary tumor resection and there is still no reported randomized control trial to address this issue.Our purpose was to assess whether palliative primary tumor resection in colorectal cancer patients with unresectable synchronous liver and/or lungs metastases is associated with improved survival and to explore the effect of surgery interaction with chemotherapy or radiation therapy on survival by using the Surveillance,Epidemiology,and End Results(SEER)Database.Methods:Patients with microscopically proven colorectal cancer were identified within the SEER Database(2010 to 2016).Propensity score matching was performed 1:1 and among the matched cohort,univariable and multivariable Cox proportional hazards regression models were performed to identify the predictors of survival.Median survival was calculated by using the Kaplan-Meier method.Results:Of 21405 colorectal cancer patients with unresectable synchronous liver and/or lungs metastases,7386 colorectal cancer patients were identified in the matched cohort.The median overall survival was 12.0 months,22.0 months in the non-resection,palliative primary tumor resection groups,respectively(P<0.001)and the corresponding median cancer-specific survival was 13.0 months,22.0 months,respectively(P<0.001).Multivariable Cox regression analysis demonstrated that surgery was independently associated with improved overall survival(hazard ratio,0.531)as well as cancer-specific survival(hazard ratio,0.516).In stratified analyses by primary tumor site and patterns of distant metastases,those advanced colorectal cancer patients with palliative primary tumor resection had better prognosis.In addition,stratified analysis revealed that trimodality therapy was associated with the greatest treatment effect followed by addition of chemotherapy to palliative primary tumor resection.Conclusions:Palliative primary tumor resection may offer therapeutic benefit among the carefully selected advanced colorectal cancer patients,and surgery-based multimodality therapy was associated with their better survival.