Clinical Analysis Of Adjuvant Radiotherapy In Patients With TD-positive Colon Cancer

Objective: To explore the value of radiotherapy after radical resection of colon cancer for patients with M0 stage colorectal adenocarcinoma with positive tumor deposits,and to find the groups that benefit from adjuvant radiotherapy.Methods: The sample included patients diagnosed with colorectal adenocarcinoma in the SEER database between January 1,2010 to December 31,2013.According to the filter,3177 qualified patients with M0 stage colorectal adenocarcinoma with positive tumor deposition were identified from the SEER database.In addition,other information extracted from the SEER database includes general information(gender,age and year of diagnosis),tumor pathological information(pathological staging,distant metastasis,tumor location,tumor diameter,nerve infiltration,N staging,T staging,preoperative carcinoembryonic antigen(CEA)preoperative levels and information on chemotherapy and radiotherapy)and survival data(follow-up time and death factor).Using chi-square test comparing different clinical pathologic factors and characteristics,and the PSM method was used for1:1 matching of the crowd,Cox model and K-M analysis curve were performed using R software(version 3.5.1)and SPSS statistical software(version 24.0),the queue before and after the match research,analysis Clinical and pathological factors associated with OS and CSS,then use K-M method and Cox model to perform subgroup analysis to explore the prognostic value of adjuvant postoperative radiotherapy in the total study cohort and in different subgroups.Results: 3177 qualified patients involved in this study,containing 68 patients(2%)who received adjuvant radiotherapy and 3109 patients(98%)who did not.The median follow-up time was 55 months in the NORT group,55 months in the RT group,and 59 months in the RT group.Comparison of age(P =0.032),gender(P=0.015),tumor location(P<0.001),T staging(P<0.001)there were significant differences among the 4 factors.After matching,the median follow-up time of the population was 53 months,the median follow-up time of the NORT group was 51 months,and the median follow-up time of the RT group was 59 months.After PSM,the differences of various factors between the groups were all reduced,and there was no significant difference in factors.The total population NORT group:3-year OS(63.6%),5-year OS(53.5%),3-year CSS(73.6%)and 5-year CSS(66.8%).The NORT group after PSM: OS(58.8%),5 years 3 years OS(47.1%),CSS 3 years(61.7%)and 5 years CSS(51.5%),RT group: 3 years OS OS(69.1%),5 years(54.4%),CSS 3 years(73.5%)and 5 years CSS(61.8%).K-M method showed no significant improvement in OS and CSS after adjuvant radiotherapy,either before or after matching.According to Cox analysis,factors contain neurologic invasion,specific chemotherapy,age,tumor location,degree of differentiation,T staging and N staging were significantly related to OS and CSS.After propensity score matching,the differences between the various clinical pathologic factors of patients reduced earlier and had no statistical significance,the Cox analysis results show that in all tumor depositional positive in patients with colonic carcinoma,T staging is significantly correlated factors of CSS(HR1.8(1.1-3.2),p = 0.028,changes to the OS and N staging(N2 HR 2.5(1.3-4.7),p= 0.001)and CSS(N2 stage HR was 2.7(1.4-5.2),P =0.002),and the changes of other factors had no significant effect on prognosis.Kaplan-Meier analysis of the study cohort showed no significant improvement in OS and CSS after adjuvant radiotherapy,either before or after matching.In the subgroup analysis,there was no improvement in the prognosis of patients in T3(OS P =0.27,CSS P =0.37),T4(OS P =0.42,CSS P =0.22),N0(OS P =0.45,CSS P =0.38),and N2(OS P =0.43,CSS P=0.31)in the radiotherapy group compared with those in the non-radiotherapy group.However,in the N-stage study,patients with stage N1 were found to have better performance on both OS(P =0.041)and CSS(P =0.015)after adjuvant postoperative radiotherapy.Cox analysis results of N1 subgroup showed that clear chemotherapy(P =0.014)and radiotherapy(P =0.030)had significant improvement in OS;Radiotherapy(P =0.023)was significantly associated with improvement in CSS.Conclusions: this study found that adjuvant radiotherapy improved the prognosis of a subset of patients with TD-positive colorectal adenocarcinoma,with stage N1 patients in this population receiving greater survival benefits(including OS and CSS)from adjuvant radiotherapy.This conclusion is promissing to offer a basis for drowing treatment programs for this population.