Predicting The Efficacy Of Adjuvant Chemotherapy In Stage Ⅱ Colorectal Cancer Based On Inflammatory Markers

Background: Colorectal cancer is is the third most commonly diagnosed cancer and ranks second in terms of mortality.Adjuvant chemotherapy is an important means to improve postoperative survival rate and quality of life in patients with colorectal cancer.However,the effect of adjuvant chemotherapy in stage II colorectal cancer remains controversial.Although there have been several studies,most of them have not found a survival benefit from adjuvant chemotherapy in patients with stage II colorectal cancer.In a comprehensive review of relevant studies,several treatment guidelines recommend adjuvant chemotherapy for high-risk stage II colorectal cancer patients.However,the definition of high-risk factors only refers to prognosis and does not consider the additional survival benefit brought by adjuvant chemotherapy alone.At present,there is no evidence to prove the correlation between stage II high-risk factors and the choice of adjuvant chemotherapy.In the process of exploring the predictive indicators of chemotherapy effect,there have been several studies appling inflammatory markers in some advanced cancer with metastasis,but no similar studies have been conducted in stage II colorectal cancer.The purpose of this study is to analyze the relationship between several common inflammatory markers and the effect of adjuvant chemotherapy in stage II colorectal cancer and to select the optimal predictive marker.Methods: A total of 708 patients with stage II colorectal cancer were included in this study.The subpopulation treatment effect pattern plot(STEPP)was used to identify the optimal inflammatory marker and its cut-off values,and propensity score matching(PSM)was used to balance the differences between the chemotherapy and non-chemotherapy group.Survival analysis was performed based on overall survival(OS)and cancer-specific survival(CSS),and Kaplan-Meier method with Log-rank test and Cox regression model were used.The correlation between each variable and the effect of adjuvant chemotherapy was evaluated by interaction analysis,and patient survival was visually described using restricted mean survival time(RMST).Results: According to STEPP analysis,the platelet to lymphocyte ratio(PLR)was selected as the optimal predictive marker,and the cut-off value was determined to be 130.In the overall survival analysis with integrated dataset,PLR level was significantly correlated with the effect of adjuvant chemotherapy(interaction P=0.027): in the PLR<130 subgroup,there was no significant difference in OS between chemotherapy and non-chemotherapy patients(RMST: 56.0 vs 56.0 months,HR:0.983,95%CI:0.528-1.829);In the PLR≥130 subgroup,chemotherapy patients had significantly better OS than non-chemotherapy patients(RMST: 56.5 vs 51.3 months,HR:0.371,95%CI :0.212-0.649).In the cancer-specific survival analysis,there was no significant correlation between PLR level and chemotherapy effect(interaction P=0.116): in the PLR<130 subgroup,there was no significant difference in CSS between chemotherapy and non-chemotherapy patients(RMST: 56.0 vs 56.0 months,HR: 1.016,95%CI: 0.494 to 2.087);In the PLR≥130 subgroup,chemotherapy patients had significantly better CSS than non-chemotherapy patients(RMST: 56.5 months vs.51.3 months,HR: 0.440,95%CI: 0.217-0.893).In the overall survival analysis of the matched dataset,PLR level was still significantly correlated with the effect of adjuvant chemotherapy(interaction P=0.038): in the PLR<130 subgroup,there was no significant difference in OS between chemotherapy and non-chemotherapy patients(RMST: 54.9 months vs.55.3 months,HR:1.080,95%CI: 0.495-2.355);In the PLR≥130 subgroup,chemotherapy patients had significantly better OS than non-chemotherapy patients(RMST: 57.6 vs 51.3 months,HR:0.272,95%CI: 0.102-0.726).In the cancer-specific survival analysis,there was no significant correlation between PLR level and chemotherapy effect(interaction P=0.231):in the PLR<130 subgroup,there was no significant difference in CSS between chemotherapy and non-chemotherapy patients(RMST: 54.9 months vs.55.3 months,HR:0.963,95%CI: 0.379-2.449);In the PLR≥130 subgroup,chemotherapy patients tended to have a survival benefit(RMST: 57.6 months vs.51.3 months,HR: 0.372,95%CI:0.100-1.374).Conclusions: PLR can predict the effect of adjuvant chemotherapy in stage II colorectal cancer.