Correlation Study Of Hematological Indicators In Predicting Pathological Response After Neoadjuvant Chemoradiotherapy In Locally Advanced Rectal Cancer

Objective: Neoadjuvant chemoradiotherapy(NRCT)for locally advanced rectal cancer can effectively reduce the volume of the tumor,reduce the local stage,and even transform unresectable tumors into resectable tumors,thereby increasing the rate of radical resection and the rate of sphincter preservation.It can improve the prognosis of cancer patients.The purpose of our study was to retrospectively evaluate the relationship between peripheral hematological indexes and their changes before and after NCRT in patients with locally advanced rectal cancer and tumor pathological response,to find hematological indexes that can predict the tumor pathological response after NCRT,and to establish Related predictive models to more effectively guide individualized precision treatment plans for rectal cancer patients.Methods: Our study retrospectively analyzed the clinical data of 202 patients with rectal cancer who received neoadjuvant chemoradiotherapy and radical surgery in Sichuan Cancer Hospital.According to the postoperative pathological results and the tumor regression grading(TRG)system recommended by the 7th edition of the American Joint Committee on Cancer Staging,the patients were divided into a good pathological response group(TRG score 0-1)and a poor pathological response group(TRG score 2-3).Univariate analysis and Logistic multivariate regression analysis were used to search for hematological indexes that can predict the pathological response of rectal cancer after neoadjuvant chemoradiotherapy.The independent risk factors screened out by multivariate Logistic multivariate regression were imported into R software and a nomogram prediction model was established,and the discrimination of the model was evaluated by Bootstrap method and ROC curve and the consistency test was carried out.Results: Among the 202 patients,38(18.8%)achieved TRG 0;42(20.8%)had TRG 1;92(45.5%)had TRG 2;and 30 had TRG 3.(14.9%).Univariate analysis showed that age(P<0.001),tumor length(P=0.02),preoperative T stage(P=0.043),distance from the lower edge of the tumor to the anal edge(P=0.029),and CEA level before NCRT(P=0.029)= 0.005),preoperative CEA level(P < 0.001),changes in lymphocytes and platelets were related to the pathological response of rectal cancer after neoadjuvant chemoradiotherapy,and the differences were statistically significant.Multivariate analysis showed that age(P=0.003,OR=0.352,95%CI: 0.176-0.703),tumor distance from the anus(P=0.037,OR=2.113,95%CI: 1.047-4.266),preoperative CEA(P=0.005,OR=0.372,95%CI: 0.187-0.74),changes in lymphocytes(P=0.002,OR=0.297,95%CI: 0.136-0.648),changes in platelets(P=0.045,OR=2.016,95)%CI:1.015-4.004)was an independent risk factor affecting the pathological response after NCRT in locally advanced rectal cancer.The independent risk factors were imported into R software to construct a nomogram model,the area under the ROC curve was 0.76,and the slope of the calibration curve of the nomogram was close to 1.Conclusion:Low preoperative CEA level,young age,high level of tumor inferior margin from the anal verge,maintained circulating lymphocyte level and decreased platelet level after NCRT are important factors affecting the success of locally advanced rectal cancer after neoadjuvant chemoradiotherapy,and are helpful for predicting Pathological response after neoadjuvant chemoradiotherapy in locally advanced rectal cancer.The establishment of a nomogram prediction model has good discrimination and consistency,and can provide some guidance for the prediction of pathological response after neoadjuvant chemoradiotherapy for locally advanced rectal cancer.