Analysis Of Related Factors Of Tumor Downstaging After Neoadjuvant Treatment Of Rectal Cancer

Objective:Analyze the related factors that affect the tumor downstaging after neoadjuvant therapy in patients with locally advanced rectal cancer,and explore the benefit of neoadjuvant therapy in different patients.Provide theoretical basis for clinical neoadjuvant therapy and provide individualized treatment for different patients.Methods: The clinical data of patients with locally advanced rectal cancer who underwent neoadjuvant chemoradiotherapy and surgery from January 2012 to December 2019 were retrospectively studied.In this study,gender,age,T and N stages before neoadjuvant treatment,histological type,tumor differentiation degree,tumor general type,tumor distance from anus,whether there is nerve or vascular invasion,chemotherapy program,interval between neoadjuvant treatment and operation,carcinoembryonic antigen(CEA),carbohydrate antigen199(CA199),hemoglobin,albumin,prealbumin,low density lipoprotein chesterol(LDL-C),immunoglobulin A(Ig A),immunoglobulin G(Ig G),immunoglobulin M(Ig M),a total of 25 clinical factors.Univariate analysis and logistic regression analysis were used to analyze the influencing factors of tumor downstaging and pathological complete remission(p CR)after neoadjuvant radiotherapy and chemotherapy for rectal cancer.Results: After screening,a total of 96 patients were included in this study,of which 64(66.7%)patients had a T staging decreased,81(79.0%)patients had a N staging decreased,and 23(24.0%)patients achieved p CR.Univariate analysis showed that T staging before neoadjuvant treatment(P <0.001)was related to T downstaging after neoadjuvant therapy,N staging before neoadjuvant treatment(P=0.002)was related to N downstaging after neoadjuvant therapy,and CEA≤5ug/L before neoadjuvant treatment(P=0.009)was related to p CR after neoadjuvant treatment.Multivariate regression analysis showed that T staging before neoadjuvant treatment(P=0.001)was an independent factor affecting T-downstaging after neoadjuvant treatment;N staging before neoadjuvant treatment(P=0.001),CEA≤5ug/L(P=0.019)was an independent factor affecting N-downstaging after neoadjuvant treatment;CEA≤5ug /L(P=0.011)before neoadjuvant treatmentwas was an independent factor Independent factors of PCR after neoadjuvant treatment for locally advanced rectal cancer.Both univariate and multivariate analysis showed that the tumor downstaging was not related to CA199,hemoglobin,albumin,prealbumin,LDL-C,Ig A,Ig G,Ig M and whether XELOX regimen was used(P>0.05).Conclusion: Most patients with locally advanced rectal cancer after neoadjuvant chemoradiotherapy can get an effective downstaging,and a small proportion can reach p CR.The stage of T and N before treatment may be an independent influencing factor of T and N downstaging after neoadjuvant chemoradiotherapy for locally advanced rectal cancer.CEA≤5ug/L before neoadjuvant therapy can be used as predictors of p CR after neoadjuvant chemoradiotherapy for locally advanced rectal cancer.CA199,hemoglobin,albumin,prealbumin,etc.cannot be used as predictors of tumor downstaging after neoadjuvant chemoradiotherapy for locally advanced rectal cancer.There is no difference between single-agent application of 5-fluorouracil and XELOX regimen in neoadjuvant chemoradiotherapy for locally advanced rectal cancer.