Comparative Analysis Of The Short-term Curative Effect Of Two Neoadjuvant Therapy Modes For Locally Advanced Rectal Cancer

Objective:To explore the impact of the neoadjuvant therapy treatment modalities on the short-term curative effect of locally advanced rectal cancer,and the related predictive analysis affecting the treatment efficacy of locally advanced rectal cancer.Methods:The clinical data of LARC(locally advanced rectal cancer)patients treated by Liaoning Cancer Hospital from January 2019 to December 2022 were retrospectively collected.The clinical data of LARC(locally advanced rectal cancer)patients were divided into INCT(induction neoadjuvant chemotherapy)and CNCT(consolidation neoadjuvant chemotherapy)groups according to different neoadjuvant therapy modalities,and general information,the treatment status,short-term curative efficacy,toxic side effects of the two groups were recorded respectively.SPSS 25.0 software was used to perform statistical analysis on the differences in efficacy between the two groups and the analysis of predictors of pCR and anus preservation rate.Results:1.The relationship between the CNCT group and the INCT group and the clinical efficacy and toxicity: The rate of T descending,clinical descending,and c CR reached after neoadjuvant therapy in the CNCT group was better than that in the INCT group.(77.3% vs 37.0%,P=0.000;83.5% vs 63.0%,P=0.005;29.9% vs 14.8%,P=0.039).The proportion of grade 3-4 acute toxicity in the CNCT group was similar to that in the INCT group(21.6% vs 29.6%,P=0.274).2.The relationship of the pCR rate and sphincter preservation rate between the CNCT group and the INCT group: the downstaging of pathological T staging and The downstaging of pathological clinical staging in the CNCT group was better than that in the INCT group(80.4% vs 42.6%,P=0.000;90.0% vs 70.4%,P=0.001).The pCR rate of the CNCT group was better than that of the INCT group(34.0% vs 16.7%,P=0.023).Among patients with lower rectal cancer,the rate of rectal preservation in the CNCT group was better than that in the INCT group(66.1% vs 44.1%,P=0.039).The proportion of preventive stoma in CNCT group was similar to INCT group(37.1% vs38.9%,P =0.829).3.Analysis of factors affecting pCR-related indicators of locally advanced rectal cancer after full-course neoadjuvant therapy combined with radical resection of rectal cancer.CEA before treatment,NLR before treatment,different TNT pattern and pCR rate are closely related.Univariate analysis showed that the pCR rate of the CEA≤5ng/ml group before treatment was higher than that of the CEA>5ng/ml group(41.0% vs 13.7%,OR=0.228,P=0.000).According to the ROC curve,the best cut-off value of NLR to predict pCR was 1.69.The pCR rate of the NLR≤1.69 group before treatment was higher than that of the NLR>1.69 group(46.4% vs 23.6%,OR=0.356,P=0.017).The pCR rate in the CNCT group was higher than that in the INCT group(34.0% vs 17.6%,OR=2.578,P=0.025).The results of multivariate analysis showed that CEA before treatment(OR=0.238,P=0.001),NLR before treatment(OR=0.329,P=0.018),and TNT pattern(OR=2.455,P=0.048)were independent predictors of pCR.4.Analysis of the factors affecting the preservation of anus-related indicators after total neoadjuvant therapy combined with radical resection of locally advanced rectal cancer.CEA before treatment,distance from the anal verge,different TNT patterns,clinical T stage downstaging,clinical stage downstaging,c CR reached and pCR rate are closely related.The results of univariate analysis showed that the anal preservation rate in the group with a distance from the anal verge ≥ 4 cm was higher than that in the group<4 cm(84.3% vs 26.2%,P=0.000),and the anal preservation rate in the group with CEA ≤ 5.0 ng/ml before treatment was greater than 5.0 The ng/ml group was higher(68.5% vs 43.6%,P=0.016).The anal preservation rate of the CNCT group was higher than that of the INCT group(66.1% vs 44.1%,P=0.039).The anal preservation rate of the clinical T stage downstaging group was higher than that of the non-downstaging group(70.4% vs 41.0%,P=0.005).The anal preservation rate of the downstaging group was higher than that of the non-downstaging group(64.7% vs40.0%,P=0.032).The anal preservation rate of the c CR group was higher than that in the non-c CR group(80.8% vs 49.3%,P=0.006).The results of multivariate analysis showed that the distance from the anal verge(OR=49.497,P=0.000),CEA before treatment(OR=0.198,P=0.028),and clinical stage(OR=0.089,P=0.020)were independent predictors of anus preservation.Conclusion:This study suggests that compared with INCT,CNCT treatment can effectively improve the tumor downstaging rate,pCR rate,and anus preservation rate without increasing grade 3-4 toxicity.Pre-treatment CEA,pre-treatment NLR,and CNCT mode were independent predictors of achieving pCR after neoadjuvant therapy in LARC.Factors that affect the rate of anus preservation include: distance from the anal verge,pre-treatment CEA,CNCT pattern,and clinical stage downstaging,among which the distance from the anal verge,pre-treatment CEA,and clinical stage are independent predictors of anus preservation after neoadjuvant therapy for lower LARC.