CT-L1 Level Instead Of L3 Level Body Composition To Predicte The Efficacy Of Neoadjuvant Chemotherapy For Breast Cancer

Background and Objective:Neoadjuvant Chemotherapy(NACT)is the standard treatment for locally advanced Breast Cancer(BC).However,there are still some patients who cann’t benefit from Neoadjuvant Chemotherapy(NACT),and even have cancer progression.How to accurately predict the efficacy of Breast Cancer Neoadjuvant Chemotherapy(BCNACT)is an urgent problem to be solved.Many researchers have made a large number of attempts and found that body composition is related to the efficacy of BCNACT.CT is the gold standard for assessing body composition.Studies have found that abdominal CT-L3 body composition has a predictive effect on Tumor Regression Grade(TRG)of BC,but most BC patients do not need abdominal CT,only chest CT.In particular,under the policy of Diagnosis Related Groups(DRGs)payment in China’s medical insurance,it is also an inevitable trend to reduce unnecessary examinations.Therefore,this study aims to discuss whether CT-L1 body composition can be used instead of CT-L3 body composition to predict the efficacy of BCNACT.If feasible,the results of this study could be extended to more patients.Methods:A total of 174 female patients with primary BC who underwent NACT and completed surgery in the First Hospital of Lanzhou University from July 2018 to June 2022 were included in the study.The basic data of patients were reviewed,including age、menstrual status、Body Mass Index(BMI)、initial tumor size and axillary lymph node status;Body composition indicators of CT-L1 and CT-L3:Skeletal muscle area(SMA),Skeletal muscle index(SMI),Intermuscular fat area(IMFA),Intermuscular fat index(IMFI),Subcutaneous fat area(SFA),Subcutaneous fat index(SFI),Visceral fat area(VFA),Visceral fat index(VFI);Immunohistochemical results:Estrogen receptor(ER),cell proliferation nuclear antigen(Ki67),Progesterone receptor(PR),Human epidermal growth factor receptor(HER-2).Firstly,the correlation between body composition parameters at CT-L1 level and CT-L3 level was analyzed by Spearman.According to the postoperative pathological results,the patients were divided into MP(Miller and Payne)grade as the standard of good regression grade group(defined as the reduction of invasive cancer cells by more than90%,G4-5)and poor regression grade group(defined as the reduction of invasive cancer cells by less than 90%,G1-3).According to the recist solid tumor criteria,the patients were divided into the good clinical response group(defined as the sum of the diameter of all measurable lesions less than 30%of the baseline,,complete response and partial response)and the poor clinical response group(defined as all measurable lesions not decreasing or even increasing,stable disease and progressive disease).Univariate and multivariate binary logistic regression analysis and subgroup analysis(according to molecular classification,breast cancer was divided into luminal type,HER-2 positive type and triple-negative type)were used to determine the predictive factors of BCNACT pathological response and clinical response,respectively.The accuracy of the prediction model was evaluated by the area under the Receiver Operating Characteristic(ROC)curve.Results:1.Spearman analysis showed that the body composition parameters at CT-L1 level were correlated with those at CT-L3 level(SMA,SMI,IMFA,IMFI,SFA,SFI,VFA,VFI correlation coefficients were 0.76,0.78,0.89,0.89,0.73,0.75,0.90,respectively;0.91),and all P<0.01.2.Univariate analysis found that:In patients with luminal BC,Initial tumor T>2cm,NACT regimen without taxane,skeletal muscle area(SMA)<89.60cm~2,skeletal muscle index(SMI)<32.92 cm~2/m~2,visceral fat area(VFA)<107.5 cm~2 and visceral fat index(VFI)<25.99 cm~2/m~2 had worse pathological regression grade(P=0.002;P=0.039;P=0.001;P=0.001;P=0.025;P=0.035).BC patients with age≥49years,menopause,Ki67(-),no taxane-containing chemotherapy and SMI<32.92 cm~2/m~2 had poor clinical response(P=0.001;P=0.010;P=0.030;P=0.003;P=0.029).In the HER-2 positive subgroup,patients with age<49 years,SMI<32.92cm~2/m~2,and IMFA<12.00cm~2 had worse pathological regression grade(P=0.044;P=0.012;P=0.026).Patients with BMI≥24kg/m~2 and ER(-)had better clinical response(P=0.014;P=0.014).In patients with triple-negative BC,patients with BMI≥24 kg/m~2 had better clinical response(P=0.042).3.Multivariate logistic regression analysis showed that in patients with luminal BC,initial tumor size and SMI were independent influencing factors for regression grade(OR:0.180,95%CI:0.054-0.600;OR:0.180,95%CI:0.054-0.600).SMI and NACT regimen were independent influencing factors for clinical remission(OR:0.313,95%CI:0.109-0.902;OR:3.366,95%CI:1.035-10.948).In HER-2(-)BC patients,SMI was an independent influencing factor of withdrawal grade(OR:3.606,95%CI:1.075-12.097).In triple negative BC patients,menstrual status was an independent factor for clinical remission(OR:11.859,95%CI:1.006-139.735).Conclusions:There is a strong correlation between the body composition parameters of CT-L1 and CT-L3.The body composition of CT-L1 can be used instead of CT-L3 to predict the pathological response and clinical response of breast cancer after neoadjuvant chemotherapy.In the luminal breast cancer subgroup,BC patients with low SMI had poor pathological response and clinical response,and BC patients with larger initial tumor had poor pathological response,while there was no statistical correlation between initial tumor size and clinical response.In the HER-2 positive subtype subgroup,BC patients with low SMI had poor pathological remission,and there was no correlation between SMI and clinical remission.