To Investigate The Relationship Between L3SMI And Nutritional Risk And Overall Suvival Prognosis Of Colorectal Cancer

Background:Global data for 2018 shows that the mortality rate of patients with colorectal cancer(CRC)has increased to the second place.Surgery is the only radical cure for colorectal cancer.The overall survival rate of postoperative patients is affected by a variety of factors.Myopenia is a hot topic of current research.It is common in cancer patients and is associated with prognosis,malnutrition and systemic inflammation.In recent years,many studies have shown that skeletal muscle loss is a factor affecting the prognosis of patients with colorectal cancer,and L3 SMI can be used as a standard to evaluate myopenia.However,current studies on L3 SMI and colorectal cancer are mostly concentrated in Europe and the United States and other developed countries,and the diagnostic criteria of myopenia are controversial.In addition,domestic studies on long-term prognosis and nutritional risk of L3 SMI and colorectal cancer after surgery have not formed a complete system.Objective:The purpose of this study was to explore the relationship between L3 skeletal muscle mass index(L3SMI)and the nutritional risk status of colorectalcancer patients and their postoperative total survival.Methods :A retrospective analysis of 518 patients with stage I-III colorectal cancer who underwent radical resection was performed at the First Affiliated Hospital of Guangxi Medical University from January 2012 to December 2014.By preoperative computed tomography(CT),the ratio of the sum of the skeletal muscle area of the lower third lumbar vertebrae(L3)to the height was determined to be L3SMI(cm2/m2).According to the lowest 25% sex ratio in L3 skeletal muscle,it was defined as the muscle reduction group-low L3 SMI group(Q1).The preoperative nutritional risk was assessed by the NRS2002 Nutritional Risk Screening Scale.The total score was ?3 for nutritional risk and the total score was <3 for no nutritional risk.The patients were divided into two groups,namely normal nutrition group and malnutrition group.Statistical analysis was performed using SPSS 22.0 software.The chi-square test was used to compare the count data.At the same time,the logistic correlation between L3 SMI and nutritional risk was analyzed.For survival prognosis,the survival curve was constructed by Kaplan-Meier method,and the difference between groups was compared by Log-rank test and the Cox proportional hazard model was used.multi-factor analysis.Result:1.The relationship between the clinical data of colorectal cancer and L3SMI(Q1,Q2,Q3 and Q4)showed that age,ALB level,BMI,NRS2002 nutrition risk screening,histological grade,surgical approach,CA199,and nutrition prognostic index(PIN)were statistically significant as compared with L3SMI(p < 0.05).2.Correlation analysis between clinical data of colorectal cancer andL3SMI(Q1,Q2-4)of the two groups showed statistically significant differences in age,ALB level,BMI,NRS2002 nutritional risk screening,histological grading,surgical method,PIN and L3SMI(p < 0.05).3.The clinical data of colorectal cancer and the univariate analysis of NRS2002 nutritional risk screening suggested statistically significant differences in age,ALB,BMI,PIN,tumor site,gross pathological type,and L3 SMI and nutritional risk.4.Multivariate Logistic regression analysis of NRS2002 nutritional risk screening showed that PIN(p =0.013),BMI(p < 0.001),and L3SMI(p < 0.001)were independent risk factors for nutritional risk in colorectal cancer patients.5.Univariate analysis of clinical data and survival prognosis of colorectal cancer showed that T stage,N stage,tissue differentiation degree,CA199,L3 SMI and survival outcome were significantly different(P < 0.05).6.The Cox proportional risk model showed that T staging,N staging,histological grading and L3 SMI were independent risk factors for poor prognosis of colorectal cancer(P < 0.05)..7.Log-rank test showed that among TNM stage I-III patients,the overall survival rate(OS)of L3SMI(Q1)group was significantly lower than that of L3SMI(q2-4)group(P=0.0069).Among TNM stage III patients,the overall survival rate(OS)of L3SMI(Q1)patients was significantly reduced(P=0.0132)8.The CT diagnostic threshold for skeletal muscle reduction based on gender-specific quartiles: male L3 SMI ? 39.5 cm 2 / m 2,female L3 SMI ?33.6 cm 2 / m 2.Conclusion:L3SMI(Q1)can be used as an indicator to assess the nutritional risk of patients with colorectal cancer and has an adverse effect on the survival ofpatients with radical resection of stage I-III colorectal cancer.