Quantitative CT-based Analysis Of Changes In Body Composition And Their Risk Factors In Colorectal Cancer Patients Before And After Treatment

Objective: To investigate the changes and risk factors of body composition in patients with colorectal cancer(CRC)before and after treatment.Methods: A retrospective analysis of 221 patients with CRC who underwent radical surgery and postoperative intravenous chemotherapy,including 124 males and 97 females,admitted to Yiji Shan Hospital,the First Affiliated Hospital of Wannan Medical College,from January 2018 to December 2021,was performed to analyze their whole abdominal CT scan images before and after treatment.Lumbar bone mineral density(BMD),abdominal subcutaneous fat area(SFA),abdominal visceral fat area(VFA),and posterior vertebral muscle group muscle area(MA)were measured before and after treatment using quantitative CT(QCT),and the sum of abdominal SFA and abdominal VFA yielded total abdominal fat area(TFA).The region of interest(ROI)was outlined twice by the same measurer and the average was taken.Normally distributed measurement data were expressed as mean ± standard deviation,and independent sample t-test was used for two-way comparison between groups.The count data such as gender and tumor site were expressed as frequencies or percentages,and their one-way analysis was performed by chi-square test.the measurement data such as CEA and CA199 that did not conform to normal distribution were tested using non-parametric test.Paired-samples t-test was used to compare the changes of body composition before and after treatment.According to the results of the changes in body composition before and after treatment,they were divided into the group with decreased BMD in the lumbar spine and the group with no decrease in BMD in the lumbar spine,and the group with decreased MA in the posterior vertebral muscle group and the group with no decrease in MA in the posterior vertebral muscle group.The clinicopathological data and pre-treatment body composition data of the two groups were subjected to univariate analysis,respectively,and factors with P < 0.05 were used as independent variables.Risk factors affecting the decline in BMD of the lumbar spine and the decline in MA of the posterior vertebral muscle group were analyzed using binary logistic regression.Results: 1.The abdominal SFA was higher after treatment than before treatment,and the lumbar BMD and posterior vertebral group MA were lower than before treatment(P<0.05).There was no statistical difference between abdominal TFA and abdominal VFA after treatment than before treatment(P>0.05).Abdominal VFA and lumbar BMD were lower after treatment in patients ≥60 years old than before treatment(P<0.05).There was no statistical difference in each body composition before and after treatment in patients <60 years old(P>0.05).In male patients,abdominal TFA and abdominal SFA were higher after treatment than before treatment,and lumbar BMD and posterior vertebral muscle group MA were lower than before treatment(P<0.05).In female patients,abdominal TFA and abdominal VFA were lower after treatment than before treatment(P<0.05).2.According to the lumbar spine BMD values before and after treatment,they were divided into the group with decreased lumbar spine BMD and the group with no decrease in lumbar spine BMD.Univariate analysis showed that gender,tumor length diameter,pre-treatment abdominal SFA,surgical modality,co-morbidities,and tumor site were statistically different between the two groups(P<0.05).Incorporation into binary logistic regression analysis showed that male,open abdomen and colon cancer were risk factors for decreased lumbar spine BMD in CRC patients after treatment(P<0.05).3.According to the MA values of the posterior vertebral muscle group before and after treatment,they were divided into the group with decreased MA of the posterior vertebral muscle group and the group without decreased MA of the posterior vertebral muscle group.Univariate analysis showed that gender,CEA,pre-treatment lumbar spine BMD,T stage,and tumor site were statistically different between the two groups(P< 0.05).Incorporation into binary logistic regression analysis showed that male,rectal cancer,low pre-treatment BMD,and large T stage were risk factors for posterior vertebral muscle group MA decline after treatment in CRC patients(P< 0.05).Conclusion: 1.Radical surgery and postoperative intravenous chemotherapy in CRC patients affect their body composition,with an increase in abdominal SFA and a decrease in lumbar BMD and posterior vertebral muscle group MA after treatment.Patients ≥60 years of age have decreased abdominal VFA and lumbar spine BMD after treatment.Male patients had increased abdominal TFA and abdominal SFA and decreased lumbar spine BMD and posterior vertebral muscle group MA after treatment.In female patients,abdominal TFA and abdominal VFA decreased after treatment.2.Male,open or colon cancer patients with radical surgery and postoperative intravenous chemotherapy are more likely to cause a decrease in lumbar spine BMD.3.Male,rectal cancer,patients with lower lumbar spine BMD before treatment or larger T-stage before treatment,after radical surgery and postoperative intravenous chemotherapy,are more likely to cause a decrease in MA of the posterior vertebral muscle group.