Prognostic value of computed tomography associated body composition measurement changes in metastatic colorectal cancer patients

Background: Sarcopenia is associated with poor prognosis in metastatic colorectal cancer (mCRC) patients.Purpose: To investigate the prognostic value of body composition measurement changes measured by computed tomography (CT) in mCRC patients.Material and Methods: The abdominal skeletal muscle density (SMD) and skeletal muscle (SMI) indices, as well as the visceral (VATI) and subcutaneous fat tissue (SATI) indices, were calculated by automatic segmentation method on the abdominal CT images obtained before (n = 71) and after chemotherapy (n = 52). Skeletal muscle gauge (SMG = SMD x SMI) was calculated. We calculated the percentage change of body composition measurements with respect to the first measurements. The cutoff value for the change in SMG was calculated by receiver operating characteristic analysis. Kaplan-Meier and Cox regression analyses were performed to calculate the prognostic value of age, gender, tumor location, metastasis site and carcinoembriogenic antigen (CEA) elevation, hypoalbuminemia, body mass index classification, presence of sarcopenia and SMG changes in terms of overall survival.Results: There was a significant association between SMG change and mortality (P = 0.037). According to survival analyses, highly decreased SMG, hypoalbuminemia and CEA variables of the patients were the significant factors (P < 0.001, P = 0.015 and P = 0.019, respectively). According to multivariate regression analysis, hypoalbuminemia (P = 0.004, hazard ratio = 3.60) and highly decreased SMG (P < 0.001, hazard ratio = 14.98) were found to be significant prognostic factors together.Conclusion: In mCRC patients, hypoalbuminemia and highly decreased SMG are significant prognostic factors for overall survival. Therefore, we suggest that the change in SMG calculated in follow-up images should also be evaluated in the prognosis estimation of this patient group.