Background: Sarcopenia, the age-related loss of muscle mass, is a negative prognostic factor in gastrointestinal cancer. Sarcopenia combined with visceral obesity (sarcopenic obesity) is associated with poor outcomes. We explored the influence of obesity and other factors on the prognosis of patients with colorectal cancer diagnosed with sarcopenia. Methods: We enrolled 211 patients with colorectal cancer diagnosed with preoperative sarcopenic obesity who underwent radical resection at Osaka University Hospital between January 2009 and January 2012. Muscle mass was assessed using the psoas muscle mass index. Obesity was evaluated by measuring the visceral fat area in the umbilical region. Patients were categorized into two groups: sarcopenia with obesity (SO) and sarcopenia without obesity (non-SO). Overall survival, cancer-specific survival, and cancer-related relapse-free survival (CRRFS) were compared between the two groups. Patient characteristics, including age, sex, body mass index, serum albumin, C-reactive protein, tumor markers, prognostic nutritional index (PNI), modified Glasgow prognostic score (mGPS), and geriatric nutritional risk index (GNRI), were also analyzed. Results: CRRFS was significantly shorter in the SO group than in the non-SO group (p = 0.028). PNI, mGPS, and GNRI were not identified as significant prognostic factors for CRRFS. Multivariate analysis highlighted sarcopenic obesity, elevated carcinoembryonic antigen levels, and unfavorable histological types as significant predictors of poor CRRFS outcomes. Conclusions: Sarcopenic obesity is an independent predictor of poor prognosis in patients with CRC. Thus, interventions aimed at increasing muscle mass and reducing visceral fat could potentially improve the prognosis of these patients.
Keywords: colorectal cancer; obesity; sarcopenia.