Synergistic prognostic impact of hemoglobin and skeletal muscle index in patients with colorectal cancer

Abstract

Background & aims: Recent studies have indicated that comorbidities such as sarcopenia and anemia can influence the prognosis of patients with colorectal cancer (CRC). However, the synergistic effects of sarcopenia and anemia on the survival of CRC patients are not yet comprehensively understood. This study aimed to investigate the relationship between anemia and sarcopenia and their synergistic effect on survival in patients with CRC. Methods: A total of 1629 patients who underwent colorectal surgery were retrospectively reviewed. Patients were categorized into four hemoglobin-sarcopenia combined classifications (HS grade) according to their hemoglobin and skeletal muscle index (SMI) levels: hemoglobin low/SMI low (HS1), hemoglobin low/SMI high (HS2), hemoglobin high/SMI low (HS3), and hemoglobin high/SMI high (HS4). Association with overall survival (OS) was analyzed using both univariable and multivariable analyses. Results: In total, 1024 patients with stage I-III CRC were analyzed. Patient allocation according to HS grade was 124 (12.1%) in HS1, 298 (29.1%) in HS2, 135 (13.2%) in HS3, and 467 (45.6%) in HS4. The Kaplan-Meier curves of OS showed statistically significant differences according to anemia and sarcopenia status as well as to HS grade (all P < 0.001). Univariable analysis of factors associated with OS revealed statistical significance in absence of anemia (hazard ratio [HR] 0.550, 95% confidence interval [CI] 0.400–0.756, P < 0.001], absence of sarcopenia (HR 0.560, P < 0.001), and HS grade (HS2, HR 0.515, P = 0.002; HS3, HR 0.468, P = 0.006; HS4, HR 0.325, P < 0.001). Multivariable analysis showed that compared to the HS1 group, the HS2 and HS4 groups showed significantly better OS (HS2, HR 0.527, 95% CI 0.340–0.817, P = 0.004; HS4, HR 0.574, 95% CI 0.361–0.912, P = 0.018). Conclusions: Sarcopenia, characterized by a low SMI and the presence of anemia before surgery, was associated with reduced OS among patients with non-metastatic CRC.