Sarcopenia is Associated With Oncological Prognosis and the Incidence of Secondary Cancer in Patients With Middle/Lower Rectal Cancer.

OBJECTIVE

This study evaluated the clinical implications of sarcopenia for patients with rectal cancer according to cancer progression.

SUMMARY BACKGROUND DATA: The negative impact of body composition on long-term outcome has been demonstrated for various malignancies.

METHODS

We retrospectively reviewed 708 patients with rectal cancer who underwent curative resection at our institution between 2003 and 2020. Factors contributing to long-term outcomes and the incidence of secondary cancer (ISC) were analyzed. Psoas muscle mass index (PMI) was assessed using preoperative computed tomography. Sarcopenia was defined using the PMI cut-off values for Asian adults (6.36 cm2/m2 for males and 3.92 cm2/m2 for females).

RESULTS

Sarcopenia was identified in 306 patients (43.2%). Sarcopenia was associated with advanced age, low body mass index, smoking history, and advanced T-stage. Multivariate analysis showed sarcopenia was an independent poor prognostic factor for OS (HR 1.71; P = .0102) and cancer-specific survival (HR 1.64; P = .0490). Patients with sarcopenia had significantly higher mortality due to cancer-related death in stages III and IV, whereas non-rectal cancer-related death, including secondary cancer, was markedly increased in stage 0-II sarcopenic rectal patients. Five-year cumulative ISC in patients with and without sarcopenia was 11.8% and 5.9%, respectively. Multivariate analysis revealed that sarcopenia was an independent predictive factor for ISC (HR 2.05; P = .0063).

CONCLUSIONS

Sarcopenia helps predict survival outcomes and cause of death according to cancer stage for patients with middle/lower rectal cancer who underwent radical surgery. Furthermore, sarcopenia increased the development of secondary cancer in those patients.