Evaluation of sarcopenia's relationship with overall survival and treatment toxicity in soft tissue sarcomas

The aim of our study is to evaluate the relationship between sarcopenia, overall survival (OS), and chemotherapy toxicity in patients with unresectable/metastatic soft tissue sarcoma (STS) treated with adriamycin and ifosfamide.

Patients with unresectable/metastatic STS over the age of 18, diagnosed between 2015 and 2023, were included in the study. The study was conducted retrospectively in a single center. Total muscle volume at the lumbar 3 (L3) vertebra level was measured from the patient's computer tomography (CT) images. The skeletal muscle index (SMI) was calculated for each patient. Additionally, the prognostic nutritional index (PNI) was calculated for each patient using blood values.

Fifty-eight patients were included in the study. The median age of the patients was 51 years, Thirty-six (62.1%) were female and 22 (37.9%) were male. The SMI median was 49 cm²/m² in male patients. ROC analysis demonstrated a statistically significant prediction of OS when the SMI index was < 49.2 cm²/m². In female patients, the median SMI was 40 cm²/m². ROC analysis demonstrated a statistically significant prediction of OS when the SMI index was < 40.3 cm²/m². Median OS in the SMI < 49 cm²/m² male group was 9 months (95% CI 7.99-10.08). In the SMI ≥ 49 cm²/m² male group, the median OS was 30.2 months (95% CI 0.0-66.66). OS was statistically significant between the two groups (p = 0.003). The median OS in the SMI < 40 cm²/m² female group was 20.5 months (95% CI 7.69-33.30). In the SMI ≥ 40 cm²/m² female group, the median OS was 59.1 months (95% CI 21.36-96.98). OS was statistically significant between the two groups (p = 0.025). The relationship of SMI, as well as PNI, age, and Eastern Cooperative Oncology Group performance status (ECOG PS) with OS, was assessed. The relationship between SMI and chemotherapy toxicity was also evaluated. Chemotherapy-related toxicity was found to be significantly higher in sarcopenic patients (male SMI < 49 cm²/m², female SMI < 40 cm²/m²) (p = 0.025).

A significant relationship was found between SMI and OS, but no significant relationship was found between PNI and OS. A significant relationship was also detected between SMI and treatment toxicity. Our study reveals that evaluating ECOG PS and sarcopenia in addition to grade and histological subtype when making treatment decisions will be associated with longer survival and less toxicity.