Quantity of lower muscle as a promising prognostic factor for overall survival in patients with bone and soft tissue...

Various prognostic factors of bone sarcoma (BS) and soft tissue sarcoma (STS) have been investigated in the past. Recent reports indicate that muscle quantity is related to prognosis of older cancer patients. However, to the best of our knowledge, there are no reports on the relationship between femoral muscle volume and overall survival (OS), local recurrence-free survival (LRFS), or metastasis-free survival (MFS) in patients with BS and STS aged ≥18 years.

Clinicopathological data of 119 patients with BS and STS treated between 2014 and 2023 at a single institution were retrospectively analyzed. Based on positron emission tomography-computed tomography information, the quantity of femoral muscles, psoas muscle index at the L3 level, and triceps surae muscle were investigated in four age groups (19-39, 40-59, 60-74, >75 years). Sex, age, tumor size, location, grade, American Joint Committee on Cancer stage, history of chemotherapy, history of radiation therapy, American Society of Anesthesiologists-Physical Status, and muscle volumes were evaluated using Cox proportional hazards regression models. Five-year survival rates were assessed using the Kaplan-Meier method.

Median follow-up was 34 months (interquartile range, 17-64). Five-year OS, LRFS, and MFS rates were 73.7 %, 86.6 %, and 76.7 %, respectively. In multivariate analysis, tumor stage IV and decreased all-femoral muscle volume were significantly associated with poor OS.

Decreased femoral muscle volume is a significant factor associated with poor OS. Therefore, it may be important for adult patients to maintain postoperative all-femoral muscle volume as much as possible.