Background: Adolescents and young adult (AYA) patients with sarcoma are at heightened risk of reduced physical capacity and disease-related weakness. Sit-to-stand (STS) performance correlates with lower extremity functionality and activities of daily living; however, little is known regarding the relationship between muscular status and STS performance in patients with sarcoma. This study assessed STS performance in patients with sarcoma and the association between STS performance and the skeletal muscle index (SMI) and skeletal muscle density (SMD). Methods: This study included 30 patients with sarcoma (15-39 years old) treated with high-dose doxorubicin. Patients performed the five-times-STS test before starting treatment and 1 year after the baseline test. STS performance was correlated with SMI and SMD. SMI and SMD were quantified using computed tomography scans taken at the level of the 4th thoracic vertebra (T4). Results: Mean performance on the STS test at baseline and 1 year was 2.2-fold and 1.8-fold slower than the age-matched general population, respectively. A lower SMI was associated with worse performance on the STS test (p = 0.01). Similarly, lower SMD at baseline was also associated with poorer STS performance (p < 0.01). Conclusion: Patients with sarcoma have very poor STS performance at baseline and 1 year, which was accompanied by low SMI and SMD at T4.The inability for AYAs to return to healthy age normative STS standards by 1 year may indicate a need for early interventions to enhance skeletal muscle recovery and promote physical activity during and after treatment.

中文翻译：

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患有肉瘤的青少年和年轻成年患者的坐姿表现不佳。

背景：患有肉瘤的青少年和年轻成人 (AYA) 患者身体能力下降和疾病相关虚弱的风险更高。坐立（STS）表现与下肢功能和日常生活活动相关；然而，关于肉瘤患者的肌肉状态和 STS 表现之间的关系知之甚少。本研究评估了肉瘤患者的 STS 表现以及 STS 表现与骨骼肌指数 (SMI) 和骨骼肌密度 (SMD) 之间的关联。方法：本研究纳入了 30 名接受大剂量阿霉素治​​疗的肉瘤患者（15-39 岁）。患者在开始治疗前和基线测试后 1 年进行了五次 STS 测试。STS 性能与 SMI 和 SMD 相关。使用在第 4 胸椎 (T4) 水平进行的计算机断层扫描对 SMI 和 SMD 进行量化。结果：基线和 1 年时 STS 测试的平均表现分别比年龄匹配的一般人群慢 2.2 倍和 1.8 倍。较低的 SMI 与较差的 STS 测试表现相关 (p = 0.01)。同样，基线时较低的 SMD 也与较差的 STS 性能相关 (p < 0.01)。结论：肉瘤患者在基线和 1 年时的 STS 表现非常差，并伴有低 SMI 和 T4 时的 SMD。AYAs 无法在 1 年内恢复到健康年龄规范 STS 标准可能表明需要早期干预以增强骨骼肌恢复并促进治疗期间和治疗后的身体活动。