Baracos V E, Arribas L
Division of Palliative Care Medicine, Department of Oncology, University of Alberta, Edmonton, Canada;.
Clinical Nutrition Unit, Catalan Institute of Oncology (ICO), Barcelona, Spain; IDIBELL, L'Hospitalet de Llobregat, Barcelona, Spain; University of Barcelona, Barcelona, Spain.
Ann Oncol. 2018 Feb;29 Suppl 2:ii1-ii9. doi: 10.1093/annonc/mdx810. Epub 2019 Dec 4.
Body composition, defined as the proportions and distribution of lean and fat tissues in the human body, is an emergent theme in clinical oncology. Severe muscle depletion (sarcopenia) is most easily overlooked in obese patients; the advent of secondary analysis of oncologic images provides a precise and specific assessment of sarcopenia. Here, we review the definitions, prevalence and clinical implications of sarcopenic obesity (SO) in medical and surgical oncology. Reported prevalence of SO varies due to the heterogeneity in the definitions and the variability in the cut points used to define low muscle mass and high fat mass. Prevalence of SO in advanced solid tumor patient populations average 9% (range 2.3%-14.6%) overall, and one in four (24.7%, range 5.9%-39.2%) patients with body mass index ≥ 30 kg/m are sarcopenic. SO is independently associated with higher mortality and higher rate of complications in systemic and surgical cancer treatment, across multiple cancer sites and treatment plans. These associations remain unexplained, however, it has been hypothesized that patients with sarcopenia are generally unfit and unable to tolerate stress. Another proposed mechanism relates to increased exposure to antineoplastic therapy, i.e. a large fat mass would be expected to inflate drug dose in BSA-based treatments, causing an increased rate of dose-limiting toxicity. Pharmacokinetic data are needed to confirm or refute this hypothesis. Old age, deconditioning, cancer progression, acute or chronic nonmalignant disease and drug side-effects are suggested causes of muscle loss, and it is unknown the degree to which this can be reversed. Sarcopenia can be readily detected before start of cancer treatment, however, clinical management protocols for SO patients require development. Studies of cancer treatment dose-modulation are in progress.
身体组成被定义为人体中瘦组织和脂肪组织的比例及分布，是临床肿瘤学中一个新出现的主题。严重肌肉消耗（肌少症）在肥胖患者中最容易被忽视；肿瘤影像二次分析的出现为肌少症提供了精确且特异的评估。在此，我们综述了医学和外科肿瘤学中肥胖型肌少症（SO）的定义、患病率及临床意义。由于定义的异质性以及用于定义低肌肉量和高脂肪量的切点的变异性，报道的SO患病率有所不同。晚期实体瘤患者群体中SO的总体患病率平均为9%（范围为2.3%-14.6%），体重指数≥30 kg/m²的患者中有四分之一（24.7%，范围为5.9%-39.2%）患有肌少症。在多个癌症部位和治疗方案中，SO与全身和外科癌症治疗中较高的死亡率及较高的并发症发生率独立相关。然而，这些关联的原因尚不清楚，不过据推测，肌少症患者通常身体状况不佳且无法耐受应激。另一种提出的机制与抗肿瘤治疗暴露增加有关，即在基于体表面积的治疗中，大量脂肪会使药物剂量增加，导致剂量限制毒性发生率升高。需要药代动力学数据来证实或反驳这一假设。老年、身体机能减退、癌症进展、急性或慢性非恶性疾病以及药物副作用被认为是肌肉流失的原因，而这种流失能在多大程度上得到逆转尚不清楚。在癌症治疗开始前就能很容易地检测到肌少症，然而，需要制定针对SO患者的临床管理方案。癌症治疗剂量调整的研究正在进行中。
