Department of Surgery, Hiroshima City Asa Citizens Hospital, Kabe-minami 2-1-1, Asakita-ku, Hiroshima, 7310293, Japan.
Department of Surgery, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
Int J Clin Oncol. 2021 Mar;26(3):523-531. doi: 10.1007/s10147-020-01833-4. Epub 2020 Nov 23.
Skeletal muscle loss is a hallmark of malignancies, including advanced gastric cancer (GC). Although programmed death (PD)-1 inhibitors, including nivolumab, have promising anti-cancer effects, there is limited information regarding markers that can predict these therapeutic effects, which include PD-ligand 1 (PD-L1) expression and the tumor mutation burden. Therefore, we evaluated whether the baseline psoas muscle mass index (PMI, a surrogate for skeletal muscle mass) could predict the response of GC to nivolumab treatment, based on progression-free survival (PFS), the objective response rate, and the disease control rate.
This retrospective study evaluated 31 Japanese patients who received nivolumab for advanced GC and underwent imaging analysis between November 2017 and November 2019. The computed tomography results were used to estimate the psoas major muscle mass. Sex-specific cut-off values were used for the PMI, with low PMI values defined as < 3.6 cm/m for male patients and < 2.9 cm/m for female patients.
The median PFS interval was 2.3 months for the patients with stage IV GC. Nine patients (29%) had a low baseline PMI, and these patients had significantly shorter median PFS than the group with a non-low baseline PMI (0.5 months vs. 2.4 months, P = 0.004).
As a surrogate marker for skeletal muscle loss, the PMI may be useful for predicting the response to nivolumab among patients with advanced GC.
骨骼肌减少是包括晚期胃癌（GC）在内的多种恶性肿瘤的标志。尽管程序性死亡（PD）-1 抑制剂，包括纳武利尤单抗，具有有前景的抗癌作用，但关于可预测这些治疗效果的标志物的信息有限，这些标志物包括 PD-配体 1（PD-L1）表达和肿瘤突变负担。因此，我们评估了基线竖脊肌质量指数（PMI，骨骼肌质量的替代指标）是否可以根据无进展生存期（PFS）、客观缓解率和疾病控制率来预测 GC 对纳武利尤单抗治疗的反应。
这项回顾性研究评估了 31 名接受纳武利尤单抗治疗晚期 GC 并于 2017 年 11 月至 2019 年 11 月期间进行影像学分析的日本患者。使用计算机断层扫描结果来估计竖脊肌主要肌肉质量。使用性别特异性截断值来确定 PMI，男性患者的低 PMI 值定义为 <3.6cm/m，女性患者的低 PMI 值定义为 <2.9cm/m。
IV 期 GC 患者的中位 PFS 间隔为 2.3 个月。9 名患者（29%）基线 PMI 较低，与非低基线 PMI 组相比，这些患者的中位 PFS 明显更短（0.5 个月比 2.4 个月，P=0.004）。
作为骨骼肌丢失的替代标志物，PMI 可能有助于预测晚期 GC 患者对纳武利尤单抗的反应。
