Department of Radiology, Royal Marsden Hospital, Sutton, United Kingdom.
Division of Radiotherapy and Imaging, Institute of Cancer Research, London, United Kingdom.
PLoS One. 2022 Jul 7;17(7):e0270950. doi: 10.1371/journal.pone.0270950. eCollection 2022.
The spleen is a lymphoid organ and we hypothesize that clinical benefit to immunotherapy may present with an increase in splenic volume during treatment. The purpose of this study was to investigate whether changes in splenic volume could be observed in those showing clinical benefit versus those not showing clinical benefit to pembrolizumab treatment in non-small cell lung cancer (NSCLC) patients.
In this study, 70 patients with locally advanced or metastatic NSCLC treated with pembrolizumab; and who underwent baseline CT scan within 2 weeks before treatment and follow-up CT within 3 months after commencing immunotherapy were retrospectively evaluated. The splenic volume on each CT was segmented manually by outlining the splenic contour on every image and the total volume summated. We compared the splenic volume in those achieving a clinical benefit and those not achieving clinical benefit, using non-parametric Wilcoxon signed-rank test. Clinical benefit was defined as stable disease or partial response lasting for greater than 24 weeks. A p-value of <0.05 was considered statistically significant.
There were 23 responders and 47 non-responders based on iRECIST criteria and 35 patients with clinical benefit and 35 without clinical benefit. There was no significant difference in the median pre-treatment volume (175 vs 187 cm3, p = 0.34), post-treatment volume (168 vs 167 cm3, p = 0.39) or change in splenic volume (-0.002 vs 0.0002 cm3, p = 0.97) between the two groups. No significant differences were also found between the splenic volume of patients with partial response, stable disease or progressive disease (p>0.017). Moreover, there was no statistically significant difference between progression-free survival and time to disease progression when the splenic volume was categorized as smaller or larger than the median pre-treatment or post-treatment volume (p>0.05).
No significant differences were observed in the splenic volume of those showing clinical benefit versus those without clinical benefit to pembrolizumab treatment in NSCLC patients. CT splenic volume cannot be used as a potentially simple biomarker of response to immunotherapy.
脾脏是一个淋巴器官，我们假设在治疗过程中，脾脏体积的增加可能与免疫治疗的临床获益有关。本研究的目的是探讨在接受派姆单抗治疗的非小细胞肺癌（NSCLC）患者中，是否可以观察到那些表现出临床获益的患者与那些未表现出临床获益的患者之间的脾脏体积变化。
本研究回顾性分析了 70 例接受派姆单抗治疗的局部晚期或转移性 NSCLC 患者，这些患者在治疗前 2 周内行基线 CT 扫描，在开始免疫治疗后 3 个月内行随访 CT 扫描。在每幅图像上勾画脾脏轮廓，手动分割脾脏体积，并将其总和。我们比较了临床获益者和未获益者的脾脏体积，使用非参数 Wilcoxon 符号秩检验。临床获益定义为持续 24 周以上的稳定疾病或部分缓解。p 值<0.05 被认为具有统计学意义。
根据 iRECIST 标准，有 23 例患者为应答者，47 例患者为无应答者，35 例患者有临床获益，35 例患者无临床获益。两组患者的中位治疗前脾脏体积（175 vs 187 cm3，p = 0.34）、治疗后脾脏体积（168 vs 167 cm3，p = 0.39）或脾脏体积变化（-0.002 vs 0.0002 cm3，p = 0.97）均无显著差异。部分缓解、稳定疾病或进展性疾病患者的脾脏体积也无显著差异（p>0.017）。此外，当脾脏体积分为治疗前或治疗后体积中位数以下或以上时，无进展生存期和疾病进展时间之间无统计学差异（p>0.05）。
在接受派姆单抗治疗的 NSCLC 患者中，临床获益者与无临床获益者的脾脏体积无显著差异。CT 脾脏体积不能作为免疫治疗反应的潜在简单生物标志物。
