肿瘤细胞上的程序性细胞死亡配体-1（PD-L1）可以被降解为可溶性形式（sPD-L1）并进入血液循环，然而，sPD-L1在周边血液中的临床意义在非小细胞肺癌（NSCLC）中尚待阐明。我们在手术期间监测了患有可手术治疗的NSCLC患者的血浆sPD-L1水平，并评估了肿瘤组织中的PD-L1阳性细胞。然后，回顾性分析了术前血浆sPD-L1水平与无复发存活期（RFS）之间的相关性。在接受根治手术的患者中（n=61），手术后1个月血浆sPD-L1水平（中位数；63.5 pg/mL）显著增加（72.2 pg/mL，P<0.001）。包括肿瘤细胞和肿瘤相关巨噬细胞（TAMs）的PD-L1阳性细胞的综合评分与术前血浆sPD-L1水平显著相关。在术前血浆sPD-L1水平较高的患者中，相对于术前tcPD-L1表达强度高的患者，术前tcPD-L1表达强度低的患者的5年RFS概率显著差（分别为33.3%和87.5%，P=0.016；95% CI, 0.013-0.964）。在前者组中，PD-L1阳性TAMs的浸润明显高于后者组（分别为246.4和76.6个计数/ mm2，P =0.003）。在NSCLC中，血浆sPD-L1可以反映PD-L1阳性TAMs的积累，而不仅仅是PD-L1阳性肿瘤细胞。在术前血浆sPD-L1水平较高的患者中，术后预后取决于PD-L1阳性细胞（肿瘤细胞或TAMs）是sPD-L1的主要来源。因此，同时测量血浆sPD-L1水平和肿瘤细胞和TAMs的PD-L1表达情况有助于评估可手术NSCLC的术后预后。© 2023. The Author(s).

Programmed cell death-ligand 1 (PD-L1) on tumor cells can be degraded to soluble form (sPD-L1) and enter circulation, however, the clinical significances of sPD-L1 in peripheral blood remains to be elucidated in non-small-cell lung cancer (NSCLC). We monitored plasma sPD-L1 levels during perioperative periods and evaluated PD-L1-positive cells in tumor tissues in patients with operable NSCLC. Then the correlation between preoperative plasma sPD-L1 levels and relapse-free survival (RFS) was analyzed retrospectively. In patients who underwent radical surgery (n = 61), plasma sPD-L1 levels (median; 63.5 pg/mL) significantly increased 1 month after surgery (72.2 pg/mL, P < 0.001). The combined score of PD-L1-positive cells including tumor cells and tumor-associated macrophages (TAMs) was significantly associated with preoperative plasma sPD-L1 levels. In patients with high levels of preoperative plasma sPD-L1, the probability of 5-year RFS was significantly poor for patients with low PD-L1 expression intensity of tumor cells (tcPD-L1) compared with those with high tcPD-L1 (33.3% vs. 87.5%, respectively, P = 0.016; 95% CI, 0.013-0.964). In former group, PD-L1-positive TAMs were markedly infiltrating compared with those from latter group (246.4 vs. 76.6 counts/mm2, respectively, P = 0.003). In NSCLC, plasma sPD-L1 can reflect the accumulation of PD-L1-posotive TAMs, not just PD-L1-positive tumor cells. In patients with high levels of preoperative plasma sPD-L1, the prognoses after surgery depends on which PD-L1-positive cells, tumor cells or TAMs, are the primary source of the sPD-L1. Thus, measuring both plasma sPD-L1 levels and PD-L1 expression status of tumor cells and TAMs is of benefit for assessment of postoperative prognosis in operable NSCLC.© 2023. The Author(s).