新辅助化疗免疫治疗（NCIT）已经在非小细胞肺癌（NSCLC）的治疗上取得了巨大成功，然而，该治疗的内在机制仍然不清楚。本回顾性研究纳入了32例接受NCIT后进行手术治疗的IIA-IIIC期NSCLC患者。对每位患者在NCIT前后收集的样本进行了多重免疫荧光染色（mIF）和图像分析实验。RNA分析用于确认mIF结果。在纳入的患者中，有14例获得了显著病理学反应或病理学完全缓解（pCR），被定义为“反应组”，而18例患者对NCIT没有良好反应，被定义为“非反应组”。 mIF实验结果显示，在NCIT后与NCIT前相比，肿瘤免疫淋巴细胞（TILs）在间质区域显著增加（p=0.03），而在肿瘤区域无显著变化（p=0.86）。无论是反应组还是非反应组，在NCIT后，CD8+ T细胞的百分比和三级淋巴结结构计数均显著增加。反应组中的CD3+ T细胞和FOXP3+细胞明显减少，而非反应组中的CD3+ T细胞和FOXP3+细胞保持不变或增加。对比反应组和非反应组的结果显示，NCIT前的CD3+细胞、FOXP3+细胞和CD8+/PD-1+细胞可能作为新辅助免疫治疗反应的预测指标。RNA分析证实了NCIT后TILs的增加。NCIT前的免疫细胞浸润与病理学完全缓解呈正相关，这为选择更有可能从NCIT中受益的患者提供了可靠的预测指标。© 2023年。外科肿瘤学会。

Neoadjuvant chemoimmunotherapy treatment (NCIT) has achieved great success for non-small cell lung cancer (NSCLC); however, the intrinsic mechanism underlying this treatment remains unclear.Thirty-two patients with stage IIA-IIIC NSCLC who underwent surgery after NCIT were included in this retrospective study. Multiplex immunofluorescence (mIF) staining and image analysis assays were performed on the samples collected before and after NCIT for each patient. RNA analyses was applied to confirm the mIF results.Among the enrolled patients, 14 achieved major pathological response or pathological complete response (pCR) and were defined as the 'response' group, whereas 18 patients did not respond well to NCIT and were defined as the 'nonresponse' group. The results of the mIF assays revealed an overall increase in tumor immune lymphocytes (TILs) after NCIT in the stroma area (p = 0.03) rather than the tumor area (p = 0.86). The percentage of CD8+ T cells and tertiary lymphoid structure counts in both the response and nonresponse groups increased significantly after NCIT compared with before NCIT. CD3+ T cells and FOXP3+ cells decreased significantly in the response group but remained unchanged or increased in the nonresponse group. A comparison of the response and nonresponse groups showed that CD3, FOXP3+ and CD8+/PD-1+ cells before NCIT may serve as predictors of the response to neoadjuvant immunotherapy. The RNA analyses confirmed the mIF results that TILs were elevated after NCIT.The infiltration of immune cells before NCIT was correlated with pathologic complete response, which enhanced the TILs as a promising predictor for selecting patients who were more likely to benefit from NCIT.© 2023. Society of Surgical Oncology.