# Prediction of Spatial Distance of CAFs-TAECs for Pathological Response to Neoadjuvant Chemoimmunotherapy in Lung Squamous Cell Carcinoma

## TL;DR

The study finds that the spatial distance between cancer-related cells predicts better treatment response in lung cancer patients receiving immunotherapy.

## Contribution

A novel spatial relationship between CAFs and TAECs is identified as a predictor of pathological response to neoadjuvant chemoimmunotherapy in lung squamous cell carcinoma.

## Key findings

- Lung squamous cell carcinoma shows higher MPR rates compared to lung adenocarcinoma in neoadjuvant chemoimmunotherapy.
- Greater spatial distance between CAFs and TAECs correlates with better MPR in squamous cell carcinoma patients.
- Low TAECs density is associated with improved MPR outcomes in neoadjuvant chemoimmunotherapy.

## Abstract

新辅助治疗策略在非小细胞肺癌（non-small cell lung cancer, NSCLC）的综合治疗中具有重要地位。然而，肺鳞状细胞癌对新辅助治疗疗效普遍优于肺腺癌。本文旨在明确基线癌症相关成纤维细胞（cancer-associated fibroblasts, CAFs）与肿瘤相关血管内皮细胞（tumor-associated endothelial cells, TAECs）对肺鳞状细胞癌和肺腺癌不同新辅助治疗疗效的影响。

回顾性收集2018年1月1日至2023年12月31日在山东省肿瘤医院接受新辅助化疗（neoadjuvant chemotherapy, NAC）或新辅助化免（neoadjuvant chemoimmunotherapy, NAIC）治疗的104例II-III期NSCLC患者的治疗前活检样本。全自动组织微阵列制作仪构建组织芯片，并运用多色免疫荧光（α-SMA/CD31/CK/DAPI）技术染色CAFs（α-SMA+/CK-）和TAECs（CD31+/CK-），定量CAFs和TAECs的密度、CAFs与TAECs的最近邻距离及接近度（30 μm）。χ2检验确定组间主要病理缓解（major pathological response, MPR）差异，其定义为经新辅助治疗后，术后切除标本中存活肿瘤细胞比例≤10%。Mann-Whitney U检验分析定量资料组间差异，受试者工作特征（receiver operating characteristic, ROC）曲线确定免疫指标对NAIC MPR的预测性能。

104例接受新辅助治疗的NSCLC患者中，35例接受了NAIC，69例接受了NAC。在总体患者中，肺鳞状细胞癌较肺腺癌更易发生MPR（50.0% vs 22.4%, P=0.006）；在NAIC患者中，这一趋势仍然存在（72.7% vs 30.8%, P=0.038）；在NAC患者中，两者的MPR率无差异。NAIC或NAC治疗前，肺鳞状细胞癌与肺腺癌的程序性死亡配体1（programmed death ligand 1, PD-L1）/程序性细胞死亡受体1（programmed cell death 1, PD-1）表达、CAFs及TAECs的密度、CAFs与TAECs的最近邻距离、CAFs与TAECs的接近度（30 μm）均无差异。在接受NAIC治疗的肺鳞状细胞癌患者中，MPR较NMPR基线瘤内PD-L1/PD-1表达、CAFs及TAECs的密度无统计学差意义，而CAFs与TAECs的距离更远（最近邻距离：31.2 vs 24.7 μm，P=0.038），且CAFs 30 μm内TAECs的数量更少（接近度：1.1 vs 3.6，P=0.038）。单因素Cox回归显示，低TAECs密度与接受NAIC后MPR有关（OR=36.00, 95%CI: 2.68-1486.88, P=0.019）。ROC曲线进一步证实，基线CAFs-TAECs最近邻距离与接近度（30 μm）预测肺鳞状细胞癌NAIC MPR的曲线下面积（area under the curve, AUC）、敏感度和特异度均分别为0.893、0.857和1.000。

CAFs与TAECs的空间距离更远、肺鳞状细胞癌接受NAIC后更易MPR，这可能与CAFs与TAECs的相互作用降低、肿瘤相关血管生成减少有关。

Baseline characteristics of patients with ADC and SCC

Differences in efficacy between NAIC and NAC in different histologic subtypes

DAPI: blue; CK: blue-green; α-SMA: red; CD31: pink.

Differences in TME characteristics between SCC and ADC patients with baseline NAIC and NAC

Differences in baseline TME between NAIC and NAC

Differences in TME characteristics between MPR and NMPR patients with baseline SCC and ADC

Univariate analysis of the impact of NAIC MPR and NMPR