Background/Objectives: There is an increasing need for methods that provide improved insight into the molecular basis of colorectal cancer (CRC) and thus a better understanding of its morphological heterogeneity. The objectives of this study were to evaluate the use of imaging mass spectrometry (IMS) to examine tumor margins and gain insight into the molecular heterogeneity of CRC.Methods: An observational study involving 10 cases was conducted. Native tissue samples were collected during the subject’s surgery, and consecutively taken tissue sections were immediately prepared for light microscopic and IMS analysis. IMS was performed across the 200–1000 Da mass range, divided into four sub-ranges, using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI TOF MS) in both negative and positive modes of ionization. For tumor margin and tissue heterogeneity assessment, image segmentation was used. Segmented MS images were analyzed against the respective light microscopy images of hematoxylin-eosin-stained tissue sections.Results: Quantitative analysis of the sample collection indicated that IMS enabled correct recognition of tumor margin in the 800–1000 Da range using binary segmentation. Denary image segmentation depicted tissue heterogeneity in greater detail. The strongestm/zsignals specific to tumor, peritumor, and margins were identified and tentatively annotated: aside from dCTP, all other compounds were patient-specific, indicating interindividual variations in the molecular composition of CRC.Conclusions: IMS provides new insights into the morphological and biochemical properties of CRC: binary segmented MS images can clearly depict the tumor margin in the 800–1000 Da range, while denary segmented MS images depict intra- and inter-individual molecular heterogeneity of CRC.
背景/目的：目前越来越需要能够更深入揭示结直肠癌（CRC）分子基础、从而更好理解其形态异质性的研究方法。本研究旨在评估成像质谱（IMS）在肿瘤边界分析及探索CRC分子异质性方面的应用价值。方法：开展了一项包含10例病例的观察性研究。在受试者手术过程中采集原始组织样本，并连续制备组织切片用于光学显微镜及IMS分析。采用基质辅助激光解吸/电离飞行时间质谱（MALDI TOF MS），在正负离子模式下对200-1000 Da质量范围（分为四个子范围）进行IMS检测。通过图像分割技术评估肿瘤边界及组织异质性，并将分割后的质谱图像与苏木精-伊红染色组织切片的对应光学显微图像进行比对分析。结果：样本集的定量分析表明，在800-1000 Da范围内使用二元分割法时，IMS能准确识别肿瘤边界。十进制图像分割法则更精细地展现了组织异质性特征。研究鉴定并初步注释了肿瘤区、瘤周区及边界区最具特征性的质荷比信号：除dCTP外，其余化合物均呈现患者特异性，表明CRC分子组成存在个体间差异。结论：IMS为CRC的形态学与生化特性研究提供了新视角：二元分割质谱图像可清晰呈现800-1000 Da范围内的肿瘤边界，而十进制分割质谱图像则能同时展现CRC个体内及个体间的分子异质性特征。
肿瘤(癌症)患者之家