(0622) Comparative Analysis of Spatial Transcriptome Evaluation of Early Stage Tongue Cancer With and Without Metastasis

Introduction: Decision making on performing neck dissection on the patients with early tongue cancers is still based on the clinicoradiologic characteristics. Several studies have demonstrated that certain genomic biomarkers can be applied and give valuable information with regard to the possibility of neck metastasis of early tongue cancers. This study aimed to anlayze the spatial transcriptomic evaluation of early tongue cancers and reveal the difference between patients with neck metastasis and without metastasis.

Methods: In total, 8 patients with early tongue cancer were included in spatial transcriptomic analysis, and they were distributed into 2 groups: groups with neck metastasis (4 patients) and without metastasis (4 patients). FFPE samples of primary tumors of each patients were sectioned on positive charged slide, and 20 regions of interest for spatial transcriptomics were marked. CosMx SMI (NanoString) single cell in situ analysis was performed on the 8 samples and a total of 160 regions of interest (FOV). Differentially expressed genes were analyzed and compared between the group with neck metastasis and without metastasis. RNAseq using the bulk tissue was also performed for the reference and comparison.

Results: Leiden clustering revealed there was 5 types of cancer cell clusters. Among them, cluster 8 was significantly abundant in group without neck metastasis, while clusters 6 and 14 were predominant in group with neck metastasis. DEGs with adjusted p-value lower than 0.01 and log2FC greater than 1.5 were as follows: CXCL14, EGFR, COL17A1, MMP1, TPM2, KRT15, TGFBI, IGFBP6, MT2A, ITGA6, CAV1, FN1, and ITM2B. David pathway analysis revealed that DEGs were associated with extracellular matrix organization, focal adhesion, basement membrane, and integrin binding. In the stromal area, there was significant prominent cell type of M2 macrophage in group without neck metastasis.

Conclusions: Spatial transcriptome analysis on the neck metastasis of early tongue cancer revealed that invasive front of primary tumor showed differently expressed genes associated with tumor adhesion.