Abstract

We investigated the correlation between CD8/PDL1 immunohistochemical reactivity and gene alterations in cutaneous squamous cell carcinoma (cSCC) to identify tumorigenic genes and search for new treatments. We examined 27 cSCCs cases. Primary diagnosis showed 13 patients with metastasis and 14 patients with no metastasis. At first, we performed immunohistochemical analysis for CD8 and PD-L1 for 27 cSCC to search for tumor-immunoresponce. Next, the extracted DNA from 27 cSCC was performed next-generation sequencing (NGS) using iSeq 100 (Illumina) and the target genes for NGS were 50 cancer-associated genes. Immunohistochemistry revealed tumor-infiltrating lymphocytes (TILs) with a high-positive staining score in non-metastatic cSCCs. Tumors without metastasis might be related to the presence of CD8+ TILs. The cases without metastasis were predominantly in the sun-exposed areas of the body, and the number of the gene variation was relatively low in NGS sequencing. There was no relationship between tumor size, tumor depth, PD-L1 positivity, and the number of gene variations with or without tumor metastasis. In genetical analysis, ERBB4 and NPM1 are newly detected in this study and might be involved in tumorigenesis in cSCC. Additionally, GNAQ, GNAS, JAK2 NRAS, IDH2, and CTNNB1 were only shown in cSCCs, and these cancer-related genes might be related to tumor metastasis. These genes have a possibility for a new treatment target.

Financial Disclosure:

Speaker	Inegligible Company	Affililation/Relationship	Ongoing/Ended	Role
Haruto Nishida, MD, PhD	Ministry of Education, Culture, Sports, Science and Technology	Kakenhi (grant)	Ongoing	Poster Presenter