Abstract
Abstract Sebaceous carcinoma (SC) is a malignant neoplasm that predominantly arises from the sebaceous glands of the ocular adnexa. It is the second most common malignant eyelid neoplasm in the United States. No standardized treatment exists, but surgical excision is the mainstay of therapy. Therapeutic advances have been stagnant largely due to a limited understanding of SC tumor biology. We performed single-cell RNA sequencing to profile primary ocular adnexal SC and gain insights into its tumor microenvironment. Ocular adnexal SC has extensive intra-tumoral heterogeneity at the transcriptional level. Dimensionality reduction via principal component analysis was performed to identify major cell types. 8 clusters were detected, including clusters for cancer epithelial cells and various immune cells. Transcriptional programs were related to pathways in cancer, immune response, and antigen processing and processing, among others. We identified unique subpopulations of tumor-infiltrating immune cells, including plasma B cells, GNLY+ natural killer cells, CD8+ T cells, memory T cells, and CD20+ B cells. This complex ecosystem of tumor and immune cells provides new insights into SC biology. Additional patient samples we be analyzed in the immediate future. Follow-up mechanistic studies are needed to clarify the roles of the identified immune cells and how they can be exploited for immunotherapeutic approaches. Citation Format: Ryan Alexander Gallo, Michelle G. Zhang, David T. Tse, Daniel Pelaez, Andrew J. Rong. Single-cell RNA sequencing reveals insights into the intra-tumoral heterogeneity and tumor microenvironment of ocular adnexal sebaceous carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1717.