Abstract C114: Lymph circulating tumor cells are phenotypically different from tumor cells circulating in the blood

Abstract

Abstract Breast cancer is the most common cancer in women. However, metastasis is the leading cause of death. When the tumor cell migrates from the primary tumor, it can disseminate into the blood circulation or lymphatic system. It has been proven that 80% of malignant carcinoma choose the lymphatic system over the vascular system. Despite the importance of sentinel lymph node (SLN) metastasis as a staging marker, lymphatically disseminated tumor cells (LCTCs) in transit from the primary tumor to the SLN have never been captured, characterized and compared to blood-borne tumor cells (BCTCs) in the same host. Here we use a microsurgical technique to collect draining lymph in situ from a growing tumor prior to its entry in SLN in syngeneic animals and patients with breast cancer. Unlike BCTC, LCTCs are found in clusters that exhibit a hybrid epithelial-mesenchymal phenotype, display a cancer stem cell CD44hi, CD24hi, ALDHA1hi signature, grow as mammospheres and are highly tumorigenic. We also showed that the lymph is enriched in tumor-derived exosome proteins and EGF growth factor. Characterization of LCTCs vs. BCTCs and the compilation of tumor-derived factors en route to the SLN can provide insights into the metastatic process and has relevance to cancer immunotherapy. Citation Format: Odalys J. Torres-Luquis, Sulma I. Mohammed. Lymph circulating tumor cells are phenotypically different from tumor cells circulating in the blood [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr C114.