Tumor draining lymph nodes (TDLNs) are located in the routes of lymphatic drainage from a primary tumor and have the highest metastasis in various types of solid tumors. TDLNs are considered as a tissue to activate the antitumor immunity, where antigen-specific effector T cells are generated and released to the blood stream. These effector T cells then infiltrate into the tumor site and attack cancer cells. However, T cell receptor (TCR) repertoire in TDLNs has not been well characterized. We performed TCR sequencing of cancer tissues, corresponding normal mucosa tissues and a total of 203 regional lymph nodes, including 67 metastasis-positive lymph nodes from 23 colorectal cancer patients with lymph node metastasis. Metastasis-positive lymph nodes showed a significantly lower TCR diversity and shared TCR clones more frequently with primary tumor tissues compared to metastasis-negative TDLNs. Hierarchical clustering and principal component analyses also supported that TCR repertoires in metastasis-positive TDLNs were more similar to primary tumor tissues than metastasis-negative TDLNs. These finding suggest that cancer-reactive T cell clones might expand in the metastasis-positive TDLNs, although we have not tested their reactivity against cancer cells. We are now examining whether the T cells in TDLNs can recognized autologous cancer cells.

Citation Format: Kazuma Kiyotani, Tatsuo Matsuda, Eisaku Miyauchi, Yu-Wen Hsu, Satoshi Nagayama, Makda Zewde, Jae-Hyun Park, Taigo Kato, Makiko Harada, Nobuaki Suzuki, Hiroaki Nagano, Shoichi Hazama, Yusuke Nakamura. Comparison of TCR repertoires between cancer tissues and lymph nodes in colorectal cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1091.