マウス腸骨下リンパ節に，ルシフェラーゼ発現性腫瘍細胞を移植してみる[1].

固有腋窩リンパ節に転移: リンパ行性転移(左).
遠隔臓器に転移: 血行性転移（右).

図. 腸骨下リンパ節に腫瘍細胞を移植すると, リンパ管を経由して固有腋窩リンパ節に転移が確認される. 移植後14日目に臓器を摘出し, ルシフェラーゼ活性を測定. 肝臓や肺を含め, 全身のリンパ節にも転移が確認される[1].

われわれは, 腫瘍細胞がリンパ節を介して血流にのって遠隔臓器に転移する形態を，

リンパ節介在血行性転移理論として提唱している[2-4].

この理論に基づき開発された手法が, リンパ行性薬物送達法である[5-8].

原発巣の確認段階で，リンパ節転移の予防的治療が重要である．

参考文献
[1] L. Li, S. Mori, M. Sakamoto, S. Takahashi, T. Kodama, Mouse model of lymph node metastasis via afferent lymphatic vessels for development of imaging modalities, PloS one, 8 (2013) e55797.
[2] T. Kodama, S. Mori, M. Nose, Tumor cell invasion from the marginal sinus into extranodal veins during early-stage lymph node metastasis can be a starting point for hematogenous metastasis, Journal of Cancer Metastasis and Treatment, 4 (2018) 56.
[3] L. Shao, K. Takeda, S. Kato, S. Mori, T. Kodama, Communication between lymphatic and venous systems in mice, Journal of immunological methods, 424 (2015) 100-105.
[4] K. Takeda, S. Mori, T. Kodama, Study of fluid dynamics reveals direct communications between lymphatic vessels and venous blood vessels at lymph nodes of mice, Journal of immunological methods, 445 (2017) 1-9.
[5] H. Fujii, S. Horie, A. Sukhbaatar, R. Mishra, M. Sakamoto, S. Mori, T. Kodama, Treatment of false-negative metastatic lymph nodes by a lymphatic drug delivery system with 5-fluorouracil, Cancer Med, 8 (2019) 2241-2251.
[6] R. Fukumura, A. Sukhbaatar, R. Mishura, M. Sakamoto, S. Mori, T. Kodama, Study of the physicochemical properties of drugs suitable for administration using a lymphatic drug delivery system, Cancer Sci, (2021).
[7] T. Kodama, D. Matsuki, A. Tada, K. Takeda, S. Mori, New concept for the prevention and treatment of metastatic lymph nodes using chemotherapy administered via the lymphatic network, Scientific reports, 6 (2016) 32506.
[8] A. Tada, S. Horie, S. Mori, T. Kodama, Therapeutic effect of cisplatin given with a lymphatic drug delivery system on false-negative metastatic lymph nodes, Cancer Sci, 108 (2017) 2115-2121.