Lymph and lymphatic capillaries in cancer

Abstract

Lymph forms from the fluid that is forced out of capillaries and -postcapillary venules by hydrostatic pressures, into the interstitium around the vessel. This protein-rich fluid flows through the extracellular matrix and between cells bathing them in nutrients and oxygen and carrying away cellular metabolites and waste products where it is collected by lymphatic capillaries and on to lymph nodes. As with the physiological situation, interstitial fluid and lymph also form within and around tumors, which are collected from cancer-associated tissues. What does change in this situation, however, is the surroundings in which lymph is generated and the tissues exposed to the resulting fluid. The environment in which lymph is formed and transported via can modify its composition and have drastic effects on cells and tissues downstream. This chapter explores the roles of lymphatic function, lymph transport, and their far-reaching implications in cancer development and progression. We pay particular attention to the mechanisms of lymph formation and composition, lymph clearance and resulting cellular effects, the impact on potential antitumour immune responses, methods to identify and measure lymphatic function, and new approaches to exploit or target lymphatics for therapy.