OPINION Lymphatic and interstitial flow in the tumour microenvironment: linking mechanobiology with immunity

Tumours often engage the lymphatic system in order to invade and metastasize. The tumour-draining lymph node may be an immune-privileged site that protects the tumour from host immunity, and lymph flow that drains tumours is often increased, enhancing communication between the tumour and the sentinel node. In addition to increasing the transport of tumour antigens and regulatory cytokines to the lymph node, increased lymph flow in the tumour margin causes mechanical stress-induced changes in stromal cells that stiffen the matrix and alter the immune microenvironment of the tumour. We propose that synergies between lymphatic drainage and flow-induced mechanotransduction in the stroma promote tumour immune escape by appropriating lymphatic mechanisms of peripheral tolerance.