Figure 2.

Base case. The combination of autologous chemotaxis and upstream migration indicates ”metastatic” behavior. All variables are dimensionless according Table 1. The figures illustrate the net effect of autologous chemotaxis and upstream cell migration as expressed in (7), both of which are caused by the flow of IF from the tumor toward the peritumoral lymphatics. (a) Clusters of tumor cells migrate in a finger-like pattern. (b) Proteases are produced by the tumor cells and skewed in flow direction. (c) ECM-released chemokines are skewed in the flow direction. Higher concentration of chemokines are seen in the peritumoral region where the lymphatics are placed with an accumulation at the lymphatics. (d) The IF pressure $P_{\text{w}}$ (0.4 dimensionless corresponds to 4000 Pa = 30 mmHg) reflects a characteristic elevated pressure in the central part of the tumor with a rapid decrease at its rim. The position of the four lymphatics are seen from the plot of $P_{\text{w}}$. (e) The IF velocity field ${\mathbf{u}}_{\text{w}}$ (1.0 dimensionless $\sim$ 1 $\mu \text{m}/\text{s}$) corresponds to the interstitial fluid pressure $P_{\text{w}}$ with a dominating outgoing fluid flow from the the tumor periphery toward the four lymphatics where it is adsorbed (while it is stagnant in the center of the core).