Lymphatic Metastasis Dynamics of Breast Cancer

The lymphatic system is an extensive vascular network that can be considered the primary way to spread metastatic breast cancer cells (BCCs). The dynamics by which BCCs travel to distant sites in the lymph nodes has just been well understood. Particle tracking techniques were used to analyze the behavior of BCCs and standard solid particles of different diameters that were used to simulate cell flow in the lymph. Distinct differences between BCC and particle behavior indicate that morphology and size affect their response to lymphatic flow conditions^{64 (link)}.
The BCCs adhered together and formed aggregate particles whose behavior was irregular. At the lymph flow rate, the MCF-7s were uniformly distributed across the channel compared to MDA-MB-231 cells that moved in the central region, indicating that metastatic MDA-MB-231 cells are subjected to a lower range of shear stresses in vivo. This suggests that size and deformability must be considered when modeling BCC behavior in the lymphatics. Human breast cell lines MDA-MB-231 (11–22 μm), MCF-7 (11–19 μm), and WBCs (6–16 μm), were used in this study^{64 (link),65 (link)}. Since about two-thirds of WBCs are in the range of 12–14 μm and about one-third of WBCs are in the range of 6–9 μm, the average diameter is assumed to be about 12 μm. Table 1 shows the characteristics of the cells used in this research; these cells were obtained from the Biotechnology Center of Tarbiat Modares University.Table 1

Characteristics of cells floating in the lymphatic system.

Cell type	mcf-7 (μm)	mda-mb-231 (μm)	wbc (μm)
Min diameter	11	11	6
Max diameter	19	22	16
Average diameter	15	18	12