Figure 2.

Summary of the major work being conducted in the application of SHG to tumor progression. (a) The tumor collagen framework undergoes significant restructuring which can increase the efficiency of cell travel away from the primary tumor. Morphological analysis of restructuring can subsequently be utilized to predict survival rates in breast cancer patients ²⁸. Furthermore, analysis of scattering directionality can be used to understand how matrix microstructure changes with progression ⁶³. (b) SHG is being used to monitor how tumor cells and host cells such as macrophages interact in the tumor microenvironment while using collagen as a framework to move towards blood vessels ⁵². (c) Many in vivo and ex vivo studies are underway to better understand the pathways connecting tumor cells, macrophages, fibroblasts and the reorganization of collagen in the ECM ⁴⁴, ⁵³.