**Abstract**

Integrins are surface adhesion molecules that, upon binding to ligands, cluster to form adhesion complexes. These adhesion complexes are comprised of structural and regulatory proteins that modulate a variety of cellular behaviors including differentiation, growth, and migration through bidirectional signaling activities. Aberrant integrin expression and activation in ovarian cancer plays a key role in the detachment of cancer cells from primary sites as well as migration, invasion, and spheroid formation. An emerging area is the activation or rearrangement of integrins due to mechanical stress in the tumor microenvironment, particularly in response to fluid shear stress imparted by currents of malignant ascites. This chapter describes the role of integrins in ovarian cancer with an emphasis on crosstalk with survival pathways, the effect of malignant ascites, and discusses the literature on integrin-targeting approaches in ovarian cancer, including targeted photochemistry for therapy and imaging.

**Keywords:** ovarian cancer, integrins, ascites, photodynamic therapy, targeted photochemistry
