Fig. 1. Outcomes of DTCs.

Disseminated breast cancer tumor cells may grow into detectable metastases, reach an equilibrium in tumor dormancy, become single-cell dormant or senescent, or die. Both dormancy and senescence are marked by cell cycle arrest, but senescence is associated with increased β-galactosidase (β-gal) activity and expression of a senescence-associated secretory phenotype (SASP), whereas dormancy is associated with reduced expression of PI3K-AKT, an increase in the ratio of phosphorylated p38 to phosphorylated ERK expression, and potential for relapse. Figure created in BioRender.