Figure 2.

Schematic illustration of some chemotherapy-triggered responses in cancer cells. Most chemotherapeutic drugs induce DNA damage and activate the DDR. If the extent of damage is severe, the cell may die—e.g., through apoptosis. If the damage is sub-lethal, the cell may enter a state of senescence. This senescence response may represent a mechanism of inducing clinical tumour stasis (growth arrest) but in some situations such growth-arrested cells may re-enter the cell cycle and cause disease recurrence. In addition, the release of SASP by senescent cells may contribute to tumour recurrence as well as having an immune stimulatory function. The balance of these various processes will vary, depending on the host tissue and the type and degree of stimuli.