What makes tumor cells radiosensitive?

Answer 1

Simply: tumor cells tend to be more radiosensitive because they spend more time on average undergoing uncontrolled mitosis than normal cells. Since mitosis is the most sensitive phase of the cell cycle (phase through which the cell is most easily lethally damaged by radiation), their risk is increased. On another note, depending on which genes are causing the cell to become cancerous, certain blockers that would prevent a cell whose DNA had been damaged by radiation might not stop that cell from moving into mitosis, failing, and committing apoptosis (preprogrammed cell death).

Answer 2

Tumor cells are typically more radiosensitive than normal cells because they have faster cell division rates and reduced DNA repair mechanisms. This makes them more prone to DNA damage caused by radiation, leading to increased susceptibility to radiation-induced cell death. Additionally, tumor cells often have compromised cell cycle checkpoints, which can further contribute to their radiosensitivity.