How chemotherapy kills cancer cells. Chemotherapy kills cells that are in the process of splitting into 2 new cells. This is how normal body tissues grow. But cancer cells divide much more often than normal cells, so they are more likely to be killed by chemotherapy.Some chemotherapy drugs kill dividing cells by damaging the part of the control centre inside each cell that makes it divide.artial remission means the treatment has killed some of the cells, but not all. The cancer has shrunk, but can still be seen on scans and doesn't appear to be growing. The treatment may have stopped the cancer from growing.