Why chemo medication doesn't work on everyone?

Chemotherapy medications target rapidly dividing cancer cells, but not all tumors have the same growth patterns or characteristics. Genetic mutations, the tumor microenvironment, and individual patient factors, such as overall health and genetic makeup, can influence how effectively chemotherapy works. Additionally, some cancer cells may develop resistance to the drugs over time, rendering treatment less effective. This variability underscores the need for personalized treatment approaches in oncology.