Chemotherapy is the use of anti-cancer (cytotoxic) drugs to destroy cancer cells. Various roles of chemotherapy are
Primary treatment.
Adjuvant treatment.
Induction treatment.
Neo adjuvant treatment.
Regional treatment.
Palliation.
Combination Chemotherapy is better because
It provides maximal cell kill with minimal toxicity.
It provides a broader range of interaction between drugs & tumour cells in heteogenous tumour population.
It may slow the subsequent development of drug resistance
