Multidrug resistance to alkylating agents and platinum compounds: state of our knowledge.

Resistance to platinum-containing drugs and alkylating agents is multifactorial. Relapsed patients and those who have an incomplete response to induction chemotherapy are unlikely to achieve a complete response to other treatments. This pattern of resistance to therapy is very broad in that patients not only fail to respond to drugs from the same pharmacologic classes as used in primary treatment, but also do not respond to other available drugs or irradiation. Using ovarian cancer as a prototype tumor, researchers have initiated laboratory studies to determine the mechanisms responsible for this drug-resistance phenotype. Insights into this action may promote development of therapeutic strategies to prevent the onset of resistance or reverse resistance when it occurs.