[Combination chemotherapy--present status and problems]

Principles for the development of effective clinical combination chemotherapy has been recognized for many years, and many trials have been continue to be used in the design of more effective combinations. Drugs to be used in the combination chemotherapy regimen are as follows: 1) Only those drugs proven effective should be combined, 2) Each drugs have a different mechanism of action, 3) Each drug have a different spectrum of toxicities, 4) Each drugs should be administered at their adequate dose intensity and schedule. Optimally, all agents would be administered simultaneously, but they can be administered in alternating sequence. However, the available results have not provided definitive evidence for the development of adequate, effective combination chemotherapy. Prospective randomized comparisons will eventually elucidate the better regimens. Further studies are warranted.