Several extremely interesting new developments have taken place in clinical cancer research in the past year. Cellular pharmacology of anti-neoplastic agents has continued gathering momentum. More insight has been acquired into the mechanisms of drug resistance where multi-drug resistance (MDR) is the center of interest. It is important in this research to define clinical resistance at the cellular level by using tumor biopsies from patients sensitive or resistant to chemotherapy and MDR reverters. The use of high-dose chemotherapy, as another approach to overcoming drug resistance is proving to be quite successful in lymphomas and is now being tested in chemosensitive tumors. Major emphasis has been put on improving the tolerability of high-dose chemotherapy. G-CSF and GM-CSF have allowed the possibility of delivering significantly higher doses of chemotherapy, achieving higher complete remission rates. Several studies are also investigating the potential role of G-CSF and GM-CSF in myelodisplastic syndromes.

The finding that differentiating agents like retinoids are capable of inducing remissions in acute promyelocytic leukemia is extremely exciting.