The role of the human tumor stem cell assay in medical oncology.

The human tumor stem cell assay is a technique that allows in vitro sensitivity testing of antineoplastic agents against cells from tumor specimens removed from patients. This assay predicts clinical response to drugs and permits individualization of chemotherapy. It is more accurate in predicting drug resistance than drug sensitivity. Although there are technical problems with the assay, it has been successfully applied to nearly every possible type of human solid tumor and can be performed using cells from malignant effusions as well. Screening of new agents for activity against a range of human tumor specimens may prove to be the most important application of the human tumor stem cell assay.