Breast cancer--response rates to chemotherapeutic agents studied in vitro.

Background: The biological efficacy of, and spectrum of action of, agents used in treatment of breast cancer are important issues in therapy planning.

Materials And Methods: Techniques used involve monolayer culture and a quantitative microtiter plate-based chemo-response assay. Precision Therapeutics' overall assessability rate is 90% for tumors of all types. In this study, 148 specimens derived from breast cancer were studied. Of these, 111 were additionally studied histopathologically. Ninety-two percent of the 111 specimens were confirmed to be epithelioid in nature and, thus, compatible with cells of breast cancer origin.

Results: In vitro chemo-response profiles indicated that individual agents stratified into groups, with cyclophosphamide and fluorouracil demonstrating responses of 69% and 57% respectively; doxorubicin, 45%; and docetaxel, paclitaxel and gemcitabine, 39, 27 and 36%, respectively.

Conclusion: The spectrum of responsiveness of the individual agents was variable and not completely overlapping, as shown by the Venn diagrams.