APPLICATION OF THE ADENOSINE TRIPHOSPHATE-CELL VIABILITY ASSAY IN HUMAN BREAST-CANCER CHEMOSENSITIVITY TESTING - A REPORT ON THE 1ST RESULTS

Chemosensitivity testing in vitro of breast cancer has been difficult because of small tumor volume, an even smaller yield of viable cells a fter disaggregation, and the low evaluability rate and sensitivity of current assays. We have employed an alternative approach that quantita tes intracellular adenosine triphosphate (ATP) as a measure of cell vi ability. This ATP-cell viability assay (ATP-CVA) determines in vitro t umor cell viability after exposure to chemotherapeutic agents in compa rison to untreated controls following 6 days of incubation. Sixty-one fresh breast cancer specimens upon testing yielded an evaluability rat e of 95%. Forty-seven of the tumors were untreated primary breast canc ers, the remaining 14 were from patients with metastatic disease. Corr elations of in vitro drug sensitivity with in vivo response were obtai ned for 17 treatment regimens in 14 patients with metastatic breast ca ncer. The level of sensitivity was 90% and the specificity 86%. These preliminary data demonstrated the ATP-CVA to be a practical in vitro a pproach to breast cancer testing. It will require a larger clinical st udy for confirmation. (C) 1993 Wiley-Liss, Inc.