This presentation gives a summary of the chemosensitivity test results in breast cancer using the ATP-Cell-Viability Assay (ATP-CVA). Other assays and test systems for chemosensitivity testing are also evaluated. Our results with the ATP-CVA in breast cancer cell lines showed that this test system is a reproducible and reliable tool in the screening of new drugs. Our results with drug combinations showed that with the ATP-CVA and the "median effect principle" synergistic and antagonistic effects can be reliably calculated. The application of the ATP- CVA in fresh human breast cancer made it possible to test tumor chemosensitivity in individual patients. We found an evaluability rate of the ATP-CVA of 95% in 116 patients. The chemosensitivity profiles of the tested tumors revealed a big heterogeneity of chemosensitivity results for single and drug combinations. The 22 in vitro/in vivo correlations from patients with metastatic breast cancer treated with at least three cycles of chemotherapy showed a sensitivity of the ATP-CVA of 92% and a specificity of 89%.
Conclusions: These data are encouraging and further investigations on chemosensitivity testing of fresh tumours are currently ongoing in a prospective study at the University of Zurich.