[In vitro chemosensitivity testing with the human tumor stem cell assay (HTSCA) in breast cancer]

Clonogenic assays have attracted most attention in the field of chemosensitivity testing procedures. For many practical reasons and theoretical considerations detailed in this paper the human tumour stem cell assay (HTSCA) has proven most suitable for this purpose. The slightly modified method originally described by Hamburger and Salmon was used for testing tumour specimens of patients with breast cancer. 77 samples from 65 different patients were sent to our laboratory. 51% of the specimens were suitable for testing. 56% of all tested samples were biopsies and 44% were effusions. To enhance cell yield and viability solid tumours were disaggregated enzymatically using an enzyme cocktail consisting of collagenase 0.15% and DNase 0.015%. The median viability of the solid samples was 55%, that of the effusions was 91%. 44% of the culture samples showed colony growth (greater than 5 colonies per control plate) and 28% sufficient colony growth (greater than 20 colonies per control plate). The average number of colonies per control plate was 65, the average cloning efficiency was 0.0111%. Half of the samples with sufficient colony growth (5/11) was adequate for drug prediction. Positive correlation of sensitivity was observed in 2/2 and correct resistance prediction in 3/3.