[Cloning of solid tumors in double agar (human tumor stem cell assay]

62 specimens from 37 patients with solid malignant tumours were cloned by the human tumour stem cell assay (HTSCA). The growth rate, the use of two different disaggregation methods and their influence on vitality and plating efficiency were analyzed as well as the cloning rate from different tumour regions and metastases. The growth rate was 68%, and there was a significant difference in the vitality, depending on which mode of disaggregation was used. Enzymatic disaggregation showed a higher vitality than the mechanical method, although there was no difference in plating efficiency (PE). There was a marked heterogeneity in the PE of specimens from different sites of the same tumour and lymph node metastases (variation coefficient 0.507 and 2.093 respectively). The possibilities and limitations of the HTSCA are discussed with respect to our own results and those in the literature.