Chemosensitivity of malignant human brain tumors. Preliminary results

Tumor cell proliferation and morphological changes in tumor cells under the influence of different cytostatic agents were measured in an in vitro assay to determine chemosensitivity of human malignant brain tumors. Aliquots of 2 to 5 x 10(4) cells of a tumor cell suspension (prepared from biopsy specimen by mechanical and enzymatic disintegration) were incubated for 72 hr in the presence of different cytostatic agents. After another nine days of incubation in fresh medium, cell proliferation was calculated by incorporation of 14C-leucine and 3H-uridine and measurement in a liquid scintillation counter. Morphological changes in tumor cells were evaluated in Labtek tissue culture slides cultured under identical conditions. All drugs were tested in pharmacologically achievable concentrations. In vitro BCNU-sensitivity of 7/17 patients correlated with a postoperative recurrence free interval of 15.1 months, in vitro BCNU-resistance of 10/17 patients correlated with a postoperative recurrence free interval of 6.38 months (p less than 0.001). Tumors of lower grades of malignancy (astrocytoma III, malignant ependymoma, medulloblastoma) in our series have a statistically significant higher median BCNU-sensitivity (63.5%, p less than 0.05) and are sensitive to more drugs (3.6 drugs, median out of six selected drugs, p less than 0.01) than tumors of higher grades of malignancy (astrocytoma IV, glioblastoma multiforme; 29.54% BCNU-sensitivity, 1.4 effective drugs). In our series differences of BCNU-tumor sensitivity and number of effective drugs were not statistically significant if related to age and sex of tumor bearing patients. We think this assay provides the opportunity to test a large number of drugs in a very short period of time. Results may indicate alternative drug regimen for those patients resistant to conventional chemotherapy.