Klin Onkol 2000; 13(Speciál2 2000): 33-36.
Summary: We have analyzed in vitro drug resistance in 745 solid tumors by means of cytotoxic MTT-assay. The successful performance of the drug resistance assay, mainly depended on vitality of isolated tumor cells and/or their bacterial contamination. The test was successfully performed in 75.65% patients with breast carcinoma, 92.41% lung carcinoma, 77.90% oesophageal and stomach carcinoma, 79.66% colorectal carcinoma, in 76.62% malignant brain tumors and 78.30% patients with sarcoma. The sensitivities of individual anti-cancer drugs with sufficient quantity of patient samples (>10) were analyzed in all above mentioned diagnoses. The effectiveness of tested cytotoxic drugs under in vitro conditions for each carcinoma was determined by evaluating median of individual TCS50 values (50% tumor cell survival). The patients with TCS50 above median are drug resistant, while those with TCS50 below median are considered as drug sensitive. Our preliminary data suggest for different drug sensitivity profiles of patients suffering from various malignant diseases, indirectly confirming different in vivo response rates when those drugs are used in monotherapy.
