Klin Onkol 2000; 13(Speciál2 2000): 62-64.
Summary: Cancer chemotherapy may be optimized based on chemoresistance testing. In theory, the ineffective drug could be omitted and even replaced by another with pre-tested sensitivity. In indirect testing following parameters can be investigated: a) proliferation, apoptosis, regulatory proteins etc. as markers of biological activity of tumors, b) specific detoxication mechanisms and enzymes of drug metabolism as P-glycoprotein, thymidilate synthase, glutathion-S-transferase, etc., c) specific receptors for inhibitory drugs as steroid hormone receptors, HER2 receptor, etc. Direct testing is based on direct contact of cancer cells in tissue culture with a particular anti-cancer drug. Primary chemoresistant tumors as are melanomas, gliomas, soft tissue sarcomas, kidney carcinomas, non-small cell lung carcinomas, uterine cancer, hormone-independent prostatic carcinomas and especially malignant tumors of upper gastrointestinal tract, pancreas and bile ducts are among the first candidates for chemoresistance testing. Chemotherapy response rates in such tumors rarely achieve 15 to 30%. Even the tumors with good primary responses to standardized chemotherapy regimens as are breast, colorectal, testicular and ovarian cancers may qualify for chemoresistance testing in case of progression under standard chemotherapy or recurrence after therapy. The authors suggest the need for studies correlating the laboratory results with clinical outcomes in order to promote a vision of tailored chemotherapy.
