[Analyses of factors influencing the chemosensitivity of human tumors xenografted into nude mice (I)].

Experimental single-agent chemotherapies using 11 anticancer agents for 15 human cancers xenografted into nude mice revealed that each cancer line seemed to retain a degree of individuality in its spectrum of chemosensitivity irrespective of whether it originated from the same organ or whether it was of a similar histologic type. As possibly factors relevant to this chemosensitivity, we investigated the following 9 parameters in cancer tissue or cancer-bearing mice, i.e., grade of differentiation, vascularity, percentage necrosis, volume doubling time, labeling index (LI), LDH activity, tissue/serum LDH ratio, thymidine phosphorylase activity, and serum CEA. Values of these parameters remained markedly constant within each cancer line. The relationships between these 9 parameters and chemosensitivities to the 11 drugs were investigated in 15 cancer lines. A statistically significant relationship was noted in 22% of the 99 such combinations. Parameters showing a close correlation to chemosensitivity differed from drug to drug, such as ADR vs LI and vascularity, 5'-DFUR vs CEA and vascularity, and MMC vs LDH ratio and grade of differentiation. It was concluded that the chemosensitivity of cancer lines to each drug is a result of various interacting factors.