[An in vitro sensitivity assay of anti-cancer agents by measuring the inhibition rate of DNA synthesis (3H-thymidine uptake) of cancer cells--clinical study].

In this paper, we demonstrated a selection system of anti-cancer agents (ACA) using discontinuous Ficoll density gradient method (DFDGM) for purification of tumor cells and 3H-Thymidine for evaluation of DNA synthesis of tumor cells. The tumor cells, purified to more than 80% by DFDGM, were contacted with ACAs for 3 days from the culture initiation and tumor suppression rate (TSR) by ACAs were calculated by following formula; TSR = ACA(-)cpm-ACA(+)cpm-background cpm divided by ACA(-)cpm-background cpm X 100% 7 ACAs; Mitomycin C (MMC), Adriamycin (ADM), 5-Fluorouracil (5-FU), Cytosine Arabinoside (Ara-C), Carbazilquinone (CQ), ACNU and Cis-platinum (CDDP) were examined in 106 cancers; 60 breast cancers, 18 gastric cancers, 23 colorectal cancers and 5 others. ADM and CQ showed high TSR against breast cancers, CQ against gastric cancers, and 5-FU and CQ against colorectal cancers, respectively. The reliability of this ACA selection system should be evaluated by future clinical studies, however, we stress that ACA should be selected by not only the effect on tumor cells but also the effect on immunity of the host, in future.