Abstract: BACKGROUND ＆ AIM: To investigate the chemosensitivity of eight anti-cancer drugs in breast cancer cells of different individual. MATERIAL AND METHODS: The breast cancer cells from 41 patients were being exposed to eight anti-cancer drugs for 48 h, at concentration according to 1 plasma peak concentration(1 PPC). The inhibition rate of tumor cells was used in vitro MTT assay to determine chemosensitivity. RESULTS: At amount of 1×105 tumor cells/perwell in the present of 1 PPC, the breast cancer cells had higher chemosensitivity to the EADM, MTZ treatment with the inhibition rate of (44.30±10.66) ％, (44.14±13.05) ％ than other of drugs, and but they were of no significant. A statistically significant difference was P<0.01,P<0.05 and P<0.05 in chemosensitivity of eight drugs between clinical stages,pathology types and lymphoid metastasis. CONCLUSION: Eight anti-cancer drugs had a difference chemosensitivity to the breast cancer cells from 41 patients. The In vitro MTT assay was essential for predicting chemosensitivity of individual breast cancer patients.

Key words: anti-cancer drug, breast cancer, chemosensitivity