Breast cancer ranks as the second most frequent cancer in women in Korea, and the rate is gradually increasing. Compared to European countries and USA., the Korean breast cancer occurs at a younger age (mean age: 47) than in western countries (mean age: 60). We suppose that there is some biological differences between Korean and western breast cancer. This study was designed to determine the target chemotherapy agents for use on individual patients and define target patients for chemotherapy during the post-op period. Additionally, we desired to acquire primary data for further proteomic analysis of patients.

Twenty-one patients with breast cancer were entered in this study. Tumor specimens were taken and informed consent was obtained for use of the samples in drug sensitivity testing. MTS[3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxy methoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt] assay was able to be preformed in 16 patients (success rate, 76.2 percent). We used four drugs including Adriamycin, Epirubicin, 5-FU, and Taxol.

In the axillary lymph node negative group, 5-FU (56.62%) and Taxol (53.85%) were sensitive drugs. There were no sensitive drugs in the p53 over-expression group. In the wild p53 group, 5-FU was the only sensitive drug. 5-FU was sensitive in both the ER and PR positive groups. Taxol was sensitive in the c-erbB2 low expression group.

We obtained the results for chemosensitivity of breast cancer of Korean women. 5-FU and Taxol were relatively sensitive drugs, however we believe further data should be collected and added to obtain complete chemosensitivity results.