In vitro chemosensitivity testing of primary and recurrent breast carcinomas and its clinical significance.

In this study, in vitro chemosensitivity testing was conducted on primary cultured breast cancer cells from 96 patients with breast cancer, and the results showed that the cells from a few patients with primary breast cancer developed multidrug resistance (MDR) prior to the first chemotherapy exposure. All the cells from the recurrent cancer patients had MDR. The findings suggested that patients having MDR would benefit from high-dose chemotherapy (HDC) regimens. In vitro chemosensitivity screening, which was aimed at improving the therapeutic efficacy and minimizing side effects, helps in choosing individualized treatment for breast cancer.