Clinical significance of the histoculture drug response assay in breast cancer

Background/Aim: Despite the fact that breast cancer patients are generally administered systemic chemotherapy after surgical treatment, predictive factors that allow optimization of chemotherapy are needed. The histoculture drug response assay (HDRA) is a clinically practical in vitro drug-response assay for identifying optimal anticancer agents. Patients and Methods: Thirty-eight primary breast cancer patients who underwent surgical treatment without receiving systemic neoadjuvant therapy were analyzed. We retrospectively examined the relationships between clinicopathological factors and the HDRA results of 5 anticancer agents (mitomycin C (MMC), 5-fluorouracil (5-FU), doxorubicin hydrochloride (ADM), cisplatin (CDDP) and paclitaxel (PTX)). Results: The relationships between the inhibition rates of anticancer drugs and clinicopathological factors were not significant, except for nuclear grade and venous invasion with the inhibition rate of 5-FU. We also established the threshold inhibition rate for PTX. The paclitaxel inhibition rate was significantly associated with disease-free survival (DFS). Conclusion: HDRA results were independent from the clinicopathological factors of breast cancer patients demonstrating that individualized treatment is needed.