RESUMO
Background: In recent decades neoadjuvant therapies such as combined chemotherapy and radiotherapy have been introduced for cancer management. Compared with monotherapy modalities, neoadjuvant therapy is associated with greater effectiveness while having minor side effects. Docetaxel is a chemotherapy agent for breast cancer treatment which can blocks the cell cycle at the G2/M phase which has shown special sensitivity to the ionizing radiation and hence causes cell death. To the best of our knowledge, there are currently no reports that explore the synergistic effects of Docetaxel and ionizing radiation on MCF-7 cancer cell death. Methods: We divided cells into four different groups; control, cells which got in touch with Docetaxel, cells that with exposure to radiotherapy and cells which were influenced with combination of Docetaxel and radiotherapy. In vitro cell viability tests were done at different concentration of Docetaxel and different dose of radiation for 24, 48 and 72 h after the experiment. Results: Results showed that the cytotoxicity was depending on the doses of radiation and Docetaxel. Radiation at 2 Gy dose was unable to produce significant effects neither in the radiation-only nor in the neoadjuvant therapy groups. However, the synergistic effects of neoadjuvant therapy were apparent at 4 and 6 Gy doses of radiation which could exert more significant cytotoxic effects on MCF-7 cells. Conclusions: Study findings suggest that neoadjuvant therapy by using Docetaxel and 4 and 6 Gy ionizing radiation has synergistic effects on MCF-7 cell death and produces more significant results compared with monotherapy modalities (AU)