Radiation reduces carboplatin sensitivity and enhances nedaplatin sensitivity in cervical squamous cell carcinoma in vitro.

Background: The study was performed to examine how the platinum anticancer drugs other than cisplatin, such as carboplatin (CBDCA) and nedaplatin (NEP) can be effectively used in chemoradiotherapy for cervical squamous cell carcinoma patients.
Materials and Methods: The radiosensitive human cervical squamous cell carcinoma cell line ME180 was examined to investigate the radiation effects on CBDCA and NEP sensitivities of the cells.
Results: Irradiation significantly reduced cellular CBDCA sensitivity. There were no significant changes in CBDCA sensitivity between the cells concurrently irradiated and those treated with CBDCA 8 h before or 8 h after irradiation. However NEP sensitivity of the cells treated 8 h before or 8 h after irradiation was significantly higher than that in cells concurrently irradiated.
Conclusions: Although CBDCA sensitivity in the concurrently irradiated cells is reduced, NEP sensitivity is enhanced by irradiation. NEP, but not CBDCA, therefore, may be a candidate anticancer drug for concurrent chemoradiotherapy for cervical cancer. For the greatest efficacy, NEP should be administered to patients several hours before or after irradiation.