Low-Doses of Chemotherapy Drug Could Cause Liver Metastasis

Mouse models of paclitaxel lower than clinical doses showed an increase of liver metastases.

A recent study found that low-doses of paclitaxel (PTX), a common chemotherapy for breast cancer, was shown to increase the likelihood of liver metastasis in mouse models.

In a study published in the FEBS Journal, researchers compared the clinical dose of PTX with a lower than typical clinical dose in mouse models of breast cancer. They discovered that the 2 different doses had completely different effects on the tumor.

At the clinical dose, the drug had beneficial effects, and was shown to have tumor-killing efficacy that halted malignancies. However, the low-dose of PTX created more liver metastasis in the mouse models.

When examined further, researchers found that low-dose PTX acts as a powerful inducer for breast cancer progression in a nuclear factor-kB (NF-kB)-dependent manner, according to the study.

Researchers found that the metastases in the liver grew much more quickly than in the group receiving the clinical dose of PTX. An upregulation of the breast cancer factor CCL20 was also discovered.

Low-doses were shown to induce inflammatory response. The low-dose causes PTX to lose function as a tumor suppressor and forces tumor metastasis by inducing the repolarization of tumor cells and the reconstruction of the host environment, according to the study.

Lowering the dose of PTX to reduce any toxic side effects could potentially cause metastasis and not be beneficial for the patient, the study concluded.