Doxorubicin treatment increases metastasis of prostate tumor (R3327-MatLyLu)

Doxorubicin (Dx) effects on metastatic spreading of prostate cancer were investigated using a rat metastatic tumor (R3327-MatLyLu). Intravenous injection of monodispersed tumor cells resulted in tumor nodule formation in the lungs. A simultaneous bolus injection of Dx (3.2 mg/Kg) caused a significant decrease in lung colony formation and growth. However, Dx administered during the course of spontaneous metastasis, or as adjuvant chemotherapy 24 hours before surgical removal of primary tumor, caused a significant increase in metastasis to the lungs. It is concluded that an intravenous doxorubicin bolus injection does not provide an antimetastatic effect, but increases metastatic spreading of prostate tumor.