[Potentiation of focal ultrasound treatment of prostate adenocarcinoma by concomitant chemotherapy with estramustine phosphate and paclitaxel].

STUDY OBJECTIVES To demonstrate a synergistic action between high intensity focal ultrasound (HIFU) and combination chemotherapy with paclitaxel and estramustine phosphate (EMP) on a prostate cancer model. MATERIAL AND METHODS The animal model used in this study was the Copenhagen rat and the tumour model is a Dunning R 3327-AT 2 hormone-independent prostatic adenocarcinoma cell line. Chemotherapy was administered once a week for 4 weeks according to 2 modalities: low-dose with paclitaxel 2 mg/kg/day, 1 day per week and EMP 50 mg/kg/day, 3 days per week; or high-dose with paclitaxel 3 mg/kg/day, 1 day per week and EMP 75 mg/kg/day, 3 days per week. Treatment with HIFU was performed at the second week and only 55% of the tumour volume was treated. The study was conducted on 42 rats divided into 6 arms: Control, HIFU, low-dose paclitaxel-EMP, high-dose paclitaxel-EMP, HIFU + low-dose paclitaxel-EMP and HIFU + high-dose paclitaxel-EMP. Study endpoints were the course of tumour volume and animal survival. RESULTS After two weeks of treatment, a statistically significant difference for tumour volume was observed between the various arms of the study (p < 0.0001). The HIFU-chemotherapy arm and, to a lesser degree, the chemotherapy only arm, presented the lowest tumour progression. CONCLUSION The combination of HIFU + paclitaxel-EMP is more effective than treatment with HIFU alone or paclitaxel-EMP alone on growth of the Dunning tumour, right from the first weeks of treatment.