The addition of estramustine to other chemotherapeutic agents that affect microtubule function may improve their efficacy15, 16, 17, 18. A phase III trial compared vinblastine versus the combination of vinblastine plus estramustine as treatment for patients with hormone-refractory prostate cancer. They showed that the association of estramustine and vinblastine was superior to vinblastine alone for time to progression, PSA response and survival (Hudes et al., ASCO 2002). In addition, Berry et al. found that estramustine/paclitaxel improved PSA response rate but not overall survival compared with paclitaxel alone (Berry et al. ASCO2001).