A post hoc analysis of data from the Mainsail study has shown that treatment with eight or more cycles of docetaxel is associated with improved overall survival rates in men with prostate cancer. Patients involved in the Mainsail study received either docetaxel, prednisone and lenalidomide or docetaxel, prednisone and placebo; however, men in the lenalidomide arm received fewer cycles of docetaxel owing to the toxic effects of the combination treatment. Irrespective of whether lenalidomide was part of their treatment regime, men who underwent more cycles of docetaxel had significantly superior overall survival.