A method of treatment and/or prevention of cancer comprises administering agents which cause increased intracellular granularity in cancer cells, at least in an amount sufficient to inhibit proliferation of such cells and preferably in an amount sufficient to lead to cancer cell death. The method is particularly directed to refractory cancer, particularly hormone refractory prostate cancer. The agents identified cause increased intracellular granularity in the cancer cells, and also convert adherent cancer cells to non-adherent cancer cells, leading to cancer cell death. Using the present invention, cancer cells undergo increased intracellular granularity at relatively low agent concentrations, while also inhibiting cell proliferation. Increased concentrations lead to conversion of adherent cancer cells to non-adherent cancer cells, then to cell death. While the exact mechanism of cancer cell degradation and death is not completely understood, the treated cancer cells, including refractory prostate cancer cells, give indications of cell death through an autophagic mechanism. Pharmaceutical compositions related to the presently disclosed methods are also disclosed.