Docetaxel With or Without Imatinib Mesylate in Treating Patients With Androgen-Independent Prostate Cancer and Bone Metastases

RATIONALE: Drugs used in chemotherapy, such as docetaxel, work in different ways to stop tumor cells from dividing so they stop growing or die. Imatinib mesylate may stop the growth of tumor cells by blocking the enzymes necessary for their growth. Combining docetaxel with imatinib mesylate may be effective treatment for androgen-independent prostate cancer and bone metastases. PURPOSE: This randomized phase II trial is studying docetaxel and imatinib mesylate to see how well they work compared to docetaxel alone in treating patients with androgen-independent prostate cancer and bone metastases.