Docetaxel and Erlotinib in Treating Older Patients With Prostate Cancer

RATIONALE: Drugs used in chemotherapy, such as docetaxel, work in different ways to stop tumor cells from dividing so they stop growing or die. Erlotinib may stop the growth of tumor cells by blocking the enzymes necessary for their growth. Combining docetaxel with erlotinib may kill more tumor cells. PURPOSE: This phase II trial is studying how well giving docetaxel together with erlotinib works in treating older patients with progressive prostate cancer that has not responded to hormone therapy.