Docetaxel and Erlotinib in Treating Older Patients With Prostate Cancer

Inclusion Criteria * Histologically confirmed adenocarcinoma of the prostate. * Disease progression following primary or secondary hormonal therapy. * All patients must be maintained on GnRH analog during this study. * Serum PSA must be \> 20 ng/mL in patients without bidimensionally measurable disease or bone disease. * Age \> 65 years. * Karnofsky performance status of \> 70%. * Life Expectancy of \> 12 weeks. * Peripheral neuropathy, if present must be \< grade 1 by NCI criteria. * Radionuclide bone scan and chest /abdominal/pelvic CT scan must be obtained in all patients within 4 weeks prior to cycle 1/day 1. * Sexually active men must be willing to consent to using effective contraception while on treatment and for 6 months following treatment. * No concomitant use of prostata or saw palmetto. * Testosterone must be castrate levels(\< 50 ng/ml). * WBC \> 2.8 x 109/L * Granulocytes \> 1.5 x 109/L * Platelets \> 100 x 109/L * Hemoglobin \> 8.0 g/dL * Serum creatinine \< 2.1 * Total bilirubin \< ULN * Alkaline Phosphatase \< 2.5 ULN AND ALT/AST \< 2.0 ULN OR Alkaline Phosphatase 2.6-3.9 ULN, AND ALT/AST \<1.5 ULN OR Patients with known bone involvement may be included with alkaline phosphatase \> 4.0 ULN, IF ALT and AST and total bilirubin are within the normal range and the bone involvement is thought to account for elevated alkaline phosphatase. * PT, INR should be within physiologic limits, i.e. INR 0.7 - 1.5. If patient is receiving anticoagulation therapy then INR should be within the range of 2.0 - 3.5. Exclusion Criteria * Any major surgery or radiotherapy, within 4 weeks prior to cycle 1/day 1 (within 12 weeks for previous treatment with strontium-89, rhenium, or sumarium). * Hormonal therapy, with the exception of androgen deprivation therapy and stable regimens of prednisone and dexamethasone, (no change within 2 weeks prior to cycle1/day 1). Prior prostate hormonal treatment must have been discontinued at least four weeks (6 weeks for Casodex) prior to cycle1/day 1. * Cardiovascular: Uncontrolled hypertension (resting blood pressure \>160/100 mm/Hg); clinical episodes of congestive heart failure, angina pectoris, or myocardial infarction within the last year. * Any active infections (requiring IV antibiotics). * Any prior chemotherapy. * Not reliable for adequate follow-up. * History of severe hypersensitivity reaction to drugs formulated with polysorbate 80. * Brain metastases or (clinical signs of) brain involvement or leptomeningeal disease. * Patients with a history of another malignancy during the last 5 years other than prostate cancer, nonmelanomatous skin cancer or in situ bladder cancer (Stage T1a). * Concurrent commercial or investigational antineoplastic therapy.