Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically confirmed adenocarcinoma of the prostate

- Progressive disease after a prior docetaxel-based regimen OR failed a prior
docetaxel-based regimen

- Hormone-refractory disease, meeting 1 of the following criteria:

- Radiologically measurable disease

- Prostate-specific antigen (PSA) progression* while on hormonal therapy
(including withdrawal from a direct antagonist) NOTE: *If the confirmatory PSA
value is less than the screening PSA value, then an additional test for rising
PSA is required to document progression

- Must have underwent prior surgical castration OR currently be on a luteinizing
hormone-releasing hormone agonist

PATIENT CHARACTERISTICS:

- ANC > 1,500/mm³

- Platelet count > 100,000/mm³

- Hemoglobin > 10 g/dL (in the absence of packed red blood cell transfusions within the
past 4 weeks)

- Creatinine < 2 mg/dL

- AST and ALT < 2 times upper limit of normal (ULN)

- Alkaline phosphatase < 2 times ULN

- Fertile patients must use effective double-method contraception during and for 1
month after completion of study treatment

- No other malignancy within the past 5 years except basal cell carcinoma

- No clinically significant New York Heart Association class II-IV cardiovascular
disease

- No evidence of severe or uncontrolled systemic disease (e.g., unstable or
uncompensated respiratory, cardiac, hepatic, or renal disease)

- No unresolved chronic toxicity > grade 2 from prior anticancer therapy, with the
exception of alopecia

- No other significant clinical disorder or laboratory finding that would preclude
study participation

- No known severe hypersensitivity to gefitinib or any of the excipients of this
product

- No evidence of clinically active interstitial lung disease

- Patients with chronic, stable radiographic changes who are asymptomatic are
eligible

PRIOR CONCURRENT THERAPY:

- See Disease Characteristics

- At least 4 weeks since prior cytotoxic therapy

- At least 4 weeks since prior direct antagonists, including flutamide and nilutamide

- At least 6 weeks since prior bicalutamide

- At least 30 days since prior nonapproved or investigational drugs

- More than 4 weeks since prior palliative radiotherapy

- The irradiated lesion must not be used to assess response rate

- No prior gefitinib or etoposide

- No concurrent palliative radiotherapy

- No concurrent chemotherapeutic agents

- No concurrent phenytoin, carbamazepine, rifampin, barbiturates, or Hypericum
perforatum (St. John's wort)

- No concurrent hormones except antiandrogen therapy, steroids for adrenal failure,
hormones for nondisease-related conditions (e.g., insulin for diabetes), or
intermittent dexamethasone as an antiemetic

- No concurrent initiation of IV and/or oral bisphosphonates specifically for
symptomatic bone metastases