Lapatinib in Treating Patients With Recurrent or Metastatic Prostate Cancer

Inclusion Criteria: * Patients must have histologically or cytologically confirmed prostate cancer that is recurrent after local therapy, and/or metastatic carcinoma confirmed to be of prostate origin * Patients must have recurrent and/or metastatic disease that is progressive and not amenable to surgery or curative radiotherapy; progressive disease is defined as: * Three consecutive rising PSAs, at least 4 weeks apart with an absolute increase of at least 0.5 * PSA doubling time of less than one year * PSA \> 2.0 * For recurrent disease following local therapy (surgery/radiation), prior neoadjuvant or adjuvant hormones are allowed if completed more than a year prior to study entry; for metastatic disease, no prior medical therapy (hormonal, corticosteroid, chemotherapy) is allowed * Life expectancy of greater than 12 weeks * ECOG performance status 0,1, or 2 * Leukocytes \>= 3,000/uL * Absolute neutrophil count \>= 1,500/uL * Platelets \>= 100,000/uL * Total bilirubin within normal institutional limits * AST(SGOT)/ALT(SGPT) =\< 2.5 X institutional upper limit of normal * Creatinine within normal institutional limits or creatinine clearance \>= 60 mL/min/1.73 m\^2 for patients with creatinine levels above institutional normal * Cardiac ejection fraction within the institutional range of normal as measured by echocardiogram or MUGA scan; note that baseline and on treatment scans should be performed using the same modality and preferably at the same institution * Must b…