Phenylbutyrate in Treating Patients With Refractory Solid Tumors or Lymphoma

DISEASE CHARACTERISTICS:

• Histologically or cytologically confirmed solid tumor or lymphoma that is progressive or refractory to conventional therapy or for which no effective therapy is known
• Priority given to hormone-refractory prostate cancer and melanoma
• No untreated CNS metastases
• Head CT not required in the absence of clinical signs or symptoms but recommended for metastatic melanoma

PATIENT CHARACTERISTICS:

• Age: 18 and over
• Performance status: ECOG 0-2
• Life expectancy: At least 3 months
• WBC greater than 2,000/mm3 OR absolute neutrophil count greater than 1,500/mm3
• Platelet count greater than 100,000/mm3
• Hemoglobin greater than 9 g/dL
• Bilirubin less than 1.5 mg/dL
• AST/ALT less than 1.5 times normal
• Creatinine less than 2.0 mg/dL
• Obstructive uropathy allowed if relieved by nephrostomy or other appropriate device
• Left ventricular ejection fraction greater than 40% by MUGA or normal by echocardiogram
• No history of congestive heart failure
• No uncontrolled hypertension (diastolic greater than 110 mm Hg)
• Forced expiratory volume (1 second) greater than 1.5 L/min
• No active infection, including HIV or viral hepatitis
• No active seizure disorder
• No clinical evidence of increased intracranial pressure
• No baseline dementia (mini-mental exam less than 23)
• No autoimmune disease, including systemic lupus erythematosus, scleroderma, or other connective tissue illness
• No nonmalignant medical or psychiatric problem of sufficient severity to limit full compliance with study or to pose undue risk
• Not pregnant or nursing
• Adequate contraception required of fertile patients for 2 weeks prior to, during, and for 3 months after study
• Normal gastrointestinal function with ability to tolerate large intake of oral volume required for phenylbutyrate administration
• Patients with persistent nausea or moderate to severe anorexia may not be good candidates for study

PRIOR CONCURRENT THERAPY:

• Fully recovered from all prior therapy
• Prior suramin allowed if serum suramin level less than 50 micrograms/mL at entry
• At least 28 days since chemotherapy
• No prior phenylacetate, phenylbutyrate, or antineoplaston therapy
• The following may be continued during study:
• Luteinizing hormone-releasing hormone agonist with evidence of tumor progression (e.g., rising prostate-specific antigen, new lesions on bone scan) despite therapy
• Adrenal steroid replacement (if needed)
• Dexamethasone or other steroids
• At least 4-6 weeks since flutamide with evidence of PSA progression required (if possible)
• At least 28 days since radiotherapy
• At least 28 days since major surgery