RATIONALE: Antineoplastons are naturally occurring substances that may also be made in the laboratory. Antineoplastons may inhibit the growth of cancer cells.

PURPOSE: This phase II trial is studying how well antineoplaston therapy works in treating patients with cancer of the esophagus.

OBJECTIVES:

• Provide antineoplastons A10 and AS2-1 as treatment for patients with incurable adenocarcinoma of the esophagus.
• Describe the response to, tolerance to, and side effects of this regimen in these patients.

OUTLINE: This is an open-label study.

Patients receive gradually escalating doses of antineoplaston A10 and antineoplaston AS2-1 by intravenous injection 6 times daily until the maximum tolerated dose is reached. Treatment continues for at least 2 months in the absence of disease progression or unacceptable toxicity. Patients achieving a complete response (CR) continue treatment for at least 8 months beyond CR. Patients achieving a partial response or stable disease continue treatment until disease progression.

Tumors are measured every 2 months for 1 year and then every 3 months for the second year.

PROJECTED ACCRUAL: Approximately 20-40 patients will be accrued for this study.

DISEASE CHARACTERISTICS:

• Histologically confirmed adenocarcinoma of the esophagus that is unlikely to respond to existing therapy and for which no curative therapy exists

• Meets 1 of the following criteria:

  • Metastatic disease
  • Not curable with surgery or radiotherapy
• Measurable disease by MRI or CT scan

PATIENT CHARACTERISTICS:

Age:

• 18 and over

Performance status:

• Karnofsky 60-100%

Life expectancy:

• At least 2 months

Hematopoietic:

• WBC at least 2000/mm3
• Platelet count at least 50,000/mm3

Hepatic:

• No hepatic failure
• Bilirubin no greater than 2.5 mg/dL
• SGOT and SGPT no greater than 5 times upper limit of normal

Renal:

• Creatinine no greater than 2.5 mg/ml
• No history of renal conditions that contraindicate high dosages of sodium

Cardiovascular:

• No chronic or congestive heart failure
• No uncontrolled hypertension
• No other cardiovascular conditions that contraindicate high dosages of sodium

Pulmonary:

• No serious lung disease, such as severe chronic obstructive pulmonary disease

Other:

• Not pregnant or nursing
• Fertile patients must use effective contraception during and for 4 weeks after study participation
• No medical illness, psychiatric illness, or non-malignant systemic disease that would preclude study treatment
• No active infection

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• At least 4 weeks since prior immunotherapy and recovered

Chemotherapy:

• At least 4 weeks since prior chemotherapy (6 weeks for nitrosoureas) and recovered

Endocrine therapy:

• Concurrent steroids allowed

Radiotherapy:

• At least 8 weeks since prior radiotherapy (except in patients with multiple tumors who have received radiotherapy to some of their tumors) and recovered

Surgery:

• Recovered from prior surgery

Other:

• No prior antineoplaston therapy
• Prior cytodifferentiating agents allowed