RATIONALE: Inserting the gene for interleukin-12 into a person's skin tumor cells may make the body build an immune response to kill tumor cells.

PURPOSE: Phase I trial to study the effectiveness of interleukin-12 gene therapy in treating patients who have skin metastases.

OBJECTIVES:

• Determine the safety and toxicity of interleukin-12 gene in patients with spontaneous skin metastases.
• Determine the antitumor immune response in patients treated with this regimen.
• Compare the toxicity of this regimen administered for 1 week vs 2 weeks in these patients.
• Compare the local and systemic antitumor response in patients treated with this regimen administered for 1 week vs 2 weeks.

OUTLINE: Patients are stratified according to number of tumor sites (1 vs 2 vs 3 or more). Patients are assigned to 1 of 2 treatment arms.

• Group A: Patients receive interleukin-12 gene intratumorally over 5 minutes on days 1, 3, and 5.
• Group B: Patients receive IL-12 gene intratumorally over 5 minutes on days 1, 3, 5, 8, 10, and 12.

Patients with stable or responding disease may receive 1 subsequent course beginning on day 29.

Patients are followed at 3, 6, and 12 months.

PROJECTED ACCRUAL: A total of 12 patients (6 per treatment group) will be accrued for this study.

DISEASE CHARACTERISTICS:

• Histologically confirmed solid malignancy

  • Surgically or medically incurable disease
  • No standard chemotherapy or radiotherapy exists for this disease

• Tumor of at least 0.5 cm but no more than 2.5 cm infiltrating into or underlying the skin

  • Cutaneous metastases, subcutaneous metastases, or tumor-involved lymph nodes that are easily palpable

PATIENT CHARACTERISTICS:

Age:

• 18 and over

Performance status:

• ECOG 0-1

Life expectancy:

• More than 3 months

Hematopoietic:

• WBC greater than 3,000/mm^3
• Platelet count greater than 80,000/mm^3

Hepatic:

• Bilirubin less than 2.0 mg/dL

Renal:

• Creatinine less than 2.0 mg/dL

Other:

• HIV negative
• No active infections requiring antibiotic, antiviral, or antifungal treatment
• No other active malignancy
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• At least 1 month since prior immunotherapy
• No concurrent colony-stimulating factors

Chemotherapy:

• See Disease Characteristics
• At least 1 month since prior chemotherapy

Endocrine therapy:

• At least 1 month since prior steroids (other than intermittent use as an antiemetic or topical agent)
• No concurrent steroids

Radiotherapy:

• See Disease Characteristics
• Prior radiotherapy to vaccine site allowed provided there is documentation of progressive disease

Surgery:

• See Disease Characteristics
• No prior organ allografts

Other:

• No other concurrent antineoplastic therapy
• No other concurrent investigational drugs