Interleukin-12 Gene Therapy in Treating Patients With Skin Metastases

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