Antiviral Therapy in Treating Patients With Kaposi's Sarcoma With or Without HIV Infection

DISEASE CHARACTERISTICS: Biopsy-proven Kaposi's sarcoma (KS) HIV infection (measured by ELISA and Western blot) allowed NCI pathology review required At least 5 measurable lesions required No prior local therapy to indicator lesions Lesions evaluable by noninvasive methods No actively bleeding or critically located KS of immediate risk to patient or at the discretion of the Principal Investigator and/or Study Chairperson No pulmonary or other potentially acutely life-threatening KS lesions PATIENT CHARACTERISTICS: Age: 18 and over Performance status: Karnofsky 70-100% Life expectancy: More than 3 months Hematopoietic: Absolute neutrophil count at least 750/mm3 Platelet count at least 75,000/mm3 Hemoglobin at least 11 g/dL (10 g/dL in women) CD4 count greater than 50 cells per cubic millimeter Hepatic: Bilirubin no greater than 1.5 times normal (unless due to Gilbert's disease) Patients on protease inhibitors may have bilirubin no greater than 3.5 mg/dL (direct bilirubin no greater than 0.2 mg/dL) AST/ALT no greater than 75 IU/mL Alkaline phosphatase no greater than 2.5 times normal Renal: Creatinine less than 1.5 mg/dL Creatinine clearance (calculated) greater than 55 mL/min Proteinuria less than 2+ Cardiovascular: No significant EKG abnormality Other: No actively life-threatening infection At least 14 days since treatment for serious infection No known clinically significant allergy to probenecid or sulfa No grade 3 or worse clinical or laboratory toxicity other than lympho…