Purpose: We assessed whether interleukin-8 (IL-8), one of the first cytokines expressed in the urine after bacillus Calmette-Guerin (BCG) therapy for superficial urothelial tumors, may serve as a prognostic factor for treatment response.
Materials and methods: Of 20 patients with superficial urothelial cancer of the urinary tract treated with BCG 13 had superficial bladder cancer and 7 received BCG perfusion of the upper urinary tract due to inoperability, solitary kidney, renal insufficiency or bilateral disease. After intravesical instillation of 120 mg. BCG or after 2-hour perfusion of the upper urinary tract with 360 mg. BCG urine was collected at 6-hour intervals. IL-8 was determined by solid phase double ligand enzyme-linked immunosorbent assay.
Results: IL-8 was stable in the urine for more than 48 hours. At a median followup of 36.5 months treatment failure occurred in 10 of the 20 patients, including 3 with recurrence, 6 with progressive disease and 1 with extensive carcinoma in situ. IL-8 excretion was more than 4,000 ng. in the first 6 hours after BCG therapy in all 10 patients who remained disease-free. In 9 of the 10 patients with recurrent disease IL-8 excretion was less than 4,000 ng. in the first 6 hours after BCG therapy. Patients secreting less than 4,000 ng. IL-8 into the urine during the first 6 hours after BCG therapy had a significantly higher risk of tumor recurrence and progression (p <0.0002).
Conclusions: Due to its stability and kinetics IL-8 determined in urine collected during the first 6 hours after BCG therapy may prove to be a prognostic factor for tumor recurrence and progression after BCG therapy.