Purpose: Our purpose was to determine whether urinary interleukin-8 (IL-8) levels could be used to predict a tumor-free response to intravesical bacillus Calmette-Guerin (BCG) therapy in bladder cancer patients.
Materials and methods: A total of 46 patients with superficial bladder cancer underwent an initial 6-week course of intravesical BCG therapy after transurethral resection. Voided urine samples were collected immediately before BCG instillations 1 and 6. Urine samples were centrifuged at 1,500 rpm for 8 minutes, and the supernatant was stored at -20 C. An enzyme-linked immunosorbent assay technique was used to measure urinary IL-8 levels. The Jaffé method was used to measure urinary creatinine. Results were expressed as the IL-8/creatinine ratio. Patients were followed with cystoscopy and urinary cytology every 3 months to detect bladder tumor recurrence.
Results: IL-8/creatinine ratios were measured in 31 patients before BCG therapy and were undetectable in 15. After 5 weeks of intravesical BCG therapy, IL-8/creatinine ratios fell in 27 patients (59%), were unchanged in 10 (22%) and rose in 9 (19%). Mean followup was 20.9 months (range 3 to 48). There was no association between the direction of change in IL-8/creatinine ratio and response to intravesical BCG therapy (p = 0.5).
Conclusions: Urinary IL-8 levels obtained before intravesical BCG therapy and after instillation 5 of BCG were not helpful in predicting tumor recurrences in bladder cancer patients.