Urinary interleukin-8 predicts the response of standard and low dose intravesical bacillus Calmette-Guerin (modified Danish 1331 strain) for superficial bladder cancer

Purpose: We determined whether the proinflammatory cytokine interleukin-8 (IL-8) can serve as a predictor for the response to standard (120 mg.) and low (40 mg.) dose intravesical. bacillus Calmette-Guerin (BCG) (modified Danish 1331 strain) for managing superficial bladder cancer in patients at risk for recurrence and progression. Materials and Methods: We randomized 26 patients with superficial bladder cancer to receive a 6-week course of standard dose 120 mg. or low dose 40 mg. intravesical BCG. Voided urine samples were collected immediately before and after (2 and 4 hours) BCG instillation. Urine samples were centrifuged at 1,500 rpm for 8 minutes and stored at -80C. IL-8 was measured using a commercial enzyme-linked immunosorbent assay. Patients were monitored for recurrence, progression and side effects of BCG treatment at 3-month intervals. Results: At a median followup of 24 months (range 12 to 30), 5 and 6 patients who received a standard and low dose, respectively had disease recurrence and/or progression (nonresponders). At 4 hours after BCG mean Il-8 levels plus or minus SD were significantly higher in responders than in nonresponders (1,099.33 +/- 708.51 versus 261.82 +/- 182.66 pg./ml., p = 0.001). There was no difference at 4 hours in mean IL-8 levels in the standard and low dose groups (596.92 +/- 546 and 893 +/- 798.67 pg./ml., respectively, p = 0.28). In all patients who remained disease-free IL-8 levels were greater than 400 pg./ml. In 9 of the 11 patients with disease recurrence/progression IL-8 levels were less than 400 pg./ml. Conclusions: IL-8 secretion after the initial intravesical BCG instillation strongly correlates with the possibility of future recurrence/progression. The quantitative IL-8 response to low and standard dose intravesical BCG (Danish 1331) is similar.