Evaluation of an unconventional treatment modality with mistletoe lectin to prevent recurrence of superficial bladder cancer:: A randomized phase II trial

Purpose: The indication for topic chemotherapy or immunotherapy for well differentiated, noninvasive superficial bladder cancer remains controversial. Side effects of these treatments promoted use of unconventional therapies with cytokines, immunomodulators and mistletoe extracts. However, there are no controlled clinical data available on the efficacy of these extracts for bladder cancer. We evaluate the influence of subcutaneously applicated mistletoe lectin on bladder tumor recurrence after transurethral resection. Materials and Methods: The study consists of 45 patients with pTa G1-2 bladder cancer treated with transurethral resection during a 3-year period. Median patient age was 65 years and 33 patients were male. The study cohort was randomly divided into a treatment group receiving adjuvant therapy with mistletoe lectin and a control group receiving no additional treatment. Patients in the treatment group received mistletoe lectin according to schedule 2 weeks after transurethral resection. Clinical followup was assessed 3, 6, 9, 12 and 18 months after the initial resection, and included uretherocystoscopy. Results: Both study arms comprised similar patients with regard to total number of previous tumors (mean 2.6 versus 2.9), number of primary lesions (14 versus 12) and number of recurrent tumors (8 versus 11). After followup of 18 months the recurrence-free interval in both study arms was similar (p = 0.76) and the total number of recurrences comparable (p = 0.48). Conclusions: Subcutaneous use of mistletoe lectin as adjuvant treatment after transurethral resection does not seem to affect the time to first recurrence, total number of recurrences or recurrence-free outcome.