Frequency of Tumor Recurrence: A Strong Predictor of Stage Progression in Initially Diagnosed Nonmuscle Invasive Bladder Cancer

Purpose: Patients with nonmuscle invasive bladder cancer usually experience multiple instances of tumor recurrence until stage progression occurs. However, it has not yet been fully evaluated whether the timing and/or pattern of tumor recurrence could affect subsequent stage progression. We examined whether the frequency of tumor recurrence provides additional predictive information concerning stage progression. Materials and Methods: A total of 484 patients with initially diagnosed nonmuscle invasive bladder cancer were identified between 1985 and 2006 at our institution. Median followup was 7.2 years. Frequency of tumor recurrence was analyzed to determine if it affected subsequent stage progression. Results: Of these patients 40 (8.3%) experienced stage progression during followup. Using Kaplan-Meier analysis subsequent stage progression could be most strongly predicted in patients with a recurrence rate of 1 or more per year during the first 2 years, although similar results were observed for various cutoff periods and recurrence rates. The 10-year progression-free survival rate was 58.0% in patients with a recurrence rate of 1 or more per year and 93.3% in their counterparts (p <0.001). Multivariate analysis demonstrated that the appearance of tumor grade 3 (p = 0.027, risk ratio 2.36), carcinoma in situ (p = 0.045, risk ratio 2.44) and a recurrence rate of 1 or more per year during the first 2 years (p <0.001, risk ratio 7.40) were independent risk factors for subsequent stage progression. Conclusions: Frequency of tumor recurrence is a strong predictor of subsequent stage progression in patients initially diagnosed with nonmuscle invasive bladder cancer. More appropriate followup and aggressive treatment due to a higher malignant potential for stage progression might be recommended in patients with a recurrence rate of 1 or more per year during the first 2 years.