This prospective study was designed to assess the prognostic value of tumor-associated antigens, designated 19A211, M344, T138, and T43, with respect to recurrence of primary superficial bladder cancer. Between September 1990 and April 1992, all patients with primary superficial bladder tumors treated by endoscopic resection in 15 participating hospitals were enrolled. Immunostaining for 19A211 and M344 was performed on paraffin-embedded material, and for T43 and T138 on frozen tissue. Antigenic expression was evaluated blindly by a single pathologist. Patients were followed up with the standard schedule of control cystoscopies. Cox regression was used to estimate hazard ratios (HRs) for first recurrence, and Poisson regression was used to estimate recurrence rate ratios and tumor rate ratios adjusted for primary tumor characteristics. By March 1994, 2254 follow-up cystoscopies had been performed on 368 of the 382 study patients, and tumor recurrence was detected in 55.7% of patients. Positivity to 19A211 was detected in 90% of primary tumors, its expression being associated with a decrease in first recurrence hazard ]HR, 0.65; 95% confidence interval (CI), 0.42-1.03] and in recurrence rate (recurrence rate ratio, 0.70; 95% CI, 0.53-0.92). Positivity to T138 was detected in 15% of tumors, and its expression was associated with an increase in first recurrence hazard (HR, 1.43; 95% CI, 0.92-2.22) and in recurrence rate (recurrence rate ratio, 1.31; 95% CI, 1.00-1.72). Positivity to M344 was detected in 71% of tumors, and its expression was associated with an increase in tumor rate (tumor rate ratio, 1.77; 95% CI, 1.41-1.97). T43 expression was not associated with recurrence end points. In conclusion, recurrence of superficial bladder cancer was associated with antigenic expression of 19A211, T138, and M344, independently of primary tumor characteristics.