The impact of purified protein derivative prior to intravesical bacillus Calmette-Guérin for the treatment of patients with non-muscle invasive bladder cancer.

Background: The aim of this study is to investigate the impact of the intradermal injection of purified protein derivative (PPD) and PPD skin test reactions on the oncological outcomes of patients with non-muscle invasive bladder cancer (NMIBC) treated by trans-urethral resection of bladder tumor (TURBT) and adjuvant intravesical BCG.

Methods: The study included 100 consecutive patients with NMIBC prospectively given intradermal PPD 1-2 weeks before starting BCG therapy. Another 100 patients with NMIBC not given intradermal PPD before starting BCG were chosen as a historical control. The control group was chosen to be matching with the study group regarding baseline characteristics. The study group was divided into 2 subgroups with positive and negative reaction to PPD skin test. Oncological outcomes, immunological markers (TNF-α and IL-6) changes and BCG side effects were evaluated.

Results: There were no significant differences between patients who received PPD or not regarding the 2-year recurrence free survival (RFS) rates and progression-free survival (PFS) rates and immunological markers changes. The 2-year RFS and PFS rates were significantly higher in patients with positive reactions. Post-induction values of immunological markers increased in all patients with a significant increase in patients with positive reactions. BCG side effects were significantly higher in patients with positive reactions.

Conclusions: The intradermal injection of PPD before intravesical BCG has no impact on oncological outcomes of patients with NMIBC treated with TURBT and intravesical BCG. However, the PPD skin test reactions before BCG therapy can predict the oncological outcomes, BCG side effects and the immunological outcomes of patients.