Purified Protein Derivative (PPD), is commonly used for the detection of patients who may be infected by tuberculosis. The protein is derived from the tuberculosis bacillus (TB) and injected into the dermis, were an immune reaction occurs if the patients has been previously exposed to TB. The hypothesis of the abstract is that injection of patients with PPD prior to BCG may will the immune system for BCG intravesical therapy, leading to improve effectiveness.
The study included a total of 498 NMIBC treated with intravesical BCG at Keio University. Of them, 320 (64.3%) received the PPD skin test prior to BCG therapy. The PPD skin test was performed 1 to 2 weeks prior to the start of adjuvant BCG therapy. The association between PPD test priming and clinical outcomes following in BCG treatment was evaluated. Patients who received PPD priming had a significantly higher incidence of pT1 (40.6%) and lower incidence of concomitant CIS (16.9%) as compared to the non-PPD group (28.1% and 24.2%, respectively). The 5-year recurrence-free survival (RFS) rate of patients in the PPD group was 66.6±2.8%, which was significantly higher than in those who did not underwent PPD priming (59.1±4.1%, p=0.048, Figure). Univariate Cox regression analysis revealed that tumor multiplicity (p=0.002), the presence of concomitant CIS (p=0.042) and receiving the PPD skin test (p=0.048) were associated with tumor recurrence. Multivariate Cox regression analysis revealed that tumor multiplicity (hazard ratio [HR] of 1.886, p=0.002), recurrent tumor (HR of 1.589, p=0.017), and receiving the PPD skin test (HR of 0.720, p=0.038) were independently associated with tumor recurrence. There was no significant association in progression-free survival between the PPD group and non-PPD groups (p=0.753). The rate of any BCG-related side effects in the PPD group was 56.6%, which was significantly higher than that in the non-PPD group (36.5%, p<0.001), suggesting successful priming.
In this retrospective trial, administrating of PPD prior to BCG effectiveness appears to improve the efficacy of BCG intravesical therapy. The study does have some limitations which are that PPD may be a indirect measure of a more competent and previously primed immune system rather than the result of a true priming strategy.
Presenter: Naoya Niwa, MD (Keio University, Tokyo Japan)
Written by: Andres F. Correa, MD, Urologic Oncology Fellow, Fox Chase Cancer Center, Philadelphia, PA at the 2018 AUA Annual Meeting - May 18 - 21, 2018 – San Francisco, CA USA