The study performed a retrospective review of 97 patients treated with a second BCG induction for BCG-relapsing tumor. Of these patients, 71 (73.2%) and 26 (26.8%) underwent initial BCG treatment d with the Tokyo-172 strain and Connaught strain, respectively. At second BCG induction, 28 (28.9%) patients were given a different BCG strain (switching group), and 69 (71.1%) patients were given the same BCG strain (non-switching group). The study defined four distinct groups: Tokyo-172 to Tokyo-172 strain, Connaught to Connaught strain, Tokyo-172 to Connaught strain, and Connaught to Tokyo-172 strain. The 5-year recurrence-free survival (RFS) rates for the above groups were 52.9±7.7%, 63.5±14.8%, 85.7±9.4%, 41.0±14.7%, respectively. here was no significant difference in RFS between the switching and non-switching groups (64.7±9.6% vs. 54.8±6.9%, p=0.427). There was also no significant difference in the progression-free survival rate between the switching and non-switching groups (95.4±2.6% vs. 96.0±3.9%, p=0.674). Side effects were significantly lower in the switching-group compared to the non-switching group (32% vs. 63%, p<0.05).
In summary, switching of BGC strains did not have a significant effect on RFS on patients with BCG-relapsing disease treated with a second BCG induction. BCG related side effects appear significantly lower in patients in whom the BCG strain was changed at second induction. The study has several limitations mainly the low numbers used in the analysis. Given bladder cancer heterogeneity the study will need a significantly higher number of patients to note a difference. Moreover, the presenter acknowledges that significant strain cross-over could have occurred during maintenance regimens which confounds the results presented.
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