MD Andersons Cancer Center (TX) team published (March 30, 2021) the result of their studies.
The result from the study
518 patients received adequate BCG at a median 26 days from TUR (range 6‐188 days).
Adequate BCG: at least 5/6 induction instillations with 2 additional instillations comprising either maintenance or repeat induction
45 patients (9%) developed BCG intolerance at a median 12th instillation (range 7‐33).
Time fromTURB to BCG did not cause any difference in BCG intolerance, recurrence-free survival, and progression-free survival.
The conclusion from the study
The rates of tolerability and response to adequate BCG are not predicated on the timing of induction BCG instillation after TUR.
Early administration in properly selected patients is safe, and delays do not affect therapeutic response.
Below is the link to the test result
bjui-journals.onlinelibrary.wiley.com/doi/10.1111/bju.15413 
