I was on 60mg of simvastatin (Zocor) when I got BCG. My general physician and my urologist didn't seem to think there was any problem with it. However, I didn't do any personal research on it at the time either. Just never thought of it. I failed BCG after a couple of doses anyway so I guess it didn't matter much in my case.
Here is one study on it:
BCG and Statins
Starts at the bottom of page 2705 (1st page). This is from 2006. It is not clear if taking statins prior (but going off during treatment) was looked at all. So, based on information in this study it might not make a difference even if you went off during BCG since you've been taking it. My personal (not medical) opinion is that it would need a group that didn't take statins, a group that took statins but stopped prior to starting BCG, and group that took statins and stayed on them through BCG treatments in order to be relevant. I would think it would be beneficial to even further stratify the statin users by the amount of statins they use. Is 20mg ok but 60mg not ok? That type of thing. That's not medicine, that's just basic scientific theory that they teach in fourth grade. But I have to tell you that I am often amazed when reading these studies that the research methods and control groups don't really even follow what we learned as kids to be basic research methodology.... (oh well different story for a different day).
This following study is one from two years later and looks to be more comprehensive and says no statiscal significance so patients should not be discouraged from continuing with the statins.
Journal of Urology MSK study
This might be a really good question for you to ask Dr. Lamm on his website. Also worth asking your urologist.
Even with studies like these, you can't tell who may have sponsored it. For example, did a non-statin drug maker for lowering cholestoral fund the first study and statin maker fund the second? Were they purely done for research purposes by the doctors without being specifically funded by someone? That's why I'd ask the doctor for sure in this case.
Now if there were 40 or 50 studies and they all seemed to come up with similar results....STILL ask the doctor.
You don't want to just stop taking something without the doctor knowing and it may not even be worth the risk.
In your case, since you just started and it's a low dose, the doctors (Lamm and yours) may have some ideas about your particular situation.
Mike