It's been a year and a half since I last posted to this thread. I like to remain true to my word that I'll keep everyone posted on how this has worked for us. It doesn't seem like others are taking this approach, and perhaps we are the only ones here who have tried it, but it seems to be working for us.
Recap: I originally came here for support and advice after my husband was diagnosed with yet another bladder tumor. He probably had five or six tumors at least over the course of this disease (it's hard for me to recall because he had several before we were married). Of those, only one was slightly invasive but most were not. Anyway, I was here to get better educated after the most recent tumor at that point was found.
Around that same time, someone initiated this thread. My husband and I decided to try the mustard seed powder after I read about it here. We ordered the kind of mustard seed that the study mentioned, and we started grinding it and making our own capsules. Rick started taking one capsule per day.
I'm happy to say that my husband remains tumor free. This, for us, is remarkable. Prior to starting the mustard seed we were removing a tumor every six months or so. Today he is stable, and has been since we began using the mustard seed, which was (according to the dates on the forum) 3 years and 8 months ago.
Of course we are not involved in any scientific research and we are only one case. I work in the field of medical research and so I know that in layman's terms this is an anecdote, whereas in the parlance of a medical journal this would be called a case study. Not statistically significant, but interesting enough that further attention might be warranted.
Our thinking on this has been that we had little to lose. We don't know if there are potential harms to the long term ingestion of mustard seed, but we seem to be seeing important benefits with no harms so far. I don't want to be seen as offering medical advice, but if you came to me as a friend and asked me about this, I'd suggest it's worth a try-- especially if your cancer is not invasive. Perhaps our experience is an anomaly, but we've done really well since starting this, so I just wanted to share that. I doubt I'll be back to update on this, as there seems very little interest, but I thought maybe someone in the group might be interested in the information.