There are many black salve/bloodroot salve naysayers, but I've had nothing but success with it. I've used it on my horse, husband and dad. lol
My best gelding had an aggressive sarcoid, and it was gone it 2 weeks. My daddy had numerous carcinomas burned, removed etc., from the dermatologist only to have them reappear months later. Once he used the bloodroot salve, they never reappeared. Same with my husband.
It's a very old remedy, and in our world (rodeo/ranching) a well known remedy for sarcoids, cancer & carcinomas. There's no one size fits all cause. There are many parasitic, and viral connections to cancer, carcinomas, and sarcoids. There is a belief that sarcoids are strictly a virus, but there is a parasitic connection as well. Same with carcinomas. In some cases there is a viral connection, in others a parasitic connection. The guy who makes Clean Horse salve is an expert on this subject.
It's def. worth a try for $50. We use Clean Horse (cleanhorse.com), and this man's product has worked great for us, and people we know. There are several bloodroot sources, although it's getting harder to find. If you try black salve, aka cowboy mud, bloodroot salve, etc, just make sure they have good reviews, and have the same ingredients as cleanhorse.com. Must have those ingredients for it to work.
It's not as caustic or aggressive as people think. I actually think it's less aggressive, as does not damage healthy cells. It only destroys cells that need to GO! Good luck!