Anti-parasitic drug nitazoxanide (NTZ) used to treat human tapeworm infection has been shown to inhibit growth of human prostate and colon cancers:
https://labiotech.eu/medical/prostate-cancer-parasite-norway/
Years ago, I came across a book written on alternative medicine.
The woman who wrote it claimed cancer was caused by tapeworms and that it was easy to cure. She recommended buying anti-parasite medicine at the drugstore to “cure” your cancer.
I figured she must be a quack. I laughed at the book. But maybe she was onto something...