Can Fenben Treat Colorectal Cancer?

Fenben is a medication commonly used to treat parasites and worms (roundworms, hookworms, whipworms and some tapeworms) in animals. It is a member of the benzimidazole carbamate family of anthelmintics and has been in use for about 50 years. It is a commonly available product in the veterinary industry, with common brand names including Pancur and Safe-Guard.

The use of fenbendazole to treat cancer is currently popular, with the Joe Tippens Protocol (http://www.joetippensprotocol.com/). It’s not clear if the protocol has any significant benefits beyond reducing side effects from other cancer treatments and preventing recurrence of disease, but it has gained wide popularity online due to a series of articles by a man claiming to have used the medication to treat his own lung cancer and cure himself.

A recent study using mouse models found that fenbendazole was able to cause tumors to shrink and to kill existing cancer cells. The research also indicated that fenbendazole might be effective in treating colorectal cancer.

In SNU-C5 and SNU-C5/5-FUR CRC cell lines, fenbendazole treatment resulted in G2/M arrest, apoptosis, autophagy and ferroptosis. It also activated p53-mediated apoptosis and reduced mutant p53 expression in both types of cells. However, necroptosis was only partially activated, possibly due to lack of phosphorylation of MLKL. The authors also found that fenbendazole induced autophagy via Beclin-1 and increased LC3-I and Atg7 expression in both SNU-C5 and SNU-C5/5-FUR cells. Immunoblotting analyses showed that fenbendazole triggered the phosphorylation of RIP and RIP3 kinases, leading to cleavage of caspase-8.