In a series of YouTube videos and on TikTok, an unlicensed veterinarian has claimed that a common dog dewormer drug can cure cancer in humans. The claims have been widely shared online and are based on an anecdotal account of a man from Oklahoma who said taking fenbendazole and other supplements cured him of a small-cell lung cancer that spread to his organs and bones. The video has also been shared by other unlicensed “veterinarians” who have since been reprimanded by their professional associations for posting the clips.
Cancer Research UK has debunked the claim and warned people that fenbendazole is not a cancer treatment and can harm health. The charity says the evidence is “insufficient” and that fenbendazole has not been tested in clinical trials to establish whether it is safe and effective for use in humans.
The drug, also known as mebendazole, is a parasitic worm medicine that kills roundworms and hookworms by blocking the formation of tubulin. Tubulin is both a micro-skeleton for the inner cell and a highway for transport, so mebendazole starves the parasites by collapsing their internal structure and stopping them from getting food. Scientists have found that it can also kill cancer cells in petri dish experiments, but it’s not been proven to work in people.
According to a new study published in Scientific Reports, fenbendazole may be able to help fight cancer because it doesn’t allow cancer cells to develop resistance to the drug, unlike many chemotherapy drugs. The researchers found that fenbendazole targets the cellular pathways that control cancer cell survival and death, including p53, p21, autophagy, ferroptosis, and necroptosis. It is believed to be able to do this by partially altering the microtubule network in the cell, as well as by increasing p53 expression and triggering apoptosis and necroptosis in 5-FU-sensitive cancer cells.
In 5-fluorouracil-resistant SNU-C5/5-FUR CRC cells, fenbendazole induced G2/M arrest, apoptosis, and necroptosis by increasing the expression of the protein LC3 and Atg7 and inhibiting the activity of caspase-8. Moreover, fenbendazole triggered ferroptosis and reduced autophagy in the 5-FU-resistant cells by decreasing the expression of Beclin-1 and GPX4.
The scientists also found that fenbendazole is more effective in tumour cells that contain wild type p53 than in those with mutant p53. This is thought to be because the mutant p53 proteins are more resistant to the drug, while wild type p53 has more active protein that can help it respond to fenbendazole.
The researchers also gave fenbendazole to mice with cancer and found that it reduced the size of their tumours. They concluded that fenbendazole might be an effective anti-cancer drug because it is an antiparasitic agent and cancer cells cannot build up resistance to it like they do with most chemotherapy drugs. They added that elephants, which have 20 copies of p53 in their genome, are less likely to get cancer than human beings, because they can’t build up resistance to the natural anti-parasitic medicine mebendazole, and that this suggests that fenbendazole might work on cancer in humans as well. fenbendazole for humans cancer