Fenben, also known as fenbendazole, is a drug commonly used in animals to deworm them of parasites like Ascaris and hookworm. It is part of the benzimidazole carbamate family of drugs (I coined BZ) and it has been safely in human use for about six decades. There are animal studies that suggest anthelmintics could have cancer-fighting properties and some are in clinical trials but turning animal tests into approved cancer treatments is a long journey.
Social media have increased the diffusion of information among nonmedical individuals. These platforms facilitate the dissemination of complex medical information, but they can also disseminate false medical facts. In particular, online social networks such as Facebook and TikTok allow users to share videos of unlicensed veterinarians promoting alternative medicine. This has led to a rise in popularity of these videos and the use of fenben as a cancer treatment.
In a case report, a patient with advanced nonsmall cell lung cancer (NSCLC) obtained information on the antitumor activity of oral fenbendazole from social media and self-administered it. The patient experienced severe liver injury that was attributed to her self-administration of the medication. Despite this, she refused to discontinue the fenbendazole therapy and continued it for two months. During that period, her CEA levels decreased and she felt better, but she lost a significant amount of weight. Ultimately, she was treated with pembrolizumab monotherapy and achieved clinical benefit.
The fenbendazole (FBZ) and mebendazole (MBZ) are members of the benzimidazole family and function as antiparasitic agents. These compounds are derived from B vitamins and have a similar chemical structure to the hypoxia-selective nitroheterocyclic cytotoxins and radiosensitizers. They have been shown to have cytotoxic activities in a number of preclinical studies, including blocking tumor progression and reducing tumor cell growth. They also have a unique property in that they can cross the blood-brain barrier, which could be useful in brain cancers and other cancers that metastasize to the brain.
These drugs inhibit microtubules, which are like little ropes that help cells to grow and move around. Because cancer cells grow and reproduce more rapidly than healthy cells, preventing the formation of these microtubules can lead to cell death. Fenbendazole is able to kill cancer cells without harming normal cells, so it can be used as part of an integrated cancer treatment regimen.
Several studies have investigated the effects of FBZ and MBZ on cancer growth and radiation responses. Using cell culture experiments, they have found that fenbendazole has a high concentration of cytotoxicity and can increase the efficacy of standard cancer treatments. They have also found that fenbendazole can work alongside radiotherapy to decrease the amount of radiation needed to destroy the cancer cell. fenben