Despite the fact that animal anthelmintics, such as the antiparasitic drug fenbendazole, kill parasites and have been shown to reduce tumor size in laboratory experiments, no peer-reviewed study has found evidence that they can cure cancer in humans. However, some patients have reported that their cancers shrank when they took fenbendazole.
To determine the possible reasons for this observation, a focus group interview (FGI) was conducted with 21 lung cancer patients who self-administered fenbendazole. Patients were asked to complete a semi-structured questionnaire concerning their acquisition channel of general cancer information, the quality of this information, and their perception toward fenbendazole.
The hypothesis that fenbendazole has some antitumor activity was tested by the addition of varying concentrations of fenbendazole to cells treated with a series of doses of docetaxel in vitro. Cell viability was determined using a colony formation assay. The results show that the presence of fenbendazole did not alter the sensitivity to docetaxel. Furthermore, when the effect of fenbendazole was examined in cultures subjected to severe hypoxia, a marked increase in cytotoxicity occurred. Severe hypoxia increased the toxicity of 2-h treatments with low concentrations of fenbendazole, and also enhanced the synergistic effects of a high concentration with docetaxel. The results demonstrate that fenbendazole may alter cell-cycle progression and prevent mitotic catastrophe in hypoxic cells by inhibiting tubulin polymerization. This mechanism is similar to that of hypoxia-selective nitroheterocyclic chemotherapeutic agents and radiosensitizers, such as the taxanes and vinca alkaloids. fenbendazole cancer