The 2020 “fenbendazole stage 4 cancer” scandal caused by false information disseminated through social media has raised public awareness of the need for effective health communication. However, it has been difficult for health authorities to respond due to the rapid spread of illegitimate information on complementary alternative medicine. We conducted a focus group interview (FGI) with 21 lung cancer patients to understand their acquisition pattern and perception of the false information about fenbendazole. We found that patients acquired general cancer information daily through various media channels, and they actively cross-checked it. However, patients did not access the original video of Joe Tippens that received media attention, and thus the obtained information was influenced by media coverage.
We also found that a patient with advanced nonsmall cell lung cancer (NSCLC) was able to obtain the information on fenbendazole’s antitumor activity via social media and self-administered it. This resulted in severe liver injury in the patient. Interviews with the patient revealed that she had been taking oral fenbendazole for a month solely on the basis of social media reports suggesting its effectiveness against cancer. After stopping self-administering fenbendazole, the patient’s liver injury recovered spontaneously.
Our study suggests that repurposing drugs with demonstrated toxicity for a different condition can reduce the time and cost needed to develop new compounds. Fenbendazole (methyl N-(6-phenylsulfanyl-1H-benzimidazol-2-yl) carbamate) is a broad-spectrum benzimidazole anthelmintic drug that is widely used in various animal species. It exerts its anthelmintic action by binding to the microtubule subunits and inhibiting their polymerization. In addition, it has recently been reported that fenbendazole exhibits a moderate degree of antitumor activity.
In a mouse model of metastatic lung cancer, fenbendazole significantly reduced the growth of tumors in mice treated with paclitaxel. The results suggest that the antitumor effect of fenbendazole may be due to its ability to inhibit cancer cells’ proliferation by blocking the formation of a cyclin A-dependent signaling pathway.
We also investigated whether fenbendazole could enhance the antitumor effect of paclitaxel in a human cancer cell line, EMT6. We found that the cytotoxic and cytostatic effects of fenbendazole were enhanced when it was added to paclitaxel in vitro. The cell culture data showed that fenbendazole could increase the sensitivity of EMT6 cells to paclitaxel by increasing its ability to cross the cytoplasmic membrane. In addition, a 24-h treatment with high concentrations of fenbendazole reduced the clonogenicity of EMT6 cultures, whereas lower concentrations did not affect these properties. These findings suggest that fenbendazole can be used as an additive to improve the efficacy of chemotherapy in patients with metastatic NSCLC. However, further studies are necessary to determine the optimal dosage of fenbendazole and its clinical applications for treating NSCLC in patients with a stage 4 cancer.