The Testing Evidence for Using Mebendazole for Treating Thyroid Cancer

Executive Summary

• This article covers the evidence I could find for Mebendazole as a treatment for Thyroid Cancer.

Article Summary

Studies demonstrate that Mebendazole is effective against cancer, we then cover how Mebendazole works against cancer by explaining the mechanisms of action, and then the impacts of Mebendazole on cancer.

Introduction

This article provides an overview covering the evidence for Mebendazole and related drugs versus Thyroid Cancer.

Many articles on this website cover the evidence for the benefits of Mebendazole for cancer. But the question of which specific cancers Mebendazole has been proven effective is a constant source of questions.

The most common Benzimidazoles are Fenbendazole, Mebendazole and Albendazole. In our analysis, we include research for all three drugs together in articles as they are very similar to one another and it improves the ability to tie together different studies. You may see the following terms/acronyms used.

• FZ or FBZ means Fenbendazole
• MBZ means Mebendazole
• AZ means Albendazole

Cancer Type #7: Thyroid Cancer

The following quote is from the article Mebendazole inhibits tumor growth and prevents lung metastasis in models of advanced thyroid cancer.

The most common thyroid malignancy is papillary thyroid cancer. While a majority respond to therapy and have a favorable prognosis, some papillary thyroid cancers persist. This subset may dedifferentiate to anaplastic thyroid cancer, an aggressive, highly invasive and rapidly fatal cancer. Thyroid cancer patients at risk for disease progression and metastasis need earlier, safer and more effective therapies. The purpose of this translational study was to determine if mebendazole could be repurposed to effectively treat thyroid cancer, in particular before metastasis. In vitro, mebendazole potently inhibited the growth of a panel of human papillary and anaplastic thyroid cancer cells. In papillary (B-CPAP) and anaplastic (8505c) cell lines, mebendazole increased the percentage of cells in G2 / M cell cycle arrest and induced late stage apoptosis by activation of the caspase-3 pathway. In aggressive 8505c cells, mebendazole significantly repressed migratory and invasive potential in a wound healing and transwell invasion assay and inhibited expression of phosphorylated Akt and Stat3 and reduced Gli1. In vivo, mebendazole treatment resulted in significant orthotopic thyroid tumor regression (B-CPAP) and growth arrest (8505c), with treated tumors displaying reduced expression of the proliferation maker KI67 and less vascular epithelium as indicated by CD31+ immunohistochemistry. Most importantly, daily oral mebendazole prevented established thyroid tumors from metastasizing to the lung. Given the low toxicity and published anticancer mechanisms of mebendazole, this novel preclinical study of mebendazole in thyroid cancer has promising therapeutic implications for patients with treatment refractory papillary or anaplastic thyroid cancer.

The following quote is from the article Mebendazole prevents distant organ metastases in part by decreasing ITGβ4 expression and cancer stemness.

In vitro MBZ reduces human TNBC cell migration
In addition, MBZ has been shown to reduce the migration and invasion of thyroid and gastric cancer cells [16, 28] and more recently in MDA-MB-231 cells [29]. Therefore, we used two independent assays to determine whether MBZ could also inhibit the migration of TNBC cells. First, we performed a wound-healing assay to assess the ability of MBZ to inhibit cell migration in vitro. SUM159 and MDA-MB-231 cells were grown to confluence, and a single scratch (or wound) was generated (0 h). The cells were treated with MBZ at a concentration of 0.25 μM, 0.35 μM, 0.5 μM, or with DMSO as vehicle control. The wounds were imaged at time 0 h, 12 h, and 24 h to calculate the average area of the wound covered with cancer cells.

Compared to the vehicle control, MBZ treatment significantly decreased the average healing speed of the wound starting 12 h post-treatment with a 0.35 μM MBZ concentration in MDA-MB-231 cells (Fig. 3A, B). In a second migration assay, MBZ reduced the ability of SUM159 and MDA-MB-231 cells to migrate through Transwell pores following 48 h of pre-treatment with 0.5 μM and 1 μM of MBZ as compared to DMSO (Fig. 3C, D). Given the correlation between migratory ability and metastasis [36], our results suggest that even if a cell can survive MBZ treatment, it has a reduced capacity to migrate, and likely a decreased ability to metastasize.

That is they are referring to wound healing in cancer cells.

Adding up the Studies of Mebendazole Versus Cancer

There are many studies of Fenbendazole, Mebendazole, Albendazole, and other Benzimidazole derivatives versus cancer.

Due to the success of these studies and the information published in the study publications, the specific mechanisms by which these Benzimidazole-based Anthelmintics work against cancer are at this point well understood. There has not been a study published for every cancer type using one of the Benzimidazole derivatives. There are a very large number of different cancer types and limited funding for this type of research.

How Many Major Cancer Types Are There Studies For?

When I completed my analysis, I found 18 different types of cancer types which demonstrated effectiveness versus cancer. In many cases, these different cancer types had multiple cancer studies testing the different Benzimidazole derivatives.

Cancer centers do not apply the large body of published studies on the effectiveness of Benzimidazole derivatives to include as part of their treatment offerings. This is true even though Fenbendazole has been demonstrated to improve chemotherapy outcomes.

To understand the mechanisms by which Benzimidazole derivatives work against cancer, see the following few examples. To see all of the known mechanisms that I have compiled from all of the studies see the article on the mechanisms listed below.

The Multiple Mechanisms by Which Mebendazole Works Against Cancer

There are many ways in which Mebendazole works against cancer including.

• Reducing metastasis
• Increase autophagy
• Increase cancer cell death or apoptosis
• and much more

This topic is covered in the article By How Many Different Mechanisms Does Menbendazole Fight Cancer?