Is a common worm medication the cure for aggressive cancer?

Cancer treatment has come a long way. From therapies like chemotherapy, radiation, targeted drugs, and immunotherapy, modern medicine offers different treatment options that can significantly improve survival rates and also the quality of life for many patients.

Yet, for some rare and aggressive cancers, effective treatments remain limited. A medication originally developed to treat pinworm infections could offer a new line of defense against one of the aggressive cancers, according to a study. A new study led by University of Arizona Cancer Center researchers found that pinworm medication has the potential to treat aggressive skin cancer. The findings are published in the Journal of Clinical Investigation.Pinworm medication to treat skin cancer

Merkel cell carcinoma is an aggressive form of skin cancer. It is a rare but fast-growing neuroendocrine cancer that is three to five times more likely than melanoma to be deadly. Response rates to current therapies such as surgery, radiation, and immunotherapy are limited, resulting in a need for effective and broadly applicable therapeutics.“Merkel cell carcinoma is increasing in incidence. Even though it’s a rare cancer type, it mimics a lot of properties that other cancers have,” senior author Megha Padi, PhD, a U of A Cancer Center member and an assistant professor in the U of A College of Science, said in a statement.

The researchers found that a common pinworm medication may stop and reverse cancer growth in Merkel cell carcinoma. The medication is pyrvinium pamoate, which was approved by the Food and Drug Administration (FDA) in 1955 to treat pinworms. This drug has been shown to have antitumor potential in several different cancers, including breast, colorectal, pancreatic, and bladder cancers. However, this is the first time it has been studied in models of Merkel cell carcinoma.The study

To understand if the pinworm medication is effective in treating Merkel cell carcinoma, the researchers tested it in laboratory models. They found that pyrvinium pamoate inhibited cancer cell growth and reversed the cancer’s neuroendocrine features. This medication helped to reduce tumour growth in mouse models of Merkel cell carcinoma.

“This is a hypothesis, but some people think the reason an antiparasitic agent could be effective against cancers is because tumors are a little bit like parasites in our body.

Parasites and tumors must develop ways to use scarce resources in their host to feed themselves and allow for unlimited multiplication. If the pathways that they have hijacked to feed themselves are the same, then you get lucky, and you have a tumor type that could be amenable to killing by these antiparasitic drugs,” Padi said.

The researchers decided to test pyrvinium pamoate after discovering the Wnt signaling pathway as one of the molecular mechanisms that drives the transition of normal cells into Merkel cell carcinoma. Pyrvinium pamoate is a known Wnt pathway inhibitor. While the pinworm medication has shown promise in treating aggressive forms of cancer, the researchers added that further research is needed to optimize treatment protocols for the development of pyrvinium pamoate as a clinically useful medication for Merkel cell carcinoma.