Will ultrasound and light treat melanomas in pigs? Scientific advancements have made it possible to use light to shrink and kill cancer cells, but some types of cancer, like melanomas, don’t respond well to this new treatment.
Texas A&M University researchers are collaborating on new studies to evaluate the effectiveness of ultrasound and light, or photodynamic therapy, to treat melanomas in pigs.
“In photodynamic therapy, we introduce a chemical that is absorbed by skin cancer cells. The chemical only reacts when exposed to a certain kind of light, which causes new molecules to form that destroy the cancer cells,” Vanderlei Bagnato, a professor in the Department of Biomedical Engineering, said in a release.
Photodynamic therapy eliminates about 95% of lesions for non-melanoma skin cancers. It is very cost-effective and non-invasive, Bagnato explained.
“But treating melanomas with light-based therapy is problematic for several reasons. First, the pigment in the cancer cells sometimes interferes with the light. Secondly, melanomas are more prone than other skin cancers to regrow and metastasize — or spread to other parts of the body — if they are not removed completely,” he said.
Finding a more effective way to treat melanoma using photodynamic therapy could open doors, researchers say, for low-cost, non-invasive treatments in pigs, humans and other mammals.
“In addition to advancing human medicine, we’re hoping that this project can bring photodynamic therapy to veterinary medicine — not just in pigs but in other species that develop melanomas, too,” Jennifer Fridley, a clinical assistant professor in the College of Veterinary Medicine and Biomedical Sciences’ Department of Large Animal Clinical Sciences and the director of Veterinary Medical Park, said in a release.
Photodynamic therapy has recently become the primary treatment for non-melanoma skin cancers because of its low cost and high efficiency.
“There are several ways to introduce the therapy drug to the cancer — recently, we have begun using microneedles,” Bagnato said. “They are actually made of the drug itself, so when they dissolve into the skin, there is nothing left behind. The entire process can be done in under an hour and doesn’t require any surgery.”
Bagnato said skin cancer patients with diabetes, a very common condition in the U.S., could benefit from photodynamic therapy. People with diabetes need to avoid surgery whenever possible because diabetes causes poor blood flow to the body’s tissues. Photodynamic therapy offers a much safer treatment than surgery with fewer chances of complications.
What is the Most Effective Combination?
Bagnato and his research partners will test a combination of drugs, delivery mechanisms and types of light to see which combinations are the most effective.
In addition, they will test another type of wavelength — ultrasound. This sonodynamic therapy is similar to photodynamic therapy except that it uses sound instead of light, the release said.
“When we insert certain drugs into the cancer cells, they become little reactors that create tiny explosions when hit by ultrasound waves,” Bagnato said. “We hope to combine both photodynamic and sonodynamic therapy to eliminate melanomas more completely, without the risk of regrowth and metastasis. It is my hope that this research can become the foundation for further specialized cancer research for pets and other animals at the VMBS.”
Researchers will collect skin cell samples from a herd of pigs in the new study. The pigs once belonged to Duane Kraemer, a now-retired VMBS senior professor who was instrumental in the creation of CC, the world’s first cloned cat.
“The pigs in this study are a kind that have a tendency to develop melanomas, but aren’t really affected by them,” Fridley said. “In fact, sometimes their melanomas regress on their own, which is one reason why they are important to study.”
Your Next Read: Don’t Back Down From the Hard Stuff in the Pork Industry
