MINNEAPOLIS — The goal of the Shine On project is to develop an effective way to detect and prevent canine hemangiosarcoma, a cancer of the blood vessels that often affects the heart and spleen. Researchers use a blood test to look for the cells responsible for establishing the disease then follow up with an experimental treatment that attacks those cells and prevents a tumor from developing.
The work is led by Jaime Modiano, professor of Oncology and Comparative Medicine in the Department of Veterinary Clinical Sciences at the University of Minnesota.
“This project began because of our relationship with the Golden Retriever Club,” Modiano said. “Members of that organization aren’t looking for another treatment option like chemotherapy, surgery or radiation that might extend a dog’s life, they want a transformational cure.”
During the first phase, the project enrolled both healthy dogs and those that had been diagnosed with HSA. Blood samples were tested from 125 dogs to refine a test developed in an earlier research project.
“In phase two we looked exclusively at dogs that had HSA,” Modiano said. “We will follow these dogs through any and all treatments. Some of the dogs are still living, so this part of the project is ongoing.”
Modiano said that phase three is the project’s Holy Grail.
“We’re now conducting routine blood tests on more than 200 healthy dogs older than six — currently only golden retrievers, Portuguese water dogs and boxers,” Modiano said. “We run the test then ask questions. If there’s no evidence of the target cells, how long does that remain true? If the cells are present, did the dog develop a tumor?”
HSA treatment and prevention
Dogs participating in testing are not required to visit the University of Minnesota. Their veterinarian takes the blood sample and sends it to researchers. If a dog does test positive for the target cells, however, they must go to the university to receive the preventative treatment.
“HSA is very common in dogs,” Modiano said. “We estimate tens of thousands of cases in the U.S. each year. There is an idea that the disease is more common in certain breeds than others, but that stems from imperfect registries. It can occur in any animal with blood vessels, but it’s most common in dogs. It also occurs most often in dogs older than 10, but we’ve seen it in a 9-week-old puppy.”
Modiano said the disease can be treated with traditional therapies, depending on how advanced the tumor is and where it is located. Surgery can be used to remove the visible tumor and chemotherapy may be effective in removing what can’t be seen. These measures might extend a dog’s life, but don’t provide a cure.
“Less than 50% of dogs with HSA survive four to six months and only about 10% will be alive one year after their diagnosis,” Modiano said. “Virtually every dog diagnosed with the disease will die from it.”
The same drug being tested to prevent HSA has also been used to treat dogs that have the disease. Modiano said that some of the dogs — 25-30% — did well for a long time after treatment.
“Malignant cells are the eggs that start the tumor,” Modiano added. “They need to build a home and make the environment comfortable. eBAT finds that home and burns it down. Those malignant cells have nowhere to go. Once a tumor develops, though, it’s like a fortified castle with a moat and sentries and it’s much harder to destroy.”
The treatment is administered over the course of a week. One injection each on Monday, Wednesday and Friday.
“That’s the simplicity and the magic,” Modiano said. “After treatment, the target cells go away and we’ve hopefully offered protection for some time or even for a lifetime. The study will follow enrolled dogs for the rest of their lives to track individual outcomes.”
A world that doesn’t fear cancer
“Part and parcel to this project is creating a world that doesn’t fear cancer” Modiano said. “Some people ask, ‘why not try to eliminate cancer?’ I don’t think that’s realistic. Cancer is a risk of life. Genes undergo mutations, and as long as there is life there will be cancer.”
Modiano said one advantage to working in comparative science is the ability to evaluate the entire animal kingdom. Every animal is susceptible to cancer, but the amount of risk varies widely. On average, though, animals have about a 5% risk of developing the disease.
“But in some species, including humans, dogs and cats, the cancer rate is much higher — approximately 25%,” Modiano said. “Two-hundred years ago, the average human lifespan was 35-40 years; three to five years for dogs and five to seven years for cats.
“Now humans live 80 years, dogs live 10 to 12 and cats can exceed 20 years. These are the only species that have broken the longevity barrier. In species that don’t often develop the disease, evolution has created cancer protections for their lifespan. That’s why younger animals don’t usually contract the disease. When dogs reach eight to 10 years of age, that protection begins to break down.”
Modiano said health care, hygiene and nutrition have successfully extended our lives and those of our domestic pets, but evolution hasn’t been able to keep pace.
“There are a few ways to approach this realization,” Modiano said. “One is to rejoice in the good we've done and celebrate a longer life expectancy. Another is to fear the ongoing risk of developing cancer. The more objective approach is to continue to explore what can we do about it: screen for and treat risk factors so cancer continues to become much less impactful.”