An experimental vaccine for bone cancer in dogs could offer a road map for a human version of the treatment, researchers report.
More than 10 000 cases of bone cancer in dogs occur in the United States each year. But the disease is not common in humans, with only 800 to 900 cases a year. About half of those cases occur in children and teens.
Made from dog's own tumour
The new vaccine is made from a dog's own tumour and targets specific cancer cells and eliminates the need for chemotherapy, which can cause toxic side effects, according to the University of Missouri researchers.
"A vaccine is made out of the dog's own tumour for the dog's immune system to recognise," explained Jeffrey Bryan, a professor of oncology at the College of Veterinary Medicine. He is also director of the university's Comparative Oncology Radiobiology and Epigenetics Laboratory.
Dogs that received the vaccine had more than 400 days of remission, compared with about 270 days for dogs that received chemotherapy in a separate study by the US National Cancer Institute.
"The dogs received no chemotherapy and received only immunotherapy after their surgery. It's the first time that dogs with osteosarcoma [bone cancer] have experienced prolonged survival without receiving chemotherapy, which is really exciting," Bryan said in a university news release.
This treatment uses a dog's own lymphocytes, which "are immune cells that recognise where pathogens are hiding in the body and then kill the cells harbouring those pathogens," Bryan said.
"After we remove the tumour, we create a vaccine using the dog's tumour cells to stimulate anti-tumour lymphocytes," that are then transfused into the dog, he explained.
"These cells are activated and essentially really angry at whatever they are supposed to attack. When put back into the body, they should identify and destroy tumour cells. Ideally, this immune response would destroy every last tumour cell," Bryan said.
However, animal studies do not always pan out in humans.
The study was presented recently at the Veterinary Cancer Society Annual Conference in Louisville, Kentucky. Such research is considered preliminary until published in a peer-reviewed journal.
The team plans to continue its research with the goal of eventually conducting clinical trials of the vaccine therapy to treat bone cancer and other types of cancers in people.
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