Wednesday, December 7, 2016
New canine cancer treatment protocol give hope for human cases.
New canine cancer treatment protocol gives hope for human cases. Flyer, a 70-pound golden retriever, lies patiently on her left side on an examination table as technicians scurry around, placing little sandbags on her legs and neck to keep her still. She's getting chest X-rays to answer a critical question: Has a deadly bone cancer spread to her lungs? When the session is over, Martha MaloneyHuss, a veterinarian at the University of Pennsylvania's Ryan Veterinary Hospital, glances at the images. "I don't see anything hugely obvious," she says, "but we'll see what the radiologist says." Oblivious to the good news, Flyer hops down the hall on three legs, eager to find her owner. After the 8-year-old retriever began limping last year, she was diagnosed with osteosarcoma, a painful, aggressive cancer that often strikes Great Danes, Irish wolfhounds and other large breeds. At Penn Vet, she got the standard treatment: One of her left legs was amputated, and she underwent chemotherapy. Yet even as she adjusted to chasing squirrels, her prognosis was bleak. Most dogs die in about a year when the disease resurfaces in the lungs. The Penn vets recommended an experimental vaccine designed to prevent or delay the cancer's return; Flyer's owner was enthusiastic. The dog got three intravenous doses as part of a clinical trial and now returns to Penn periodically for X-rays. "Every day I pray that she will stay cancer-free," said her owner, Bob Street, who lives in Mullica Hill, New Jersey. "And that this treatment will work for other dogs and for people."Flyer is part of a burgeoning field called "comparative oncology." It focuses on finding new ways to treat cancer in pets, mostly dogs, in an effort to develop innovative treatments for people and animals. The growing interest in dogs reflects researchers' frustration with the standard approach to developing cancer treatments: testing them in lab animals, especially mice. Mice don't normally get cancer - it must be induced - and the immune systems in many strains of lab mice have been altered. That makes them especially poor models for immunotherapy, a rapidly growing field of medicine that directs patients' own immune systems to fight their cancer. Dogs, on the other hand, get cancer naturally, just as people do, and have intact immune systems. more