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Treating dogs with breast cancer, and aiding research for humans

The lady was a tramp. That was part of her charm. Scarred, a tad surly. An alpha female if there ever was one. Duchess was her name. Liz Hardt, a softie for a tough dog, was smitten.

Veterinary surgeon Chloe Wormser examines Frosting at the University of Pennsylvania Veterinary Hospital.
Veterinary surgeon Chloe Wormser examines Frosting at the University of Pennsylvania Veterinary Hospital.Read moreJESSICA GRIFFIN / Staff Photographer

The lady was a tramp. That was part of her charm.

Scarred, a tad surly. An alpha female if there ever was one. Duchess was her name. Liz Hardt, a softie for a tough dog, was smitten.

"I fell in love with her immediately," said Hardt, a veterinary nurse. "She was a big, bad dog."

But there was something else. A kind of bond.

Hardt was a cancer survivor. Duchess was, too.

The pair met through a program that gives new meaning to the saying, "Who rescued whom?"

Through the Shelter Canine Mammary Tumor Program, breast tumors are removed from homeless dogs that would otherwise go untreated and quite likely die. The dogs are then put up for adoption.

At the same time, the dogs and their tumors are contributing to research on breast cancer in humans.

"The dogs can really help us understand breast carcinogenesis," said Karin Sorenmo, who founded and directs the program at the University of Pennsylvania's Ryan Veterinary Hospital.

Shelter dogs turn out to be excellent subjects for the study of how breast cancers form.

For one thing, dogs have 10 mammary glands, compared with humans' two. Because spaying makes breast cancer less likely, homeless dogs are more likely to have it.

"We've had dogs that have had 30 different mammary tumors," said Sorenmo, a Penn Vet professor of oncology.

Her team can study molecular changes in tumors at various stages, and how they are affected by different aspects of the surrounding body. The goal is to better understand how and why breast cancer develops.

If they can, doctors would be "better able to predict which tumors warrant early, aggressive treatment and which are unlikely to spread," sparing patients unnecessary toxic therapies, said Susan Volk, a Penn veterinary surgeon and researcher who joined the project two years ago.

The team says it expects to present data for its first two publications soon. One study examined patterns in connective tissue that can be seen on a biopsy. Another tracked gene activity in dogs with multiple tumors.

"Dogs actually have a lot of similarities to humans," said Olga Troyanskaya, a Princeton University professor of genomics and computer scientist who has worked with Sorenmo on the project since it began in 2009.

Estrogen plays a role in the development of both human and canine mammary tumors. People and dogs often share living environments, said Troyanskaya, whose work at Princeton primarily involves human data.

And shelter dogs are better research subjects than laboratory mice. Given the rodents' limited life spans, cancer must be induced. The dogs have developed it naturally, like humans.

At Penn's Abramson Cancer Center, oncologist Susan Domchek called the canine program "an extraordinary initiative" to link human and veterinary medicine.

"This project enables us to gain insights regarding the molecular sequence of events in breast cancer in a way that is challenging in our human patients," said Domchek, who directs a group that focuses on the BRCA gene mutations that can put women at high risk of developing breast cancer.

That is the kind of potential that Sorenmo and Troyanskaya speak passionately about. But that is not what brought them together.

It all started with a dog.

"I had a German shepherd who was like my baby. She had cancer," Troyanskaya said. "We were told we had a week. She went from perfectly fine to 'a week.' I said, 'I don't think so.' "

She started asking around about top veterinary oncologists. That led her to Sorenmo.

The shepherd made it well past a week, and the two scientists became partners.

Cancer has taken people dear to both of them. And as dog lovers, they believe in the second chances the program provides.

The help is not open-ended. The tumors are removed surgically - the equivalent of a mastectomy. If new mammary tumors develop, the program will perform additional surgery free of charge.

While chemotherapy is not advised in all cases of canine cancer, it can sometimes extend lives. But the shelter program does not have the money to provide free chemo.

Still, it has helped many dogs find futures that they would not have otherwise had. Of the 200 or so dogs that have been treated through the program, about 30 percent have been adopted, and most of the others have gone on to long-term foster homes, Sorenmo said.


A sweet-natured beagle named Frosting was Patient No. 196, referred by the Pennsylvania SPCA. The day before her surgery last month, she was at Penn for an exam. As surgeon Chloe Wormser felt gently for her tumors, a cooperative Frosting, about age 5, kept mostly still, save for wagging her tail.

The surgery went well, and she soon returned to her foster home, available for adoption.

Next patient: Midnight, 6, a black Great Dane, who was in to get stitches out. She was referred by J & Co Rescue in , Gloucester County. She had been living with the Franklinville rescue's Marisue Kendall and her family; her three daughters were more than happy to oversee Midnight's suture removal.

"She doesn't quite understand her size," Kendall explained, laughing, as the long, lean, 100-pound dog tried to cuddle with Ella, her 8-year-old daughter.

Local animal shelters and rescues are avid supporters of the program.

"It's been wonderful for us to participate," said Grace Kelly Herbert, whose Finding Shelter rescue in Norristown has had six dogs treated. "The program has offered the help the dogs need and, even better, it helps people."

One of those dogs is Heidi, a miniature dachshund getting on in years. She had been a puppy mill dog - as many as 14 litters in about 12 years - and after her last two litters were stillborn, was going to be euthanized.

Abby and David Rankin came across her through a shelter event and took her to their Bala Cynwyd home for a trial run despite misgivings about her age and medical history.

That was almost two years ago.

"She's such an awesome dog," said Abby, a child counselor.

Penn provides free periodic checkups as part of the program. So far, so good.

"Nothing is for sure. For us it was worth it, giving her a good life," Abby said. "And she is doing so much for humans in their research."


Liz Hardt and Duchess met on the job.

Back in 2014, Hardt, the Penn Vet nurse, spotted this bruiser of a mastiff when she first came in for the mammary program. An 11-pound tumor was removed from the 100-pound dog.

"I knew she would struggle finding a home because she was older and aggressive, a large breed," said Hardt, who works in oncology.

But Hardt, who as a teenager survived stage 4 Hodgkin's lymphoma, saw something else, too.

"I just knew she was a good dog, and she deserved a chance."

So Hardt, 29, took Duchess, about age 6, home to Roxborough. She promised her husband it would be only temporary.


Duchess was a good dog. She got along well with their corgi and shepherd, barked at mailmen, chased cats, and loved to go on hikes and runs. Knowing that the dog's type of cancer was likely to metastasize, the couple decided to pay for chemo.

But early this year, they learned the cancer was back, this time in her liver and a lung. She had surgery and seemed to be doing well.

Several months later, however, Duchess' head had taken on an odd tilt. Her coordination was off. The cancer had returned again - this time in her brain.

On July 8, after two seemingly good years, Hardt and her husband decided to say good-bye to Duchess before she suffered. The doctors and nurses who had taken care of her, along with the couple, were by the dog's side as she was euthanized.

She is missed - "a big, empty hole in our life," Hardt said.

And adopting her in the first place?

"I would say, 100 percent, it was the best decision I ever made."