When a new Tripawds member visits our Discussion Forums to find answers about canine bone cancer, if we don't have the information, we'll ask a professional. During our visit with Dr. Johnny Chretin, head of oncology at VCA Animal Hospital West Los Angeles Oncology Center, we wanted to know a little more about chondrosarcoma in dogs.

Chondrosarcoma in Dogs

According to the American College of Veterinary Surgeons, chondrosarcoma is the second most common primary tumor of the axial and appendicular skeleton, after osteosarcoma. Only five to 10 percent of all primary canine bone tumors are of this type. However, compared to osteosarcoma, chondrosarcoma is uncommon. Like osteosarcoma, chondrosarcoma is a metastatic disease that spreads.

Chondrosarcoma is often found in cartilage of flat bones like the ribs, but sometimes presents itself as apendicular disease on thigh and leg bones. At first glance, it looks like osteosarcoma but it's a slower moving disease. The tumors are much more resistant to chemotherapy than other types. As a result, surgery is the primary way to treat the disease as long as the tumors are in one part of the body and haven't metastasized.

As Dr. Chretin discusses in the following video, chemotherapy is "a long shot" and has not been shown to be as effective in treating it.

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Chemotherapy and Chondrosarcoma

Like many cancers, chondrosarcoma behaves similarly in dogs and people. And unfortunately when it comes to treating it with chemotherapy, the success rate is typically less than 20 percent. That may sound positive, but in the oncology world, if a therapy doesn't work for patients at least 30 to 40 percent of the time, it's not considered to be effective or a good option.

Dr. Chretin states that there haven't been any good, large scale studies done on dogs with chondrosarcoma who were treated with chemotherapy. However, plenty of studies done with humans indicate that the odds of success are just as slim for dogs.

“Unless there is a significant reason why we should give them chemotherapy,” says Dr. Chretin, “it's hard to recommend it (chemo), because it doesn't work in people and based on what we know, it's probably not going to work for the majority of dogs.”

Although Dr. Chretin doesn't recommend chemotherapy as a primary treatment for chondrosarcoma, if the dog isn't a candidate for surgery, the tumor can be treated with radiation therapy to alleviate pain. However Dr. Chretin cautions clients to remember that “we're not treating the tumor, just treating what the tumor is doing to the patient.”

Stay Tuned for More Canine Cancer Oncology News

This is the latest in a series of video interviews with Dr. Chretin at VCA Animal Hospital West Los Angeles. Stay tuned for additional interview clips with Dr. Chretin that offer informative advice about canine bone cancers, such as:

• Cisplatin and Doxorubicin Side Effects in Dogs
• Bone tumor removals: do they promote or prolong metastasis?
• Does the location of a primary tumor impact cancer development?
• Thoughts about combining holistic and traditional oncology therapies

Tripwds sends sincere thanks to Dr. Chretin and his helpful staff for allowing us to bring this impawtant information to you!

Recommended Reading:

Vet Info: Chondrosarcoma in Dogs

American College of Veterinary Surgeons: Bone Tumors in Cats and Dogs

Tripawds Discussion Forums: Chondrosarcoma

Tripawds News Blog: Bisphosphonates; When Amputation Isn't an Option

VCA Animal Hospitals: Bone and Joint Tumors in Dogs