Oncology Consultation

My happy Christmas Dog!

What's the next step after receiving the bad news that your best friend has cancer? Well after crying your eyes out, you gather your wits and schedule an appointment with an oncologist. I recommend this even if you don't think you will pursue any further treatment. Even if your general practitioner is the greatest on the planet I still think the additional information you will gain from a visit to the oncologist is invaluable. They went through 4 more years of special training to become experts in this field and are the most up to date on the latest treatments. They may also know of a study going on that your pet may be eligible for. They will also give you a prognosis in months. Which you may want to hear and it may help guide your decision making process. Personally I am not a huge fan of the "months to live" statement because all dogs are different and that can give one a false sense of hope or despair. But it does give one an idea of the effectiveness of the various treatments.

In the case of osteosarcoma the most aggressive approach to treatment is amputation of the effected limb and injectable chemotherapy. This will buy your dog 10-12 months.

If your dog is not a good candidate for amputation, you can consider a limb spare procedure depending on where the tumor is. There is a surgical procedure where they remove the tumor and replace it with a plate and/or bone graft. There is also a special type of radiation called stereotactic radiosurgery that will kill the tumor. This type of radiation is only done in a few places. Colorado State and University of Florida are two, there may be more in the USA that I am not aware of. A limb spare procedure plus injectable chemotherapy will buy your dog 10-12 months.

Just amputation without chemotherapy gains an average of 3 months.

Palliative radiation is a type of radiation that just relieves the pain, but doesn't kill the tumor. Palliative radiation plus injectable chemotherapy plus a bisphosphonate (a drug that helps build bone strength) may give your dog about 9 months.

All these projections are based on a dog WITHOUT evidence of metastases in the lungs. Unfortunately when there is gross evidence on x-rays that there are nodules in the lungs you can subtract about 3-4 months from all these estimates.

So what to do? With Christmas coming there is going to be a delay no matter what procedure we choose.  I need some time to digest the information and make a decision. Until we decide on the next step I am controlling Cody's pain with the following drugs: Tramadol (a pain killer related to morphine), Previcox (a non-steroidal anti-inflammatory), and Gabapentin (a seizure medication that is thought to help with neurologic pain). Cody has also been wearing a pain patch of Fentanyl since his biopsy procedure. Fentanyl is 100 times stronger than morphine. He seems pretty comfortable with the patch on, but I hope I can do something more to treat the pain.

Cancer Returns

It has been a while since I updated Cody's blog because, well... you know the saying "no news is good news!" He had been cruising along without problems until September, 2012. In September he started having intermittent non-weight bearing lameness of his left hind leg. It would get better with chiropractic adjustments and laser therapy and then he would stop using the leg again. I took radiographs (x-rays) of his left stifle (knee) and chest in September and didn't see anything of note on the x-rays. I even had the chest films looked at by a radiologist. I did not have the stifle film looked at, which I regret now because it turns out there was a suspicious area present, even in September. Note - if your veterinarian recommends having the radiographs reviewed by a radiologist say yes! They might catch something your general practitioner missed.
In early December I took more x-rays because the problem was becoming more frequent and not resolving with any treatment or after adding on more pain medications.
Well, bummer of all bummers, this set of radiographs showed a suspicious area on his femur AND if that weren't bad enough, his chest x-rays showed nodules that were not there in September. Knowing that those sort of patterns on radiographs usually mean osteosarcoma I dissolved into a sobbing puddle of mush and just hugged my dog like the world was ending. Of course I held out some hope that the problem would be a lesser evil like a fungal infection or less aggressive cancer.

The tumor is the area that looks "moth-eaten" at his distal femur.

Cody had a bone biopsy done on December 11, 2012. The results were chondroblastic osteosarcoma, low grade. It isn't much reassurance that the tumor is "low grade." An osteosarcoma is an aggressive bone cancer and usually by the time we (veterinarians) identify it on radiographs there already is microscopic spread to the lungs. Cody is already showing nodules (small masses) in his lungs. The thing is, in his case, we can't be sure just by the radiographs that the nodules are metastases from his osteosarcoma. They could be recurrence of his previous lung cancer or they could be metastases from his osteosarcoma. Could we biopsy them? Well, it would be difficult and require a CT scan and probably wouldn't really change anything we do at this point.

You can make out small round densities (lighter areas) that are the nodules.