Page 1394 - Clinical Small Animal Internal Medicine

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1332 Section 11 Oncologic Disease

levels believed to be required for the beneficial effects of CSA had a MST of six years, grade II MST approximately
VetBooks.ir ABPs against neoplastic bony lesions. Pamidronate is the half as long, and grade III CSA only associated with a
MST of 0.9 years. Metastatic rate was similarly depend-
most commonly used ABP in veterinary medicine as it is
the most reasonably priced. Infusions of pamidronate
III dogs developing pulmonary metastasis. Prognosis for
were shown to be well tolerated in dogs and resulted in ent upon grade, with 0%, 31%, and 50% of grade I, II, and
increased tumor bone mineral density and pain reduc- appendicular HSA is less favorable than other diseases,
tion for four months in 28% of dogs with osteosarcoma. due to the extremely high metastatic potential.
When used in combination with palliative radiation Variable prognoses have been described for axial OSA
therapy, pamidronate also appeared to improve limb based on location and type of treatment. Overall, small
function when compared with radiation therapy alone. dogs have a more favorable prognosis than large dogs,
Another ABP, zoledronate, is much more expensive at irrespective of location. Mandibular OSA has a better
this time; zoledronate appears superior to pamidronate prognosis than other locations; when complete surgical
in that 50% of dogs achieved pain alleviation for greater margins are achieved after surgical excision, a 70% one‐
than four months in one study. year survival rate is reported. Negative prognostic indi-
cators include incomplete surgical resection, larger dogs,
elevated ALP, and large tumors. Maxillary OSA has a
Prognosis reported MST of approximately five months.
As with appendicular tumors, CSA of the axial skeleton
For dogs with appendicular osteosarcoma that are has a significantly better prognosis than OSA. Nasal CSA
treated with amputation alone, the MST is less than six has a low metastatic rate and reported MST of 210–580
months. Amputation followed with chemotherapy sig- days. Rib CSA treated with surgical excision has a MST of
nificantly improves prognosis, with MST approximately 1080 days. Grade, location, and completeness of surgical
twice as long and between 25% and 62% of dogs alive at excision have all been noted as possible prognostic indi-
one year. Longer survival times are associated with peri- cators; however, only small case numbers have been eval-
osteal or parosteal OSA, small stature, and dogs develop- uated. Similarly, MLO has moderate metastatic potential
ing surgical site infections after a limb‐sparing surgery. but improved overall survival times when compared to
Negative prognostic indicators include elevated serum OSA. Mandibular location, low histologic grade, and
ALP, dogs developing OSA when they are less than complete surgical excision were positive prognostic fac-
5 years old, metastatic disease (bone, lymph node or tors. MST after surgery ranges from 630 to 797 days, with
lung), increased tumor necrosis, proximal humeral loca- median time to metastasis between 420 and 542 days.
tion, and larger tumor size. Amputation for cats with Prognosis associated with joint tumors is variable
appendicular osteosarcoma is often curative, although depending on type of tumor and whether complete exci-
metastasis can occur. sion is possible. Synovial cell sarcomas treated with com-
Chondrosarcoma has better survival times compared plete excision may have a MST of greater than two years
to OSA, with histologic grade the most important prog- with surgery alone. Histiocytic disease typically exhibits
nostic factor. After amputation alone, dogs with grade I a much more aggressive clinical course.