OBJECTIVE To determine survival times of selected dogs with metastatic (stage III) osteosarcoma, whether disease-free interval (DFI) was associated with survival time after diagnosis of stage III disease (ie, stage III survival time), and whether a survival benefit of metastasectomy existed.
DESIGN Retrospective case series with nested cohort study.
ANIMALS 194 client-owned dogs treated for histologically confirmed appendicular osteosarcoma from 1997 through 2009.
PROCEDURES Dogs were included if they had stage I or II osteosarcoma at the time of initial evaluation, had amputation of the affected appendage and ≥ 1 dose of chemotherapy afterward, and developed metastasis within the follow-up period or prior to death. Data collected from the medical records included signalment, primary tumor location, clinical and laboratory findings, whether metastasectomy was performed, and outcome. Various factors were examined for associations with outcome.
RESULTS Dogs that received no treatment for the metastasis had a median survival time between 49 and 57 days after diagnosis of stage III osteosarcoma. Duration of the preceding DFI had no association with this period. Metastasectomy alone was associated with a longer median stage III survival time (232 days) than no metastasectomy (49 days). Among all dogs identified as qualifying for pulmonary metastasectomy on the basis of < 3 pulmonary nodules visible on thoracic radiographs and a DFI > 275 days (n = 21), a survival advantage was also identified for those that actually received pulmonary metastasectomy (6).
CONCLUSIONS AND CLINICAL RELEVANCE Preceding DFI had no influence on survival time of dogs with stage III osteosarcoma. Metastasectomy was associated with an increase in survival time for selected dogs.
Objective—To evaluate the efficacy and toxicity of an alternating carboplatin and doxorubicin chemotherapy protocol in dogs with putative microscopic metastases after amputation for appendicular osteosarcoma and assess patient-, tumor-, and treatment-related factors for associations with prognosis.
Design—Retrospective case series.
Animals—50 client-owned dogs.
Procedures—Records of dogs that underwent amputation for appendicular osteosarcoma and received an alternating carboplatin and doxorubicin chemotherapy protocol were reviewed. Dogs had full staging and were free of detectable metastases prior to chemotherapy. Data on disease-free interval (DFI), survival time, and toxicoses were retrieved from medical records and owner or referring veterinarian communications.
Results—Median DFI was 202 days. Median survival time was 258 days. Twenty-nine (58%) dogs completed the protocol as planned, and the rest were withdrawn typically because of metastases or toxicoses. Grade 3 or 4 myelosuppression was reported in 9 of 50 (18%) dogs and grade 3 or 4 gastrointestinal toxicosis in 6 of 50 (12%) dogs. There were no chemotherapy-related fatalities. Univariate factors associated with significant improvement in DFI included tumor location (radius), receiving doxorubicin as the first drug, starting chemotherapy more than 14 days after amputation, and no rib lesions on preamputation bone scans. Multivariate factors associated with a significant improvement in survival time were tumor location (radius) and completing chemotherapy.
Conclusions and Clinical Relevance—Alternating administration of carboplatin and doxorubicin resulted in DFI and survival time similar to those reported for single-agent protocols. Clients should be counseled regarding the likelihood of toxicoses. Relevance of sequence and timing of starting chemotherapy should be further evaluated.
Objective—To assess survival time in dogs that underwent treatment for stage III osteosarcoma and evaluate factors affecting survival.
Design—Retrospective case series.
Animals—90 dogs with stage III osteosarcoma.
Procedures—Records in the osteosarcoma database at the Animal Cancer Center at Colorado State University from 1985 to 2004 were searched for dogs with metastatic disease at the time of evaluation. Dogs were included in the study if they had metastasis to any site and if treatment was initiated. A Kaplan-Meier survival analysis was performed, and the influences of age, sex, breed, primary tumor site, metastatic sites, and treatment on outcome were analyzed via log-rank analysis.
Results—Median survival time was 76 days, with a range of 0 to 1,583 days. No significant differences in survival times on the basis of age, sex, breed, or primary site were observed. Breeds and primary tumor sites were typical of those usually associated with osteosarcoma in dogs. Dogs treated palliatively with radiation therapy and chemotherapy had a significantly longer survival time (130 days) than dogs in all other treatment groups. Dogs treated with surgery alone had a significantly shorter survival time (3 days) than dogs treated with surgery and chemotherapy (78 days). Dogs with bone metastases had a longer survival time than dogs with soft tissue metastases.
Conclusions and Clinical Relevance—Treatment of dogs with stage III osteosarcoma can result in various survival times. Dogs with metastasis to bone and dogs that were treated palliatively with radiation and chemotherapy had the longest survival times.
Objective—To determine the incidence of regional
lymph node metastasis in dogs with appendicular
osteosarcoma and determine whether regional lymph
node metastasis was associated with shortened disease-free interval or survival time.
Animals—228 dogs with appendicular osteosarcoma
in which regional lymph nodes were examined histologically
at the time of limb amputation.
Procedure—Information collected from the medical
records included signalment; affected site; initial
serum alkaline phosphatase activity; whether treatment
involved adjuvant chemotherapy and, if so,
chemotherapeutic agents administered and number of
treatments; disease-free interval; and survival time.
Results—10 (4.4%) dogs had histologic evidence of
regional lymph node metastasis at the time of amputation.
Median disease-free interval for dogs without
regional lymph node metastasis (238 days; range, 0 to
1,067 days) was significantly longer than median disease-free interval for dogs with regional lymph node metastasis (48 days; range, 2 to 269 days). Median
survival time for dogs without lymph node metastasis
(318 days; range, 20 to 1,711 days) was significantly
longer than median survival time for dogs with lymph
node metastasis (59 days; range, 19 to 365 days).
Conclusions and Clinical Relevance—Results suggest
that regional lymph node metastasis is rare in dogs with
appendicular osteosarcoma but that dogs with lymph
node metastasis have a poorer prognosis than do dogs
without. (J Am Vet Med Assoc 2005;226:1364–1367)
Objective—To describe the biological behavior, clinical outcome, and prognostic factors of osteosarcoma of the maxilla, mandible, or calvarium in dogs.
Design—Retrospective case series.
Animals—183 client-owned dogs with osteosarcoma of the maxilla, mandible, or calvarium.
Procedures—Medical records for dogs treated for osteosarcoma of the maxilla, mandible, or calvarium from 1986 through 2012 were reviewed. Dogs with a histopathologic diagnosis of osteosarcoma and treated for a primary tumor arising from these bones of the head were included.
Results—Mean age was 9.3 years, and body weight was 31.8 kg (70.0 lb). Most dogs (124/183 [67.8%]) were purebred, and the most common primary tumor site was the maxilla (80 [43.7%]). Treatments included palliative medical treatment only (11/183 [6.0%]), coarsely fractionated radiation therapy (RT; 12 [6.6%]), fractionated or stereotactic RT (18 [9.8%]), surgery (135 [73.8%]), and both surgery and fractionated RT (7 [3.8%]). Eighty-three (45.4%) dogs received adjuvant chemotherapy. Local recurrence or progression occurred in 80 of 156 (51.3%) dogs, and 60 of 156 (38.5%) dogs developed distant metastases. Median survival time for all dogs was 239 days. Dogs that underwent surgery had a median survival time of 329 days. Histologically tumor-free surgical margins were associated with significantly decreased hazards of progression or recurrence (hazard ratio [HR], 0.4) and death (HR, 0.5). Dogs with osteosarcoma of the calvarium had a significantly greater hazard of local recurrence or progression (HR, 2.0).
Conclusions and Clinical Relevance—In this study, tumor excision in dogs with histologically tumor-free margins resulted in better local control and longer survival time than did other treatment types.
Objective—To evaluate clinical characteristics, outcome, and prognostic variables in a cohort of dogs surviving > 1 year after an initial diagnosis of osteosarcoma.
Design—Retrospective case series.
Animals—90 client-owned dogs.
Procedures—Medical records for an 11-year period from 1997 through 2008 were reviewed, and patients with appendicular osteosarcoma that lived > 1 year after initial histopathologic diagnosis were studied. Variables including signalment, weight, serum alkaline phosphatase activity, tumor location, surgery, and adjuvant therapies were recorded. Median survival times were calculated by means of a Kaplan-Meier survival function. Univariate analysis was conducted to compare the survival function for categorical variables, and the Cox proportional hazard model was used to evaluate the likelihood of death > 1 year after diagnosis on the basis of the selected risk factors.
Results—90 dogs met the inclusion criteria; clinical laboratory information was not available in all cases. Median age was 8.2 years (range, 2.7 to 13.3 years), and median weight was 38 kg (83.6 lb; range, 21 to 80 kg [46.2 to 176 lb]). Serum alkaline phosphatase activity was high in 29 of 60 (48%) dogs. The most common tumor location was the distal portion of the radius (54/90 [60%]). Eighty-nine of 90 (99%) dogs underwent surgery, and 78 (87%) received chemotherapy. Overall, 49 of 90 (54%) dogs developed metastatic disease. The median survival time beyond 1 year was 243 days (range, 1 to 1,899 days). Dogs that developed a surgical-site infection after limb-sparing surgery had a significantly improved prognosis > 1 year after osteosarcoma diagnosis, compared with dogs that did not develop infections.
Conclusions and Clinical Relevance—Results of the present study indicated that dogs with an initial diagnosis of osteosarcoma that lived > 1 year had a median survival time beyond the initial year of approximately 8 months. As reported previously, the development of a surgical-site infection in dogs undergoing a limb-sparing surgery significantly affected prognosis and warrants further study.
Objective—To examine the effect of adjuvant doxorubicin
chemotherapy on outcome in dogs with highgrade
(grade 3) soft tissue sarcomas (HGSTSs).
Design—Retrospective case series.
Procedures—Medical records of dogs with HGSTSs
were reviewed. Dogs treated with surgery alone or
receiving single-agent doxorubicin chemotherapy
postoperatively were included in the study. Owners
and referring veterinarians were contacted for followup
information. Slides from histologic sections were
reviewed to confirm the diagnosis of HGSTSs. Cases
in which follow-up examination was not performed
and radiation therapy or chemotherapy other than
doxorubicin was administered were excluded.
Results—39 dogs met inclusion criteria. Twenty-one
dogs received adjuvant doxorubicin. Tumor-, patient-,
and treatment-related variables were not significantly
associated with measured outcomes including local,
metastatic, and overall disease-free intervals as well
as survival time. Overall median disease-free interval
was 724 days with a median survival time of 856 days
for all dogs.
Conclusions and Clinical Relevance—Adjuvant doxorubicin-based chemotherapy did not benefit this population of dogs with HGSTSs. Outcome for visceral HGSTSs
was similar to that of nonvisceral HGSTSs in these cases.
(J Am Vet Med Assoc 2005;227:1442–1448)
To describe complications and outcomes of dogs undergoing unilateral thyroidectomy for the treatment of thyroid tumors.
156 dogs undergoing unilateral thyroidectomy for a naturally occurring thyroid tumor.
Dogs that underwent a unilateral thyroidectomy in 2003 through 2015 were included in a multi-institutional retrospective study. For each dog, information gathered through evaluation of electronic and paper records included perioperative complications, short-term outcome (survival to discharge from the hospital vs nonsurvival), and long-term outcome (survival time).
In the perioperative period, complications occurred in 31 of the 156 (19.9%) dogs; hemorrhage was the most common intraoperative complication (12 [7.7%] dogs). Five of 156 (3.2%) dogs received a blood transfusion; these 5 dogs were among the 12 dogs that had hemorrhage listed as an intraoperative complication. Immediately after surgery, the most common complication was aspiration pneumonia (5 [3.2%] dogs). One hundred fifty-three of 156 (98.1%) dogs that underwent unilateral thyroidectomy survived to discharge from the hospital. One hundred-thirteen dogs were lost to follow-up; from the available data, the median survival time was 911 days (95% confidence interval, 704 to 1,466 days).
CONCLUSIONS AND CLINICAL RELEVANCE
Results indicated that unilateral thyroidectomy in dogs with a naturally occurring thyroid tumor was associated with a perioperative mortality rate of 1.9% and a complication rate of 19.9% and that hemorrhage and aspiration pneumonia were the most common complications. Long-term survival of dogs undergoing unilateral thyroidectomy for the treatment of thyroid tumors was not uncommon.