Results of surgical treatment in 65 dogs with osteosarcoma.

Clinical and necropsy findings were obtained from case records for 65 dogs treated surgically for osteosarcoma at the University of Pennsylvania Small Animal Hospital between July, 1952, and July, 1973, inclusive. The median age of the dogs was 6 years. There were 39 males and 26 females. All but 5 of the 65 dogs weighed more than 16 kg. Sixty-two of the osteosarcomas arose from the limbs and 3 from the ribs. The median duration of presurgical clinical signs was 6 weeks, with a range of 1 day to 24 weeks. There were no statistical correlations between the postsurigical survival times and the age, sex, or breed of the dog, the site of the osteosarcoma, or the duration of the presurgical clinical signs. Of the 40 dogs with known lung metastases, 11 also had hypertrophic pulmonary osteoarthropathy. The median survival time was 18 weeks, with a range of 3 to greater than 578 weeks. Twenty-six percent were alive 6 months potoperatively, 13.8% were still alive at 9 months, and 10.7% survived more than 1 year. The total median duration of the disease was 24 weeks (range, 8 greater than 578 weeks).     

Hemimaxillectomy for the treatment of oral tumors in 69 dogs.

Hemimaxillectomy was performed in 69 dogs for the treatment of benign or malignant maxillary tumors. Eighteen dogs with ameloblastomas had a median disease-free interval of 21.5 months (range, 1 to 76 months), with a 72% 1-year survival time. There was recurrence in three dogs, with metastasis after malignant transformation in one of them. Based on calculated survival curves, seven dogs with squamous cell carcinoma had a median survival time of 19.2 months (range, 2 to 24 months), with a 57% 1-year survival time. There was local recurrence in two dogs. Twenty-three dogs with melanoma had a median survival time of 9.1 months (range, 1 to 46 months), and a 27% 1-year survival time. Twelve dogs died or were euthanatized because of recurrence or metastases. Fifteen dogs with fibrosarcoma had a median survival time of 12.2 months. Eight dogs died or were euthanatized because of recurrence or metastases. Six dogs with osteosarcoma had a median survival time of 4.6 months (range, 1 to 12.5 months), with a 17% 1-year survival time. Five dogs died or were euthanatized for recurrence or metastases. Tumor size or location and type of partial maxillectomy performed did not affect survival.     

Results of Partial Mandibulectomy for the Treatment of Oral Tumors in 142 Dogs

Partial mandibulectomy was performed for the treatment of benign or malignant oral tumors in 142 dogs. Forty-two dogs with a benign tumor (ameloblastoma) had a 22.5 month (range, 6 to 74 months) median disease-free interval, with a 97% 1-year survival rate; there was local recurrence in one dog. Twenty-four dogs with squamous cell carcinoma had a disease-free interval of 26 months (range, 6 to 84 months), with a 91% 1-year survival rate; recurrence and metastasis developed in two dogs and metastatic disease in one dog. Based on survival curves, 37 dogs with a melanoma had a median survival time of 9.9 months (range, 1 to 36 months), with a 21% 1-year survival rate; 20 dogs died or were euthanatized for recurrent or metastatic disease. Twenty dogs with osteosarcoma had a median survival time of 13.6 months (range, 3 to 28 months), with a 35% 1-year survival rate; nine dogs died or were euthanatized for recurrent or metastatic disease. Nineteen dogs with fibrosarcoma had median survival time of 10.6 months (range, 3 to 32 months), with a 50% 1-year survival rate; 12 dogs died or were euthanatized for recurrent or metastatic disease. Results of this and previous studies demonstrated that partial mandibulectomy was effective in prolonging survival and decreasing recurrence for squamous cell carcinoma and ameloblastoma. Progressive disease and corresponding low survival times were common in dogs with melanoma, osteosarcoma, and fibrosarcoma. There were no differences in survival times or the progression of disease among five partial hemimandibulectomy procedures. The high rates of recurrence and metastasis in dogs with these tumors suggest a need for evaluation of ancillary chemotherapy and local radiation therapy to decrease the prevalence of progressive disease.     

Canine Osteosarcoma

Osteosarcoma was diagnosed in 38 dogs. Thirty-six tumors originated from the appendicular skeleton and two from the axial skeleton. Nineteen of the dogs were treated with amputation alone, and 19 were treated with amputation and adjuvant chemotherapy consisting of doxorubicin and cisplatin. The 36 dogs with appendicular osteosarcoma had complete amputation of the affected limb, whereas the two dogs with osteosarcoma of the axial skeleton had an en bloc resection. The mean survival of the 19 dogs treated with amputation alone was 218 days (median, 175 days). Ten dogs were alive at 6 months and four survived 1 year. None of the dogs survived longer than 16 months. Radiographic lesions consistent with metastatic osteosarcoma were seen after surgery in the nine dogs in which radiographs were taken. The mean survival of the 19 dogs treated with amputation and chemotherapy was 415 days (median, 300 days). Drug toxicity was not observed. Fifteen dogs were alive at 6 months, seven dogs were alive at 1 year, 5 dogs were alive at 2 years, and two dogs were alive at 3 years or longer. One dog is alive and well at 25 months. Radiographic lesions suggestive of metastatic osteosarcoma developed in the other 18 dogs. The 19 dogs treated with amputation and chemotherapy had significantly longer survival times than the dogs treated with amputation alone.     

Use of cisplatin for treatment of appendicular osteosarcoma in dogs

Nineteen dogs were treated for osteosarcoma of the appendicular skeleton. Eleven dogs treated by amputation and adjunctive cisplatin chemotherapy had a significantly longer (P less than 0.003) median survival time of 43 weeks (range, 20 to 108 weeks) than did 8 dogs whose median survival time was 14.5 weeks (range, 8 to 46 weeks) after amputation alone. All 11 dogs given cisplatin were evaluated for signs of drug toxicosis. Transient episodes of vomiting were recorded in 9 of 11 dogs. Additional toxic effects included gradual decreases in endogenous creatinine clearance in 3 dogs and thrombocytopenia in 1 dog. On the basis of prolonged survival times and minimal adverse effects, we concluded that cisplatin has promise as an effective and relatively nontoxic agent, when combined with amputation, for treatment of dogs with osteosarcoma of the appendicular skeleton.     

Evaluation of survival times after limb amputation, with and without subsequent administration of cisplatin, for treatment of appendicular osteosarcoma in dogs: 30 cases (1979-1990).

Appendicular osteosarcoma was diagnosed in 30 dogs. Fifteen dogs were treated by limb amputation alone, and 15 dogs were treated by limb amputation followed by 2 doses of cisplatin given IV approximately 2 and 7 weeks after limb removal. Mean survival time after limb amputation alone +/- SD was 190 +/- 138 days (median, 168 days); 7 dogs survived longer than 6 months, and 3 dogs survived more than 1 year. Fourteen of 15 dogs treated by amputation and administration of cisplatin survived a mean of 315 +/- 158 days (median, 290 days) after amputation, and 1 dog was still alive at 1,095 days; 13 dogs survived longer than 6 months and 5 dogs survived more than 1 year. Survival time was significantly (P less than 0.05) greater in dogs given cisplatin.     

Primary thoracic wall tumours of mesenchymal origin in dogs: a retrospective study of 46 cases

Forty-three of the chest wall tumours in 46 dogs were malignant; five had metastases apparent at the time of presentation, five more had metastases discovered intraoperatively. Surgical resection of the tumours was associated with a significantly better outcome than conservative management. The median survival times after surgery for dogs with osteosarcoma was 17 weeks, for dogs with fibrosarcoma it was 26 weeks and for dogs with chondrosarcoma it was 250 weeks. En bloc excision of primary tumours affecting the chest wall was associated with minimal morbidity, but long-term survival was limited by distant metastases, primarily to the lungs. The tumours recurred in only three dogs. Early, radical surgical excision is recommended in the management of tumours of the chest wall. The prognosis depends on the histologic type of tumour and a histological diagnosis is mandatory before excision.     

Oncologic outcome after curative-intent treatment in 39 dogs with primary chest wall tumors (1992-2005)

Objective— To describe the clinical features and determine oncologic outcome and prognostic factors for dogs with primary tumors of the osseous chest wall. Study Design— Historical cohort. Animals— Dogs (n=39) with spontaneous tumors involving the chest wall. Methods— Medical records were reviewed for dogs with rib and/or sternal tumors treated by chest wall resection and reconstruction. Signalment, preoperative clinical features, reconstruction technique, and oncologic outcome (local tumor recurrence, metastasis, and survival time) were determined from medical records and by telephone contact with owners and referring veterinarians. Oncologic outcome and prognostic factors were determined using Kaplan–Meier survival analysis and Cox proportional hazards. Logistic regression was used to determine if increased serum alkaline phosphatase (ALP) concentration was associated with tumor type. Results— Of the 39 dogs with tumors arising from the chest wall, 25 had osteosarcoma, 12 had chondrosarcoma, and 2 dogs had hemangiosarcoma. Median survival time (MST) for dogs with rib osteosarcoma was 290 days. Increased activity of total ALP significantly decreased survival in dogs with osteosarcoma (210 days versus 675 days, P=.0035). MST for dogs with rib chondrosarcoma was not reached (mean 1301 days) and survival was significantly greater than all other types of rib tumors (P=.0321). Conclusion— Rib tumors should be resected with wide margins to decrease the risk of incomplete excision, because local tumor recurrence has a significant impact on the survival time. The prognosis for dogs with rib chondrosarcoma is very good, but guarded for other types of tumors. Clinical Relevance— Osteosarcoma and chondrosarcoma are the most common primary tumors of the chest wall. Prognosis for dogs with primary rib chondrosarcoma is very good with surgery alone, but surgery and adjunctive chemotherapy is recommended for dogs with primary rib osteosarcoma and the prognosis remains guarded.     

Incidence and prognostic importance of lymph node metastases in dogs with appendicular osteosarcoma: 228 cases (1986-2003)

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. DESIGN: Retrospective study. 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.     

Evaluation of survival time in dogs with stage III osteosarcoma that undergo treatment: 90 cases (1985-2004)

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.     

Treatment of canine appendicular osteosarcoma using cobalt 60 radiation and intraarterial cisplatin.

Twelve dogs with appendicular osteosarcoma were treated with 24-40 Gy of cobalt 60 radiation and two doses of intraarterial cisplatin. Improvement in limb function occurred in four dogs, and three dogs, which had only mild initial lameness, had no worsening of their lameness post-treatment. In nine dogs in which local control was evaluable, eight had local failure, with the median (95% CI) duration of local control being 5.9 (4.6, 6.7) months. Two dogs had metastatic disease before therapy, and an additional nine dogs had metastatic disease at a median time of 6.4 months. Pathologic fracture was present in four dogs; two fractures occurred before treatment and two were documented at the time of tumor recurrence. Median (95% CI) survival time for all 12 dogs was 4.9 (3.4, 6.8) months. Excluding the two dogs with preexisting metastatic disease, median survival time was 6.7 months. Three dogs survived longer than 1 year. This mode of therapy was well tolerated and may be considered an alternative to amputation or limb-sparing surgical procedures in selected dogs with appendicular osteosarcoma.     

Treatment of Canine Appendicular Osteosarcoma Using Cobalt 60 Radiation and Intraarterial Cisplatin

Twelve dogs with appendicular osteosarcoma were treated with 24–40 Gy of cobalt 60 radiation and two doses of intraarterial cisplatin. Improvement in limb function occurred in four dogs, and three dogs, which had only mild initial lameness, had no worsening of their lameness post-treatment. In nine dogs in which local control was evaluable, eight had local failure, with the median (95% CI) duration of local control being 5.9 (4.6, 6.7) months. Two dogs had metastatic disease before therapy, and an additional nine dogs had metastatic disease at a median time of 6.4 months. Pathologic fracture was present in four dogs; two fractures occurred before treatment and two were documented at the time of tumor recurrence. Median (95% CI) survival time for all 12 dogs was 4.9 (3.4, 6.8) months. Excluding the two dogs with preexisting metastatic disease, median survival time was 6.7 months. Three dogs survived longer than 1 year. This mode of therapy was well tolerated and may be considered an alternative to amputation or limb-sparing surgical procedures in selected dogs with appendicular osteosarcoma.     

Nonangiogenic and nonlymphomatous sarcomas of the canine spleen: 57 cases (1975-1987)

The case records of and histopathologic findings in 57 dogs with nonangiogenic and nonlymphomatous splenic sarcomas were reviewed. Splenic neoplasms in these dogs included leiomyosarcoma, fibrosarcoma, undifferentiated sarcoma, liposarcoma, osteosarcoma, chondrosarcoma, myxosarcoma, rhabdomyosarcoma, and fibrous histiocytoma. The clinical signs associated with splenic sarcoma included anorexia or decreased appetite, abdominal distention, polydipsia, lethargy, vomiting, weight loss, and weakness. An abdominal mass was detected in 86% of the dogs by use of abdominal palpation (63%), and/or abdominal radiography (74%). The diagnosis was based on histopathologic findings in the spleen. Abdominal exploratory surgery was performed on 43 of the 57 dogs. Twenty-seven dogs were treated by splenectomy, and 16 were euthanatized at the time of surgery because of widespread metastatic lesions. Of the 14 dogs on which surgery was not performed, 11 were euthanatized on the basis of results of preoperative diagnostic tests, and the remaining 3 dogs had splenic neoplasms that were incidental findings at necropsy. Of the 27 surgically treated dogs, 5 died in the immediate postoperative period, 12 died or were euthanatized within 1 year after splenectomy, and only 5 dogs survived greater than or equal to 1 year. Three dogs were lost to follow-up evaluation, and 2 were still alive 6 and 7 months after surgery. The median survival time of the 22 dogs for which survival was known was 2.5 months. The median survival time for 11 dogs with no obvious metastasis at the time of splenectomy was 9 months.(ABSTRACT TRUNCATED AT 250 WORDS)     

Outcome following treatment of soft tissue and visceral extraskeletal osteosarcoma in 33 dogs: 2008–2013

Extraskeletal osteosarcoma (EOS) is a rare, highly malignant mesenchymal neoplasm arising from viscera or soft tissues characterised by the formation of osteoid in the absence of bone involvement. Owing to the rarity of these neoplasms very little information exists on treatment outcomes. The purpose of this study was to describe the outcome following surgical treatment of non‐mammary and non‐thyroidal soft tissue and visceral EOS in dogs. Thirty‐three dogs were identified; the most common primary tumour site was the spleen. Dogs that had wide or radical tumour excision had longer survival times compared with dogs that had only marginal tumour excision performed [median survival time of 90 days (range: 0–458 days) versus median survival time of 13 days (range: 0–20 days)]. The use of surgery should be considered in the management of dogs with non‐mammary and non‐thyroidal soft tissue and visceral EOS.     

Amputation and Cisplatin for Treatment of Canine Osteosarcoma

Seventy-one dogs with histologically confirmed appendicular osteosarcoma were evaluated. Seventeen dogs were treated with amputation and two postoperative [corrected] doses of IV cisplatin given 21 days apart (group 1). Nineteen dogs were treated with IV cisplatin 21 days before amputation, with a second dose given immediately after amputation (group 2). Thirty-five dogs were treated by amputation of the affected limb with no chemotherapy (group 3). The median disease-free interval for group 1 was 226 days, and 177 days for group 2. This was not significantly different. The median survival time was 262 days for group 1, 282 days for group 2 and 119 days for group 3. Group 1 and 2 dogs had survival times that were significantly longer than for dogs in group 3. Two IV courses of cisplatin given before or after amputation appears to improve the survival of dogs with osteosarcoma.     

Treatment of dogs with osteosarcoma by administration of cisplatin after amputation or limb-sparing surgery: 22 cases (1987-1990).

Twenty-two dogs with appendicular osteosarcoma were treated by amputation (n = 17) or limb-sparing surgery (n = 5). All dogs were given cisplatin (60 mg/m2 of body surface, IV) at 3-week intervals, beginning 1 week after surgery. Number of cisplatin treatments ranged from 1 to 6. Survival data for the 22 dogs were compared with survival data from a historical control group consisting of 162 dogs with appendicular osteosarcoma treated by amputation alone. Median survival time for the 22 dogs given cisplatin was estimated to be 46.4 weeks, and 1- and 2-year survival rates were estimated to be 45.5 and 20.9%, respectively. Survival time was significantly (P less than 0.0001) longer for treated dogs than for control dogs. Statistically significant relation was not found between survival time and number of cisplatin treatments. Three dogs were alive with no evidence of disease at the time of reporting. Of the remaining 19 dogs, 14 (73.4%) were euthanatized for problems documented to be related to metastases. Nine (47.4%) dogs were euthanatized because of bone metastases, and 5 (26.3%) were euthanatized because of pulmonary metastases. The proportion of dogs euthanatized because of bone metastases was significantly (P less than 0.0001) higher for treated than for control dogs. Median survival times for dogs developing bone and lung metastases were estimated to be 51.2 weeks and 21.2 weeks, respectively; however, this difference was not statistically significant. One local tumor recurrence was observed among dogs that had limb-sparing surgery. Significant difference in survival time was not observed between dogs that had limb-sparing surgery and dogs that underwent amputation.     

Radiotherapy of malignant nasal tumors in 67 dogs

The nasal cavity of 67 dogs with malignant nasal neoplasia was treated with radiation. Preirradiation surgical cytoreduction of the tumor was done in 41 dogs. Fifty dogs were irradiated by use of 10 fractions over 22 days, and 17 dogs were given a similar total dose in 5 fractions over 35 days. The range of survival times (0.5 to 42 months), median survival time (8.5 months), and 1- and 2-year survival rates (38% and 30%, respectively) were better than those expected for other methods of treatment. Serious complications were few (4%). Survival times for dogs were determined on the basis of histologic tumor type and on the basis of megavoltage (cobalt or linear accelerator) vs softer deep radiation (cesium or orthovoltage) treatment, with or without cytoreductive surgery. Survival times of 10 dogs given softer radiation without surgery were shorter than those of 14 dogs that were given softer radiation and had cytoreductive surgery. Survival times of dogs that were given softer radiation and had surgery were similar to those of dogs that were given megavoltage radiation only. Cytoreductive surgery did not improve survival times for dogs that were given megavoltage radiation. Median survival time for 38 dogs with adenocarcinoma was 12 months, compared with 6 months for 14 dogs with squamous cell or undifferentiated carcinoma. Median survival time for 16 dogs with a variety of sarcomas was 11.2 months. Survival times of dogs with adenocarcinoma or sarcoma were significantly better (P less than 0.02 or 0.03) than for dogs with squamous cell or undifferentiated carcinoma. Necropsies were performed on 27 of 58 dogs that died or were euthanatized.(ABSTRACT TRUNCATED AT 250 WORDS)     

Orthovoltage radiotherapy of acanthomatous epulides in 39 dogs

Acanthomatous epulides in 39 dogs were treated with orthovoltage x-rays. The acanthomatous epulis recurred in only 3 dogs, 2 of which were successfully retreated with x-rays. Malignant tumors other than acanthomatous epulis developed at the site of the irradiated acanthomatous epulis in 7 of the dogs. Five of the tumors were squamous cell carcinoma, one was a fibrosarcoma, and one was an osteosarcoma. The range of survival times (1 to 102 months), mean survival time (38 months), median survival time (37 months), 1-year survival rate (85%), and 2-year survival rate (67%) were encouraging and suggested that the described treatment was satisfactory for acanthomatous epulides. Cause of death in most dogs was not related to the acanthomatous epulis.     

Proximal radial and distal humeral osteosarcoma in 12 dogs

Twelve dogs were diagnosed with osteosarcoma of the proximal radius or distal humerus from 1990 to 2002, representing 1.0% of all dogs diagnosed with appendicular osteosarcoma. The median body weight (29.8 kg) was significantly less than that of dogs with appendicular osteosarcoma at other sites. Ten dogs were treated with amputation and chemotherapy. These dogs had a metastatic rate of 60%, a median metastasis-free interval of 356 days, and a median survival time of 824 days. There were no significant differences in metastasis-free interval or survival time between dogs with osteosarcoma of the proximal radius or distal humerus and dogs with appendicular osteosarcoma at other sites.     

Biologic Behavior and Clinical Outcome of 25 Dogs with Canine Appendicular Chondrosarcoma Treated by Amputation: A Veterinary Society of Surgical Oncology Retrospective Study

Objective— To characterize biologic behavior, clinical outcome, and effect of histologic grade on prognosis for dogs with appendicular chondrosarcoma treated by amputation alone. Study Design— Case series. Animals— Dogs (n=25) with appendicular chondrosarcoma. Methods— Medical records were searched to identify dogs with appendicular chondrosarcoma treated by limb amputation alone. Information recorded included signalment, anatomic location, radiographic appearance, and development of metastasis. Histopathologic diagnosis was confirmed and graded (1, 2, or 3). Survival curves were generated by the Kaplan–Meier method and the association between covariates (gender, age, weight, and tumor grade) and survival were evaluated using the univariate proportional hazards model. Results— Histopathology slides were available for 25 dogs. Rates of pulmonary metastasis were as follows: grade 1–0%, grade 2–31%, and grade 3–50%. Overall median survival time (MST) was 979 days. Age, weight, and sex were not significantly associated with survival (P=.16; .33; and .31, respectively). Survival was significantly associated with tumor grade (P=.008), with dogs with tumor grade of 1, 2, and 3 having MSTs of 6, 2.7, and 0.9 years, respectively. Conclusion— Canine appendicular chondrosarcoma can be treated effectively with amputation alone. Low to intermediate grade chondrosarcoma has a good prognosis, whereas high‐grade tumors appear to behave aggressively. Clinical Relevance— The overall prognosis for appendicular chondrosarcoma is better than that of appendicular osteosarcoma treated by amputation alone or in combination with chemotherapy.