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Objective—

To characterize survival times, disease-free intervals, and prognostic variables in ferrets with pancreatic beta cell neoplasia.

Design—

Retrospective study.

Animals—

20 ferrets with histologically confirmed pancreatic beta cell tumors.

Procedure—

Medical records of ferrets with pancreatic beta cell tumors were reviewed. Variables such as age, sex, duration of clinical signs, existence of other neoplasia, single versus multiple masses in the pancreas, benign or malignant histologic features, and the type of treatment used at redevelopment of clinical signs were examined to determine their relationship to survival times and disease-free intervals.

Results—

Duration of clinical signs prior to diagnosis and initial surgery was inversely correlated with survival time and disease-free interval. Overall median survival time for all ferrets with pancreatic beta cell tumors was 483 days. Median disease-free interval for ferrets that had abdominal surgery for pancreatic beta cell tumor removal was 240 days. Distant tumor metastasis was not found in this group of ferrets, but local tumor recurrence was common. In 4 ferrets that had a second celiotomy, removal of recurrent pancreatic tumors did not prolong survival but did result in a second disease-free interval.

Clinical Implications—

Pancreatic beta cell tumors should be considered in ferrets over 2 years of age that have clinical signs of seizures, episodic lethargy, ptyalism, ataxia, and hind limb weakness. In the study reported here, complete surgical excision of the tumor resulted in temporary resolution of clinical signs in ferrets; however, redevelopment of clinical signs at a later time was common. (J Am Vet Med Assoc 1996;209:1737–1740)

Free access
in Journal of the American Veterinary Medical Association

Abstract

Objective–To describe the clinical features, surgical and histologic findings, biological behavior, and outcome of dogs with retroperitoneal sarcomas.

Design–Retrospective study.

Animals–14 dogs.

Procedures–Medical and pathology records from 1992 to 2002 of dogs with tumors originating in the retroperitoneal space were reviewed. Dogs with retroperitoneal tumors originating from the adrenal glands, kidneys, or ureters were excluded. Inclusion criteria included observation of a tumor arising from the retroperitoneal space during exploratory surgery or necropsy and histologic confirmation of tumor type. Details of clinical signs, diagnostic findings, surgical management, and outcome were determined from medical records and telephone interviews with veterinarians and owners.

Results–Retroperitoneal sarcoma was diagnosed in 14 dogs, 2 at necropsy and 12 during exploratory surgery. Hemangiosarcoma was the most common histologic diagnosis. Seven dogs had regional extension of the sarcoma into adjacent organs, and 4 dogs had metastatic disease. Grossly complete resection was possible in 6 dogs. Cytoreductive surgery or incisional biopsy was performed in the remaining dogs. Two dogs were treated with palliative radiation therapy (1 intraoperatively and 1 postoperatively). Three dogs received adjunctive chemotherapy, although none completed the targeted course because of development of local recurrence or metastatic disease. Local recurrence was reported in 2 of 12 dogs and metastasis in 10 of 14 dogs. Thirteen dogs died or were euthanatized as a result of the retroperitoneal sarcoma; 1 dog was alive and disease-free 410 days after surgery. Median survival time was 37.5 days.

Conclusions and Clinical Relevance–In dogs, retroperitoneal sarcomas are aggressive tumors with a high rate of local recurrence and metastasis, and a poor survival time. (J Am Vet Med Assoc 2004;224: 1471–1477)

Full access
in Journal of the American Veterinary Medical Association

Abstract

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.

Full access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine the efficacy of primary re-excision alone for treatment of soft tissue sarcomas after recent incomplete resection, the frequency and clinical importance of detecting residual tumor in resected scars, and prognostic factors associated with the procedure.

Design—Retrospective case series.

Animals—41 dogs.

Procedures—Medical records of dogs that had undergone recent incomplete excision of a soft tissue sarcoma at a referring veterinary practice and subsequent re-excision of the scar at the Colorado State University Veterinary Medical Center were reviewed.Owners and referring veterinarians were contacted for follow-up information.Slides from re-excised specimens were reviewed.Dogs that underwent radiation therapy after the re-excision procedure were excluded.

Results—41 dogs met the inclusion criteria, and long-term follow-up information was available for 39 dogs.Median follow-up time was 816 days.Local recurrence of tumor developed in 6 of 39 (15%) dogs, and distant metastasis occurred in 4 of 39 (10%) dogs.Healthy tis sue margins of 0.5 to 3.5 cm were achieved at re-excision. Residual tumor was identified in 9 of 41 (22%) resected scars.No tumor-, patient-, or treatment-related variables were associated with local recurrence except for the presence of liposarcoma or fibrosarcoma or whether fine-needle aspiration had been performed prior to surgery.

Conclusions and Clinical Relevance—After incomplete resection of soft tissue sarcomas, resection of local tissue should be performed, even if excisable tissue margins appear narrow.A long-term favorable prognosis is achievable without radiation therapy or amputation. The presence of residual tumor in resected scar tissue should not be used to predict local recurrence.

Full access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To evaluate risk factors for outcome for dogs with adrenal gland tumors with or without invasion of the caudal vena cava treated via adrenalectomy.

Design—Retrospective study.

Animals—86 dogs that underwent adrenalectomy for treatment of adrenal gland tumors.

Procedures—Medical records of dogs that underwent adrenalectomy for treatment of an adrenal gland tumor from 1993 to 2009 were reviewed; data collected including signalment, clinical signs, diagnostic test findings, treatments prior to surgery, findings at surgery including additional procedures performed and extent of caudal vena caval invasion (local invasion [caudal to the hepatic portion of the vena cava] or extensive invasion [cranial to the hepatic portion of the vena cava]), procedures performed during surgery, histopathologic diagnosis, perioperative complications, follow-up data, and necropsy findings.

Results—Of the 86 dogs, 14 had adenomas, 45 had adrenocortical carcinomas, and 27 had pheochromocytomas. Fourteen dogs had invasion of the caudal vena cava; of these tumors, 7 were locally invasive and 7 were extensively invasive. Risk factors for poor short-term survival (death within 14 days following surgery) were vena caval invasion, extent of invasion, pheochromocytoma, intraoperative transfusion, and postoperative factors including disseminated intravascular coagulation, pancreatitis, hypotension, hypoxemia, and renal failure. Multivariate analysis of risk factors for poor short-term survival revealed that extensive invasion was the most important factor. Regardless of extent of invasion or tumor type, long-term survival was possible.

Conclusions and Clinical Relevance—Invasion of the caudal vena cava, particularly tumor thrombus extension beyond the hepatic hilus, was associated with a higher postoperative mortality rate, but did not affect long-term prognosis in dogs undergoing adrenalectomy because of an adrenal gland tumor.

Full access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To identify matrix metalloproteinases (MMP) 2 and 9 in canine tumor tissue and to compare the amount of activity to that in unaffected stromal tissue.

Animals—30 dogs with spontaneously developing, high-grade osteosarcoma.

Procedure—Tumor and nearby stromal tissue (muscle) were obtained at the time of surgery. Specimens were homogenized, and supernatants were assayed, using gelatin zymography. Human derived standards were run concurrently. Densitometry was done to obtain a semiquantitative arbitrary unit value for each specimen. The amount of activity in tumor tissue was compared with the amount in stromal tissue.

Results—Gelatinolytic bands were observed from the analysis of all tumor tissues and in most stromal tissues. These bands migrated in the same molecular weight area as the human MMP 2 and 9 standards. Gelatinolytic activity could be quenched by the addition of 50 mM EDTA and 1 µg of synthetic tissue inhibitor of metalloproteinase (TIMP) 2 per 100 ml. There was significantly more gelatinolytic activity in tumor tissue than in stromal tissue.

Conclusions and Clinical Relevance—MMP 2 and 9 are detectable in canine neoplastic tissue. matrix metalloproteinases activity in tumor tissue is higher than in unaffected stromal tissue, indicating that canine MMP may be involved in the pathogenesis of tumor growth and metastasis. (Am J Vet Res 2000;61:111–114)

Full access
in American Journal of Veterinary Research

Abstract

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.

Full access
in Journal of the American Veterinary Medical Association

Abstract

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. (J Am Vet Med Assoc 2005;226:1364–1367)

Full access
in Journal of the American Veterinary Medical Association

Objective—

To determine whether alkaline phosphatase activity in dogs with appendicular osteosarcoma can be used as a prognostic indicator.

Design—

Retrospective study.

Animals—

75 dogs with appendicular osteosarcoma.

Procedure—

Serum total alkaline phosphatase (TALP) and bone-specific alkaline phosphatase (BALP) activities were determined from archival serum samples obtained at various times during treatment of appendicular osteosarcoma and follow-up evaluations. Associations among activities of TALP and BALP and survival and disease-free intervals, percentage of bone length involved with tumor, histologic subtype, and method of surgical treatment were evaluated.

Results—

High activities of TALP and BALP before surgery were significantly associated with shorter survival and disease-free intervals in dogs undergoing surgery (amputation or limb-sparing procedure) and adjuvant chemotherapy. Activity of BALP significantly decreased in 29 dogs for which postoperative samples were available. Failure of BALP activity to decrease after surgery was correlated with shorter survival and disease-free intervals.

Clinical Implications—

Activities of TALP and BALP in serum are important prognostic factors for appendicular osteosarcoma in dogs. Prognostic factors may help clinicians initiate more aggressive treatment for dogs that are at higher risk of death or relapse. (J Am Vet Med Assoc 1998:213:1002-1006)

Free access
in Journal of the American Veterinary Medical Association

Objective

To determine results of surgery for treatment of soft-tissue sarcomas in dogs and to identify prognostic variables that can be used to predict outcome.

Design

Retrospective case series.

Animals

Dogs with soft-tissue sarcomas that had surgical treatment only.

Procedure

Records were examined for clinically relevant data. Histologic samples were reviewed. Follow-up information was obtained by physical examination or telephone conversations with referring veterinarians or owners.

Results

75 dogs with soft-tissue sarcomas of the trunk and extremities were identified. Median age was 10.6 years. Malignant peripheral nerve sheath tumors were of a significantly lower grade than other tumors. Tumors recurred locally in 11 of 75 (15%) dogs. Evaluation for lack of tumor cells at surgical margins was prognostic for local recurrence. Metastatic disease developed in 13 of 75 (17%) dogs. Tumor mitotic rate was prognostic for development of metastasis. Twenty-five of 75 (33%) dogs died of tumor-related causes. Percentage of tumor necrosis and tumor mitotic rate were prognostic for survival time. Median survival time was 1,416 days.

Clinical Implications

On the basis of a low local recurrence rate and high median survival time, wide excision of tumor margins or radical surgery appeared to be an effective means for managing soft-tissue sarcomas of the trunk and extremities. Analysis of histologic characteristics for prognosis supported use of preoperative biopsy. Surgical margins should be evaluated, and early use of aggressive surgery is indicated in the management of soft-tissue sarcomas in dogs. (J Am Vet Med Assoc 1997;211:1147–1151)

Free access
in Journal of the American Veterinary Medical Association