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Abstract

Objective—To evaluate the outcome of resection of simultaneous discrete bilateral mobile thyroid gland carcinomas (TGCs) in dogs.

Design—Retrospective case series.

Animals—15 dogs with resected simultaneous discrete bilateral mobile TGCs.

Procedures—Medical records (from 1994 to 2010) were searched for dogs with the appropriate diagnosis and treatment. Information collected included signalment, clinical signs, diagnostic test results, tumor mobility (mobile tumor identified by movement ≥ 1 cm in all planes during palpation), complications, adjuvant treatments, and outcome.

Results—Mobile, discrete, bilateral TGCs were removed in all dogs. Among the 15 dogs, complete parathyroidectomies were necessary in 9; parathyroid tissue was reimplanted in 4 and preserved in 2. Complications included hemorrhage and laryngeal nerve trauma, but without serious consequences. Thirteen dogs received calcitriol with or without supplemental calcium after surgery. In the immediate postoperative period, hypocalcemia developed and was corrected in 11 dogs. At the end of the study, 7 dogs continued to receive calcitriol with or without supplemental calcium, and 8 dogs required long-term thyroid hormone treatment. Six dogs received adjuvant chemotherapy. Local tumor recurrence or de novo distant metastasis was not detected at each dog's last follow-up examination. Median survival time was 38.3 months. Three dogs were lost to follow-up, 8 survived (4.3 to 77 months after surgery), and 4 died of unrelated causes.

Conclusions and Clinical Relevance—In dogs with TGCs undergoing bilateral thyroid lobectomies, a successful outcome can be expected, even when parathyroid gland tissue cannot be preserved. The role of adjuvant chemotherapy in treatment outcome was not clearly defined.

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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.

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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.

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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.

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in Journal of the American Veterinary Medical Association

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.

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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)

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in American Journal of Veterinary Research

Abstract

Objective—To evaluate the outcome in terms of progression-free interval (PFI) and overall survival time (ST) after curative-intent resection of oral melanoma in dogs.

Design—Retrospective case series.

Animals—70 client-owned dogs.

Procedures—An electronic medical record search and review was performed for dogs that underwent curative-intent resection of oral melanoma (May 1, 1998, to December 31, 2011). Information gathered included signalment, oral location of tumor, staging results, type of surgery, type of adjuvant therapy, findings on histologic evaluation, and outcome.

Results—36 (51.4%), 16 (22.9%), 13 (18.6%), and 1 (1.4%) of 70 dogs had tumors classified as stage I, II, III, and IV, respectively; tumor stage could not be determined for 4 (5.7%) dogs because of the lack of tumor size information. Fifty-one (72.9%) dogs had tumors completely excised. Twenty-nine (41.4%) dogs received adjuvant therapy. Median PFI and ST were 508 and 723 days, respectively. Thirty-two (45.7%) dogs had disease progression. Significant associations with PFI or ST were found for administration of adjuvant therapy, presence of metastatic disease at the time of diagnosis, higher tumor stage (III or IV), increased tumor size (> 3 cm), and sexually intact female dogs. Administration of adjuvant treatment was associated with a 130% increased hazard (hazard ratio, 2.3; 95% confidence interval [CI], 1.0 to 5.0) of disease progression; the presence of metastases at the time of diagnosis was associated with a 281% increased hazard (hazard ratio, 3.8; 95% CI, 1.5 to 9.6) of death.

Conclusions and Clinical Relevance—Results indicated that dogs with oral melanoma can have a long PFI and ST after resection with wide margins.

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in Journal of the American Veterinary Medical Association

Abstract

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.

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in Journal of the American Veterinary Medical Association

Abstract

OBJECTIVE To assess for any association between a history of tibial plateau leveling osteotomy (TPLO) and subsequent development of proximal tibial osteosarcoma in dogs.

DESIGN Matched case-control study.

ANIMALS 34 client-owned dogs in which proximal tibial osteosarcoma was diagnosed between January 2005 and December 2012 (cases) and 79 dogs without osteosarcoma, matched 3:1 to cases (when possible) by age, breed, and initial examination date (controls).

PROCEDURES Information on each case and control was collected from the medical records and other sources regarding date of birth, sex and neuter status, body weight, breed, and whether TPLO had been performed ≥ 1 year ago. A multivariable conditional logistic regression model was constructed to evaluate associations of body weight and history of TPLO with the outcome of proximal tibial osteosarcoma in dogs.

RESULTS After adjusting for body weight in the multivariable model, dogs with a history of TPLO were 40 times as likely to develop proximal tibial osteosarcoma as were dogs with no history of TPLO. In addition, each 1-kg (2.2-lb) increase in body weight was associated with an 11% increase in the odds of proximal tibial osteosarcoma.

CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that dogs with a history of TPLO were at increased risk of developing osteosarcoma of the proximal region of the tibia relative to dogs with no such history. Therefore, it is important for proximal tibial osteosarcoma to be included among the differential diagnoses for new or worsening hind limb lameness in dogs that underwent TPLO ≥ 1 year previously.

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in Journal of the American Veterinary Medical Association