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Summary

Medical records of 15 dogs with infiltrative lipoma, 1 of which had 2 lesions, were reviewed. Median age of affected dogs was 6.0 years, and median weight was 30.5 kg. The ratio of females to males was 4:1. Eight of the dogs were Labrador Retrievers. In 8 dogs, the lesions had previously been excised. There was not any apparent site predilection. Excision was the only treatment in all 15 dogs, and follow-up information was available for all dogs. Two dogs, each of which had 1 tumor, were euthanatized immediately after surgery, because the tumor could not be completely excised. Of the remaining 14 tumors, 5 (36%) recurred. Median time to recurrence for these 5 tumors was 239 days (range, 96 to 487 days). By means of Kaplan-Meier analysis, the percentage of dogs disease free 1 year after surgery was calculated to be 67%.

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in Journal of the American Veterinary Medical Association

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.

Full access
in Journal of the American Veterinary Medical Association

Summary

Before dogs with lung tumors were treated by adoptive immunotherapy, the ability of canine blood lymphocytes (pbl) from the peripheral circulation to differentiate in vitro in the presence of human recombinant interleukin-2 (rIL-2) and become tumoricidal was investigated. The pbl from healthy dogs (n = 6) and dogs with lung tumors (n = 5) were grown in culture medium alone, in the presence of rIL-2 to generate lymphokine-activated killer (lak) cells, or with phytohemagglutinin (pha) and rIL-2 to generate autologous-stimulated lymphocytes (asl). After 4 days, cytotoxicity by the asl, lak, and pbl was determined in a 4-hour 51chromium-release assay. Target cells in the assay were short-term cultured enzyme digests of autologous (self), allogeneic (genetically different) primary tumors, and Raji, the xenogeneic human lymphoma cell line. The pbl cultured without rIL-2 were not cytotoxic against any tumor. However, when a dog's pbl were activated in vitro, they killed the dog's own tumor, asl more effectively than lak cells. Pulmonary adenocarcinomas and an osteosarcoma metastasis to lung were among the autologous tumors assayed. Against an allogeneic canine osteosarcoma, asl generated from healthy dogs were significantly more cytolytic than lak from healthy dogs, or than asl generated from tumorbearing dogs. Cytotoxicity was greater against allogeneic tumor than against Raji. Lectin-dependent cellular cytotoxicity, tested by including pha in the assay medium with lymphocytes and Raji cells, by asl and lak was greater than cytotoxicity of Raji without pha. Because asl were more cytolytic than lak against all targets in vitro, they may be more beneficial than lak for immunotherapy of canine tumors.

Free access
in American Journal of Veterinary Research

Summary

Medical records of 23 dogs in which thymoma was diagnosed between Jan 1, 1980 and Dec 31, 1991 were reviewed. All thymomas were located in the cranial mediastinum. Eleven dogs had mega-esophagus, and myasthenia gravis was confirmed in 7 of these 11. One dog developed clinical signs of myasthenia gravis after removal of the thymoma. Concurrent, nonthymic neoplasms were found in 5 dogs, and 2 had hypercalcemia. Three dogs developed third-degree atrioventricular heart block, 1 of which had generalized myositis involving the cardiac muscle.

None of the dogs had evidence of distant metastasis. Histologically, the predominant tumor types were differentiated epithelial type (9/23) and lymphocyte-rich type (6/23). Clear cells (large cells with nonstaining cytoplasm) comprised ≥ 50% of the cell population in tumors from 5 dogs. Mast cells were detected histologically in 85% of the thymomas evaluated. Sixteen dogs were treated, and in 15 of these, surgery was the primary means of treatment. Six of the 9 dogs with megaesophagus that underwent surgery died or were euthanized within 1 week of diagnosis; whereas only 1 of the 4 dogs without megaesophagus that underwent surgery died within 1 week of diagnosis. Two dogs underwent surgery and received adjuvant chemotherapy. One dog died of complications associated with chemotherapy. One dog was treated with chemotherapy alone and survived 14 months. Seven dogs did not undergo treatment; 4 of these were euthanatized immediately after the mass was first discovered.

By means of univariate analysis, age (≤ 8 years old vs > 8 years old), megaesophagus (present vs not present), and histologic type were found to be significantly (P ≤ 0.05) associated with survival time. Only megaesophagus was found to be significantly associated with survival time by multivariate analysis. Dogs with megaesophagus had a Kaplan-Meier median survival time of 4 days. Kaplan-Meier median survival time for dogs without megaesophagus could not be calculated, because most dogs died of causes unrelated to the thymoma and were censored. Kaplan-Meier 1-year survival rate was 83% for dogs without megaesophagus.

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

Summary:

A study was undertaken to determine the effect chemotherapy had when used to treat 45 dogs with measurable metastatic osteosarcoma. The primary tumor was histologically confirmed as an osteosarcoma in each case. Thirty-nine dogs had the primary tumor surgically removed. Twenty-four of these dogs were treated adjunctively with cisplatin (70 mg/m2 of body surface, IV, q 3 weeks; median 2 doses, range 1 to 6 doses) prior to the onset of metastasis. The remaining 6 dogs from which the primary tumor was not surgically removed were diagnosed as having metastatic osteosarcoma in addition to the primary tumor on initial examination.

The median time from initial examination until the development of metastatic disease was 115 days (range, 27 to 1,199 days). The location of the metastatic disease was lungs (31 dogs), bone (3 dogs), soft tissue (1 dog), and multiple sites including lungs, bone, and soft tissue sites (10 dogs). The metastatic lesions were confirmed by pretreatment biopsy (n = 8) or cytologic evaluation (n = 2) in 10 cases and at necropsy in 27 cases. The remaining 8 cases were diagnosed radiographically as multiple metastatic lesions in the lungs consistent with metastatic osteosarcoma.

The metastatic disease was treated with cisplatin in 31 dogs (70 mg/m2, IV, q 3 weeks; median 2 doses, range 1 to 4 doses), doxorubicin in 11 dogs (30 mg/m2, IV, q 3 weeks; median 2 doses, range 1 to 3 doses), and mitoxantrone in 3 dogs (5 mg/m2, IV, q 3 weeks; median 2 doses, range 1 to 3 doses). Eight dogs that had metastatic disease treated with cisplatin were also given doxorubicin; 2 dogs treated with either doxorubicin or mitoxantrone were treated subsequently with cisplatin. The extent of neoplastic disease was determined immediately before the first dose of chemotherapy, and then every 3 to 6 weeks thereafter unless the dog had signs compatible with progressive disease, in which case, an evaluation was done more frequently. Each dog was treated with one chemotherapeutic agent until the dog developed progressive disease, or until the dog's quality of life diminished to an unacceptable level as determined by the owner or attending veterinarian. One dog treated with doxorubicin achieved partial remission. The duration of the partial remission was 21 days, and the lesion was confirmed to be osteosarcoma on necropsy 159 days after the metastatic disease was diagnosed. The median survival time of the other 44 dogs that did not respond to treatment from the time the metastatic disease was diagnosed was 61 days (range, 14 to 192 days). Cisplatin, doxorubicin, and mitoxantrone chemotherapy appear to be ineffective for the treatment of measurable metastatic osteosarcoma in the dog.

Free access
in Journal of the American Veterinary Medical Association