Ruthanne Chun

Postoperative Radiotherapy for Canine Soft Tissue Sarcoma

Thirty-five dogs with 37 soft tissue sarcoma tumors that were incompletely excised and treated with radiotherapy in the postoperative, adjuvant setting were reviewed. Variables evaluated included age, sex, tumor site, tumor histology, total tumor radiation dose, radiotherapy field size. time to recurrence, and survival. The majority of tumors were fibrosarcomas and hemangiopericytomas, but small numbers of other tumor types were also represented. Total tumor radiation dose ranged from 42 to 57 Gy given in 3- to 4.2-Gy daily fractions on a Monday through Friday schedule. Overall median survival was 1,851 days. Median time to local recurrence was greater than 798 days. Soft-tissue sarcoma tumors at oral sites had a statistically significant lower median survival (540 days) as compared to other tumor sites (2,270 days). Radiotherapy may be a useful adjuvant therapy for incompletely excised soft-tissue sarcomas with a reasonable expectation for long-term patient survival.

Preclinical trial of doxorubicin entrapped in sterically stabilized liposomes in dogs with spontaneously arising malignant tumors

AbstractPurpose: To prospectively evaluate the short-term toxicoses associated with pegylated-liposomal doxorubicin (Doxil) administered to dogs with measurable tumors of various histologic types and sites. Preliminary information regarding efficacy was also generated. Methods: A group of 51 dogs with histologically confirmed malignancies received a total of 103 Doxil treatments given i.v. every 3 weeks at dosages ranging from 0.75 to 1.1 mg/kg in the context of a phase I dose-escalation trial. Acute and short-term toxicities as well as tumor response and duration of response were characterized. Results: The maximally tolerated dose in tumor-bearing dogs was established as 1.0 mg/kg i.v. every 3 weeks. The dose-limiting toxicity was a cutaneous toxicity clinically resembling palmar-plantar erythrodysesthesia (PPES). An overall response rate of 25.5% was observed with five complete responders and eight partial responders. Conclusions: Doxil appeared to be well tolerated at dosages similar to those tolerated for free doxorubicin in tumor-bearing dogs. PPES was the dose-limiting toxicity encountered, rather than myelosuppresion as is the case with free doxorubicin in dogs. Doxil as a single agent may have a broad spectrum of activity and deserves further evaluation.

Cisplatin and Doxorubicin Combination Chemotherapy for the Treatment of Canine Osteosarcoma: A Pilot Study

Sixteen dogs with histologically confirmed appendicular osteosarcoma were treated by amputation followed by cisplatin and doxorubicin chemotherapy. All dogs began chemotherapy within 24 hours of surgery. Cisplatin was administered at 50 mg/m2 intravenously (IV) concurrent with saline-induced diuresis. Doxorubicin was administered 24 hours later at 15 mg/m2 as a slow IV bolus. This protocol was given on a 21-day cycle for 4 cycles. No dose delays were required, but dose reduction of doxorubicin was required in 2 dogs because of neutropenia. Thoracic radiography was performed every 2 months after completion of therapy to monitor for metastatic disease. Two dogs were still alive and free from disease at the time of last contact (24 and 75 months, respectively). Postmortem examinations were performed on 13 of the 14 dogs that died. Eight of these dogs were euthanized because of metastatic osteosarcoma. Of the remaining 5 dogs, euthanasia was performed because of complications of idiopathic megaesophagus (n = 1), arthritis (n = 2), and hemangiosarcoma (n = 2). The median disease-free interval and survival times were 15.7 and 18 months, respectively. When compared to a historical group of 36 dogs with appendicular osteosarcoma treated with surgery and 4 doses of cisplatin. both disease-free interval and overall survival were significantly longer in the study population (P < .015 and P < .007, respectively).

Toxicity and efficacy of cisplatin and doxorubicin combination chemotherapy for the treatment of canine osteosarcoma.

Thirty-five dogs with appendicular osteosarcoma underwent amputation and chemotherapy with cisplatin and doxorubicin every 21 days for up to four cycles. Sixteen dogs completed all four cycles. Two dogs had therapy discontinued because of metastases. The remaining 17 dogs experienced toxicities necessitating protocol alteration or discontinuation. The median survival time of 300 days was not improved over previously reported single-agent protocols, but the 10 dogs that survived to a year lived a median of 510 days.

Comparison of three-view thoracic radiography and computed tomography for detection of pulmonary nodules in dogs with neoplasia

OBJECTIVE To compare the detection of pulmonary nodules by use of 3-view thoracic radiography and CT in dogs with confirmed neoplasia. DESIGN Prospective case series. ANIMALS 33 dogs of various breeds. PROCEDURES 3 interpreters independently evaluated 3-view thoracic radiography images. The location and size of pulmonary nodules were recorded. Computed tomographic scans of the thorax were obtained and evaluated by a single interpreter. The location, size, margin, internal architecture, and density of pulmonary nodules were recorded. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated for thoracic radiography (with CT as the gold standard). RESULTS 21 of 33 (64%) dogs had pulmonary nodules or masses detected on CT. Of the dogs that had positive CT findings, 17 of 21 (81%) had pulmonary nodules or masses detected on radiographs by at least 1 interpreter. Sensitivity of radiography ranged from 71% to 95%, and specificity ranged from 67% to 92%. Radiography had a positive predictive value of 83% to 94% and a negative predictive value of 65% to 89%. The 4 dogs that were negative for nodules on thoracic radiography but positive on CT were all large-breed to giant-breed dogs with osteosarcoma. CONCLUSIONS AND CLINICAL RELEVANCE CT was more sensitive than radiography for detection of pulmonary nodules. This was particularly evident in large-breed to giant-breed dogs. Thoracic CT is recommended in large-breed to giant-breed dogs with osteosarcoma if the detection of pulmonary nodules will change treatment.

Predictors of outcome in dogs treated with adjuvant carboplatin for appendicular osteosarcoma: 65 cases (1996-2006)

OBJECTIVE To determine outcomes and prognostic factors for those outcomes in dogs with appendicular osteosarcoma treated with curative-intent surgery and adjuvant carboplatin. DESIGN Retrospective case series. ANIMALS 65 client-owned dogs with appendicular osteosarcoma and no evidence of gross metastatic disease at the time of diagnosis. PROCEDURES Medical records of dogs that underwent limb amputation or distal ulnectomy and adjuvant carboplatin treatment for appendicular osteosarcoma were reviewed. Adverse effects of chemotherapy and findings regarding preoperative biopsy specimens and postoperative diagnostic imaging were recorded. Signalment, clinical history, and chemotherapy variables were evaluated for associations with outcome. Histologic grade and other variables were evaluated for association with outcome for 38 tumors that were retrospectively graded. RESULTS The median disease-free interval was 137 days (95% confidence interval [CI], 112 to 177 days). Median survival time was 277 days (95% CI, 203 to 355 days). The 1-, 2-, and 3-year survival rates were 36%, 22%, and 19%, respectively. None of the chemotherapy variables were associated with outcome. Preoperative proteinuria was the only clinical variable associated with poor outcome. Histologic features of tumors associated with a poor outcome were intravascular invasion, mitotic index > 5 in 3 microscopic hpfs, and grade III classification. CONCLUSIONS AND CLINICAL RELEVANCE Carboplatin administration was well tolerated and resulted in a disease-free interval and median survival time similar to those of other published protocols.

Lymphoma: which chemotherapy protocol and why?

Lymphoma is the most common hematologic neoplasm of dogs. Although the order of drug administration and duration of the maintenance portion of the protocol vary considerably, most oncologists agree that a doxorubicin-based (eg, CHOP) combination chemotherapy protocol provides the longest period of disease control and overall survival. The use of a prolonged maintenance phase is no longer recommended, but consolidation therapy may prove to be of benefit. Further, combination of chemotherapy with half- or whole-body radiation therapy or even bone marrow transplant is advocated by some institutions. The goal of this article is to summarize the current literature regarding chemotherapy for dogs with high-grade lymphoma and provide recommendations for therapy in a variety of different scenarios.

Treatment of Feline Gastrointestinal Small-Cell Lymphoma With Chlorambucil and Glucocorticoids

Gastrointestinal (GI) lymphoma is the most frequently diagnosed form of lymphoma in the cat and is categorized into two distinct forms based on the size of neoplastic lymphocytes. Treatments for both large- and small-cell GI lymphoma have been described previously; however, multiple chemotherapy protocols were used, a minimal amount of histopathological characterization was provided, and, in most studies, the majority of diagnoses were obtained via endoscopic pinch biopsies. Twenty-eight cats (24 with full-thickness intestinal biopsies) were diagnosed with small-cell GI lymphoma and treated with a combination of chlorambucil and glucocorticoids. The majority of cases were strongly CD3+, and many displayed epitheliotropism. The overall clinical response rate was 96%, with a median clinical remission duration of 786 days. Follow-up identified seven cats with relapsed disease-all of which were treated with a rescue protocol of cyclophosphamide and glucocorticoids; the response rate was 100%, and four of the 28 cats were diagnosed with a second malignancy.

Large Granular Lymphocytosis, Lymphocyte Subset Inversion, Thrombocytopenia, Dysproteinemia, and Positive Ehrlichia Serology in a Dog

A 7-year-old, mixed-breed dog was presented for evaluation of a possible lymphocytic leukemia. Results of laboratory testing included thrombocytopenia, large granular lymphocytosis, inverted CD4:CD8 ratio, hyperglobulinemia, and hypoalbuminemia. Results of a tick-borne disease panel indicated a positive immunoglobulin G serum titer (1:2,048) to Ehrlichia canis, supporting exposure to this organism. The dog responded to a combination treatment of doxycycline and prednisone. A review of the literature and novel diagnostic methods that aided in the diagnosis of this case are discussed.

Comparison of plasma cardiac troponin I concentrations among dogs with cardiac hemangiosarcoma, noncardiac hemangiosarcoma, other neoplasms, and pericardial effusion of nonhemangiosarcoma origin

OBJECTIVE To determine whether plasma cardiac troponin I (cTnl) concentrations can be used to identify cardiac involvement in dogs with hemangiosarcoma, exclude cardiac hemangiosarcoma in dogs with noncardiac hemangiosarcoma, and identify cardiac hemangiosarcoma in dogs with pericardial effusion. DESIGN Cohort study. ANIMALS 57 dogs (18 with confirmed [5 dogs] or suspected [13] cardiac hemangiosarcoma, 14 with confirmed hemangiosarcoma involving sites other than the heart [noncardiac hemangiosarcoma], 10 with pericardial effusion not caused by hemangiosarcoma, and 15 with noncardiac nonhemangiosarcoma neoplasms). PROCEDURES Plasma cTnl concentration was measured, and thoracic radiography, abdominal ultrasonography, and echocardiography were performed in each dog. The cTnl concentration was compared among groups. RESULTS Median plasma cTnl concentration in dogs with cardiac hemangiosarcoma was significantly higher than the concentration in each of the other groups. A plasma cTnl concentration > 0.25 ng/mL could be used to identify cardiac involvement in dogs with hemangiosarcoma at any site (sensitivity, 78%; specificity, 71 %). A plasma cTnl concentration > 0.25 ng/mL could be used to identify cardiac hemangiosarcoma in dogs with pericardia effusion (sensitivity, 81%; specificity, 100%). CONCLUSIONS AND CLINICAL RELEVANCE The median plasma cTnl concentration was higher in dogs with cardiac hemangiosarcoma, compared with the median concentration in dogs with hemangiosarcoma at other sites, dogs with other neoplasms, and dogs with pericardial effusion not caused by hemangiosarcoma. The plasma cTnl concentration may be used to identify cardiac involvement in dogs with hemangiosarcoma and to identify cardiac hemangiosarcoma in dogs with pericardial effusion.