Canine Cutaneous Plasmacytosis: 21 Cases (2005-2015).

BACKGROUND: Cutaneous plasmacytosis (CP) is a syndrome of multiple cutaneous plasma cell tumors, in the absence of multiple myeloma. Although rare in both humans and dogs, treatment recommendations are usually extrapolated from multiple myeloma protocols. To date, no case series of CP have been described in the veterinary literature. HYPOTHESIS/OBJECTIVES: To describe clinical presentation, determine treatment response rates and duration, and report overall survival of dogs with CP. ANIMALS: Twenty-one client-owned dogs with CP. METHODS: Medical records of 21 dogs with CP were reviewed. Diagnosis was based on histopathologic evaluation of at least 1 representative cutaneous or subcutaneous lesion in dogs with ≥3 lesions. Dogs with suspicion of multiple myeloma were excluded. RESULTS: The most commonly affected breeds were the golden (5/21) and Labrador retriever (3/21). Fourteen of 21 dogs had >10 lesions, with some having >100. Lesions commonly were described as round, raised, pink-to-red, and variably alopecic or ulcerated. The most commonly used drug protocol was combined melphalan and prednisone, with an overall response rate (ORR) of 73.7% (14/19 dogs). Single-agent lomustine was associated with a similar ORR of 71.4% (5/7 dogs). For all treatments combined, the median progression-free interval after the first treatment was 153 days. The median survival time from the first treatment was 542 days. CONCLUSIONS AND CLINICAL IMPORTANCE: Alkylating agents were effective in inducing remission of CP; corticosteroids, melphalan, and lomustine were the most commonly used drugs. Survival times were similar to those reported in dogs with multiple myeloma treated with alkylating agents.

Potency and stability of compounded cyclophosphamide: a pilot study.

Compounding of drugs for use in veterinary oncology is becoming increasingly common. We obtained 15 mg cyclophosphamide capsules from five different compounding pharmacies and performed potency analyses at two time points, as well as stability at 60 days. Potency results for four out of five and zero out of five (4/10) samples analysed were inadequate. Stability at 60 days was acceptable for all but one sample. This pilot study raises several important points of concern when compounding chemotherapy in dogs and cats. Further studies are necessary to solidify this data. Collaboration between pharmacists, veterinarians and regulatory bodies is needed to ensure safe and accurate delivery of compounded drugs to client-owned animals.

The use, publication and future directions of immunocytochemistry in veterinary medicine: a consensus of the Oncology-Pathology Working Group.

One of the primary objectives of the Oncology Pathology Working Group (OPWG), a joint initiative of the Veterinary Cancer Society and the American College of Veterinary Pathologists, is for oncologists and pathologists to collaboratively generate consensus documents to standardize aspects of and provide guidelines for oncologic pathology. Consensus is established through review of relevant peer-reviewed literature relative to a subgroup's particular focus. In this document, the authors provide descriptions of the literature reviewed, the review process, and a summary of the information gathered on immunocytochemistry. The intent of this publication is to help educate practitioners and pathologists on the process of immunocytochemistry and to provide a guide for the use of this technique in veterinary medicine. This document represents the opinions of the working group and the authors and does not constitute a formal endorsement by the American College of Veterinary Pathologists or the Veterinary Cancer Society.

Vinblastine as a second rescue for the treatment of canine multicentric lymphoma in 39 cases (2005 to 2014).

OBJECTIVES: The objective of this study was to retrospectively evaluate response and outcome of dogs with multicentric lymphoma treated with single-agent vinblastine as a second rescue. METHODS: Medical records from 39 client-owned dogs receiving vinblastine rescue treatment (having relapsed on or following completion of UW-Madison and CCNU/L-asparaginase protocols), between 2005 and 2014, were reviewed for information regarding clinical presentation, diagnostic testing, drug dosage, number of treatments, side effects, response and outcome. RESULTS: The median starting dose of vinblastine was 2·6 mg/m(2) (1·7 to 2·8 mg/m(2) ), administered weekly until disease progression. Of the 39 dogs treated, 3 dogs (7·7%) achieved a complete remission, 7 dogs (17·9%) achieved a partial response, 18 dogs (46·2%) maintained stable disease and 11 (28·2%) had progressive disease. Ten dogs (25·6%) developed a grade III or IV neutropenia, and 4 dogs (10·3%) developed grade III or IV thrombocytopenia (one dog in both categories). After starting vinblastine, the median progression-free survival was 29·5 days (0 to 77 days) and overall median survival time was 46 days (4 to 250 days). Duration of first remission was identified as a positive predictor of outcome. CLINICAL SIGNIFICANCE: Single-agent vinblastine is well tolerated in dogs with relapsed or refractory lymphoma. Responses were incomplete and short-lasting.

Retrobulbar lymphoma associated with a ballistic foreign body in a cat.

A seven-year-old domestic shorthair cat, adopted 5 years previously with a corneal perforation of the left eye, was presented for investigation of a left orbital mass. Computed tomography revealed a metallic foreign body within a contrast-enhancing, heterogeneous orbital mass. Large cell lymphoma was diagnosed from a fine needle aspirate. The cat staged negatively and was treated with L-asparaginase, prednisolone and three fractions of radiation therapy. A rapid clinical remission was obtained and the cat remained in remission for 3 years after therapy. This is the first report of large cell lymphoma likely occurring secondary to a foreign body.

Adjuvant therapy with carboplatin and pamidronate for canine appendicular osteosarcoma.

Amputation and chemotherapy are the mainstay of treatment for canine appendicular osteosarcoma (OSA). In vitro studies have demonstrated anti-tumour activity of pamidronate against canine OSA. The purpose of this study was to assess the safety of adding pamidronate to standard post-operative carboplatin chemotherapy in 17 dogs with appendicular OSA treated with limb amputation. Median disease-free interval (DFI) and median survival time (MST) were evaluated as secondary endpoints. Incidence of side effects and treatment outcomes were compared to 14 contemporary control patients treated with carboplatin alone. There were no identified side effects to the pamidronate treatment. The median DFI for the study group was 185 days compared to 172 days for the control group (P = 0.90). The MST of the study group was 311 days compared to 294 days for the control group (P = 0.89). Addition of pamidronate to carboplatin chemotherapy for the treatment of canine appendicular OSA is safe and does not impair efficacy of standard carboplatin treatment.

Retrospective evaluation of doxorubicin-piroxicam combination for the treatment of transitional cell carcinoma in dogs.

OBJECTIVES: To determine whether doxorubicin-piroxicam combination is safe and has activity against transitional cell carcinoma in dogs. METHODS: Data was collected retrospectively from 34 dogs from two institutions over a 6-year period. Signalment, clinical presentation, treatment specifics, adverse events, response, progression-free survival and overall survival time were evaluated. RESULTS: Dogs received doxorubicin every 3 weeks and daily piroxicam; 17 dogs (50%) had surgery. Clinical presentations were those typically reported for transitional cell carcinoma. Mean number of doses administered was 3·5. Of the 23 dogs with measurable disease, 14 (60·5%) had stable disease, 7 (30·5%) had progressive disease and 2 (9%) a partial response. Adverse events were generally manageable, and gastrointestinal in origin; one dog died of treatment-related complications. Overall median progression-free survival and overall survival were 103 and 168 days, respectively. Cytoreductive surgery did not result in prolongation of progression-free survival, but significantly prolonged overall survival. All dogs but one died as a result of disease progression. CLINICAL SIGNIFICANCE: Doxorubicin-piroxicam combination therapy is well-tolerated in dogs with transitional cell carcinoma although progression-free survival, overall survival and biological response rates appear modest. Combination with surgery appears to offer a survival advantage; however, this may reflect tumour location and volume. Prospective studies are necessary to compare activity of combination doxorubicin-piroxicam to currently applied therapies.

Safety evaluation of combination vinblastine and toceranib phosphate (Palladia®) in dogs: a phase I dose-finding study.

Combining drugs with known single-agent activity that lack overlapping dose-limiting toxicities (DLT) and exert antitumour activity through different mechanisms could improve clinical outcome. As toceranib and vinblastine meet these requisites, a phase I trial was performed in combination in dogs with mast cell tumours. The DLT for the simultaneous combination was neutropenia and the maximally tolerated dose was vinblastine (1.6 mg m(-2) every other week) concurrent with toceranib (3.25 mg kg(-1) PO, every other day). This represents greater than a 50% reduction in dose intensity for vinblastine (compared with single-agent use) and as such does not support this combination based on current drug combination paradigms. Although a strict adherence to dose paradigms speaks against the combination, evidence of significant activity (71% objective response) and enhanced myelosuppression suggest additive or synergistic activity. A prospective randomized evaluation comparing this combination with standard single-agent treatments would seem prudent to interrogate this potential.