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Proliferation markers are commonly used for prognostication of mast cell tumours. The aim of the study is to compare the relative abilities of Ki67 and mitotic index to predict survival in the same cohort of dogs with cutaneous MCTs. Histological grade, mitotic index and Ki67 index were performed in all samples and clinical information was obtained by a follow-up questionnaire. Ninety-five dogs were included in the study with a median follow-up of 1145 days. Survival times varied significantly between categories of histological grade, mitotic index and Ki67 index. Multivariable analyses showed that the risk of dying due to MCT was similar in dogs with increased Ki67 index [hazard ratio, HR: 3.0 (95% CI 1.3-6.8)] or increased mitotic index [HR: 2.7 (95% CI 1.1-6.5)]. In conclusion, both mitotic index and Ki67 index were able to independently differentiate MCTs with worse prognosis. This distinction is particularly meaningful in selecting intermediate grade MCTs that may benefit from more aggressive local or systemic treatment.

In humans, the aryl hydrocarbon receptor (AHR) gene battery constitutes a set of contaminant-responsive genes, which have been recently shown to be involved in the regulation of several patho-physiological conditions, including tumorigenesis. As the domestic dog represents a valuable animal model in comparative oncology, mRNA levels of cytochromes P450 1A1, 1A2 and 1B1 (CYP1A1, 1A2 and 1B1), AHR, AHR nuclear translocator (ARNT), AHR repressor (AHRR, whose partial sequence was here obtained) and cyclooxygenase-2 (COX2) were measured in dog control tissues (liver, skin, mammary gland and bone), in 47 mast cell tumors (MCTs), 32 mammary tumors (MTs), 5 osteosarcoma (OSA) and related surgical margins. Target genes were constitutively expressed in the dog, confirming the available human data. Furthermore, their pattern of expression in tumor biopsies was comparable to that already described in a variety of human cancers; in particular, both AHR and COX2 genes were up-regulated and positively correlated, while CYP1A1 and CYP1A2 mRNAs were generally poorly expressed. This work demonstrated for the first time that target mRNAs are expressed in neoplastic tissues of dogs, thereby increasing the knowledge about dog cancer biology and confirming this species as an useful animal model for comparative studies on human oncology.

Optimal chemotherapy protocols for high‐risk mast cell tumours (MCTs) are unknown. The purpose of this study was to determine the tolerability and toxicity profile of a rapidly escalating vinblastine and prednisolone protocol (VPP) in which 3.00 mg/m2 was administered once 7 days apart: at day 14 and at day 21. Dogs with chemotherapy‐naïve MCTs presenting to the Oncology Service of a single institution were prospectively enrolled to receive escalating vinblastine, and haematology and a standardised quality‐of‐life questionnaire were assessed prior to each dosage. Thirty‐four dogs were included: 30 with microscopic disease treated with adequate local therapy and four with macroscopic disease. Of 220 doses of vinblastine administered, 4% were associated with grade 3 and 4 toxicity. A total of 70% of dogs tolerated 3.00 mg/m2 given 7 days apart at day 14 and 21, although 29% of dogs developed dose‐limiting toxicities and 8% discontinued the protocol due to toxicity. In conclusion, VPP was well‐tolerated overall, although prior to further dose intensity optimisation, it is important to determine if dose intensity is linked to outcome in canine MCT to avoid unwarranted toxicity.

A 12-year-old male neutered domestic shorthair cat was presented for staging and treatment recommendations of a lingual mast cell tumour (MCT). Cytology after fine-needle aspiration of the mandibular lymph nodes revealed regional metastasis. There are limited reports of the biological behaviour, response to treatment and overall prognosis of feline oral MCT. The clinical presentation, cytological and histological features, and response to treatment of a feline lingual MCT are discussed.

The objective of this study was to determine the frequency of recommendation of adjuvant chemotherapy by UK-based general veterinary practitioners (GVPs) for canine patients with high-grade mast cell tumours (HGMCTs), splenic haemangiosarcomas (SHSs) and appendicular osteosarcomas (AOSs); to determine which chemotherapeutic protocols are used by GVPs; and to evaluate reasons why chemotherapy may or may not be recommended postoperatively. An internet survey was created in 2013 using an online programme and was distributed to GVPs. Questions relating to the use of adjuvant chemotherapy for three tumours were selected. In total, 300 responses were generated. Surgery was seen as primary therapy by most GVPs for HGMCT (91 per cent) and SHS (88 per cent), but less frequently for AOS (59 per cent). Also, 90, 40 and 57 per cent of respondents recommended adjuvant chemotherapy for HGMCT, SHS and AOS, respectively. Of these, an appropriate chemotherapy protocol was not known by 25, 51 and 36 per cent of GVPs for HGMCT, SHS and AOS, respectively. From the GVPs not recommending chemotherapy, 29, 64 and 66 per cent did not believe chemotherapy to be efficacious for these tumours. The frequency of recommendation regarding postoperative chemotherapy is variable by tumour type. Reasons given why postoperative chemotherapy is not recommended also vary by tumour type.

Gene expression analyses have been recently used in cancer research to identify genes associated with tumorigenesis and potential prognostic markers or therapeutic targets. In the present study, the transcriptome of dogs that had died because of mast cell tumours (MCTs) was characterised to identify a fingerprint having significant influence on prognosis determination and treatment selection. A dataset (GSE50433) obtained using a commercial canine DNA microarray platform was used. The transcriptome of seven biopsies obtained from dogs with histologically confirmed, surgically removed MCTs, treated with chemotherapy, and dead for MCT-related causes, was compared with the transcriptional portrait of 40 samples obtained from dogs with histologically confirmed, surgically removed MCTs and that were still alive at the end of the follow-up period. Among the differentially expressed genes (DEGs), eight transcripts were validated by quantitative real time PCR and their mRNA levels were measured in a cohort of 22 additional MCTs.Statistical analysis identified 375 DEGs (fold change 2, false discovery rate 5%). The functional annotation analysis indicated that the DEGs were associated with drug metabolism and cell cycle pathways. Particularly, members of solute carrier transporter (SLC) and UDP glucuronosyltransferase (UGT) gene families were identified as dysregulated. Principal component analysis (PCA) of the 22 additional MCTs identified the separate cluster dogs dead for MCT-related causes. SLCs and UGTs have been recently recognised in human cancer as important key factors in tumour progression and chemo-resistance. An in-depth analysis of their roles in aggressive canine MCT is warranted in future studies. (C) 2016 Elsevier Ltd. All rights reserved.

Objectives Feline intestinal mast cell tumours (FIMCTs) are rare and reportedly characterised by poor differentiation, aggressive biological behaviour and lack of reliable therapeutic aids. KIT proto-oncogene-activating mutations have never been investigated in these tumours. This study describes the main clinicopathological and microscopic features observed in 17 FIMCTs. Methods Tumour degree of differentiation, proliferative activity, Kit protein expression and KIT mutations were evaluated and correlated with survival to assess their prognostic relevance. Results Ten tumours were located in the small intestine, two in the ileocaecocolic junction, and five in the large intestine. Survival times ranged from 3–538 days. Fifteen tumours were evaluated histologically, and there were six well-differentiated, six moderately differentiated and three poorly differentiated FIMCTs. The last showed a medium-to-large deposition of collagen tissue ( P 2 ( P = 0.022) were significantly associated with decreased survival times. Twelve cases showed Kit protein immunoexpression. The Kit pattern was membranous in five cases (33.3%), focal paranuclear in five (33.3%) and diffuse cytoplasmic in two (13.3%). Cytoplasmic Kit patterns were associated with a lesser differentiation ( P = 0.015). Mutation analysis was successfully performed on 12 primary tumours and four lymph node metastases; however, no encoding mutation was detected. Conclusions and relevance Contrary to reports in the literature, FIMCTs seem to have an extremely variable biological behaviour. We propose a classification based on tumour degree of differentiation and proliferative activity. These findings need to be confirmed in larger series, and exploration of further genomic regions of KIT is warranted to clarify its role in the development and progression of these neoplasms.

This is the second in a series of articles on advanced wound management focusing on difficult wound locations and the importance of continuity of nursing care. This case deals with an eight-year-old Labrador retriever which, after removal of a mast cell tumour from the cranial right shoulder, experienced postoperative wound breakdown. One of the contributing factors was the wound location which was in an area of movement. It was difficult to maintain an appropriate dressing and this article charts the progress of how a successful outcome was achieved.

Oxidative stress status has been evaluated in depth in human medicine and its role in carcinogenesis has been clearly established. The purpose of this prospective study was to evaluate antioxidant concentrations and oxidative stress in dogs with mast cell tumours (MCTs) that had received no previous treatments, and to compare them to healthy controls. In 23 dogs with mast cell tumour and 10 healthy controls, oxidative status was assessed using the Reactive Oxygen Metabolites-derived compounds (d-ROMs) test, antioxidant activity was measured by the Biological Antioxidant Potential (BAP) test, and α-tocopherol levels were evaluated using high-performance liquid chromatography and ultraviolet analysis. At baseline, dogs with MCT had significantly higher d-ROMs (P < 0.00001) and lower BAP (P < 0.0002) compared with healthy controls. However, no significant difference was observed for α-tocopherol (P = 0.95). Results suggest that oxidative stress pattern and oxidative defence barrier are altered in dogs with newly diagnosed MCT compared with control dogs. Future studies are needed in order to assess the prognostic role of oxidative stress and to evaluate the impact of different therapeutic approaches.

Immunohistochemical expression of BAX was evaluated in 24 canine cutaneous mast cell tumours in order to verify the relationship of this expression to the histopathological grade of the lesions and its prognostic value for clinical outcome. BAX expression increased with higher histopathological grades (P=0.0148; P

none 3 cytological grading for mast cell tumours (MCTs) would be highly desirable, allowing to select the most appropriate therapeutic intervention prior to surgery. This study evaluates the applicability on fine-needle aspirations (FNAs) of the novel Kiupel grading system, based on number of mitoses, multinucleated cells, bizarre nuclei and presence of karyomegaly. Fifty consecutive cases with pre-operative cytological diagnosis were included. In cytological specimens, approximately 1000 cells were evaluated, and the histological grade was assessed on the corresponding resected specimens. On cytology, the above parameters were significantly different between histologically low-grade and high-grade tumours (P

Objective: To assess whether wounds from incomplete mast cell tumour excisions are at greater risk of healing complications than wounds from complete excisions, or cutaneous histiocytomas. Methods: Mast cell tumours and cutaneous histiocytomas submitted to Nationwide Laboratories between November 1, 2007 and April 30, 2008 were selected. Questionnaires were sent to submitting veterinarians requesting details of tumour characteristics, clinical approach to the tumour and wound healing. Results: Three hundred and eighty-six mast cell tumours and 524 cutaneous histiocytomas were identified. One hundred and eighty-five mast cell tumours and 244 cutaneous histiocytomas questionnaires were returned (47% response). Wound complications arose in 20% of mast cell tumours and 21% of cutaneous histiocytomas. Multivariable analysis confirmed that larger tumours, tumours on the feet and a soft/“baggy” appearance, were significantly associated with a greater frequency of problems, leading to delayed wound healing and dehiscence. Clinical Significance: Incomplete mast cell tumour excision does not lead to greater risk of wound complications. Mast cell tumour surgical wounds have a similar rate of wound complications as cutaneous histiocytoma wounds.

SummaryObjective: To report the use of an axial pattern flap based on the cranial cutaneous branch of the saphenous artery to close a skin defect left on the medial crus after mast cell tumour removal.Case report: A seven-year-old, 32.41 kg, neutered male mixed-breed dog had a mast cell tumour incompletely excised from the left medial crus. The resulting 6 cm linear scar was excised with 2 cm wide margins and one fascial plane for deep margins. An axial pattern skin flap incorporating the cranial cutaneous branch of the saphenous artery was used to close the resultant skin defect.Results: The histopathology report documented clean margins and the flap survived completely. A seroma developed postoperatively, however it resolved without treatment.Clinical significance: An axial pattern skin flap based on the cranial cutaneous branch of the saphenous artery is a viable option for closing medial crus skin defects in the dog.

Canine mast cell tumours (MCTs) may be graded microscopically for prognostic purposes. Grade I (well-differentiated) and grade II (intermediate differentiation) tumours have an abundance of metachromatic granules within the cytoplasm; however, grade III (poorly differentiated) MCTs may be difficult to diagnose as they frequently have fewer discernable granules. Herein we report that a cross-reactive anti-human CD1a monoclonal antibody (clone O10) may be used in immunohistochemistry to identify canine MCTs of all grades. The antibody was applied to tissue sections from 48 canine MCTs of different histological grades. Serial sections from each tumour were stained with toluidine blue and safranin O to compare diagnostic sensitivity. All MCTs were labelled positively by the CD1a antibody, but histochemical staining was often equivocal and identification of mast cells was extremely difficult in some cases. This antibody did not label neoplastic cells in cases of canine histiocytoma, plasmacytoma or amelanotic melanoma; therefore, the reagent may be a valuable marker for the diagnosis of canine MCTs, especially those tumours of histological grade III.

This thesis determined in phase 1 the pharmacokinetics and cardio-respiratory effects of diphenhydramine (DHP) in conscious research dogs administered 1 mg/kg, IV, or 2 mg/kg, IM. Phase 2 consisted of a blinded clinical trial to investigate the effectiveness of DPH in anesthetized dogs to prevent the negative cardiovascular effects associated with potential histamine release during surgical excision of mast cell tumours (MCT). Dogs were anesthetized with a balanced anesthetic and analgesic technique and then allocated to receive DPH (1 mg/kg, IV) or saline. Plasma DPH and histamine concentrations were measured and correlated with cardio-respiratory parameters. Phase 1 results provided descriptive pharmacokinetics of DPH administered IV or IM in healthy dogs. Cardio-respiratory parameters remained within normal limits during the experiment and no behavioural changes were associated with DPH administration. The IV protocol was chosen for the clinical phase 2 under anesthesia, due to a shorter time to maximal concentrations (Tmax) of 6.0 ± 0.3 min versus 45 ± 5.1 min for the IM group. During the clinical phase 2, plasma concentrations of DPH remained above concentrations considered therapeutic (25 ng/mL) in humans until the end of surgery. Despite the lack of statistical differences in histamine concentrations throughout anesthesia between groups, higher histamine concentrations were measured during maximal manipulation of the tumour. Mean arterial and diastolic blood pressures were significantly lower in DPH than in the saline group during surgical excision of the tumour. These results contradict the assumption that hypotension is more likely in dogs undergoing MCT excision that have not received DPH. Values for cardio-respiratory parameters in both groups were considered within acceptable limits for anesthetized dogs. In dogs, DPH can be administered by either IV or IM routes at 1 mg/kg and 2 mg/kg, respectively, to yield plasma concentrations that exceed therapeutic concentrations in humans without noticeable adverse behavioural or cardio-respiratory side effects. The administration of DPH prior to surgical removal of MCT in dogs did not have clear clinical anesthetic differences related to cardio-respiratory responses compared to dogs receiving a saline placebo. Ontario Veterinary College Pet Trust

Electrochemotherapy combined with peritumoral interleukin-12 (IL-12) gene electrotransfer was used for treatment of mast cell tumours in 18 client-owned dogs. Local tumour control, recurrence rate, as well as safety of combined therapy were evaluated. One month after the therapy, no side effects were recorded and good local tumour control was observed with high complete responses rate which even increased during the observation period to 72%. IL-12 gene electrotransfer resulted in 78% of patients with detectable serum IFN-γ and/or IL-12 levels. In the treated tumours vascular changes as well as minimal T-lymphocytes infiltration was observed. After 1 week, the plasmid DNA was not detected intra- or peritumorally and no horizontal gene transfer was observed. In summary, our study demonstrates high antitumour efficacy of electrochemotherapy combined with IL-12 electrotransfer, which also prevented recurrences or distant metastases, as well as its safety and feasibility in treatment of canine mast cell tumours.

Dissertação de Mestrado Integrado em Medicina Veterinária A iniciação e a progressão neoplásica têm sido relacionadas com o stress oxidativo, o qual atua como agente de lesão genética, aumentando as mutações e levando à indução de lesão do ADN (ácido desoxirribonucleico), à instabilidade do genoma, à proliferação celular, ao aumento da sobrevivência e da migração celular. A existência de neoplasia está também associada a baixas concentrações de antioxidantes no sangue. A paraoxonase sérica tipo 1 (PON1) pertence à família das proteínas de fase aguda rápida negativa com propriedades antioxidantes e por isso relacionada com doenças que envolvem o stress oxidativo e, consequentemente, com doenças neoplásicas. O presente estudo teve como objetivo a determinação do valor prognóstico da variação da atividade da PON1 em oncologia canina. Assim, foi avaliado o valor da atividade da PON1 em 48 cães, metade pertencente ao grupo controlo e os restantes ao grupo de doentes oncológicos. Entre estes foram estudados oito cães com linfoma e dezasseis com mastocitoma. Foi realizada a comparação do valor da atividade da PON1 entre os diferentes grupos de animais estudados, foram avaliadas as variações de PON1 de acordo com a idade, género e algumas alterações encontradas nos parâmetros de estado geral dos doentes oncológicos e foi estudada a função de sobrevivência. Os resultados revelaram uma diminuição dos valores da atividade da PON1 nos doentes oncológicos, variação esta mais acentuada nos animais com linfoma. Não se observaram diferenças estatisticamente significativas entre géneros e entre os animais com menos e com 10 anos ou mais. Já os animais com sinais gastrointestinais e com alterações no hemograma revelaram diferenças significativas nos valores de atividade da PON1. Foram observadas diferenças estatisticamente significativas na atividade da PON1 na sobrevida dos animais com doença oncologica. Face aos resultados obtidos pode concluir-se que, embora existam diversos fatores de prognóstico, a análise da atividade da PON1 é vantajosa nos animais que apresentam linfoma e por este facto constituir uma ajuda valiosa para os clínicos na decisão da terapêutica a aplicar e para os proprietários quanto à abordagem ao seu animal. ABSTRACT - Neoplasic initiation and progression has been related with oxidative stress, since it acts as a genetic lesion agent, increasing mutations and leading to DNA (deoxyribonucleic acid) damage, genome instability, cellular proliferation, increased survival and cell migration. Low concentrations of essential antioxidants are observed in the bloodstream, associated with the oncologic disease. Paraoxonase 1 (PON1) is a fast negative acute phase protein with antioxidant properties, thereby it is related to several diseases involving oxidative stress, and therefore with neoplastic diseases. The present study aimed to determinate the prognosis value of the PON1 activity variation in canine oncology. The sample studied consisted in 48 dogs, half of which belonged to the control group and the remaining were oncologic patients: eight with lymphoma and sixteen with mast cell tumour, in which the value of PON1 activity was measured. In theis study the value of PON1 activity of the different groups was compared, as well as the PON1 activity variations according with age, gender and some changes in the general health parameters of the oncologic patients and the survival function was studied. The results revealed a decrease in PON1 value in the oncologic patients, which was more pronounced in the lymphoma patients. No significant differences were found regarding gender and age. Only the dogs with gastrointestinal signs and with blood cell count changes revealed some statistical differences. Significant differences were observed in survival between animals with “Higher” and “Lower” PON1 activity values. Considering our results, and although there are several prognostic factors in these tumours, it can be concluded that PON1 activity analysis maybe usefull and can help the owners with their decisions concerning the therapeutic approach of their pet.

Made available in DSpace on 2018-11-26T15:28:23Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-11-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Cancer stem cells (CSCs) are related to malignancy and resistance to chemotherapy in several tumours. OCT4 is a 'pluripotency factor' that is expressed by these cells. The aim of the present study was to investigate OCT4 expression in canine cutaneous mast cell tumours (MCTs) by means of immunohistochemistry. Twenty-eight cases were evaluated and showed variable immunolabelling patterns. The dogs were treated by surgery alone and followed up for a minimum of 180 days. No significant difference was found between histopathological grades and similar results were obtained for mortality due to the disease and post-surgical survival. These preliminary results suggest that OCT4 expression is not a precise prognostic indicator for canine MCT. (C) 2015 Elsevier Ltd. All rights reserved. Univ Sao Paulo, Fac Zootecnia & Engn Alimentos, Lab Oncol Comparada & Translac, Sao Paulo, Brazil Univ Sao Paulo, Fac Med Vet & Zootecnia, Sao Paulo, Brazil Univ Metodista Sao Paulo, Sao Bernardo Do Campo, Brazil Univ Estadual Paulista, Sao Paulo, Brazil Univ Anhembi Morumbi, Sao Paulo, Brazil Univ Estadual Paulista, Sao Paulo, Brazil FAPESP: 2010/05094-5 FAPESP: 2013/13252-8

Staging of dogs with cutaneous mast cell tumours (MCTs) is an important diagnostic step. Aspiration of the liver and the spleen is often part of routine staging. This study cytologically compared mast cell numbers in fine-needle aspirates of liver and spleen of clinically normal unaffected dogs with those of dogs with cutaneous MCT and an ultrasonographically normal appearing liver and spleen. The unaffected dogs (n = 32) were selected from humane society dogs, and the affected dogs (n = 51) were selected from hospital cases. There were no statistically significant differences in each of the parameters evaluated for the liver aspirates. For splenic aspirates, affected dogs showed significantly more mast cells per cluster (P = 0.04) and more isolated mast cells per slide (P = 0.03) compared with unaffected dogs. However, no clinically important difference existed between the unaffected and affected dogs; thus, routine aspiration of an ultrasonographically normal appearing liver and spleen of dogs with cutaneous MCT does not appear to be a clinically useful staging tool.

In humans, low dietary vitamin D intake and a low vitamin D status have been linked to increased risk of cancer development. This association is starting to be explored in canines. This thesis is an investigation of the dietary vitamin D intake and vitamin D status of dogs with cancer, specifically osteosarcoma, lymphoma and mast cell tumours, in comparison to healthy dogs. Plasma 25(OH)D concentration was significantly higher in healthy dogs than in those with osteosarcoma and lymphoma, but not mast cell tumours. There was an independent effect of cancer, dietary vitamin D intake and plasma ionized calcium on plasma 25(OH)D concentrations. The independent effect of cancer suggests that dietary vitamin D intake is not responsible for observed differences in plasma 25(OH)D concentrations. Further research is needed to investigate whether decreased plasma 25(OH)D concentrations are a factor in cancer development, or a consequence of cancer. OVC Pet Trust, AAVN/Waltham Research Grant, Royal Canin

Genetic factors play a major role in carcinogenesis. Many breeds have been reported to be predisposed to mast cell tumour (MCT) development using various methods and diverse control populations. A database of 222 dogs with MCT seen at a UK university referral hospital was compared to three control populations, namely, an insured population of UK dogs, registrations with the UK Kennel Club and other dogs seen through the same hospital. Odds ratios were calculated for each breed. Boxers, Labradors, Golden Retrievers and Staffordshire Bull Terriers appeared predisposed to MCT development. English Springer Spaniels, English Cocker Spaniels, German Shepherd Dogs, West Highland White Terriers and Cavalier King Charles Spaniels were underrepresented.

A nine-year-old female Boxer dog presented with a large infected mast cell tumour (MCT) on her left hock. Diagnosis confirmation and staging occurred prior to medical management to shrink the mass lesion, followed by surgical resection. Masitinib was then administered as follow-up treatment that has successfully prevented tumour re-occurrence for the last six months.

Made available in DSpace on 2016-07-07T12:33:51Z (GMT). No. of bitstreams: 0 Previous issue date: 2013. Added 1 bitstream(s) on 2016-07-07T12:43:13Z : No. of bitstreams: 1 ISSN0035-0389-2013-108-587-588-147-150.pdf: 1390787 bytes, checksum: 7cedd586ed16d4f0da076f3f4d8746b0 (MD5) O comportamento clínico e biológico do mastocitoma cutâneo canino é bastante variável, tornando o estabelecimento do prognóstico e a escolha do melhor tratamento a ser instituí- do um desafio para os oncologistas veterinários. Embora existam inúmeros protocolos quimioterápicos descritos para o tratamento do mastocitoma cutâneo canino, os mesmos foram avaliados comparando-se grupos heterogêneos, com diferentes fatores prognósticos clínicos e histopatológicos, dificultando desta forma a escolha do melhor protocolo a ser utilizado. Pretende-se com este relato descrever os efeitos do protocolo neoadjuvante à base de vimblastina e lomustina num caso de mastocitoma grau III/ alto grau na região do períneo, de prognóstico reservado a mau, baseado nos fatores clínicos (localização, tamanho tumoral, velocidade de crescimento), características histopatológicas (grau de Patnaik e Kiupel) e imuno-histoquímica (imunomarcação de Ki-67, c-kit e glicoproteína P) desfavoráveis que respondeu favoravelmente ao tratamento instituído e apresenta até o presente momento uma sobrevida de 110 semanas sem sinais de recidiva da doença. The clinical and biological behavior of canine cutaneous mast cell tumors is highly variable, making the establishment of prognosis and choose of the best treatment to be instituted a challenge to veterinary oncologists. While there are many chemotherapeutic protocols outlined for treatment of canine cutaneous mast cell tumors, they were evaluated by comparing heterogeneous groups, with different clinical and histopathological prognostic factors, thus making it difficult to select the best protocol to use. The intention of this report is describe the effects of a neoadjuvant protocol with vinblastine and lomustine in a case of grade III / high degree mast cell tumour in perineum, with worse prognosis, based on unfavorable clinical factors (location, tumor size, growth rate ), histopathological characteristics (degree of Patnaik and Kiupel) and immunohistochemistry (immunostaining of Ki-67, kit and P-glycoprotein ) who responded favorably to treatment and has to date a survival of 110 weeks without signs of recurrence disease. Universidade Estadual Paulista, Departamento de Clínica e Cirurgia Veterinária, Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal Universidade Estadual Paulista, Departamento de Clínica Veterinária, Faculdade de Medicina Veterinária e Zootecnia de Botucatu

Completeness of mast cell tumour (MCT) excision is determined by assessment of histologically tumour-free margins (HTFM). The HTFM width necessary to prevent local recurrence (LR), recognized as histologic safety margin (HSM) in human oncology, has not been defined. We hypothesized that HTFM width would correlate with risk for LR and high-grade tumours would require wider HTFM than low-grade tumours. Records of dogs with completely excised MCTs were included. Signalment, two-tier tumour grade, tumour size, HTFM width, recurrence and therapy data was collected. High-grade (n = 39) tumours were more likely to recur than low-grade (n = 51) tumours (35.9% versus 3.9%), P

Background Canine mast cell tumour proliferation depends to a large extent on the activity of KIT, a tyrosine kinase receptor. Inhibitors of the KIT tyrosine kinase have recently been introduced and successfully applied as a therapeutic agent for this tumour type. However, little is known on the downstream target genes of this signaling pathway and molecular changes after inhibition. Results Transcriptome analysis of the canine mast cell tumour cell line C2 treated for up to 72 hours with the tyrosine kinase inhibitor masitinib identified significant changes in the expression levels of approximately 3500 genes or 16% of the canine genome. Approximately 40% of these genes had increased mRNA expression levels including genes associated with the pro-proliferative pathways of B- and T-cell receptors, chemokine receptors, steroid hormone receptors and EPO-, RAS and MAP kinase signaling. Proteome analysis of C2 cells treated for 72 hours identified 24 proteins with changed expression levels, most of which being involved in gene transcription, e.g. EIA3, EIA4, TARDBP, protein folding, e.g. HSP90, UCHL3, PDIA3 and protection from oxidative stress, GSTT3, SELENBP1. Conclusions Transcriptome and proteome analysis of neoplastic canine mast cells treated with masitinib confirmed the strong important and complex role of KIT in these cells. Approximately 16% of the total canine genome and thus the majority of the active genes were significantly transcriptionally regulated. Most of these changes were associated with reduced proliferation and metabolism of treated cells. Interestingly, several pro-proliferative pathways were up-regulated, which may represent attempts of masitinib treated cells to activate alternative pro-proliferative pathways. These pathways may contain hypothetical targets for a combination therapy with masitinib to further improve its therapeutic effect.

This work explored features of canine mast cell tumours (MCT) to improve prognosis and to discover potential therapeutic targets. Subcutaneous MCT - a subset of these tumours arising in the subcutis - are usually grouped with cutaneous MCT, but there is evidence that they may be clinically different. The first objective was to develop a grading scheme for subcutaneous MCT. Over 300 canine subcutaneous MCT were evaluated retrospectively and parameters were correlated with clinical outcomes, making this the largest retrospective survival study of these tumours to date. The results of the study showed that the majority of subcutaneous MCT had excellent outcomes and key prognostic markers were identified (mitotic index, surgical margins and degree of infiltration). A subset of the subcutaneous MCT from the retrospective study was further evaluated to assess the cellular localization of KIT - a receptor tyrosine kinase (RTK) which is dysregulated and constitutively activated in some cutaneous MCT - as well as Ki67, a proliferation marker. In addition, evaluation of mutations of c-KIT, the gene for KIT, was determined for each MCT. Cytoplasmic KIT localization and high Ki67 values were predictive of decreased survival time and time to local reoccurrence, but no c-KIT mutations were detected. The majority of canine MCT do not appear to depend solely upon KIT for tumour progression and few other RTK targets have been studied in canine MCT. Based on evidence that vascular endothelial growth factor receptors (VEGFR) and platelet-derived growth factor receptors (PDGFR) - may play a role in the progression of canine MCT; the expression and distribution of these RTK were evaluated. The results showed that canine MCT have unique expression profiles and activity of KIT, VEGFR2 and PDGFR. Two novel mast cell tumour cell lines were generated and used to assess signalling of KIT and VEGFR2 in vitro. Stimulatory and inhibitory responses were assessed and found to be different in both cell lines. Both had autophosphorylated VEGFR2 and an autocrine VEGF/VEGFR2 signalling pathway existed for both cell lines. These findings are unique and the first that identify autocrine VEGF signalling as a possible survival mechanism for canine MCT. Pet Trust Foundation, Ontario Veterinary College

Degradation of the extracellular matrix and angiogenesis are associated with tumour invasion and metastasis in human and canine neoplasia. Matrix metalloproteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs) and vascular endothelial growth factor-A (VEGF-A) are key mediators of these respective processes. Mast cell tumour (MCT) is the most common malignant cutaneous tumour in dogs. MCTs are always considered potentially malignant, but their true metastatic potential is unknown. In the present study, samples from seven grade 1, 22 grade 2 and six grade 3 MCTs were subjected to quantitative real-time polymerase chain reaction and immunohistochemistry (IHC) to evaluate MMP-2, MMP-9, membrane-type 1 MMP (MT1-MMP), TIMP-2 and VEGF-A mRNA and protein expression. Gelatin zymography (GZ) was also performed to evaluate MMP-2 and MMP-9 activity. MMP-9 and VEGF-A mRNA increased with histological grade, while TIMP-2 decreased with increasing grade. Gene expression data obtained for MMP-9, VEGF-A and TIMP-2 were confirmed by IHC for evaluation of the respective proteins. In contrast, MMP-2 and MT1-MMP had variable, but similar, expression for both mRNA and protein. Despite the high variability observed, there was correlation between MMP-2 and MT1-MMP mRNA expression (r=+0.91, P0.0001). The MMP-2:TIMP-2 and MMP-9:TIMP-1 mRNA ratios showed an imbalance between MMPs and their specific inhibitors in MCTs, which increased with the histological grade. Finally, the activities of both latent and active forms of MMP-2 and MMP-9 were evaluated by GZ and there were significant increases in their activities with increasing histological grade and immunohistochemical expression. This study demonstrates that MMP-9, TIMP-2 and VEGF-A expression is related to histological grade and suggests that these markers are possible indicators of malignancy and targets for therapeutic strategies.

Context: The acute phase protein response is part of a non-specific and complex host response to inflammation. It occurs shortly after tissue injury and may be induced by a range of different causes, including infectious, inflammatory, neoplastic, traumatic or immunological disease. Although it was conventionally believed that APPs were exclusively hepatocyte derived, there is increasing evidence to support extra-hepatic generation in neoplastic and other disease states. In people, C-reactive protein (CRP) has been shown to be of value in identifying metastatic disease from primary renal tumours as well as showing promise for monitoring rejection of renal transplants. Serum CRP correlates with survival in colorectal cancer and oesophageal squamous cell carcinoma while serum amyloid A (SAA) concentrations correlate with cancer activity, stage and prognosis in gastric tumours. Recent immunohistochemical studies in people with oesophageal carcinoma suggest that tumour tissue may itself elaborate APP with a poorer survival and outcome associated with tumours elaborating higher levels of CRP. A similar association has been seen between alpha-1 acid glycoprotein (AGP) and colorectal tumours and ovarian carcinoma.\ud \ud As yet, studies regarding APP values in neoplastic conditions in dogs are limited, and many are non-specific. In veterinary patients, elevated levels of AGP have been identified in dogs with a range of tumours with localisation to liver and splenic tissue in one study. Another study found higher levels of AGP in dogs with non-specific tumours of grade III-IV based on the WHO Tumour Node Metastasis (TNM) scale and elevated serum AGP has been documented in non-specific tumour-bearing cats. Elevated CRP levels have been documented in both dogs and cats with lymphoma and serum CRP may be used as an indicator of complete remission status in dogs with multicentric lymphoma. Elevated levels of CRP, Haptoglobin (Hp) and SAA have been identified in dogs with mammary tumours, with significant increases over normal in the presence of metastatic disease, primary tumours greater than 5cm in diameter and those with ulceration.\ud \ud In this study we evaluated an APP profile using four APPs (CRP, Hp, SAA and AGP), in dogs with mast cell tumours (MCTs) and sarcomas to assess whether the APP profile would change in reflection of tumour presence; whether the extent of any change would correlate with tumour grade; and whether the changes would differ with tumour type.\ud \ud Approach: Patients with naturally occurring MCTs and sarcomas presenting for staging and treatment were included if they met the study criteria. Criteria for inclusion were that the patient was not currently being treated with steroids, did not have a recent history of infectious or inflammatory disease other than the tumour, a definitive histological diagnosis was available and a full staging procedure was completed prior to surgery using standard oncological protocols to identify metastatic disease where present. Following surgical resection each tumour was submitted for full histological evaluation and grading to include assessment of the margins of excision. Cases were only enrolled in the study if blood sampling formed part of the clinical investigation and/or treatment, and where residual blood was available after diagnostic sampling which would otherwise have been disposed of as clinical waste. In brief, the CRP levels were determined by immunoturbidometric assay and Hp by means of haemoglobin binding capacity assay. SAA was measured with a commercial canine ELISA kit (TriDelta Development, Dublin, Ireland) and AGP was measured with a commercial radial immunodiffusion assay (J-Path Inc, Tokyo, Japan). \ud \ud Results: All comparisons using continuous data were checked for normality and equality of variances and appropriate statistical tests were employed (student’s t test operationalised as a two-sample Welch’s test for samples of unequal sizes and variances, Mann-Whitney, Chi-square and Fishers exact tests as appropriate). In MCTs, the CRP and AGP were elevated above reference ranges, Hp showed no significant change and SAA dropped relative to the reference range. In sarcoma patients CRP, Hp and AGP were all elevated above reference ranges. None of the tumour grade differences were significant apart from SAA in sarcoma patients where values in grade 2 sarcoma were significantly higher than those in grade 1.\ud \ud Interpretation and notes of caution: The numbers in our groups were small which compromises the validity of statistical evaluation so our results must be interpreted with caution. However some interesting relationships have emerged from the initial evaluation which suggests that APP profiles may have potential for screening in patients with neoplastic disease. For patients with MCTs, CRP and AGP levels would be expected to increase, with a concurrent drop in SAA levels. In sarcoma patients CRP, AGP and Hp can all be expected to increase. These initial results need to be evaluated in larger numbers of cases with naturally occurring disease to validate the findings, to assess whether the presence and extent of metastatic disease has a significant effect, and also to confirm whether the values alter after surgical resection of the primary tumour.\ud \ud Significance of findings: If there are consistent and specific changes in APP profiles associated with different tumour types in dogs, as is the case with a wide range of cancers in humans, then there may be potential for APP profiles on routine blood samples to be used as indicators of disease, or where monitoring for recurrence. Whether they could also have potential for assessment of the presence of metastatic disease and prognosis as in people is unknown as yet.

The pathogenesis of canine mast cell tumour (MCT) remains unknown. Moreover, therapeutic options are limited and resistance to targeted drugs and recurrences are common, necessitating the identification of additional cellular targets for therapy. In this study we investigated the expression of phosphorylated AKT protein in 25 archival canine MCT samples by immunohistochemistry and examined the correlation between the immunohistochemical scores and histopathological tumour grades. AKT protein was detected in all of the samples and 24 of the 25 samples expressed the phosphorylated form of the protein, albeit with variable intensity. However, when the immunohistochemical scores of weak, intermediate and strong labelling were compared with the histopathological grades of I to III, there was no strong correlation. This study suggests that canine MCT cells have activated AKT and indicates the need for further research on the role of the AKT protein and the possibility of targeting the AKT signalling pathway in MCTs.

Two dogs were treated with a hypofractionated course of radiotherapy following surgical excision of an intermediate grade mast cell tumour and a round cell tumour, respectively. Both dogs developed a sarcoma of the bone, within the irradiated site, several years after the initial radiotherapy treatment. Bone tumours arising within a previously irradiated area are well-recognized late radiotherapy side-effect in humans but have been reported infrequently in dogs. These are the first case reports to describe bone sarcomas in the appendicular skeleton at a site, which had been previously treated by a hypofractionated course of radiotherapy for an unrelated tumour.

The clinical, advanced imaging and surgical features of a case of canine extradural mast cell tumour are presented. This rare location has only been reported once before as a primary lesion, although the present case may be a metastatic lesion. Given the frequent occurrence and treatment of cutaneous mast cell tumours in dogs, the finding of spinal metastasis is an important reminder to consider metastatic neoplasia in cases of previously treated cancers presenting with spinal pain.

Lactate dehydrogenase (LDH) is commonly used in human cancer patients for prognostic purposes. Aim of this study was to determine the magnitude of serum LDH elevation in dogs with cancer compared with healthy dogs and dogs with non-neoplastic disease, and to verify whether it may support the diagnosis of specific malignancies. About 128 healthy dogs, 211 diseased dogs and 188 cancer dogs were enrolled. Dogs with cancer had significantly higher LDH than diseased (P < 0.001) and healthy dogs (P < 0.001), but large overlap was found. Dogs with lymphoma showed significantly higher LDH compared with dogs with carcinoma (P < 0.001) or mast cell tumour (MCT; P < 0.05) but not compared with other malignancies. When considering lymphoma and MCT, LDH levels were not different between early and advanced clinical stages. Measuring LDH levels may not be useful as a screening tool for cancer detection. More studies are needed to define its role in specific tumours.

A well-differentiated cutaneous mast cell tumour was diagnosed in a subadult female giant Galapagos tortoise. The tumour was a pedunculated, verrucose mass located near the base of the neck. The histological features, which were diagnostic for a mast cell tumour, included abundant intracytoplasmic granules that were stained metachromatically with Giemsa and toluidine blue stains. Mast cell tumours are rare in reptiles, and this is the first description of a mast cell tumour in a chelonian. Se diagnosticó un mastocitoma cutáneo bien diferenciado en una hembra subadulta de tortuga gigante de Galápagos. El tumor era una masa verrucosa pedunculada situada cerca de la base del cuello. Las características histológicas que eran diagnósticas de un tumor de mastocitos, incluían abundantes gránulos intracitoplasmáticos que se tiñeron con tinción de Giemsa y azul de toluidina. Los tumores de mastocitos son raros en los reptiles, y ésta es la primera es la primera descripción de un mastocitoma en un quelonio. Universidad Nacional, Costa Rica. Escuela de Medicina Veterinaria

Electrochemotherapy is a treatment that combines electroporation, i.e. application of electric pulses to the tumors, that induces under suitable conditions reversible permeabilization of cell membrane and administration of nonpermeant or poorly permeant chemotherapeutic drugs with intracellular targets, whose entry into the cells is facilitated by electroporation. In veterinary medicine, the predominant chemotherapeutic drug used in electrochemotherapy is cisplatin, followed by bleomycin. In this review, the results of the studies performed at the University of Ljubljana, Veterinary faculty are presented. Spontaneous tumors of different origin in dogs, cats and horses were treated with electrochemotherapy using either cisplatin or bleomycin. Different electroporation protocols were used and the results on antitumor effectiveness compared. The results demonstrated that electrochemotherapy is highly effective and safe local treatment regardless of tumor histology, chemotherapeutic drug or electroporation protocol used.

The Patnaik histological grade is a good method for the prediction of long-term mast cell tumour behaviour but it is influenced by subjective inter-observer variations and intratumoral heterogeneity. The present study evaluated each of the histopathological parameters used to formulate Patnaik's grade in terms of prognosis and tested whether they have a different prognostic sensitivity, thereby disclosing which could be considered more useful in the prediction of tumour recurrence and patient survival. Clinical presentation (single or multiple tumours) was also considered as possible prognostic factor. The results demonstrated that individual histological criteria together with multiple presentation may be of value in predicting the outcome of mast cell tumours. Among these, invasiveness (beta1.85; standard error 1.15) and the number of mitotic figures (beta3.01; standard error 1.18) showed high prognostic significance (Cox proportional hazard regression for censored data; chi-squared = 15.52, degree of freedom = 6, p = 0.016) and could serve as reliable prognostic indicators avoiding more subjective parameters such as cellular differentiation, nuclear morphology and tumoural pattern.