RESUMO -Tendo em vista a grande incidência das afecções oncológicas este trabalho realizou um estudo retrospectivo em 333 cães acometidos por neoplasias e atendidos no Hospital Veterinário da Universidade Federal do Paraná, Campus de Curitiba, no período de janeiro de 1998 e junho de 2002. Os animais tratados no decorrer destes anos foram catalogados e avaliados no que diz respeito ao diagnóstico, etiologia, tratamento e evolução dos tumores. As neoplasias mais freqüentes foram correlacionadas com o sexo, idade, raça e abordagem terapêutica. A alta prevalência de tumores nas fêmeas (232 casos) em relação aos machos foi correlacionada com o elevado número de neoplasias mamárias (152 casos), representando (45,64%) de todos os tumores pesquisados neste estudo. O segundo tumor mais diagnosticado foi o mastocitoma (11,7%), sendo que 46,15% destes comprometeram cães da raça Boxer. Na seqüência prevaleceram os tumores venéreos transmissíveis (3,3%), seguido dos linfossarcomas (3,3%). A forma principal de diagnóstico constou de citologia (81%) e histopatologia (93,7%). Quanto à terapêutica, 84,68% dos pacientes foram submetidos à cirurgia, 10,51% à cirurgia e quimioterapia e 4,8% foram tratados apenas com fármacos citostáticos. Como conclusão, o elevado número de cães acometidos pelas afecções oncóticas diagnosticadas demonstra a necessidade do médico veterinário dedicar-se intensivamente ao estudo da oncologia veterinária, pois o domínio desta especialidade tornou-se uma exigência do mercado de trabalho atual.Palavras chaves: Oncologia, Neoplasia, Câncer, Cães.ABSTRACT -A retrospective survey has been carried out at the Oncology Section of the Federal University of Paraná Veterinary Hospital on the prevalence of cancer in dogs. From 333 cases of neoplasia diagnosed during the period of 1998 to 2002 232 cases -72.7 % -were found in female dogs. From this total about 45.6 % of them were affected with mammary neoplasia. The second more frequent tumor found were mast cell tumors (11.7%) from which 46.15% affected dogs of Boxer breed, followed by transmissible venereal tumors (3.3 %) and lymphoma (3.3%). Diagnostics were carried out mainly by cytology (81 %) and hystopathology (93.7%) procedures. Treatment of the cancer forms diagnosed was performed mainly by surgery (84.6%) followed by surgery and chemotherapy (19.51%) and chemotherapy by means of cytotoxic drugs (10.51%). In conclusion, the increasing number of cancer cases found during these period of time at the University of Paraná Veterinary Hospital has shown the need of veterinarians and of Veterinary Medicine students to Correspondência para DE NARDI, A.B

The canine transmissible venereal tumor (CTVT) is a cancer lineage that arose several millennia ago and survives by “metastasizing” between hosts through cell transfer. The somatic mutations in this cancer record its phylogeography and evolutionary history. We constructed a time-resolved phylogeny from 546 CTVT exomes and describe the lineage’s worldwide expansion. Examining variation in mutational exposure, we identify a highly context-specific mutational process that operated early in the cancer’s evolution but subsequently vanished, correlate ultraviolet-light mutagenesis with tumor latitude, and describe tumors with heritable hyperactivity of an endogenous mutational process. CTVT displays little evidence of ongoing positive selection, and negative selection is detectable only in essential genes. We illustrate how long-lived clonal organisms capture changing mutagenic environments, and reveal that neutral genetic drift is the dominant feature of long-term cancer evolution.

Mammary neoplasms are the most frequent tumors in female dogs. Of these neoplasms, benign mixed tumors (BMTs) and carcinomas in mixed tumors (CMTs) represent a large proportion of small animal oncology diagnoses. Together with carcinosarcomas (CSs), these three neoplastic entities are characterized by the proliferation of benign or malignant epithelial, myoepithelial, and mesenchymal cells, depending on their histological types. This histological heterogeneity, in addition to their molecular heterogeneity, confers these tumors with distinct biological behavior, which results in the need for different clinical and therapeutic approaches. The present consensual document elucidates the oncological issues related to the diagnosis, prognosis, and treatment of BMTs, CMTs, and CSs of the canine mammary gland.

Canine transmissible venereal tumour (CTVT) is a clonally transmissible cancer that originated approximately 11,000 years ago and affects dogs worldwide. Despite the clonal origin of the CTVT nuclear genome, CTVT mitochondrial genomes (mtDNAs) have been acquired by periodic capture from transient hosts. We sequenced 449 complete mtDNAs from a global population of CTVTs, and show that mtDNA horizontal transfer has occurred at least five times, delineating five tumour clades whose distributions track two millennia of dog global migration. Negative selection has operated to prevent accumulation of deleterious mutations in captured mtDNA, and recombination has caused occasional mtDNA re-assortment. These findings implicate functional mtDNA as a driver of CTVT global metastatic spread, further highlighting the important role of mtDNA in cancer evolution.DOI: http://dx.doi.org/10.7554/eLife.14552.001

RESUMOObjetivando analisar a prevalência de TVT em relação ao sexo, raça, idade, localização da lesão e resposta ao tratamento quimioterapêutico foi realizado um estudo retrospectivo de 144 cães atendidos no Hospital Veterinário da Universidade de Uberaba (HVU) durante os anos de 2007 à 2012, diagnosticados com TVT através da realização de exames de cito ou histopatologia. Destes, 59% eram cães sem raça definida (SRD). Apesar de 16,7% dos cães avaliados não terem suas idades determinadas, os resultados desta pesquisa revelaram que os pacientes apresentaram idade variando entre 1 e 15 anos sendo a faixa etária entre 2 e 8 anos (40,2%) a mais afetada. Em relação ao sexo, este trabalho demonstrou que as fêmeas foram mais acometidas que os machos (66,7 e 33,3% respetivamente). Observou-se que a principal localização da neoplasia foi a vulva (65,3%), seguida pelo pênis (30,6%), cavidades nasal (3,5%) e oral (0,7%). Dentre os 54 cães que foram submetidos ao tratamento no hospital veterinário, 39 concluíram o protocolo, sendo que 33 apresentaram citorredução completa utilizando vincristina como agente único; 3 animais se encontravam em tratamento ao final do estudo e nos 3 casos em que houve quimiorresistência, os pacientes se beneficiaram de doxorrubicina. PALAVRAS-CHAVE: cão, doxorrubicina, vincistina. SUMMARYTo analyze the prevalence of TVT in relation to sex, breed, age, lesion location, and response to chemotherapeutic treatment, a retrospective study from 2007 to 2012 was conducted with dogs from the Veterinary Hospital of the University of Uberaba (HVU) diagnosed with TVT by cytology or histopathology. Which, 59% were mongrel dogs (59%). Although 16.7% of these dogs had their ages undetermined, the data of this study showed that patients were aged between 1 and 15 years being the range between 2 and 8 years (40.2%) the most affected. Regarding sexual predisposition, this study shows that females were more affected than males (66.7, 33.3% respectively). The primary site of the tumor occurrence was the vulva (65.3%), followed by the penis (30.6%), nasal (3.5%) and oral cavities (0.7%). Among 54 dogs that were treated at the hospital 39 dogs completed therapeutic protocol, of these 33 dogs had complete cytoreduction using the single-agent vincristine, 3 animals were still receiving treatment at the end of the study and in the 3 chemoresistance cases, these patients were benefited from doxorubicin treatment.