Clinical and Ultrasonographic Aspects of Benign and Malignant Mammary Tumors in Female Dogs

Paula Elisa Brandão Guedes, Hannah Bandeira Thame Daniel, Kátia Moema Oliveira Rosa Sampaio, Elizângela Barboza da Silva, Manoel Luiz Ferreira, Mário Sérgio Lima de Lavor, Rosana Maria de Oliveira Clark, Amauri Arias Wenceslau, Roueda Abou Said, Fabiana Lessa Silva

Abstract


Background: Mammary neoplasms in dogs are commonly observed in veterinary clinical routine, most of which being malignant. Hormonal stimulation, endogenous or exogenous, may possibly influence its development. In addition to clinical evaluation, ultrasound analysis can provide information about the characteristics of breast lumps. The association between clinical-epidemiological and pathological data is important for diagnosis. Therefore, given the importance of this pathology for the health of affected dogs, we aimed to evaluate the clinical and ultrasound alterations, along with the factors associated with the development of benign and malignant mammary neoplasms in female dogs. 

Materials, Methods & Results: We examined 47 samples from the mammary tumors of 35 female dogs at the Small Animal Clinic of the Veterinary Hospital (HV) of the Santa Cruz State University (UESC). The dogs underwent a complete clinical examination, with clinical staging, via TNM classification, followed by hematological, biochemical, radiological and ultrasound, abdominal, and breast exams. Breast ultrasound examination was used to evaluate the shape parameters such as, limits, margins or contour, ecotexture, echogenicity, hyperechoic halo, posterior acoustic shading, surrounding changes, and nodule components. These criteria were associated with the histopathological classification of neoplasms. Epidemiological data was studied through an adapted questionnaire containing information on risk factors associated with breast cancer. The same questionnaire was applied to tutors of 19, age-matched, female dogs with no history of breast cancer. The results revealed that most female dogs with neoplasia were over eight years of age, with no specific breed and were not castrated, and 31.4% of them had already been administered with contraceptives during the reproductive period. Ovariohysterectomy acted as a protective factor (OR 0.06) to the development of breast tumors, while contraceptive use was considered as a risk factor (OR 6.99). The average time reported between tumor perception and clinical care was 13.2 months. The caudal and inguinal abdominal breasts were the most affected. Among the samples evaluated, 76.6% were malignant, with mixed tumor carcinoma being the most frequent type and 69.4% graded in grade I. Nodules classified as malignant showed the largest diameter (P < 0.05). Breast ultrasound results revealed that tumors with heterogeneous echotextures and mixed components were associated with malignancy (P < 0.05). 

Discussion: The fact that the average age of female dogs with breast cancer was over eight years of age corroborates the literature. Considering that a greater age would mean a longer exposure to the carcinogenic initiators responsible for mutations, and to promoters, such as hormonal changes. Contraceptives increase the risk of breast lumps, while reduce that of ovariohysterectomy, in female dogs, even when performed after the second heat. The size of the nodules and ultrasound criteria related to echotexture and the type of component of the neoplasia may be used as prognostic parameters of female breast nodules. Additionally, most nodules evaluated in this study were malignant (mixed tumor carcinoma was the most common subtype), possibly due to the owners' delay in seeking veterinary care after tumor observation. Although malignant, most nodules presented with a low histopathological grading.


Background: Mammary neoplasms in dogs are commonly observed in veterinary clinicalroutine, most of which being malignant. Hormonal stimulation, endogenous or exogenous,may possibly influence its development. In addition to clinical evaluation, ultrasound analysiscan provide information about the characteristics of breast lumps. The association betweenclinical-epidemiological and pathological data is important for diagnosis. Therefore, given theimportance of this pathology for the health of affected dogs, we aimed to evaluate the clinicaland ultrasound alterations, along with the factors associated with the development of benignand malignant mammary neoplasms in female dogs.Materials, Methods &amp; Results: We examined 47

Full Text:

PDF

References


Bergman P.J. 2007. Paraneoplastic Syndromes. In: Withrow S.J. & Macewen E.G. (Eds). Small Animal Clinical Oncology. 4th edn. Philadelphia: W.B. Saunders Company, pp.77-94.

Calas M.J.G., Koch H.A. & Dutra M.V. 2007. Breast ultrasound: evaluation of echographic criteria for differentiation of breast lesions. Radiologia Brasileira. 40: 1-7.

Campos C.B. & Lavalle G.E. 2017. Exame clínico. In: Cassali G.D. (Ed). Patologia Mamária Canina: do Diagnóstico ao Tratamento. São Paulo: Editora MedVet, pp.152-159.

Cassali G.D., Bertagnoli A.C., Ferreira E., Damasceno K.A., Gamba C.O.P & Campos C.B. 2012. Canine Mammary Mixed Tumours: A Review. Veterinary Medicine International. 2012: 1-7. doi: 10.1155/2012/274608.

Cassali G.D., Lavalle G.E, Ferreira E., Estrela-Lima A., De Nardi A.B., Ghever C. &Torres R. 2014. Consensus for the Diagnosis, Prognosis and Treatment of Canine Mammary Tumors - 2013. Brazilian Journal of Veterinary Pathology. 7(2): 38-69.

Day M.J. 2004. Differential Diagnosis of Lymphadenopathy. In: Proceedings of the 29th Word Small Animal Veterinary Association World Congress – WSAVA (Rhodes, Greece). Pp.1-4.

Engelking L.R. 2010. Glândulas Mamárias. In: Engelking L.R. (Ed). Fisiologia Endócrina e Metabólica em Medicina Veterinária. 2.ed. São Paulo: Roca, pp.44-49.

Egenvall A., Bonnett B. N., Ohagën P., Olsson P., Hedhammar A. & Von Euler H. 2005. Incidence of and survival after mammary tumors in a population of over 80,000 insured female dogs in Sweden from 1995 to 2002. Preventive Veterinary Medicine. 69: 109-127.

Feliciano M.A.R., Vicente W.R.R., Leite C.A.L. & Silveira T. 2008. Abordagem ultrassonográfica da neoplasia mamária em cadelas: revisão de literature. Revista Brasileira de Reprodução Animal. 32(3): 197-201.

Feliciano M.A.R., Uscategui R.A.R., Maronezi M.C., Simões A.P.R., Silva P., Gasser B. & Vicente W.R.R. 2017. Ultrasonography methods for predicting malignancy in canine mammary tumors. PLOS One. 22: 1-14.

Ferreira E., Bertagnolli A.C., Cavalcanti M.F., Schmitt F.C. & Cassali G.D. 2009. The relationship between tumour size and expression of prognostic markers in benign and malignant canine mammary tumours. Veterinary and Comparative Oncology. 7(4): 230-235.

Ferreira E., Campos M.R.A., Nakagaki K.Y.R. & Cassali G.D. 2017. Marcadores prognósticos e preditivos no câncer de mama. In: Cassali G.D. (Ed). Patologia Mamária Canina: do Diagnóstico ao Tratamento. São Paulo: Editora MedVet, pp.141-149.

Gamba C.O., Ferreira E., Salgado B.S., Damasceno K.A., Bertagnolli A.C., Nakagaki K.Y.R. & Cassali G.D. 2017. Neoplasias malignas. In: Cassali G.D. (Ed). Patologia Mamária Canina: do Diagnóstico ao Tratamento. São Paulo: Editora MedVet, pp.91-116.

Gasser B., Rodriguez M.G.K., Uscategui R.A.R., Silva P.A., Maronezi M.C., Pavan L., Feliciano M.A.R. & Vicente W.R.R. 2018. Ultrasonographic characteristics of benign mammary lesions in bitches. Veterinarni Medicina. 63(5): 216-224.

Hanahan D. & Weinber R.A. 2000. The Hallmarks of Cancer. Cell. 100: 57-70.

Lana S.E., Rutteman G.R. & Withrow S.T. 2007. Tumors of Mammary Gland. In: Withrow S.J. & Macewen E.G. (Eds). Small Animal Clinical Oncology. 4th edn. Philadelphia: W.B. Saunders Co., pp.619-636.

Misdorp W. 2002. Tumors of the mammary gland. In: Meuten D.J. (Ed). Tumors in Domestic Animals. 4th edn. Ames: Iowa State Press, pp.575-606.

Mahmoud S.M.A., Paish E.C., Powe D.G., Macmillan R.D., Grainge M.J., Lee A.H.S., Ellis I.O. & Green A.R. 2011. Tumor-Infiltrating CD8+ Lymphocytes Predict Clinical Outcome in Breast Cancer. Journal of Clinical Oncology. 29: 1949-1955.

Nyman H.T., Nielsen O.L., Mcevoy F.J., Lee M.H., Martinussen T., Hellmen E. & Kristensen A.T. 2006. Comparison of B-mode and Doppler ultrasonographic findings with histologic features of benign and malignant mammary tumors in dogs. American Veterinary Medical Association. 67(6): 985-991.

Nunes F.C., Campos C.B. & Bertagnolli A.C. 2017. Aspectos Epidemiológicos das Neoplasias Mamárias Caninas. In: Cassali G.D. (Ed). Patologia Mamária Canina: do Diagnóstico ao Tratamento. São Paulo, Editora MedVet, pp.27-32.

Oliveira L.O., Oliveira R.T., Loretti A.P., Rodrigues R. & Driemeier D. 2003. Aspectos epidemiológicos da neoplasia mamária canina. Acta Scientiae Veterinariae. 31: 105-110.

Owen L.N. 1980. TNM Classification of Tumors in Domestic Animal. Geneva: World Health Organization, 53p.

Piculo F., Marini G., Damasceno D.C., Sinzato Y.K., Barbosa A.M.P., Matheus S.M.M. & Rodrigues G. 2014. Metodologia e equipamentos. In: Guia ilustrado da morfologia do tecido uretral de ratas [online]. São Paulo: Editora UNESP, pp.13-26.

Queiroga F.L. & Lopes C. 2002. Tumores mamários caninos - Novas perspectivas. In: Anais do Congresso de Ciências Veterinárias (Oeiras, Portugal). pp.183-190.

Schneider R., Dorn C.R. & Aylor D.O.N. 1969. Factors Influencing Canine Mammary Cancer Development and Postsurgical Survival. Journal of the National Cancer Institute. 43(6): 1249-1261.

Soler M., Dominguez E., Lucas X., Novellas R., Gomes-Coelho K.V., Espada Y. & Agut A. 2016. Comparison between ultrasonographic findings of benign and malignant canine mammary gland tumours using B-mode, colour Doppler, power Doppler and spectral Doppler. Research in Veterinary Science. 107: 141-146.

Sorenmo K.U. 2003. Canine mammary gland tumors. Veterinary Clinical Small Animal. 33: 573-596.

Toríbio J.M.M.L., Estrela-Lima A., Martins Filho E.F., Ribeiro L.G.R.R., D´assis M.J.M.H., Teixeira R.G. & Costa Neto J.M. 2012. Caracterização clínica, diagnóstico histopatológico e distribuição geográfica das neoplasias mamárias em cadelas de Salvador, Bahia. Revista Ceres. 59(4): 427-433.

Valle G.R. 2017. Aspectos fisiológicos e fisiopatológicos em cadelas. In: Cassali G.D. (Ed). Patologia Mamária Canina: do Diagnóstico ao Tratamento. São Paulo: Editora MedVet, pp.16-26.

Vannozzi I., Tesi M., Zangheri M., Innocenti V.M., Rota A., Citi S. & Poli A. 2018. B-mode ultrasound examination of canine mammary gland neoplastic lesions of small size (diameter < 2 cm). Veterinary Research Communications. 42: 137-143.




DOI: https://doi.org/10.22456/1679-9216.101276

Copyright (c) 2020 Paula Elisa Brandão Guedes, Hannah Bandeira Thame Daniel, Kátia Moema Oliveira Rosa Sampaio, Elizângela Barboza da Silva, Manoel Luiz Ferreira, Mário Sérgio Lima de Lavor, Rosana Maria de Oliveira Clark, Amauri Arias Wenceslau, Roueda Abou Said, Fabiana Lessa Silva

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.