Introduction

The clinical presentation and staging of canine mammary tumors (CMTs) is important as a predictive factor and allows a prognosis to be established and a treatment plan. The histological grading of CMTs has become a valuable tool for predicting their biological behavior. For tumors to grow progressively and metastasize, they must be able to stimulate angiogenesis.

Objectives

To evaluate the role of the microvasculature in the cancer biology related to the clinicopathological characteristics of CMTs.

Methods

Seven female dogs with mammary tubular carcinomas were selected to study the correlation of clinical characteristics of the dog, tumor appearance, staging as established by Owen (1980), tumor grade by Elston and Ellis (1998) and microvascular density (MVD) and grade obtained using Weidner et al. (1991) technique by CD31 immunostaining.

Results

The median age was 8.8 years, 85.7% (6/7) were intact females, 57.1% (4/7) had history of pseudopregnancy and 71.4% (5/7) didn't use hormones. 57.1% had fast growth, 71.4% weren't ulcerated, 57.1% had 3–5 cm, 57.1% were attached and 57.1% had lymphatic involvement during clinical examination. 42.8% (3/7) of the bitches were stage III, 28.5% (2/7) were stage IV and the others were stage I and II. At histopathology, 85.7% of the tumors were grade II. The microvessels grade mean was 2 and de MVD mean was 22.4 per 400x field. These canine mammary tubular carcinomas had fast growth with large size; the most common stage was IV with intermediate grade (II) and had moderate neovascularization.

Conclusions

The tumors evaluated are potential targets for antiangiogenic therapy, and such analysis should be performed prior to instituting anticancer therapy in dogs.