Estadiamento clínico de cadelas com carcinoma mamário e seu significado prognóstico

Abstract

Breast tumors are the most common type of cancer in intact female dog and the identification of reliable prognostic factors for this disease is important for the establishment of adequate treatment. Clinical staging is widely used in human medicine and its use as a prognostic factor in veterinary medicine has acquired significant importance. It is determined according to the TNM system in which the size of the primary lesion (T), the presence or absence of metastasis to regional lymph nodes (N) and the presence or absence of distant metastases (M) must be assessed. There is a scarcity of studies in dogs evaluating staging as a prognostic factor, so this study aimed to establish the clinical stage of female dogs with breast carcinomas, assess survival and relate survival with clinical staging, type and histological grade. Were included in this study female dogs with breast cancer, with radiographic and ultrasound examination, to assess distant metastases and perform surgical excision as a treatment for breast tumor. Samples of mammary neoplasms and regional lymph nodes were evaluated for histological type and grade and female dogs staged according to TNM. The animals were followed up to determine survival and their relationship to the staging. Survival time was considered based on date of mastectomy. The folllow up was performed by Kaplan-Meier analysis. The overall survival mean (OSM) was 667 days. The survival median of female dogs with breast carcinoma was 697 days (SD: 209,936). In the analysis of survival according to the histological type, it was found that mixed carcinomas (carcinoma in mixed tumor and complex carcinoma) and tubulopapillary carcinoma had higher survival (p = 0.001). As for histological grading, it was found that female dogs diagnosed with grade I and II carcinomas had longer survival (p = 0.001). Of the 100 animals evaluated, 75% obtained stage I, II or III, they had a survival of 1000, 853 and 686 days, respectively. Those classified as IV or V (25%) obtained 654 and 384 days, respectively. Dogs with stage IV and V had lower survival (p = 0.005). The multivariate analysis between overall survival and the predictive variables for breast carcinoma showed a correlation between survival and stage (p = 0.004), with each change of stage the risk of death increasing by 1.317 times. The results of the work demonstrate that clinical staging must be part of the protocols for the evaluation of canine breast carcinomas, presenting great prognostic significance and helping to direct the best treatment.