Estudo de caso-controle de tumores mamários em cães e o uso de fármacos contraceptivos

Abstract

Mammary neoplasms are the most prevalent tumors in female dogs, mostly at that ones with advanced age. It is known that hormones in the estrous cycle have an influence on the development of these lesions, as through receptors in the breast tissue itself, and through the release of pituitary hormones, such as growth hormone (GH). Considering this important hormonal activity in the growth of canine breast tumors (CBM), the use of reversible contraceptive methods that contain these substances are widely discussed. Due to this potential risk factor for neoplasms, the present study aimed to evaluate the influence of progestin administration on the development of mammary carcinoma in bitches at the Veterinary Hospital of the Federal University of Uberlândia (HOVET - UFU) treated from January of 2019 to December of 2020. Others risk variables were also applied, such as a frequency of applications, time elapsed since first administration and patient’s age. Through the medical record, these animals were defined between affected and not affected by CBM, each group was deferred into two other subgroups that were used of progestogens and without use of progestogens, thus obtaining 4 distinct classifications at this research. The multiple logistic regression model was used to estimate the odds ratio (OR), using the method of exclusion of non-significant variables (backward) to verify the rate between the variables. Through the statistics results, it has been verified that progestins administration was not significant for the development of CBM. The use of progestins and the time elapsed since the first application can affect the development of neoplasms. As well as the advanced age of bitches was also proven to be a risk factor for tumor developments.