Epidemiological Investigation of Canine Mammary Tumors in Mainland China Between 2017 and 2021

Abstract

Epidemiological studies enable us to analyze disease behavior, define risk factors, and establish fundamental prognostic criteria. This study aimed to determine the epidemiological and clinical characteristics of canine tumors diagnosed during the years 2017–2021. The results showed that canine mammary tumors were the most common tumors, and their relative incidence for 5-years-total was 46.71% (504/1,079), with 48.41% (244/504) of benign, and 51.59% (260/504) of malignant. Pure breeds accounted for 84.13% (424/504) of submissions, and adult female dogs (9–12 years old) were most frequently involved, followed by 5–8-year-old females. Remarkably, 2.58% (13/504) occurred in the male dogs. In addition, a high prevalence of mammary tumors (77.38%, 390/504) was diagnosed in unneutered dogs, and different incidence rates were observed in different regions (Northeast, Southeast, Northwest and Southwest China). For clinical factors, the tumor size ranged from 0.5 to 28 cm, with the 0–5 cm being the most common tumor size (47.82%, 241/504), and malignant tumors (4.33 ± 2.88 cm, mean ± SD) were bigger than benign ones (3.06 ± 1.67 cm, mean ± SD) (p < 0.001). The incidence of single tumor (55.36%, 279/504) was higher than that of multiple tumors in dogs, while the latter had a higher incidence of malignant tumors (74.67%, 168/225). According to this study, we also found that canine mammary tumors were more common in the last two pairs of mammary glands. In addition, multiple linear regression analysis showed that there was linear significant relationship between three independent variables (age, tumor size, and tumor number) and histological properties of canine mammary tumor [(p>|t|) < 0.05]. This is the first retrospective statistical analysis of such a large dataset in China to reveal the link between epidemiological clinical risks and histological diagnosis. It aids in the improvement of the host's knowledge of canine tumor disorders and the early prevention of canine mammary tumors.

The Analysis of E-Cadherin, N-Cadherin, Vimentin, HER-2, CEA, CA15-3 and SF Expression in the Diagnosis of Canine Mammary Tumors

“…The tumor size ranged from 0.2 cm to 2.9 cm (1.73 ± 0.56 cm, mean ± SD). Tumor localization was more common in the inguinal last two pairs of mammary glands, which was consistent with previous research [ 20 ]. Upon clinical examination, the dogs suffering from tumors had a distinct mass on the abdomen, in the thorax, irregular in shape and sliding on palpation ( Figure 1 A,B), and X-ray (Latero-lateral and ventro-dorsal views) revealed a mass-like effect with a slightly stronger density than the surrounding tissue in the mammary gland, without metastasis to the lungs ( Figure 1 C).…”

Risk factor analysis and clinicopathological characteristics of female dogs with mammary tumours from a single-center retrospective study in Poland

“…Similar to our results, pedigree dogs in other studies were most frequently affected (72.8%), and they accounted for 59% to 80% of the study population 3 , 7 , 45 , 47 , 59 . However, some authors reported a higher proportion of mixed-breed dogs with CMTs 6 , 25 , 55 , 61 .…”

“…The majority of bitches with malignant CMTs revealed only this tumour behaviour and one histological subtype 19 , 46 . Moreover, they were frequently affected by simple carcinoma, grade II carcinoma 46 , 47 , and had a median age of 10 years at the day of tumour diagnosis, confirming previous reports 3 , 6 , 21 , 48 , 49 . The youngest dog was 1 year old, and the oldest was 17 years old.…”

Neutrophil to lymphocyte ratio and principal component analysis offer prognostic advantage for dogs with mammary tumors

“…In Mexico, it was reported to be 17% with half of the tumors being malignant (6), while in Italy up to 54% of all tumors in female dogs were mammary tumors (7). More recently, the incidence in China was reported to be 46.7% (8), while in New Zealand it was 56% (9), and in Germany it was 64.7% (10). Thus, generally the global incidence for canine mammary tumors is 50%.…”