Vet-OncoNet: Malignancy Analysis of Neoplasms in Dogs and Cats

Abstract

Analysis of canine and feline tumor malignancy data can help clinicians identify high-risk patients and make more accurate decisions. Based on a sample of 16,272 cancer records, including 3266 cats and 13,006 dogs, collected from January 2019 to December 2021 in the Vet-OncoNet Network database, this study aimed to compare the tumor malignancy profile between cats and dogs, considering animal-related factors (sex, age, and breed), topography, and geographic location using a mixed-effects logistic regression model. Cats had a higher proportion of malignant tumors (78.7%) than dogs (46.2%), and the malignancy profile was very different regarding tumors’ topographies. The mean age of malignant tumors occurred eight months later than benign ones (9.1, SD = 3.4; 9.8, SD = 3.2), in general. Species (OR = 3.96, 95%CI 3.57: 4.39) and topography (MOR = 4.10) were the two most important determinants of malignancy risk. Female dogs had a higher risk than male dogs (OR = 1.19, 95%CI 1.08: 1.31), which does not appear to be the case in cats (OR = 0.98, 95%CI 0.77: 1.23). Breed contributed significantly to differences in malignancy risk in dogs (MOR = 1.56), particularly in pit bulls and boxers. District of residence was not so relevant in predicting malignancy risk (MOR = 1.14). In both species, the risk of malignancy increased by approximately 20% every three years. It could be hypothesized that species differences in genetic structure may contribute to tumor malignancy.

Incidence rates of the most common canine tumors based on data from the Swiss Canine Cancer Registry (2008 to 2020)

“…In accordance with previous studies, female dogs showed higher overall tumor numbers [ 5 , 6 , 8 , 17 , 18 , 20 , 22 ] and IRs [ 4 , 9 – 11 ] compared to male dogs (IR: 850 vs. 679, respectively), and a higher IRR for malignant tumors ( Table 6 ). These results may be partly influenced by relatively high numbers of tumors in the mammary gland.…”

“…The percentage of benign tumors was higher than that of malignant tumors (54.91% versus 45.09%, respectively), as reported in most previous studies in dogs [ 4 – 6 , 9 , 11 , 16 , 18 , 23 ], but different from a Japanese [ 21 ] and two Italian [ 8 , 10 ] studies, which reported 57.5%, 53%, and 51% of all tumors as malignant, respectively. The percentage of benign tumors may generally be underestimated due to less frequent pathological assessment.…”

“…Many factors can influence malignancy proportions, limiting comparisons between studies. More substantial differences in the distribution of benign and malignant tumors have been observed between species, specifically between dogs and cats [ 6 , 10 ]. However, we show distinct variations in the proportions and IRs of benign and malignant tumors between dog breeds.…”

Untitled

“…The most frequent cancer in dogs is a mammary tumour; about half of these cancers are malignant 1 . Surgical resection is the preferred treatment for mammary gland neoplasia, and radiotherapy and chemotherapy are used as adjuvant therapies to surgery 2 . Major issues with cancer treatment that restrict the amount of chemotherapeutic drugs are drug toxicity and the emergence of drug resistance 3 .…”

Trained dogs can accurately discriminate between scents of saliva samples from dogs with cancer versus healthy controls

“…4 Certain breeds are believed to be at risk for specific neoplasia, which is thought to arise due to inadvertent selection of genetic mutations predisposing to cancer, along with the selection of specific genetic traits. [4][5][6][7] Early detection of cancer is desirable because it may reduce the need for aggressive treatment and the incidence of metastasis. In addition, it may improve…”