NATIONAL SURVEY OF CAT TUMORS IN 2019: A RETROSPECTIVE STUDY

Resumo

Cancer is one of the most common causes of death in cats. Besides its clinical importance, small animals with spontaneous tumours are attractive comparative models for Oncologic studies.

Cancer registries are important to provide increased information, which can be used in epidemiological studies and prophylactic and treatment strategies. The aim of this study was to characterize the current distribution of feline tumors in Portugal. A total of 752 feline histopathology records obtained in 2019 were included and data regarding breed, sex, age, type of tumor and malignancy were recorded. Statistical analysis was conducted to detect associations between variables using an alpha value of 0.05. One or more tumours were present in 417 animals, and a total of 475 tumors were reported (63.2%, n=475/752), of which 74.7% were malignant (n=355/475). Mammary tumors were the most common (43.7%, n= 207/475), including carcinoma (n=158) and adenoma (n=36). Mammary tumors were followed in frequency by tumors of the soft/mesenchymal tissue (19.6%, n=93/475) and epithelial skin (18.4%, n=87/475), which differs from published data in other countries. Similarly, to mammary tumors, soft/mesenchymal (64,5%, n=60/93) and epithelial skin tumors (18.4%, n=87/475) were also highly malignant. In the soft/mesenchymal tumors, lipoma (18.3%, n=17/93) and fibrosarcoma (17.2%, n=16/93) were the most common types; nevertheless, other tumors were also frequent, such as mastocitoma, lymphoma and hemangiosarcoma. Finally, in the epithelial skin tumours, the most prevalent was the squamous cell carcinoma (48.3%, n=42/87). Tumor malignancy was associated with older ages (mean 10.6 ± 3.4 years, p<0,001), whereas no association was obtained between breed and tumor type or tumor malignancy. Sex was associated with tumor type, as females presented a higher risk of developing mammary tumors. To our best knowledge this is the first retrospective study of this type conducted in Portugal. Given the high frequency of malignant tumors, early diagnosis and screening for nodules is of paramount importance, both at home and at veterinary consultations.