A new study has examined how different histological classification systems can help predict survival outcomes in cats with malignant mammary tumours.
Feline mammary tumours are known to be highly aggressive cancers, often associated with poor clinical outcomes. Researchers have long investigated which clinical and pathological factors may help predict prognosis, although previous findings have not always been consistent.
In the new study, titled Feline mammary tumors: comparison of histological classifications and prognostic factors in a 3-year survival study (Part I), the research team analysed and compared two classification systems used to describe these tumours.
The researchers evaluated both the 1999 World Health Organization (WHO) classification and the updated 2019 surgical pathology classification, applying both systems to the same group of cases.
Their results showed that the 2019 classification system provided greater stratification of tumour types, offering a more detailed way to categorise feline mammary tumours and potentially improving understanding of their biological behaviour.
The study also examined several clinicopathological features that may influence prognosis.
Cats with ductal-associated carcinomas were found to have longer survival times compared with other tumour types. However, several factors were linked with poorer clinical outcomes, including:
- Presence of multiple malignant mammary tumours at the same time
- Larger tumour size
- Higher clinical stage
- Infiltrative tumour growth
- Lymphovascular invasion
All of these factors were associated with less favourable outcomes in the study.
The authors also noted that the importance of different prognostic factors may vary depending on the clinical endpoint being considered, highlighting the need for careful interpretation when assessing prognosis.
The researchers suggest that the updated classification system may provide a more accurate framework for evaluating feline mammary tumours and predicting outcomes, although further work will continue to refine understanding of how these tumours behave.
