Mammary carcinoma in the cat - clinical findings and treatment in 34 patients

Mammary cancer is an important and frequently fatal disease in cats due to the highly aggressive nature of the tumours. This retrospective study in 34 cats with mammary carcinomas describes the clinical findings and survival times depending on tumour stage and tumour status upon presentation (primary tumour or tumour recurrence). The average age of the cats was 10.2 years +/- 3.7 years (range: 4-18 years); 82% of the patients were female and 18% male. Siamese cats made up 24% of the study population and were considered to be overrepresented. Twenty cats were presented with a primary tumour; 14 had a palpable tumour recurrence after tumour resection at the referring veterinary practice. The median overall survival time (ST) of all cats with a known course of disease (n=31) was 12.7 months. Cats presented with a primary tumour had a median ST of 13 months; 3 of 16 (19%) cats experienced a local recurrence despite radical mastectomy. The overall median ST from the time of the first surgery in the 14 cats presented with a recurrent tumour was also 13 months. Calculated from the time of surgery of the recurrent tumour, the cats (n=13) had a median ST of 12.5 months. Cats with lymph node metastasis survived a median of 12.5 months, which did not differ significantly from NO patients. The course of the disease in the male cats was not different from the females. Siamese cats tended to have better survival times compared to Domestic shorthair cats.