BRAF Mutation Test – Transitional cell carcinoma in dogs

Transitional cell carcinoma (TCC) is the most common malignant tumour of the canine urinary tract.

DNA sequencing of TCC tumour cells identified a mutation of BRAF gene V595E in 65-85% of cases depending on the study.

Examination of BRAF-variant V595E

• Specificity 100%
• Sensitivity ~ 70%

Sample material

• Urine sediment
• Cell-rich smears (without cover slip)
• Solid biopsies
• Paraffin material

Strengths

• This test can be performed on the pre-stained cytology smears already submitted to the lab.
• A positive result will definitively confirm the diagnosis of TCC.

Limitations

False negative results may occur, therefore the absence of the mutation should not be used to rule out TCC as differential.

Indications

BRAF mutation analysis is recommended when cytology or histology are unable to provide a definitive diagnosis due to one of the following reasons:

• mild signs of cellular atypia, especially if associated with inflammation
• poor cell preservation
• very thick smears
• histological biopsies with artefacts