Feline mammary carcinoma: Past, present and future

The Pathology Lab at CIISA/FMV has been conducting efforts towards the understanding of the molecular mechanisms underlying the feline mammary carcinoma (FMC). So far, the detection and quantification of three novel molecular biomarkers (HER2, SDF-1, CXCR4) were optimized in tumor tissue samples and sera, and their clinical usefulness was also validated. In parallel, six FMC immunophenotypes were reported and characterized, showing similar clinicopathological features to the ones described in human breast cancer patients. In a prospective study, our group reported that queens showing triple negative basal-like or HER2-positive mammary carcinoma subtypes are associated to shorter overall survival, contrasting with queens presenting luminal A/luminal B and triple negative normal-like molecular subtypes. We also demonstrated that the frequency of HER2 overexpression in FMC is similar to what is reported in women (about 30%), although no gene amplification was detected. More recently, studies on the role of CXCR4-SDF-1 axis and of miRNAs in FMC were performed in order to explore their role in oncogenesis and to validate new diagnostic/prognostic serum biomarkers. Finally, the antitumor activity of new TK inhibitors is under evaluation, using FMC HER2-positive and HER2-negative cell lines towards the support of new specific molecular therapies.