Recomendación para la determinación de HER2 en cáncer de mama. Consenso nacional de la Sociedad Española de Anatomía Patológica (SEAP) y de la Sociedad Española de Oncología Médica (SEOM) Guidelines for HER2 testing in breast cancer. A national consensus of the Spanish Society of Pathology and the Spanish Society of Medical Oncology

SUMMARY Breast cancers with HER2 alterations are critical toidentify because such tumors require unique treatment,including the use of targeted therapies. HER2 alterationsat the DNA (amplification) and protein (overexpression)level usually occur in concert, and both in situ hybridiza-tion and immunohistochemistry can be accurate methodsto assess these alterations. However, recent studies inclu-ding those conducted by the Association for QualityAssessment of the Spanish Society of Pathology and theexperience of several national reference centres for HER2testing have suggested that serious reproducibility issuesexist with both techniques. To address this, a joint com-mittee of both the Spanish Society of Pathology and theSpanish Society of Medical Oncology has met to reviewguidelines for HER2 testing. Consensus recommendationare based not only on panellist’s experience but also inthose consensus guidelines previously reported in severalcountries, such as United Stated, United Kingdom andCanada.