Multigene signatures generate crucial prognostic information particularly useful for
cancer patients where clinical parameters and traditional immunohistochemical markers alone lead to equivocal prognosis. Clinicians are now provided with molecular tools that assist in the outline of adjuvant
therapies, namely helping decide on the extension of adjuvant endocrine
therapy or on suppressing
adjuvant chemotherapy in patients were toxic effects are particularly deleterious or when this treatment is fundamentally not needed. The importance of
cancer multigene prognostic signatures is well elucidated in the guidelines for adjuvant systemic
therapy in early-stage
breast cancer and the guidelines on disease staging that are progressively integrating gene expression assays as classification
biomarkers. In addition to the predictive and prognostic value, some genetic tests provide intrinsic subtyping classification. Herewith, we compare the molecular tests OncotypeDX, MammaPrint, Prosigna, EndoPredict,
Breast Cancer Index, Mammostrat, and IHC4 and report the eligibility of each one in the suitable setting. Through to now, there is not a commercially available multigene test that makes recommendations regarding adjuvant treatment for HER-2 and
triple negative breast cancers. Thus, these patients still receive
adjuvant chemotherapy. Importantly, triple negative
carcinomas are very heterogeneous regarding prognosis and new molecular signatures that decipher this very heterogeneous subgroup of
breast cancer may improve the clinical management of the disease.