ABSTRACT
Breast cancer is a heterogeneous disease, and its prognosis and outcome depend on multiple factors. The outcome depends on both tumor characteristics and host factors, including demographic factors, tumor characteristics, tumor growth factors or biomarkers, molecular subtypes, and host immune status. Tumor characteristics, such as tumor size, nodal status, grade, metastasis, and histopathological subtypes, have an impact on treatment as well. Aggressive adjuvant treatment is recommended for higher-grade tumors. Molecular subtypes, including luminal A, luminal B, Her2 neu enriched, and basal-like (TNBC), have high prognostic and predictive value. TNBC, Her2 neu–enriched, and luminal B cancers have a higher propensity for earlier recurrence compared to luminal A cancers. Luminal cancers are likely to be less chemosensitive, and luminal cancers with early breast cancer are best treated with surgery followed by systemic therapy. In Her2 neu–enriched cancers, neoadjuvant systemic therapy is used in most tumors more than 2 cm in size. In TNBC, the same principle is followed. Gene expression profiling can stratify breast cancer into high-, intermediate-, or low-risk cancers. Treatment can also be tailor-made according to the expression scores.
