早期和晚期乳腺癌的治疗都由分子亚型决定。尽管对于早期三阴性和HER2阳性乳腺癌患者的辅助全身治疗具有明显的益处，但在过去的乳腺癌患者中，对于内腺乳腺癌患者是否需要辅助化疗一直存在不确定性。因此，我们过去常常过度治疗或者不足治疗患者。在个体化治疗时代，基因组检测已经变得与肿瘤的解剖范围一样或更重要，用于定义内腺乳腺癌预后。有几种基因表达评估可用于考虑辅助全身治疗，根据基因组复发风险来对患者进行分类评估（例如 Oncotype、Mammaprint等）。除了高风险和低风险标志外，最近Mammaprint还宣布，具有超低风险标志的患者具有出色的预后，与低风险患者相比，8年乳癌特定生存率超过99%，不论年龄、临床风险或接受的治疗如何。只有极少数患者发生远处转移，这使得医生可以降低治疗计划。

Breast cancer treatment is determined by the molecular subtype both in the early stage and the advanced disease. While there is clear benefit from adjuvant systemic treatment for patients with early-stage triple negative and HER2 positive breast cancer, it was unclear in the past which patient with luminal breast cancer needs adjuvant chemotherapy. As a result, we used to overtreat or undertreat patients. In the era of personalized treatment, genomic panels have become as or more important than the anatomic extent of disease to define prognosis in luminal breast cancer. Several gene expression assays are available for consideration of adjuvant systemic therapy categorizing patients according to genomic risk for recurrence (e.g., Oncotype, Mammaprint, etc). Except for the high and low risk signature, more recently Mammaprint announced that patients with ultra-low risk signature have excellent prognosis, distinctive from low risk with 8-year BCSS above 99%, regardless of age, clinical risk or treatment received. Very few patients developed distant metastasis, allowing physicians to de-escalate treatment plans.