ABSTRACT

The local therapy modalities such as radiotherapy and surgery are primary treatments of Ductal Carcinoma In Situ (DCIS). However, there is a risk of ipsilateral and contralateral new breast cancer as well as local recurrence. Therefore, systemic therapy is also important in the treatment of DCIS. NSABP B-24 and UK/ANZ DCIS studies have evaluated the efficacy of tamoxifen in DCIS. These studies demonstrate that tamoxifen reduced both the ipsilateral and contralateral breast events. The most important side effects of tamoxifen therapy are endometrial cancer and thromboembolic events. In this topic, studies of aromatase inhibitors and targeted therapy have continued.