Is Adjuvant Endocrine Therapy Indicated for DCIS Patients After Complete Surgical Excision?

Data derived from pathological analysis, natural history, radiological characteristics, genomic profiling, and clinical outcome indicate that ductal carcinoma in situ (DCIS) is a heterogeneous disease; meaning that no single therapeutic strategy is best, but rather that treatment should be personalised and entail a rigorous multidisciplinary approach. The role of adjuvant endocrine therapy after surgical excision has been the subject of scientific debate in view of the in situ nature of this neoplasm. We reviewed the literature and summarised the evidence regarding the need for adjuvant endocrine therapy following complete surgical excision of DCIS through the identification of the most important outcomes, evaluation of quality of evidence, and assessment of the trade-offs involved. There is no scientific evidence that adjuvant endocrine therapy reduces the incidence of ipsilateral breast invasive recurrence or breast cancer mortality in the context of adequate local treatment of DCIS in the form of breast conserving surgery with clear surgical margins plus adjuvant radiotherapy or total mastectomy. Therefore, its routine use is not indicated. However, adjuvant endocrine therapy can be considered after a rigorous multidisciplinary discussion and patient counselling in a carefully selected subgroup of patients with high-risk estrogen receptor-positive DCIS.