Ductal carcinoma in situ of breast
ICD-10 D05.1ICD-11 2E65.2

Endocrine therapy for estrogen receptor-positive DCIS after breast-conserving surgery

Ductal carcinoma in situ (DCIS) of the breast is a non-invasive breast cancer confined within the ducts. When the tumour is estrogen receptor-positive and managed with breast-conserving surgery, adjuvant systemic therapy is a key part of the overall treatment strategy.

Clinical scenario Estrogen receptor-positive DCIS in patients who have undergone breast-conserving surgery — a setting where adjuvant endocrine treatment has demonstrated clear benefit in large randomised trials.
Treatment approach (partial summary) The evidence-based first-line approach for this scenario involves adjuvant oral endocrine therapy continued over a multi-year course. The full regimen — including agent selection, dosing, and duration — is available in the complete structured protocol.

Complete regimen details, eligibility criteria, and clinical decision points are in the full protocol →

References

DOI: 10.1093/jjco/hyae122

  • Both the NSABP B-24 and UK/ANZ DCIS trials demonstrated the effectiveness of tamoxifen after BCS for DCIS of the breast.
  • 1804 patients with DCIS after BCS were assigned to a group that received treatment with oral tamoxifen (20 mg/day) for 5 years or a group that received placebo, concurrently with RT.
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