Local Treatment in ER-positive/HER2-negative Oligo-metastatic Breast Cancer

Local Treatment in Addition to Endocrine Therapy in ER-positive/HER2-negative Oligo-metastatic Breast Cancer (CLEAR): a Multicentre, Single -Arm, Phase 2 Trial

Local treatment in addition to endocrine treatment as 1st line for oligo-metastatic ER-positive/HER2-negative breast cancer.

Local treatment included surgical resection, stereotactic body radiotherapy, palliative radiotherapy, and radiofrequency ablation. Stereotactic body radiotherapy is preferred as a radiation modality.

Endocrine therapies with/without target therapy including CDK4/6 inhibitors or mTOR inhibitors are the mainstay of 1st line treatment for ER-positive/HER2-negative metastatic breast cancer.

Inclusion Criteria:

-ER-positive/HER2-negative in primary tumor

• Oligometastases: ≤ 2 lesions in single organ or site (lung, bone, liver, adrenal glands, distant LNs)
• Recurrent cancer after completion of primary treatment (RFI≥1year)
• Metastatic lesions are feasible for resection or radiotherapy (Size≤3cm)

Exclusion Criteria:

• De Novo metastatic cancer at initial diganosis
• Recurrence-free inverval < 1 year