To evaluate whether the combination of clinicopathological factors and the use of the Oncotype DX DCIS score can avoid radiation in women with low risk DCIS who have had breast conserving surgery (BCS)
Female patient > 45 years of age with DCIS without microinvasion.
Tumour size ≤ 2.5cm.
Treated by BCS with clear resection margins ≥ 2 mm or no residual disease on re-excision.*
Oncotype DX DCIS score with a predicted 10-year risk of LR ≤10%.
Multifocal DCIS.
History of any invasive breast cancer or non-invasive breast cancer in the ipsilateral breast.
Synchronous or previous invasive or non-invasive breast cancer.
Prior history of invasive cancer within the last 5 years, excluding non-melanoma skin cancers.
Ontario Clinical Oncology Group (OCOG)
Lead sponsor
Canadian Institutes of Health Research (CIHR)
Collaborator
Hamilton Health Sciences Corporation
Collaborator