Oncotype DX DCIS: Impact on Radiotherapy Decision Making

A Study Assessing the Impact of the Oncotype DX DCIS Score on Radiotherapy Decision Making in the United Kingdom

Prospective single centre study of patients with DCIS that have undergone breast conservation surgery.

This is a single centre (Royal Marsden Hospital - Chelsea and Sutton) non-randomised trial investigating whether the Oncotype DX DCIS score changes the radiotherapy recommendation made by clinical oncologists in patients with low to moderate risk DCIS following breast conserving surgery.

Inclusion Criteria:

1. Confirmed diagnosis of DCIS
2. DCIS treated with breast conserving surgery

Exclusion Criteria:

1. Prior treatment for DCIS or invasive breast cancer in ipsilateral breast.
2. Patients with contra-indications to radiotherapy, including prior breast radiotherapy
3. Patients who undergo mastectomy for DCIS
4. Age < 45 years old
5. Patients with > 25mm DCIS
6. Patients with multifocal DCIS (defined as more than 1 distinct focus of DCIS with at least 50mm of intervening benign tissue)
7. Patients with invasive (including microinvasion) disease
8. Patients with positive axillary nodal disease (including isolated tumour cells)
9. Patients with close (<1mm) or positive radial margins (unless maximally surgically excised or no further DCIS on re-excision)
10. Patients recommended adjuvant endocrine therapy