Does the Oncotype DCIS score impact treatment decisions?

Abstract

91 Background: The Oncotype Dx DCIS Score has been developed and validated for risk recurrence in ductal carcinoma in situ. It is a 12 gene assay performed on an individual patient’s tumor. The results give information about the 10 year risk of any in-breast event and the 10 year risk of an invasive breast cancer. The clinical validation study was based on patients enrolled in ECOG 5194. The purpose of our study was to evaluate the impact of the DCIS Score on recommendations for adjuvant radiation therapy. Methods: In this IRB approved study, 27 patients at our institution underwent evaluation with the DCIS Score from April 2012 to February 2013. All patients had specimens submitted for DCIS Scores. 14 patients had margins of 3 mm or greater. 12 patients had margins of 1 mm to 2.5 mm, and 1 patient had margins that were less than 1 mm from the DCIS. The mean age was 56.8 years, with a range of 40-79 years old. The DCIS Score is reported on a scale of 0-100. All patients underwent consultation with radiation oncology. The radiation oncologists formulated their preliminary recommendation prior to reviewing the patients’ DCIS Scores. The final recommendation for radiation treatment was rendered after reviewing the DCIS Score. We then compared the pre-DCIS Score and post-DCIS score treatment recommendations. Results: 21 patients (78%) were advised to have adjuvant radiation therapy. 6 patients (22%) were advised not to undergo adjuvant radiation based on their clinical and pathologic features. Although the DCIS Score did not change treatment recommendations for any patient in this study group, it did confirm initial treatment recommendations. For the patients who were advised not to have radiation, their DCIS Scores were 0-31. Conclusions: The DCIS Score is a validated tool to assess the local risk of recurrence for ductal carcinoma in situ. In our study population, the results of the DCIS Score did not alter treatment in any patient. It is important to note that in the 6 patients who were advised not to have radiation, the low DCIS Score confirmed the radiation oncologist’s perceived low risk of recurrence. In order to increase confidence in results of the DCIS Score, further studies need to be performed.