ONCOTYPE DX ASSAY IN BRCA POSITIVE, ER POSITIVE BREAST CANCER PATIENTS

Naama Halpern ¹ Amir Sonnenblick ¹ Luna Kadouri ¹ Beatrice Uziely ¹ Yael Goldberg ¹ Daniela Katz ¹ Tanir Allweis ^2,3 Luba Divinsky ¹ Irit Merlet ¹ Bella Maly ⁴ Michal Sagi ⁵ Tamar Hamburger ¹ Einat Carmon ² Tamar Peretz ¹

¹Sharette Institute of Oncology, Hadassah Hebrew University Medical Center, Jerusalem
²Department of Surgery, Hadassah Hebrew University Medical Center, Jerusalem
³Sarah Markowitz Breast Center, Kaplan Medical Center, Rehovot
⁴Department of Pathology, Hadassah Hebrew University Medical Center, Jerusalem
⁵Department of Human Genetics, Hadassah Hebrew University Medical Center, Jerusalem

Background:

Oncotype DX is a 21-gene RT-PCR assay which quantifies the likelihood of breast cancer recurrence and the potential benefit of chemotherapy in patients with early stage, ER positive, Tamoxifen treated breast cancer. Breast cancer in BRCA carriers is considered more aggressive. The aim of our study was to evaluate whether Oncotype Dx recurrence score distribution is different in breast cancer patients with inherited BRCA mutation.

Methods:

The Oncotype DX assay has been used atHadassahMedicalCentersince 2004 on specimens from over 450 patients. We analyzed and compared clinicopathological characteristics and Oncotype Dx recurrence scores of BRCA carriers versus non- BRCA or unknown status of BRCA patients.

Results:

Ten patients had validated inherited BRCA mutation, five of them are BRCA1 carriers and five BRCA2 carriers. There were no significant differences in the clinicopathological characteristics between the two groups. Oncotype Dx recurrence score distribution between low, intermediate and high risk groups was not significantly different. The mean recurrence score was 18.48 for the non- BRCA or unknown status of BRCA patients and 22.8 for the BRCA carriers patients. This difference was not statistically significant.

Conclusion:

Estrogen receptor positive breast cancer tumors from BRCA carriers does not display a significantly different Oncotype Dx recurrence score result distribution.

These preliminary data suggest Oncotype Dx assay might be used to help tailor treatment in this subset of patients, although further follow up is needed.