Oncotype DX® DCIS Score™ Represents Breakthrough in Personalizing Treatment of Pre-Invasive Breast Cancer

SAN ANTONIO, Dec. 12, 2014 -- Genomic Health, Inc. announced positive results from the second large clinical validation study of Oncotype DX® in patients with a pre-invasive form of breast cancer known as DCIS (ductal carcinoma in situ). The study, conducted by the Ontario DCIS Study Group of Sunnybrook Health Sciences Centre in Canada, reconfirmed that the Oncotype DX DCIS Score™ is a strong predictor of local recurrence, which could be either invasive breast cancer or DCIS (p < 0.001).

This largest genomic study in DCIS to date examined a broad, population-based cohort of more than 1,200 DCIS patient tumor samples collected from patients diagnosed with DCIS between 1994 and 2003 in Ontario, Canada. The primary analysis, presented at the 2014 San Antonio Breast Cancer Symposium (SABCS), included 571 patients who were treated with breast-conserving surgery where the tumor was completely removed. The results, which are consistent with those of the original ECOG-ACRIN Cancer Research group clinical validation study, demonstrated that the DCIS Score quantified the 10year risk of local recurrence beyond clinical factors such as tumor size and grade. This analysis clearly identified that the majority (62 percent) of studied DCIS patients were low risk based on the tumor biology revealed by the Oncotype DX test.