Genomic Health Announces Positive Study Results Validating Use of Oncotype DX® in DCIS Breast Cancer

Genomic Health, Inc. GHDX today announced positive results from a clinical validation study of Oncotype DX® in patients with DCIS (ductal carcinoma in situ of the breast) conducted by the Eastern Cooperative Oncology Group (ECOG), a clinical trials cooperative group supported by the National Cancer Institute. The study, presented at the 2011 CTRC-AACR San Antonio Breast Cancer Symposium, met its primary endpoint by demonstrating that a pre-specified Oncotype DX DCIS Score goes beyond traditional clinical and pathologic measures to predict the risk of local recurrence, defined as either the development of a new invasive breast cancer or the recurrence of DCIS in the same breast. Based on this validation, Genomic Health plans to make the Oncotype DX DCIS Score available to physicians and their DCIS patients on December 28, 2011. "This is the first time a multigene test has been used to differentiate lower risk DCIS, which may be considered for treatment with surgery alone, from higher risk DCIS, for which adjuvant treatment including radiation should be considered in addition to surgery," said Lawrence J. Solin, MD, FACR, FASTRO, principal investigator for this study and Chair of the Department of Radiation Oncology at Einstein Medical Center, Philadelphia. "This study adds to the growing body of evidence showing that routine microscopic pathology grading is not a reliable indicator of the risk of recurrence." Genomic Health researchers collaborated with ECOG to prospectively validate whether the Oncotype DX DCIS Score predicted 10-year local recurrence by analyzing 327 DCIS tumor specimens from patients previously enrolled in the E5194 study of breast-conserving surgery alone. The multigene DCIS Score was obtained by performing the Oncotype DX Breast Cancer test, using a pre-specified DCIS algorithm to predict local recurrence regardless of whether adjuvant tamoxifen was given. The study demonstrated that 75% of patients have a low DCIS Score as pre-specified in the study and may be able to forego radiation therapy. DCIS breast cancer patients with a low DCIS Score had a low 12% likelihood of a local recurrence, defined as either the development of a new invasive breast cancer or the recurrence of DCIS in the same breast, and an even lower 5% likelihood of developing a new invasive breast cancer. Conversely, the study demonstrated that patients with high DCIS Score had a 27% likelihood of local recurrence, of which approximately half was likely to develop a new invasive breast cancer. The DCIS Score also demonstrated consistent association with local recurrence across subgroups regardless of lesion size, grade, surgical margins, or menopausal status. "The treatment of DCIS has been highly variable in the absence of having reliable methods to select patients for treatment with surgery alone without radiation," said Steven Shak, M.D., chief medical officer, Genomic Health. "By revealing the underlying biology of DCIS, we can now help quantify the likelihood of local recurrence, which is key to devising an individualized treatment plan."