- Results Demonstrating 95 Percent or Greater Concordance Compared to FISH and IHC Presented at 2008 ASCO Breast -

- Company to Include Reporting for HER2 Gene Expression in All Oncotype DX Reports by End of 2008 -

REDWOOD CITY, Calif., Sept. 6 /PRNewswire-FirstCall/ -- Genomic Health, Inc. (Nasdaq: GHDX) today announced results from two studies demonstrating that quantitative reporting for HER2 gene expression, as measured by the company's Oncotype DX(R) breast cancer assay, has a high degree of concordance with both fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) testing. HER2 is an important marker for therapeutic decision-making for patients with breast cancer, and its measurement significantly impacts the chosen course of treatment. The research was presented at the ASCO Breast Cancer Symposium, September 5-8, 2008, in Washington, D.C.

'Many clinicians who already rely on the Recurrence Score(R) result for treatment planning have specifically requested that we provide the quantitative measure of HER2 gene expression in Oncotype DX reports,' said Steven Shak, M.D., chief medical officer of Genomic Health. 'Based on this research demonstrating the accuracy and reliability of HER2 measurement using RT-PCR, Oncotype DX can provide additional patient-specific information and insight into each patient's individual tumor biology.'

Oncotype DX uses reverse transcription-polymerase chain reaction (RT-PCR) technology to quantify gene expression of 21 genes, one of which is HER2. The two studies found high concordance for testing with Oncotype DX compared to FISH (97 percent) and IHC (95 percent). Earlier this year, Genomic Health increased the clinical utility of Oncotype DX by providing single gene reporting for the expression of estrogen and progesterone receptors. The company expects to further increase the clinical utility of its test by including single gene reporting for quantitative HER2 gene expression in all Oncotype DX reports by the end of 2008.

The first study (Abstract 13), conducted by Genomic Health and collaborators from the Eastern Cooperative Oncology Group and sanofi-aventis, demonstrated a high degree of overall concordance -- 95 percent -- between central IHC and quantitative RT-PCR using Oncotype DX for determining HER2 status. The study analyzed 755 patients with 0 to 3 positive lymph nodes who were enrolled in Intergroup study E2197, a large adjuvant breast cancer trial evaluating two different chemotherapy regimens.

The second study (Abstract 41) found a high degree of concordance -- 97 percent -- between RT-PCR using Oncotype DX and central laboratory FISH assessment of HER2 status.