diaDexus and Mayo Collaborate on Breast Cancer Diagnosis

diaDexus, Inc.(South San Francisco, CA, USA), a privately held biotechnology company, announced a collaboration with Mayo Validation Support Services (Rochester, MI, USA) to investigate a test featuring a select panel of tumor-specific genes to aid in patient risk stratification and assist in chemotherapy treatment decisions for breast cancer patients. The test uses gene expression profiling to predict recurrence of malignancy in patients diagnosed with primary invasive early stage breast cancer.

Study data presented in 2005 demonstrated that a set of eight genes were differentially expressed in patients who presented with progressive disease compared with genes from patients who were disease-free after a median follow-up of 70 months. These data indicated that the polymerase chain reaction (PCR)-based test involving these genes warranted additional investigation into its utility in identifying patients at higher risk for recurrence.

The Mayo collaboration is part of diaDexus' molecular diagnostics program focused on developing tests to aid in the prognosis and staging of breast, colorectal, and prostate cancers. PCR is a technique for amplifying DNA or RNA sequences in a laboratory in order to facilitate diagnostic testing or research.

In this larger confirmatory study with Mayo Validation Support Services, diaDexus investigators will evaluate whether the test, which includes the previously identified eight genes in addition to others, can help provide breast cancer patients with personalized prognostic information. This critical information may help physicians determine the need for chemotherapy and help improve cancer management.

The study will include tumor samples from 60 breast cancer patients who have been tracked for up to 10 years following diagnosis and initial treatment. Comparisons will be made between "good outcome” patients who showed no disease progression during 5–10 years of follow-up (30 cases), and "poor outcome” patients whose disease progressed within five years of surgery (30 cases). A control group will consist of six normal breast tissue samples.

According to Roberto Macina, diaDexus' director of molecular technology, the study is a significant step in testing the value of diaDexus' extensive cancer diagnostic portfolio for the management of breast cancer. "Our goal is to provide physicians and cancer patients with clinically valuable information that will help identify those patients with a poor prognosis who would benefit from chemotherapy, while helping to avoid chemotherapy--and its often-debilitating side effects--in those predicted to have good outcomes,” MR Macina said.



Related Links:
diaDexus
Mayo Validation Support Services