Biomarker panel identified prostate cancer with 90% accuracy

Researchers recently conducted a pilot study in which they identified a panel of up to 15 biomarkers that distinguished prostate cancer from both benign prostate disease and healthy tissue with 90% accuracy.

If this preliminary data is validated in larger ongoing studies, it could be developed into a serum protein test that may help decrease the number of unnecessary biopsies and help identify men who need treatment before the onset of symptoms.

“One of the advantages of the test is that it is relatively noninvasive. Also, it offers the potential of early detection, and therefore could potentially increase the cure rate significantly,” John Anson, PhD, vice president of biomarker discovery at Oxford Gene Technology, said during a press conference at the Fourth American Association for Cancer Research International Conference on Molecular Diagnostics in Cancer Therapeutic Development, in Denver.

According to Anson, the most effective screening tests currently available are based on a single biomarker, PSA, which is known to have a specificity of less than 50%, which generates high false-positive rates, resulting in many unnecessary surgical and radiotherapy procedures.

“The measure of clinical specificity — the measure of false positives — is much improved in this study compared to that seen with the current PSA and digital rectal examination test procedures used in diagnosis of prostate cancer,” Anson said in a press release.

In this study, researchers from Oxford Gene Technology and its subsidiary, Sense Proteomic, developed a “functional protein” microarray to detect autoantibodies in prostate cancer serum samples. They then identified the antigens to which these autoantibodies are raised and used them as biomarkers of disease.

“The appearance of autoantibodies may precede disease symptoms by many years,” Anson said. “This means that autoantibody-based diagnostic tests can enable presymptomatic and early diagnosis of disease. Early diagnosis of cancer, especially aggressive forms, could significantly increase cure rates.”

The researchers developed a microarray of 925 proteins and tested arrays using blood samples. They compared 73 samples from patients with prostate cancer with 60 samples from individuals without cancer to identify proteins on the arrays bound by autoantibodies present in the blood samples.

They identified panels of up to 15 biomarkers that distinguished prostate cancer from both benign prostate disease and healthy tissue. They currently are testing the biomarker panel in 1,800 samples drawn from patients with prostate cancer, patients without cancer and patients with other cancers or with other prostate diseases.

Anson said identifying prostate cancer from other prostate disease can be difficult because prostate disease can present similar symptoms to prostate cancer and may raise PSA levels and trigger a biopsy.

“Oxford Gene Technology expects its biomarker panel to discriminate between prostate cancer and these ‘interfering’ diseases,” he said.

Besides prostate cancer, the functional protein microarray may be applied to identify biomarker panels and develop better diagnostic tests for other cancers and autoimmune diseases. Early results in systemic lupus erythematosus and non–small cell lung cancer are encouraging, according to the researchers.

For more information:

Fallon RA. Abstract #A6. Presented at: Fourth American Association for Cancer Research International Conference on Molecular Diagnostics in Cancer Therapeutic Development; Sept. 27-30, 2010; Denver.

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