Protein could boost prostate cancer screening accuracy

A newly discovered blood protein could change the way men are screened for prostate cancer with a simple-to-use blood test, researchers say.

Led by Dr. Robert H. Getzenberg, professor of urology and director of research at the James Buchanan Brady Urological Institute at the Johns Hopkins University School of Medicine, the study detected an unprecedented 94 percent of men with prostate cancer and correctly identified 97 percent of men who don't have the disease, a far greater accuracy rate for prostate cancer than the current PSA test.

The protein, called Early Prostate Cancer Antigen or EPCA-2 is exclusively licensed to Seattle-based biotechnology company Onconome, Inc., led by CEO and co-founder Ray Cairncross.
"The results from the Johns Hopkins University research study demonstrate that the ProstaMark® EPCA-2 test is highly specific and sensitive to prostate cancer and could greatly reduce the number of unnecessary prostate biopsies," Cairncross said in a press release.

For the past 25 years, prostate-specific antigen (PSA) has been the standard in the effort to detect prostate cancer; however, it is not highly specific or sensitive. For example, 80 percent of patients with elevated PSA levels do not have prostate cancer and 15 percent of patients with normal PSA levels do have prostate cancer. Nevertheless, nearly 1.7 million prostate biopsies are performed each year based primarily on results from PSA testing and an estimated 25 million men have had at least one negative biopsy (i.e. no cancer found).

Not only was the EPCA-2 test negative in 97 percent of men who do not have prostate cancer and positive in 94 percent of men with prostate cancer, it also showed that EPCA-2 levels are highest in patients with non-organ confined prostate cancer, which is important because cancer that has spread outside of the prostate is much more deadly.

The company is also working with Johns Hopkins University on an early detection test for colon cancer, and early results indicate that the performance characteristics of the colon cancer test are similar to those achieved in the development of the prostate cancer test.

Onconome will also use its novel, proteomic technologies to assist pharmaceutical companies in developing cancer therapies and to select clinical trial candidates. The company also will collaborate with in-vivo imaging and targeted therapeutics companies to improve treatment.