Seattle, WA—Working with cancerous prostate tissues of men over 55 years of age, scientists at the Pacific Northwest Research Institute (PNRI, now PNDRI) in Seattle have identified a DNA structure (cancer DNA phenotype) that potentially signals a high risk for prostate cancer. The scientists believe that this structure can be used as a new biomarker for assessing prostate cancer risk and as a target for early intervention.

The DNA phenotype was found to be indistinguishable from the DNA structure identified in prostate tumors, and now appears to be structurally stable as it has been confirmed to be present in normal tissues surrounding tumors.

The lead researcher, Donald C. Malins, Ph.D., D.Sc., points out that this abnormal DNA structure is probably intimately associated with tumor development. Dr. Malins states that the potential exists to inhibit or eliminate this cancer DNA phenotype with drug intervention, thereby reducing the risk for prostate cancer. The study is reported this week in the early online edition of the Proceedings of the National Academy of Sciences.

Previous studies by the PNRI research team found that mice injected with a known carcinogen also produced a comparable cancer DNA phenotype about 8 weeks prior to tumor development. Encouragingly, the researchers were able to virtually eliminate this phenotype through intervention with a drug (cyclophosphamide) that also substantially delayed tumor formation.

Dr. Malins stated that the present findings, together with the previous findings with mice, "support the concept that cancer risk can be predicted by identifying the cancer DNA phenotype in normal tissues, long before any tumors appear." He also stated that "exposure to oxidizing chemical species, such as free radicals, that form in the body from environmental and/or dietary exposures to toxic chemicals likely contribute to the development of the DNA cancer phenotype."

Dr. Malins concludes that "the next important step is to demonstrate that the phenotype can actually be used by physicians to predict a man's risk of prostate cancer." Additionally, he stressed the importance of testing drugs, such as those with antioxidant properties, to eliminate or reduce the formation of the phenotype before tumors start to form.

For further information on the research and its implications, contact Donald C. Malins, Biochemical Oncology Program, PNRI, Seattle, WA, dmalins@pndri.org.