Posted on May 07, 2010, 6 a.m.
A new blood test proves 70% accurate in predicting which men have more aggressive tumors that require treatment, and identifies those men in the early stages of prostate cancer may forgo immediate treatment.
Whereas elevated Prostate Specific Antigen (PSA) levels can be a sign of prostate cancer spread in men with early cancer, the PSA test does not distinguish between slow-growing and aggressive cancers. As a result, there are suggestions that prostate cancer may be overdiagnosed and overtreated. Robert W. Veltri, from Johns Hopkins University (Maryland, USA), and colleagues have developed a new blood test, known as the Prostate Health Index (PHI). It measures three forms of PSA, including pro-PSA, a shortened molecule that is missing a few of the amino acids that make up the PSA protein, and suggested to be a highly accurate form of PSA. The team studied 71 men who were diagnosed with small, low-grade, and low-stage prostate cancer based on their PSA results. Approximately four years later, 39 had unfavorable biopsy results that signaled a need for treatment. The PHI test was performed on blood samples, banked at the time of biopsy, from all 71 men. When the researchers combined the biopsy results with the PHI data, they were able to predict 7 in 10 men that might progress, leading them to conclude that: “Measurement of the serum PHI and tissue DNA content at the time of diagnosis are able to predict which men enrolled in an [active surveillance] cohort will ultimately require treatment for [prostate cancer].”
Sumit Isharwal, Danil Makarov, Lori J. Sokoll, Patricia Landis, Cameron Marlow, Jonathan I. Epstein, Alan W. Partin, H. Ballentine Carter, Robert W. Veltri. “Serum prostate health index and biopsy tissue DNA content at the time of diagnosis predicts the need for treatment in men enrolled in an active surveillance program” (Abstract 2731/13), presented at the American Association for Cancer Research 101st Annual Meeting 2010.