New prostate cancer markers offer hope for more accurate diagnosis

May 15, 2008

Urologists can look forward to having better markers for diagnosis and staging and the opportunity to confidently offer appropriate patients less invasive Urologists can look forward to having better markers for diagnosis and staging and the opportunity to confidently offer appropriate patients less invasive procedures to minimize treatment-related morbidity.

Key Points

While there were no revolutionary advances in the diagnosis and management of localized prostate cancer during the past year, the future appears promising. Based on research being reported at the AUA annual meeting in Orlando, FL, urologists can look forward to having better markers for diagnosis and staging and the opportunity to confidently offer appropriate patients less invasive procedures to minimize treatment-related morbidity, said Richard D. Williams, MD, Rubin H. Flocks Chair, department of urology, University of Iowa, Iowa City.

Research on urinary prostate cancer gene 3 (PCA3) for improving prostate cancer detection specificity also will be presented. One group found that adding this marker to serum PSA improved the prediction of prostate cancer. However, the best PCA3 cutoff for separating normal from abnormal test results is yet to be determined, according to another study.

"These findings from biomarker re-search are encouraging, although genotyping for single nucleotide polymorphisms associated with prostate cancer risk-particularly 8q24, 17q12, and 17q24.3-likely holds the greatest promise for identifying men likely to develop prostate cancer," Dr. Williams said. "However, considering that more men with minimal (low-grade, low-volume) prostate cancer are being treated than need to be, the identification of an accurate marker predicting progressive disease remains the holy grail."

Focal subtotal therapy

In the realm of less invasive treatment, several reports underscore growing interest in focal subtotal therapy. Based on the premise that subtotal focal therapy may be ideal for men with unilateral disease, one group compared surgical pathology outcomes of radical prostatectomy patients with unilateral and bilateral disease and found rates of extracapsular ex-tension and seminal vesicle invasion were significantly lower in the unilateral disease group. However, bilateral disease was present in the majority of men included in this study as well as in another series examining tumor foci in radical prostatectomy specimens within and outside planned subtotal focal treatment plans.

"These studies provide evidence to support my belief that in the absence of an accurate progression marker and imaging techniques or tissue markers that are absolute for tumor, subtotal focal treatment is far from assuming a viable role in the management of localized prostate cancer at the present time," said Dr. Williams.

"The data on the prevalence of bilateral disease suggest subtotal focal treatment would leave untreated prostate cancer in the majority of men. While presumably the men selected for subtotal focal treatment would have predominantly low-grade, low-volume disease, the clinical significance of the residual cancer is unknown," said Dr. Williams.

Another group is presenting outcomes data from focal prostate cryoablation and is reporting a biochemical, disease free survival rate of about 82%, but with only 18 months of follow-up.

"Data on minimally invasive focal treatment such as cryotherapy and high-intensity focused ultrasound for prostate cancer are beginning to mature, but we really need data from 10 to 15 years of follow-up," said Dr. Williams.