Tool Predicts Aggressive Prostate Cancer in Men with Normal PSA

First multi-factor tool to predict individual prostate cancer risk shows promise, including the ability to identify normal PSA level patients at risk for aggressive prostate cancer.

An easy-to-assess calculator tool, or nomogram, is the first to use all known risk factors to help physicians predict individual prostate cancer risk including patients with normal PSA levels at high risk and performs better than conventional screening, reveals findings from a study published in the Journal of Clinical Oncology. "The ability to better assess prostate cancer risk on an individual basis goes a long way in making better management decisions," says Dr. Robert Nam, lead investigator and urologic oncologist, Odette Cancer Centre, Sunnybrook. "This tool will help avoid unnecessary prostate biopsies, better detect prostate cancer at an earlier, more curable stage and help identify high risk patients for ongoing surveillance who may need to make immediate diet and lifestyle changes and who may need repeat biopsies."Two years ago, at age 70, Colin Graham's PSA level was considered normal (less than or equal to 4.0 ng/ML), but when the nomogram was used to assess all his risk factors, Dr. Nam recommended a prostate biopsy. The biopsy diagnosed aggressive prostate cancer and Colin underwent immediate and successful treatment through surgery. "I can't express enough the relief I felt, knowing things were caught in time," says Graham, "and though this cancer was removed successfully, because I now know my risk, I'm also aware I still need to be monitored.""In Colin's case, though his PSA was normal, a biopsy was justified based on the nomogram. On the other hand, in the case of an older patient with a high PSA level, if the nomogram predicts a low chance of having aggressive prostate cancer, then it would be reasonable to forego a biopsy," says Dr. Nam, assistant professor, department of surgery, University of Toronto.Unlike current prostate cancer nomograms, the nomogram in this study applies more variables and looks more for patients at risk instead of management and treatment of the disease. Known risk factors and tumour markers used are age, family, history of prostate cancer, ethnicity, urinary symptoms, PSA (prostate specific antigen), free:total PSA ratio and DRE (digital rectal exam) and the nomogram is shown to perform better than conventional screening with PSA and DRE alone, especially for patients with a known normal PSA level.Sunnybrook researchers developed and validated the nomogram with 3,108 Canadian men including a subset of 408 volunteers with normal PSA levels who underwent a prostate biopsy. Of the 3,108 men, 42 per cent were diagnosed prostate cancer. Among the 408 men with a normal PSA, 24 per cent were diagnosed with prostate cancer. Further evaluation is underway with a multi-institutional, cross-Canada study.Prostate cancer is the most cancer among Canadian men. In 2007, 22,300 men will be diagnosed with prostate cancer. On average, 83 Canadian men will die of prostate cancer every week.This study was generously funded by National Cancer Institute of Canada, Terry Fox Foundation and Canadian Cancer Society.(Source: Journal of Clinical Oncology : Natalie Chung-Sayers : Sunnybrook Health Sciences Centre : October 2007)