A Canadian developed tool can help physicians predict a patient's prostate cancer risk -- including those with normal PSA levels - and performs better than conventional screening, finds a new study.
The tool is called a nomogram, a mathematical model that shows relationships between factors -- in this case: prostate cancer risk markers.
The nomogram developed by Canadian researchers combines all known risk factors and tumour markers for prostate cancer including: PSA level (prostate specific antigen), age, family history of prostate cancer, ethnicity, urinary symptoms, free:total PSA ratio and digital rectal exam (DRE).
According to the study's authors, the tool performs better than conventional screening with PSA and DRE alone, especially for patients with a known normal PSA level (less than or equal to 4.0 ng/ML).
"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 at Sunnybrook Health Sciences Centre in Toronto.
"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."
Sunnybrook researchers validated the nomogram with 3,108 Canadian men, including a subset of 408 volunteers who had normal PSA levels. All of them volunteered to undergo 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.
The study is published in the Journal of Clinical Oncology.
Colin Graham is grateful for the development of the nomogram. Two years ago, at age 70, his PSA level was considered normal. But when the nomogram was used to assess all his risk factors, Nam recommended a prostate biopsy. The biopsy diagnosed aggressive prostate cancer and Graham underwent immediate treatment through surgery. He is now cancer-free.
"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."
Nam notes that in Graham's case, a biopsy was justified based on the nomogram's results, even though his PSA was normal. In the case of an older patient with a high PSA level, if the nomogram predicted a low chance of having aggressive prostate cancer, it would be reasonable to skip the biopsy, he says.
Around 22,300 men are diagnosed with prostate cancer in Canada every year.
