Although men with untreated localized prostate cancer have high long-term survival rates, many patients undergo treatment anyway. In order to avoid unnecessary treatment, researchers want to identify methods to determine which patients will develop lethal prostate cancer. The rate of increase of PSA - a protein produced by the prostate - before prostate cancer treatment has been associated with the patient’s prognosis, which suggests that early measurements of PSA may predict the behaviour of the tumour.

To assess the accuracy of using PSA to predict prostate cancer outcome, Katja Fall, M.D., Ph.D., of the Karolinska Institute in Stockholm, and colleagues analysed the rate of change of PSA levels in 267 men from Sweden, Finland, and Iceland who were diagnosed with early localized prostate cancer. The researchers recorded the PSA levels for the first two years after diagnosis to capture the patients’ early PSA patterns. The men in the study received no curative treatment for the first two years but were closely watched for signs of progression, which is called watchful waiting.

At the end of the follow-up, 34 patients had died from prostate cancer, and 18 had developed metastatic prostate cancer but were still alive. Although initial PSA values and the rate of change were associated with later development of lethal prostate cancer, they were not accurate enough to predict lethal cancer.

"We conclude that PSA measurement is associated with prostate cancer prognosis and continues to be an important monitoring tool," the authors write. "However, early PSA characteristics perform poorly in distinguishing those who develop a lethal prostate cancer from those at low or no risk of disease progression. Therefore, better decision tools are needed for active monitoring of patients with early disease."; Source: Journal of the National Cancer Institute