A new US study challenges the current staging system that determines the extent or severity of prostate cancer that has not metastasized. Published in Cancer, the study found that there is no link between localized prostate cancer’s clinical stage and a patient’s risk of cancer recurrence after having his prostate removed.

One of the primary purposes of staging prostate cancers is to help physicians determine a patient’s prognosis. For example, a more advanced clinical stage should indicate a higher risk of cancer recurrence after treatment. Surprisingly, however, researchers have found that clinical stage is of questionable utility for predicting disease recurrence after surgical removal of the prostate (radical prostatectomy) in patients with localized prostate cancer.

Adam Reese, MD, of the University of California, San Francisco, and his colleagues questioned whether staging errors are responsible for this discrepancy. In other words, do physicians often inaccurately stage prostate cancer cases, and if so, does this account for the inconsistent reliability of clinical staging for predicting prostate cancer outcomes?

The investigators found that clinical stage was assigned incorrectly in 35.4 percent of 3,875 men in a multi-institutional national disease registry. The majority of these staging errors occurred because physicians frequently disregarded the results of transrectal ultrasound tests and incorrectly incorporated biopsy results when assigning stage.

Even after correcting these staging errors, however, there was no association between clinical stage and prostate cancer recurrence after radical prostatectomy. “Our findings question the utility of our current staging system for localized prostate cancer,” said Dr. Reese.