How many consecutively rising PSA measurements would trigger a second biopsy?
Because of the difficulty with PSA variability, one cannot determine if a PSA is truly rising on the basis of one or two measurements. At the Smilow Center, we recognize that a number of factors, including measurement variability, testosterone level, infection, inflammation and even ejaculation may result in a rise in the PSA. Therefore, a rise in more than one measurement is necessary to warrant a repeat biopsy. A concerning rate of increase is typically more than 0.5 ng/dl per year when averaged over a minimum of three measurements, including the pre-biopsy measurement.
