A Better Biopsy: Twelve Samples Instead of Six
Despite major breakthroughs in prostate biopsy over the last decade -- development of the tiny, springloaded biopsy gun, and the use of transrectal ultrasound as a real-time guide that allows urologists to see the prostate as they're removing small cores of its tissue it's still not perfect. The needle biopsy doesn't always prove, beyond all doubt, whether or not a man has prostate cancer: Sometimes, the sample, when looked at under the microscope, is too ambiguous to label definitively. Sometimes, the needle simply misses the cancerous cells.
Most cancers develop in the prostate's peripheral zone; but cancers here tend to be thin and spread laterally, like a sheet so it's not uncommon for the biopsy needle to plunge in too deep and overshoot the target area. That's why, in an attempt to get a comprehensive sample, urologists have traditionally taken what's called a "sextant" biopsy -- six samples from throughout the prostate, one on the top, middle and bottom of the gland on the right and left sides. But six is not enough, says urologist Ray Stutzman, M.D.
Taking twelve samples -- two each from the same locations -- gives a more accurate picture. "We routinely take 12 cores now," Stutzman says, although in some cases, when there's strong suspicion that cancer is present, he takes as many as 20. "I've done about the last 1,000 biopsies that way, for the last four years. It doesn't seem to increase the complications" -- there is a minor risk of bleeding or infection -- "and it doesn't seem to cause any greater discomfort."