On the spectrum of prostate cells, high-grade PIN cells are closer to being cancerous than they are to being normal. But just because a man has high-grade PIN cells in his prostate, it doesn’t necessarily mean that he has cancer there, too. “High-grade PIN is known to be strongly associated with prostate cancer, and is, indeed, probably a precursor to it,” says pathologist Jonathan Epstein, M.D., Rose-Lee and Keith Reinhard Professor of Urologic Pathology, whose work over the last decade has helped define these cells. However,because biopsies are so much more accurate than they used to be, a finding of high-grade PIN cells isn’t nearly as worrisome as it was a few years ago.

In the 1990s, when high-grade PIN turned up on a needle biopsy, men were told that they needed an immediate repeat biopsy, because cancer was hiding there somewhere— and indeed, on repeat biopsies, cancer was often found. Today, however, evidence from a large Hopkins-led study of thousands of men with prostate cancer shows that this is no longer the case: When men with high-grade PIN undergo a repeat biopsy, they are no more likely to have cancer than other men.

Why is that? The reason is better biopsies, says Epstein. “A decade ago, only four or six biopsies were taken, and if cancer was present it was often missed. Today, however,

most men undergo 12 or more biopsies,which gives us a much greater opportunity to detect cancer.”

Epstein’s advice: “If your biopsy has not been read by a pathologist who specializes in prostate cancer, the first thing you should do is get a second opinion.” If there are no other clinical indicators of prostate cancer, “I recommend that men do not need a repeat needle biopsy within the first year.”Further studies are needed, he adds, to confirm whether repeat biopsies should be performed several years after high-grade PIN is found on a needle biopsy and, if so, how often and when.