Prostate cancer and prostatic intraepithelial neoplasia: true, true, and unrelated?

It was in 1987 that McNeal and Bostwick first described intraductal dysplasia during a whole-mount pathologic investigation of 100 prostates without cancer and 100 with cancer that were diagnosed in the pre–prostate-specific antigen era. They found foci of dysplasia in 82% of the prostates harboring cancer compared with 43% in those without cancer. Interestingly, both the grade and volume of dysplasia were associated with cancer risk. With that report, pathologic evaluations of the prostate began to annotate the presence of prostatic intraepithelial neoplasia (PIN). Initially, the finding of PIN led to series examining the likelihood of finding cancer on rebiopsy after a finding of PIN (high risk) and then studies examining the molecular characteristics of PIN (found to be similar to cancer).