Malignant epithelial masses within prostatic duct lumens have been equated with several conflicting entities, including Gleason cribriform grade 3 carcinoma and cribriforming dysplasia. We identified 51 radical prostatectomy cancers containing intraductal lesions among 130 cases, with total cancer volumes between 4 and 10 cc. Such lesions with duct lumen-spanning septa or masses were rare in areas away from invasive cancer (22 foci), while dysplasia (prostatic intraepithelial neoplasia) was common (1,490 foci). Consequently, these lesions were interpreted as being part of the evolution of invasive carcinoma rather than precursors; they were designated "intraductal carcinoma" as distinct from dysplasia. Intraductal cancer areas within invasive carcinoma usually represented cancer extension within the branches of a single segment of the duct-acinar system from near the urethra to the gland capsule. In 51% of cases with intraductal spread, the invasive component produced large ( > 0.5 mm) tumor masses in perineural spaces, which in turn correlated strongly with extensive capsule penetration and frequent positive surgical margins selectively at the superior nerve pedicle. The amount of grade 4/5 cancer, the amount of intraductal carcinoma, and the large perineural tumor mass appeared to be related to postprostatectomy progression of cancer, as measured by elevation of ultrasensitive serum prostate-specific antigen. It was concluded that intraductal prostatic adenocarcinoma is a common morphologic entity with precisely defined histologic criteria and a unique biologic significance, as reflected by an enhanced capacity for extensive spread within ducts and perineural spaces. It was proposed that the diversity of diagnoses attached to most cribriform malignant lesions can be unified by the concept of this single entity.

Our report should make it easier to diagnose transition zone cancer. The 72% biochemical PSA cure rate is significantly higher than the 49% cure rate for peripheral zone cancer. Since cancer volume and percent Gleason grade 4/5 disease were the same in these 2 groups matched by cancer volume, the differences in behavior of peripheral and transition zone cancers must be sought at the molecular level unless anatomical location alone explains the differences in progression. Pathologists should differentiate transition from peripheral zone cancer when analyzing radical prostatectomy specimens.

These results indicate a weak and disappointing correlation among all pathological features of 6 systematic biopsies and radical prostatectomy specimens. The combination of 1 positive core with cancer length less than 3 mm. that contains no Gleason grade 4/5 is probably the best predictor of prostate cancer less than 0.5 cc in men with nonpalpable tumors, a cancer volume that occurred in only 10% of the 222 (23) men.

Preoperative serum PSA has a clinically useless relationship with cancer volume and grade in radical prostatectomy specimens, and a limited relationship with PSA cure rates at preoperative serum PSA levels of 2 to 9 ng./ml. Trend summaries for prostate weight on broken line regression showed that below 9 ng./ml. BPH is a strong contender for the cause of PSA elevation, constituting the primary cause of the over diagnosis of prostate cancer.