Prostatic intraepithelial neoplasia does not appear to raise serum prostate-specific antigen concentration

Conflicting findings have been reported regarding the relationship between prostatic intraepithelial neoplasia (PIN) and serum prostate-specific antigen (PSA) concentration. This study evaluates whether high-grade PIN significantly raises serum PSA concentration.

We evaluated 194 totally embedded whole-mounted radical prostatectomy specimens removed for clinically localized prostate cancer. No patient received preoperative therapy. In each specimen, the volume of high-grade PIN and carcinoma was calculated using the grid-counting method. Serum PSA concentration was determined prior to surgery. Cancer volume, gland weight, Gleason score, extraprostatic extension, and PIN volume were then compared according to serum PSA concentration and PSA density.

Of the 194 patients, 170 (88%) had high-grade PIN-associated cancer and 24 (12%) had PIN-free cancer within the specimen. PIN volume ranged from 0 to 8.1 cc (mean, 1.3) and cancer volume ranged from 0 to 56.9 cc (mean, 9.1). In a subset of 93 patients with small cancers (less than 6.0 cc), PIN volume ranged from 0 to 6.1 (mean, 0.83) and did not correlate with serum PSA concentration or PSA density (P = 0.80 and P = 0.69, respectively). In the entire study group, PIN volume did not correlate with PSA density (P = 0.17), but did correlate with serum PSA concentration (P = 0.005). Using multiple regression analysis, adjusting for cancer volume, gland weight, Gleason score, and extraprostatic extension, log PIN volume did not contribute to log serum PSA concentration (regression coefficient -0.108; P = 0.51) or log PSA density (regression coefficient -0.104; P = 0.56) in small cancers (less than 6.0 cc). In the entire study group, log PIN volume did not contribute to log serum PSA concentration (regression coefficient -0.182; P = 0.05) or log PSA density (regression coefficient -0.202; P = 0.56).

Our data indicate that high-grade PIN does not significantly contribute to serum PSA concentration. We suggest that patients with elevated serum PSA concentration found to have high-grade PIN on transrectal biopsy should not have their elevated serum PSA concentration attributed to high-grade PIN.