Objectives: Both the benign and malignant prostatic epithelial components of the prostate gland contribute to the serum prostate-specific antigen (PSA) level. Therefore, for a given PSA, the presence of benign hyperplastic prostate tissue (BHPT) may indicate a lower cancer burden. This study was performed to assess the impact of varying amounts of BHPT on PSA failure free (bNED) survival after radical prostatectomy for localized prostate cancer.
Methods: Cox regression multivariable analyses were performed to assess the ability of the clinical stage, PSA, biopsy Gleason score, and prostate gland volume to predict time to postoperative PSA failure in 885 patients.
Results: In addition to the PSA (P < 0.0001), biopsy Gleason score of 8 to 10 (P < 0.0001) and of 7 (P = 0.05), and clinical Stage T2c,3a (P < 0.0001) and T2b (P = 0.0016), the prostatectomy prostate gland volume (P < 0.0001) was a significant predictor of time to postoperative PSA failure. Patients with a prostatectomy prostate gland volume greater than 75 cm3 had a 100% 4-year bNED survival and favorable pathologic characteristics (pathologic Stage T2, 85%; prostatectomy Gleason score 6 or less, 78% and 7, 22%; and negative margins, 95%) despite a preoperative PSA of 10 to 20 ng/mL and more than 20 ng/mL in 28% and 13% of these men, respectively. In 75% of these cases, lead time bias because of PSA driven repeat biopsies provided an explanation.
Conclusions: Lead time bias because of PSA driven repeat biopsy accounted for the high 4-year bNED survival and favorable pathologic findings for most patients who had prostate cancer coexisting in a prostate gland comprised of BHPT and a total gland volume in excess of 75 cm3. An additional explanation is needed, however, for the remaining patients.