Prostate cancer: Transrectal ultrasound and pathology comparison. A preliminary study of outer gland (peripheral and central zones) and inner gland (transition zone) cancer

Abstract

A study was conducted to compare results of transrectal ultrasound with pathologic findings on 116 patients who underwent radical prostatectomy for treatment of prostate cancer. In 96% (111 of 116), transrectal ultrasound guided biopsies of a hypoechoic lesion proved cancer; seven patients had known Stage A cancer; one patient had cancer detected by palpation and not detected by ultrasound. Cancers in the outer gland (peripheral and central zones) were compared with cancers in the inner gland (transition zone) by both ultrasound and pathology. Forty-eight percent (52 of 108) of cancers originating in the outer gland showed extraprostatic extension (Stage C disease). The primary sites of tumor escape from the outer gland were the prostatic capsule (38%), anterior fibromuscular stroma (5%), seminal vesicle (18%), the base of the gland at the neurovascular bundle (21%), and the apex (31%). Twenty-two percent (17 of 54) of cancers originating in the inner gland (transition zone) showed extraprostatic extension (Stage C disease). The primary sites of tumor escape from the inner gland were the anterior fibromuscular stroma (6%) and apex (11%). Both histologic and biologic differences between outer and inner gland cancers were found when tumor size was controlled. Gleason scores were significantly different for inner and outer gland cancers, with mean scores of 6.2 +/- 1.6 and 7.4 +/- 0.9, respectively. An odds ratio of 8.6 confirmed the increased risk of extraprostatic extension for outer gland cancer. Outer gland cancers showed increased aggressive behavior of both histologic and biologic nature. The difference in biologic aggressiveness of outer and inner gland cancers has definite implications for treatment options. Use of other diagnostic parameters, such as DNA ploidy, may help to determine which cancers to treat and when to treat them; this may have more relevance for cancers originating in the inner gland. Strategic transrectal ultrasound guided biopsy affords accurate tumor mapping and staging when modes of internal spread and escape of cancer from both outer and inner gland are known. Thus, transrectal ultrasound may be our "window of observation" through which additional research may explain the histologic and biologic discrepancies between outer and inner gland cancers.

Does laser ablation prostatectomy lead to oncological compromise?

“…Of the incidental cancers identified, 82% are reported as stage T1a, the remainder being T1b. Other studies also show that the Gleason score is lower in TZ tumours than in the outer gland tumours (PZ and central zone) with Gleason 6.2 vs 7.4 [22]. These TZ tumours also have a lower risk of extraprostatic extension, of 11-22% vs 44-48% in the outer gland [21,22].…”

“…Other studies also show that the Gleason score is lower in TZ tumours than in the outer gland tumours (PZ and central zone) with Gleason 6.2 vs 7.4 [22]. These TZ tumours also have a lower risk of extraprostatic extension, of 11-22% vs 44-48% in the outer gland [21,22]. Stamey et al [23] showed that TZ cancers had a significantly higher rate of organ confinement (67% vs 43%) and Gleason grade 3 only (33% vs 18%) than PZ cancer.…”

Prostate Volumes Derived From MRI and Volume-Adjusted Serum Prostate-Specific Antigen: Correlation With Gleason Score of Prostate Cancer

“…Our semiautomated MRI-based prostate segmentation method produced total prostate volume estimates that highly correlated with prostate weight (correlation coefficient, 0.94). MRI can also be used to delineate the central gland from the PZ [13–19] because of differences in T2 relaxation times and the presence of a pseudocapsule between them [17, 40]. On T2-weighted images, it may be even possible to distinguish different histologic types (e.g., stromal vs cystic hyperplasia) of BPH [14, 16].…”

“…Typically, the transition zone (TZ) is the site of benign prostatic hyperplasia (BPH), whereas peripheral zone (PZ) cancer accounts for 75–85% of all prostate cancer cases [9]. Furthermore, compared with PZ cancer, TZ cancers often have a more favorable prognosis, with a lower Gleason score, less frequent extracapsular extension and seminal vesicle invasion, and a lower rate of biochemical recurrence [10–13]. Given these differences in cancer risk and cancer aggressiveness between the TZ and PZ, we hypothesize that prostate zonal volume information can be useful in the assessment of personalized risk of aggressive prostate cancer.…”

Role of transition zone sampling by TURP in patients with raised PSA and multiple negative transrectal ultrasound-guided prostatic biopsies

“…9 Imaging studies like TRUS or MRI have not proved reliable in the identification of TZ cancers. 10,11 Prostate cancers are often multifocal and the volume of prostate sampled by standard sextant technique is relatively small. More recent development of extended core biopsy protocols focus on lateral placement of TRUS-guided biopsies in the peripheral zone.…”