Transitional zone and anterior peripheral zone of the prostate. A correlation of small-volume cancer in the biopsy cores and high psa with positive anterior margins in radical prostatectomy specimens

MRI assessment of pathological stage and surgical margins in anterior prostate cancer (APC) using subjective and quantitative analysis

PURPOSE

To evaluate magnetic resonance imaging (MRI) for assessment of extraprostatic extension (EPE) and positive surgical margins (PSM) in anterior prostate cancer (APC).

MATERIALS AND METHODS

With Institutional Review Board approval, 25 APC (>2/3 of tumor anterior to urethra) were assessed using 3T MRI by two blinded radiologists for: size and maximal leading edge of tumor (relative to anterior fibromuscular stroma [AFMS]) on b ≥1000 sec/mm² echo-planar-MRI fused onto T₂ -weighted-MRI, invasion of AFMS and EPE. Comparisons were performed between APCs by EPE/PSM using chi-square, multivariable analysis, and receiver operator characteristic (ROC) analysis.

RESULTS

The prevalence of EPE and PSM were 52% (13/25) and 36% (9/25). Tumor sizes were larger with EPE (22.5 ± 8.4 vs. 14.7 ± 6.3, P = 0.02) and PSM (23.0 ± 9.3 vs. 16.4 ± 7.0, P = 0.06). Area under ROC curve (AUC-ROC) for the diagnosis of EPE by tumor size was 0.77 (95% confidence interval [CI] 0.58-0.95); ≥16 mm size = sensitivity/specificity 69.2/66.7%. Maximal leading edge of tumor was greater with EPE (2.4 ± 2.2 vs. -0.2 ± 3.0) and PSM (2.8 ± 2.3 vs. -0.3 ± 2.5), (P = 0.023, 0.031). AUC-ROC for diagnosis of EPE/PSM by leading edge was 0.78 (CI 0.57-0.97) and 0.75 (CI 0.56-0.94). A ≥1 mm leading edge yielded sensitivity/specificity of 76.9/75.0% and 77.8/62.5% for diagnosis of EPE/PSM. 60-72% (15-18/25) tumors invaded AFMS (k = 0.74), which was not associated with EPE/PSM (P = 0.12-0.14). Radiologists' assessment of EPE had sensitivity/specificity of 61.5-69.2/50.0-75.0% (k = 0.53).

CONCLUSION

Tumor size and leading edge of tumor relative to AFMS may enable diagnosis of EPE and positive surgical margins in APC.

LEVEL OF EVIDENCE

2 J. MAGN. RESON. IMAGING 2017;45:1296-1303.

Anterior prostate biopsy at initial and repeat evaluation: is it useful to detect significant prostate cancer?

Purpose:

Detection rate for anterior prostate cancer (PCa) in men who underwent initial and repeat biopsy has been prospectively evaluated.

Materials and Methods:

From January 2013 to March 2014, 400 patients all of Caucasian origin (median age 63.5 years) underwent initial (285 cases) and repeat (115 cases) prostate biopsy; all the men had negative digital rectal examination and the indications to biopsy were: PSA values > 10 ng/mL, PSA between 4.1-10 or 2.6-4 ng/mL with free/total PSA≤25% and ≤20%, respectively. A median of 22 (initial biopsy) and 31 cores (repeat biopsy) were transperineally performed including 4 cores of the anterior zone (AZ) and 4 cores of the AZ plus 2 cores of the transition zone (TZ), respectively.

Results:

Median PSA was 7.9 ng/mL; overall, a PCa was found in 180 (45%) patients: in 135 (47.4%) and 45 (36%) of the men who underwent initial and repeat biopsy, respectively. An exclusive PCa of the anterior zone was found in the 8.9 (initial biopsy) vs 13.3% (repeat biopsy) of the men: a single microfocus of cancer was found in the 61.2% of the cases; moreover, in 7 out 18 AZ PCa the biopsy histology was predictive of significant cancer in 2 (28.5%) and 5 (71.5%) men who underwent initial and repeat biopsy, respectively.

Conclusions:

However AZ biopsies increased detection rate for PCa (10% of the cases), the majority of AZ PCa with histological findings predictive of clinically significant cancer were found at repeat biopsy (about 70% of the cases).

Detection rate of anterior prostate cancer in 226 patients submitted to initial and repeat transperineal biopsy

OBJECTIVE

To evaluate the detection rate of anterior zone (AZ) prostate cancer (PCa) in patients submitted to initial and repeat transperineal prostate biopsy.

METHODS

From January 2013 to August 2013, 226 patients (median age 64 years) with negative digital rectal examination underwent initial (144 cases) and repeat (82 cases) transperineal prostate biopsy for PSA >10 ng/ml, PSA 4.1-10.0 or 2.6-4.0 ng/ml with free/total PSA ≤25% and ≤20%, respectively. A median of 22 versus 32 cores were performed, including 4 cores of the AZ versus 6 cores (4 anterior plus 2 cores of the transition zone, TZ) at initial versus repeat biopsy, respectively. The detection rate of PCa of the peripheral zone (PZ), AZ and TZ was prospectively evaluated.

RESULTS

The median PSA was 7.6 ng/ml; overall, a stage cT1c PCa was found in 104/226 (46%) patients, in 70 (48.6%) and 34 (41.5%) of the men who underwent initial and repeat biopsy, respectively. An AZ PCa was found in 11.5 vs. 8.8% (p = 0.32) of the patients submitted to initial versus repeat biopsy, respectively. AZ cancers demonstrated a number of positive cores (p = 0.03), greatest percentage of cancer (p = 0.001) and total percentage of cancer (p = 0.001) significantly lower in comparison with PZ PCa; moreover, 56.2 vs. 36.5% of AZ versus PZ PCa were characterized by a microfocus of cancer (p = 0.001), respectively.

CONCLUSIONS

AZ biopsies increase the detection rate of PCa (about 10% of cases) at initial and repeat biopsy, allowing reduction of the biopsy false-negative rate.

Microvascularity in transition zone prostate tumors resembles normal prostatic tissue

BACKGROUND

The objective of this study was comparison of characteristics of the microvasculature in transition zone tumor (TZT) and benign nodular hyperplasia (BPH) with normal prostatic transition zone (NTZ), applying accurate and objective quantification based on digital image analysis. Results of this study may increase understanding of prostate dynamic contrast enhanced (DCE) MRI analysis.

METHODS

Radical prostatectomy specimens of 28 patients containing TZT ranging from pT2-pT4 were used. In 11 patients a concomitant peripheral zone tumor (PZT) was present. Microvessels were visualized by CD31 immunohistochemistry. Specimens were scanned using a computer-controlled microscope with automatic recognition of microvessels. Pseudocolor maps were produced displaying microvessel density, perimeter, and area of an entire prostate transection. Mean, 75th percentile (p75) and coefficient of variation (CV) were calculated automatically in manually indicated areas of the tumor and corresponding contralateral normal tissue, and BPH.

RESULTS

Large variability was seen in TZT microvascular parameters, indicating presence of patients having both hypo and hypervascularized tumors compared to NTZ. In contrast, areas of BPH showed a more consistent increase in vascular parameters, with decreased CV. Analysis of PZT confirmed results of our previous study, with mean and p75 of all vascular parameters being significantly increased and a decrease in CV. No correlation was found for clinicopathological parameters and microvascular parameters.

CONCLUSION

Microvasculature of transition zone tumor showed increased heterogeneity compared to BPH and peripheral zone tumors, possibly explaining the difficulty of TZT detection on DCE-MRI.

'Prostatic evasive anterior tumours': the role of magnetic resonance imaging

OBJECTIVE

To review our experience and delineate the role of magnetic resonance imaging (MRI) in identifying patients presenting with a raised prostate-specific antigen (PSA) level and clinical findings suggestive of anterior predominant tumours, which appear to be significant, particularly in those with a previous negative biopsy or low-volume disease undergoing active surveillance.

PATIENTS AND METHODS

We retrospectively reviewed our database to identify patients with anteriorly predominant tumours on MRI whom had undergone prostate biopsy.

RESULTS

In all, 31 patients with anterior predominant tumours on MRI also had a positive biopsy (14 on active surveillance and 17 with previous negative biopsies). MRI was usually invoked by the presenting PSA level or PSA velocity. MRI had a positive predictive value for anterior tumours of 87% (27/31). The Gleason score distribution for the 27 men with cancer was 6 in 15; 3 + 4 in three, 4 + 3 in six and 8/9 in three. For prostatic cores, 44/85 (52%) samples from the anterior prostate had cancer. Thirteen patients had a radical prostatectomy (pT2 in three, pT3 in seven and pT4 in three); seven of the 13 had positive surgical margins and a third of them had a biochemical recurrence at the 1-year follow-up.

CONCLUSION

There is a subset of patients either having a negative biopsy or low-volume disease and who are on active surveillance who should be considered for MRI and further biopsy, as their pathology might be aggressive. An entity might be emerging with anterior predominant tumours that are impalpable, and we believe the term 'prostate evasive anterior tumour syndrome' to be appropriate. This requires further analysis in a large prospective database with consideration for triggers for MRI and targeted biopsies.

Anatomy of the anterior prostate and extraprostatic space: a contemporary surgical pathology analysis

Over 25 years ago, McNeal described a model of prostatic zonal anatomy based on autopsy dissections in various planes. As opposed to the cone-shaped organ seen in vivo, radical prostatectomy specimens are typically spherical, owing to tissue contraction at surgical removal and subsequent processing. Sectioning from apex to base yields topography at the Surgical Pathology "sign-out" that may vary from McNeal's descriptions. There are no in depth studies of anterior prostatic anatomic variability, including the periurethral region, peripheral (PZ) and transition (TZ) zones, anterior fibromuscular stroma (AFMS), and anterior extraprostatic space (EPS) using modern prosecting techniques. Detailed analysis of 197 entirely submitted, whole-mounted radical prostatectomy specimens focused on differences in zonal anatomy from apex through base, the relationship of AFMS to PZ and TZ, and the nature of the anterior EPS revealed features that may have significant impact on determination of zonal origin and pathologic staging of anteriorly situated prostate cancer. Among these observations are the predominant nature of the anterior PZ at the apex and the potential for its broad contact with the AFMS at this location, the differing volumes and location of the TZ in prostates with and without benign prostatic hyperplasia, and the composition of the anterior EPS, including adipose tissue, blood vessels, and skeletal muscle at the apex varying to include medium to large smooth muscle bundles at the base.

The clinical features of anterior prostate cancers

OBJECTIVE

To identify the clinical characteristics of anterior prostate cancers (APCs) and to compare these with posterior prostate cancers (PPCs).

PATIENTS AND METHODS

We reviewed 1290 consecutive open and laparoscopic radical prostatectomies (RPs) at the authors' institution from January 2000 to March 2004. Prostates were processed using a whole-mount technique. Each surgical specimen was reviewed by one pathologist, and tumour areas were marked, measured and mapped. Positive surgical margins (PSMs) were defined as the presence of cancer cells at the inked surface of the specimen. Specimens were then categorized by the location of their dominant tumour, i.e. pure anterior, anterior > posterior, posterior > anterior, or pure posterior. We compared the clinical and pathological characteristics of 259 patients in the pure-anterior group with the 594 in the pure-posterior group.

RESULTS

Before RP, APCs had a significantly lower biopsy Gleason score (78% vs 68% with Gleason 4-6), fewer mean biopsy cores positive (2.0 vs 2.6), a smaller median percentage of positive cores (17% vs 26%), lower clinical stage (T1 in 79% vs 62%), and higher progression-free probability estimated by preoperative nomogram (86% vs 84%) than PPCs. Patients with APCs also had more previous negative biopsy sessions. The pathological analysis of RP specimens showed that those with APCs had higher tumour volume (1.6 vs 0.83 mL) and had a higher PSM rate (12% vs 7%) than those with PPCs, despite specimens with PPCs having higher rates of extraprostatic extension (10% vs 19%).

CONCLUSIONS

APCs have lower Gleason grade and lower rates of extraprostatic extension, yet patients with anterior tumours have higher overall tumour volumes and higher PSM rates. Because current tools for detecting and staging prostate cancer can underestimate the extent of anterior prostate disease, improved methods are needed for localizing and characterizing anterior cancers.

Differentiation of benign prostatic hyperplasia from prostate cancer using prostate specific antigen dynamic profile after transrectal prostate biopsy

PURPOSE

Serum prostate specific antigen (PSA) level is increased after needle biopsy (Bx) of the prostate. This study tested the hypothesis that the prostate harboring malignant lesions demonstrates less leakage of PSA after prostate biopsy and this phenomenon can be helpful in discriminating benign from cancer diagnosis.

MATERIALS AND METHODS

This prospective study was divided into 3 separate phases. Sextant prostate biopsy was done with transrectal ultrasound guidance, and the change and PSA values after biopsy were evaluated. Phases 1 and 2 had 20 and 41 patients, respectively. PSA dynamic profiles were plotted. We defined the most appropriate timing for blood sampling and the cutoff value of the PSA ratio (post-Bx total PSA-to-pre-Bx total PSA) to be applied for further assessment. Phase 3 recruited 97 cases, of which 66 satisfied the end point criteria in which a diagnosis such as malignancy, or 3 successive benign biopsies or benign transurethral resection of prostate was obtained.

RESULTS

From phases 1 and 2 the cutoff value for the PSA ratio was 2.0, and the timing of blood sampling was 60 minutes after the biopsy. In phase 3 of those whose PSA ratio was less than 2.0, 92.6% (25) had cancer. For those whose PSA ratio was greater than 2.0, 82.1% (32) were benign. Of the 4 cases with a PSA ratio less than 2.0 and an initial benign biopsy, 3 (75%) were proven to have cancer later.

CONCLUSIONS

Evaluating the 1-hour PSA ratio might be helpful for clinicians to select the high risk patients who might have cancer in the prostate. Repeat biopsy should be suggested for cases with a smaller PSA ratio in spite of initial benign results.

Comparison of adjuvant versus salvage radiotherapy policies for postprostatectomy radiotherapy

PURPOSE

We compared the long-term results of postprostatectomy radiotherapy (RT) from two institutions, one adapting a prospective policy of adjuvant RT and the other salvage RT.

METHODS AND MATERIALS

Between 1989 and 1997, 69 patients were referred for adjuvant RT to the institution using adjuvant RT and 88 patients with evidence of recurrence were treated in the institution using salvage RT. The salvage group underwent RT after longer postoperative intervals (median, 40.3 vs. 2.9 months; p <0.0001) and had higher prostate-specific antigen (PSA) values before starting RT (4.5 vs. 0.86 ng/mL; p = 0.003). Both groups were routinely treated to a minimal total dose of 60 Gy. The treatment groups were analyzed for overall survival, disease-specific survival, distant metastasis-free survival, and biochemical recurrence-free survival (BRFS) using Cox proportional hazards modeling.

RESULTS

Of the 69 patients referred for adjuvant RT, 22 (32%) had nonzero PSA values before RT. Multivariable modeling of BRFS found only the PSA value before RT to be statistically significant (p <0.0001). RT after prostatectomy was equally effective in either setting when the pre-RT PSA level was <1 ng/mL. When the PSA value before RT was >or=1 ng/mL, the 5-year BRFS for each group was inferior.

CONCLUSION

Although the adjuvant treatment policy was associated with significantly improved BRFS, this was attributable to low pre-RT PSA values. When the treatment groups were stratified for pre-RT PSA level, the differences in BRFS were not statistically significant. Patients with a rising PSA level after prostatectomy, regardless of their initial risk, should receive prompt referral for RT.

Six additional systematic lateral cores enhance sextant biopsy prediction of pathological features at radical prostatectomy

PURPOSE

We evaluated the contribution of 6 additional systematically obtained, laterally directed biopsy cores to traditional sextant biopsy for the prediction of final pathological findings in the radical prostatectomy specimen.

MATERIALS AND METHODS

We studied 178 consecutive patients with no history of prostate biopsy in whom prostate cancer was diagnosed during an initial systematic 12 core biopsy and who subsequently underwent radical prostatectomy. Of the systematic 12 cores we compared the subset of the 6 traditional sextant cores (S6C), the set of 6 laterally directed cores (L6C) and the complete 12 core set, which included the 6 traditional sextant and the 6 laterally directed cores. Biopsy Gleason score, number of positive cores, total cancer length and percent of tumor in the biopsy sets were examined for their ability to predict extracapsular extension, total tumor volume and pathological Gleason score.

RESULTS

On univariable analyses the biopsy parameters of the complete 12 core set correlated more strongly with extracapsular extension and total tumor volume than the biopsy parameters of S6C or L6C. On multivariable analyses S6C and L6C were independent predictors of pathological features at prostatectomy.

CONCLUSIONS

The addition of 6 systematically obtained, laterally directed cores to traditional sextant biopsy improved the ability to predict pathological features at prostatectomy by a statistically and prognostically significant margin. Preoperative nomograms that use data from a full complement of 12 systematic cores, specifying sextant and laterally directed biopsy cores, should demonstrate improved performance in predicting prostatectomy pathology.

Biological selection criteria for radical prostatectomy

Tumors clinically confined to the prostate gland (T1-2) are heterogeneous with respect to pathological staging and outcome after definitive radical surgery (radical prostatectomy). The preoperative prognostic factors that could predict pathological stage and outcome of individual patients with clinically localized prostate cancer are reviewed. New preoperative factors have been identified by histological analysis of needle biopsy prostate specimens in addition to Gleason grading score, serum markers (PSA), and clinical staging. These factors are related to tumor volume, zonal origin of the tumor, and spread into the gland and surrounding tissues. Other biological factors are identified by molecular and immunohistochemical analysis (neuroendocrine differentiation, DNA content, microvessel density, and perineural invasion). Biomolecular factors can also be assessed preoperatively on serum samples (free/total PSA ratio, PSA RT-PCR). Although only a few of these factors have a role in predicting treatment failure and/or disease recurrence, the neural network analysis seems to be the most important tool for identifying patients with more aggressive disease. A combination of these new factors, also using neural networks, could be relevant in the preoperative management of patients with prostate cancer to identify those with confined disease and to select those suitable for a "nerve sparing radical prostatectomy" to preserve sexual function and to achieve definitive cancer control.