Prostate cancer with bladder neck involvement: Pathologic findings with application of a new practical method for tumor extent evaluation and recurrence-free survival after radical prostatectomy

Prostate cancer reporting and staging: needle biopsy and radical prostatectomy specimens

Prostatic adenocarcinoma remains the most common cancer affecting men. A substantial majority of patients have the diagnosis made on thin needle biopsies, most often in the absence of a palpable abnormality. Treatment choices ranging from surveillance to radical prostatectomy or radiation therapy are largely driven by the pathologic findings in the biopsy specimen. The first part of this review focuses on important morphologic parameters in needle biopsy specimens that are not covered in the accompanying articles. This includes tumor quantification as well as other parameters such a extraprostatic extension, seminal vesicle invasion, perineural invasion, and lymphovascular invasion. For those men who undergo radical prostatectomy, pathologic stage and other parameters are critical in prognostication and in determining the appropriateness of adjuvant therapy. Staging parameters, including extraprostatic extension, seminal vesicle invasion, and lymph node status are discussed here. Surgical margin status is also an important parameter and definitions and reporting of this feature are detailed. Throughout the article the current reporting guidelines published by the College of American Pathologists and the International Collaboration on Cancer Reporting are highlighted.

The Gleason pattern 4 in radical prostatectomy specimens in current practice - Quantification, morphology and concordance with biopsy

PURPOSE

The upgrading of a prostate acinar adenocarcinoma grade group 1 (GG1) between needle biopsy and prostatectomy is common. The extent of high-grade tumor and cribriform morphology are currently suggested as prognostic factors.

METHODS

We reviewed 159 prostatectomy specimens from a private laboratory and an academic/public institution in Salvador, Bahia.

RESULTS

Tumors signed as GG1 at biopsy were upgraded in 59% of all cases. These tumors showed a low frequency of non-focal extraprostatic extension (one case, 3%), extensive positive surgical margins (two cases, 6%) and seminal vesicle invasion (one case, 3%). Among GG2 and GG3 tumors at prostatectomy, the percentage of Gleason pattern 4 (Gp4) involving the gland at ≤1%, 2-5% and >5% was associated with extensive extraprostatic extension (9%, 8% and 42%, respectively) and seminal vesicle invasion (1%, 10% and 31%, respectively). The volume of Gp4 of ≤1ml, >1 to 2ml and >2ml was associated with extensive extraprostatic extension (8%, 26% and 38%, respectively), seminal vesicle invasion (2%, 21% and 33%, respectively) and non-focal positive surgical margins (12%, 26% and 29%, respectively). Some GG2 tumors (~20%) indeed showed at least one measurement of Gp4 higher than one quarter of GG3 carcinomas. Cribriform morphology showed no significant associations for other adverse pathologic prognostic factors.

CONCLUSION

Upgrading from GG1 to GG2 is associated with a very low frequency of morphologic features associated with poor prognosis. Routine quantification of Gp4 is feasible in radical prostatectomy products and seems to better stratify tumors regarding the association with other morphologic parameters of prognostic importance.

68Ga-PSMA PET/CT Detects the Location and Extent of Primary Prostate Cancer

We evaluated the accuracy of PET/CT with ⁶⁸Ga-PSMA-HBED-CC-a ⁶⁸Ga-conjugated ligand of human prostate-specific membrane antigen (PSMA)-to localize cancer in the prostate and surrounding tissue at initial diagnosis.

METHODS

Twenty-one patients with biopsy-proven prostate cancer underwent ⁶⁸Ga-PSMA-HBED-CC (⁶⁸Ga-PSMA) PET/CT at a median of 4 d (range, 0-47 d) before radical prostatectomy. Based on a 6-segment model, the Gleason score and proportion of tumor tissue within each segment (segmental tumor burden, or STB) as determined by histopathology (STB_HP) were correlated with SUV_max and STB as determined by different SUV cutoffs for ⁶⁸Ga-PSMA PET (STB_PET1-6). Furthermore, the involvement of seminal vesicles and other extracapsular extension were assessed by histopathology and PET/CT.

RESULTS

Histopathology-positive segments (n = 100 of 126; 79%) demonstrated a significantly higher mean ± SD SUV_max (11.8 ± 7.6) than histopathology-negative segments (4.9 ± 2.9; P < 0.001). Receiver-operating-characteristic analysis revealed an optimal SUV_max cutoff of 6.5 for discrimination of histopathology-positive segments from histopathology-negative segments (area under the curve, 0.84; P < 0.001), which gave 67% sensitivity, 92% specificity, a 97% positive predictive value, a 42% negative predictive value, and 72% accuracy. STB_PET3 as determined by (2 × blood SUV) + (2 × SD) correlated best with STB_HP (Pearson ρ = 0.68; P < 0.001; mean difference ± SD, 19% ± 15%). PET/CT correctly detected invasion of seminal vesicles (n = 11 of 21 patients; 52%) with 86% accuracy and tumor spread through the capsule (n = 12; 57%) with 71% accuracy.

CONCLUSION

⁶⁸Ga-PSMA PET/CT accurately detected the location and extent of primary prostate cancer. Our preliminary findings warrant further investigation of ⁶⁸Ga-PSMA PET/CT in conjunction with needle biopsy.

A modified point count method as a practical approach to assess the tumor volume and the percent gland involvement by prostate carcinoma

This study reports a modified point-count method for quantifying the extent of carcinoma in prostatectomy specimens (n=143), as adapted from Billis et al. (2003) [3]. The prostates were studied as follows: the basal/apical margins were sampled using the cone method. The remainder of the gland was divided into 12 quadrant-shaped regions that were sampled using two slices. Eight equidistant points were marked directly on the coverslip over each fragment. The points inside the tumoral areas were counted and expressed as both the percentage of prostate gland involvement by carcinoma (PGI) and the tumor volume (TV). A significant correlation between the preoperative PSA levels and each of the three quantitative estimations were observed, with improved correlations with the PGI and TV values obtained using the point-count method (viz. number of slices involved (NSI) (r=0.32), PGI (r=0.39) and TV (r=0.44)). With the data sets stratified into three categories, all three methods correlated with multiple parameters, including Gleason scores ≥7, primary Gleason scores ≥4, perineural/angiolymphatic invasion, extraprostatic extension, seminal vesicle invasion and positive margins. All three quantitative methods were associated with morphologic features of tumor progression. The results obtained using this modified point-count method correlate more strongly with preoperative PSA levels.

Should pathologists continue to use the current pT2 substaging system for reporting of radical prostatectomy specimens?

OBJECTIVES

Pathologic staging tries to maintain symmetry with clinical staging, allowing a direct comparison of both. However, in contrast to clinical substaging of T2 prostate cancers, is controversial whether pathologic T2 substaging conveys prognostic information. The aim of our study is to analyze the clinicopathologic findings and the prognostic information comparing the clinical with the pathological T2 substaging of patients submitted to radical prostatectomy.

MATERIALS AND METHODS

Using the 2009 TNM staging system, 169 patients with clinical stage T2a were compared with patients with stage T2b/T2c, and 142 patients with pathological stage T2a were compared with patients with stage T2c. All surgical specimens were step-sectioned. Using a semiquantitative point-count method for tumor extent evaluation, all insignificant tumors were excluded from analysis. Clinicopathological characteristics were compared between the groups. Biochemical recurrence data were compared using log-rank analysis, and significant predictors of time to biochemical recurrence were determined using univariate and multivariate Cox proportional hazards model.

RESULTS

There was significant difference in biochemical recurrence rates between men with clinical T2a versus T2b/T2c tumors but no difference between men with pathological T2a versus T2c tumors. No patient in pathologic stage T2b was found. On multivariate analysis, clinical stage T2b/T2c was independent predictor of time to biochemical recurrence following surgery but not pathological stage T2c.

CONCLUSIONS

There is lack of symmetry between clinical and pathological T2 substaging as predictors of time to biochemical recurrence following surgery. The findings support a reevaluation of the TNM pathologic T2 stage, which should not be substratified.

International Society of Urological Pathology (ISUP) Consensus Conference on Handling and Staging of Radical Prostatectomy Specimens. Working group 3: extraprostatic extension, lymphovascular invasion and locally advanced disease

The International Society of Urological Pathology Consensus Conference on Handling and Staging of Radical Prostatectomy Specimens in Boston made recommendations regarding the standardization of pathology reporting of radical prostatectomy specimens. Issues relating to extraprostatic extension (pT3a disease), bladder neck invasion, lymphovascular invasion and the definition of pT4 were coordinated by working group 3. It was agreed that prostate cancer can be categorized as pT3a in the absence of adipose tissue involvement when cancer bulges beyond the contour of the gland or beyond the condensed smooth muscle of the prostate at posterior and posterolateral sites. Extraprostatic extension can also be identified anteriorly. It was agreed that the location of extraprostatic extension should be reported. Although there was consensus that the amount of extraprostatic extension should be quantitated, there was no agreement as to which method of quantitation should be employed. There was overwhelming consensus that microscopic urinary bladder neck invasion by carcinoma should be reported as stage pT3a and that lymphovascular invasion by carcinoma should be reported. It is recommended that these elements are considered in the development of practice guidelines and in the daily practice of urological surgical pathology.

International Society of Urological Pathology (ISUP) Consensus Conference on Handling and Staging of Radical Prostatectomy Specimens. Working group 2: T2 substaging and prostate cancer volume

The 2009 International Society of Urological Pathology consensus conference in Boston made recommendations regarding the standardization of pathology reporting of radical prostatectomy specimens. Issues relating to the substaging of pT2 prostate cancers according to the TNM 2002/2010 system, reporting of tumor size/volume and zonal location of prostate cancers were coordinated by working group 2. A survey circulated before the consensus conference demonstrated that 74% of the 157 participants considered pT2 substaging of prostate cancer to be of clinical and/or academic relevance. The survey also revealed a considerable variation in the frequency of reporting of pT2b substage prostate cancer, which was likely a consequence of the variable methodologies used to distinguish pT2a from pT2b tumors. Overview of the literature indicates that current pT2 substaging criteria lack clinical relevance and the majority (65.5%) of conference attendees wished to discontinue pT2 substaging. Therefore, the consensus was that reporting of pT2 substages should, at present, be optional. Several studies have shown that prostate cancer volume is significantly correlated with other clinicopathological features, including Gleason score and extraprostatic extension of tumor; however, most studies fail to demonstrate this to have prognostic significance on multivariate analysis. Consensus was reached with regard to the reporting of some quantitative measure of the volume of tumor in a prostatectomy specimen, without prescribing a specific methodology. Incorporation of the zonal and/or anterior location of the dominant/index tumor in the pathology report was accepted by most participants, but a formal definition of the identifying features of the dominant/index tumor remained undecided.

Atrophy in specimens of radical prostatectomy: is there topographic relation to high-grade prostatic intraepithelial neoplasia or cancer?

INTRODUCTION

It is controversial whether there is any relationship of proliferative inflammatory atrophy (PIA) to high-grade prostatic intraepithelial neoplasia (HGPIN) and cancer (CA). It has been suggested a topographic relation and a potential of the proliferative epithelium in PIA to progress to HGPIN and/or CA. The aim of this study was to analyze in radical prostatectomies a possible topographic relation of the lesions.

MATERIALS AND METHODS

A total of 3,186 quadrants from 100 whole-mount consecutive surgical specimens were examined. The frequency of quadrants showing: only PIA, PIA+CA, PIA+HGPIN, or PIA+HGPIN+CA was determined. Extent and distance between the lesions were evaluated by a semiquantitative point-count method previously described. We also studied foci with partial or complete atrophy without inflammation. The statistical methods included the Kruskal-Wallis and the Mann-Whitney tests and the Spearman correlation coefficient.

RESULTS

The mean (range) of quadrants showing only PIA, PIA+CA, PIA+HGPIN, and PIA+HGPIN+CA was 3.29 (0-21), 2.51 (0-11), 0.77 (0-6), and 0.44 (0-4), respectively (P < 0.01). Most of the foci of PIA were significantly located in a distance >5 than <5 mm from HGPIN or CA. There was no significant correlation between extent of PIA (P = 0.64, r = 0.05) with extent of HGPIN. There was a significant negative correlation of extent of PIA (P = 0.01, r = -0.27) with extent of CA. Similar results were found considering foci either with or without inflammation. Chronic inespecific inflammation was not seen in foci of partial atrophy.

CONCLUSION

A topographic relation of PIA to HGPIN and/or CA was not supported by our study.

The prognostic significance of bladder neck invasion in prostate cancer: is microscopic involvement truly a T4 disease?

Since the widespread of prostate-specific antigen-based screening, prostate cancer at clinical stage T4 has become rare. Most bladder invasion is actually detected on radical prostatectomy specimens as a microscopic bladder neck involvement (BNI). The 2002 Tumour-Node-Metastasis (TNM) classification system classified prostate cancer with BNI within a unified pT4 category and rendered it equivalent to invasion into the pelvic wall musculature or external sphincter; this decision is controversial. Various series have assessed the clinical relevance and the effect of BNI on prognosis. This evidence-based review provides evidence that BNI should be assigned within the subset of pT3 stage, and that further improvement of the actual TNM staging system should be considered. However, BNI remains strongly associated with adverse pathology and should be regarded as a factor that worsens the prognosis of the underlying tumour stage.

Radical retropubic prostatectomy for prostate cancer with microscopic bladder neck involvement: survival and prognostic implications

OBJECTIVE

To report the oncological outcome of 106 patients who had locally advanced prostate cancer with microscopic bladder neck invasion, identified in a series of 1129 patients surgically treated with retropubic radical prostatectomy over a 12-year period.

PATIENTS AND METHODS

All specimens were reviewed. Microscopic bladder neck invasion was defined as the presence of neoplastic cells within the smooth muscle bundles of the bladder neck, with no accompanying prostatic glandular tissue on the corresponding slide. Survival was analysed for different subgroups in relation to several variables.

RESULTS

The follow-up (median 7.2 years, mean 6.68, range 0.3-14) was available for 106 patients with microscopic bladder neck invasion. Seminal vesicle invasion was present in 69.8% of the cases, lymph node involvement in 29.2%, apex infiltration in 31.8%, and positive surgical margins in 23.6%. Biochemical progression occurred in 61 (57.5%) patients, and 25 of them died from cancer. The mean (sd) biochemical progression-free survival was 0.68 (0.05), 0.59 (0.05), 0.40 (0.05) and 0.38 (0.05) at 1, 2, 5 and 10 years, respectively. Age, Gleason score and lymph node invasion were independent prognostic factors on multivariate analysis. Overall and cancer-specific survival rates were 0.75 (0.04) and 0.80 (0.04) at 5 years and 0.57 (0.04) and 0.75 (0.04) at 10 years, respectively. Univariate analysis showed that seminal vesicle invasion, lymph node involvement and surgical Gleason score > or =8 significantly increased the risk of death. On multivariate analysis only the surgical Gleason score had an independent prognostic role with regard to overall survival (P = 0.01; odds ratio 2.82, 95% confidence interval 1.2-6.4) and cancer-specific survival (P < 0.001; 8.6, 2.5-28.8).

CONCLUSIONS

In this series, overall and cancer-specific survival rates were comparable to those reported for surgically treated cT3 prostate cancers. The lack of need for external urinary diversion during the entire follow-up significantly contributed to the patients' quality of life.

Bladder neck involvement as pT4 disease in prostate cancer: implications for prognosis and patient surveillance

Since the use of prostate-specific antigen screening has become widespread, prostate cancer at clinical T4 stage has become rare. Most bladder invasion is actually detected on radical prostatectomy specimens as a microscopic bladder neck involvement (BNI). The 2002 TNM classification system classified prostate cancer with BNI within a unified pT4 category, and rendered it equivalent to invasion into pelvic wall musculature or external sphincter. This decision is controversial. Various series have studied the clinical relevance and the impact of BNI on prognosis. Our evidence-based review provides support to the assignment of BNI within the subset of pT3 stage, and suggests that further improvement of the actual TNM staging system should be considered. However, BNI remains strongly associated with adverse pathology and should be regarded as a factor that worsens the prognosis of the underlying tumor stage.

Microscopic bladder neck involvement by prostate carcinoma in radical prostatectomy specimens is not a significant independent prognostic factor

The independent prognostic importance of microscopic bladder neck involvement by prostate cancer in radical prostatectomy is questionable. We studied a cohort of 1845 patients to determine the significance of microscopic bladder neck involvement. Bladder neck involvement was defined as prostate cancer present within the coned bladder neck. We further categorized the cases as 'true bladder neck involvement' and 'false bladder neck involvement.' True bladder neck involvement required prostate cancer within thick smooth muscle bundles without intermixed benign prostatic glands. False bladder neck involvement was characterized by prostate cancer intermixed with benign prostatic glands. Bladder neck involvement was analyzed in relation to preoperative serum prostate-specific antigen (PSA) level, extraprostatic extension, seminal vesicle involvement, positive surgical margin, lymph node involvement, radical prostatectomy Gleason score, and tumor volume. Of the 90 patients (4.9%) with microscopic bladder neck involvement, 63 were further classified as true bladder neck involvement and 27 as false bladder neck involvement. In univariate model, both types of bladder neck involvement (P<0.001), true (P<0.001), and false (P=0.040), were significantly associated with increased PSA-recurrence risk compared to bladder neck negative cases. In multivariate model the PSA-recurrence relative risk associated with bladder neck involvement (true or false) was not a significant independent prognostic factor. Extraprostatic extension, seminal vesicle involvement, positive surgical margin, lymph node involvement, PSA, and Gleason score were significant independent predictors of PSA recurrence. The time to biochemical recurrence in patients with bladder neck involvement was similar to that of pT2 with positive surgical margin or pT3a with negative surgical margin patients (Kaplan-Meier curves). Bladder neck involvement was associated with other adverse pathologic features, but was not an independent predictor of PSA recurrence. In view of the previous and current data, the staging system for bladder neck involvement should be revised and patients may be best categorized as having pT3a disease.

Iatrogenic and non-iatrogenic positive margins: incidence, site, factors involved, and time to PSA progression following radical prostatectomy

INTRODUCTION

There are conflicting data regarding the incidence, site and prognostic significance of positive margins resulting from iatrogenic incision into the prostate (pT2+) or non-iatrogenic inability to excise extraprostatic extension (EPE) of tumor.

MATERIALS AND METHODS

The surgical specimens were whole-mount processed. Nerve-sparing, tumor extension and Gleason score were considered possible factors involved in positive margins. Time to PSA progression was studied using a Kaplan-Meier product-limit analysis.

RESULTS

Positive margins resulted from iatrogenic incision in 61/230 (26.52%) prostates and from EPE in 34/230 (14.78%) prostates. The site most frequently involved in pT2+ prostates was the posterolateral quadrants (40.98%); in cases with EPE both anterolateral and posterolateral quadrants (67.65%) were most frequently involved. Positive margins occurred equally in patients with and without nerve-sparing in both groups. Tumors were significantly more extensive and with higher Gleason score in patients with EPE. Time to PSA progression was similar in patients with pT2+ versus EPE and no invasion of the seminal vesicle, but was significantly shorter in patients with EPE and invasion of the seminal vesicle.

CONCLUSION

The frequency of positive margins in our institution was similar to others with large experience in performing radical prostatectomies. The higher frequency of posterolateral quadrants in iatrogenic positive margins is probably related to the preservation of adjacent vital structures and not to nerve-sparing surgery. A trend for a decreasing frequency of non-iatrogenic surgical margins may be explained by the marked increase of clinical stage T1c in recent years. More-extensive tumors and higher Gleason scores seem to influence only non-iatrogenic positive margins. Biochemical (PSA) progression in EPE must be studied by stratifying the patients into two groups: with and without seminal vesicle invasion.

Prostate cancer pathologic stage pT2b (2002 TNM staging system): does it exist?

OBJECTIVE

In the 1997 TNM staging system, tumors were classified into a single subdivision: T2a, and bilateral tumor involvement (T2b). In the 2002 TNM staging system, tumors are subclassified as T2a (less than one half of one lobe involvement), T2b (more than one half of one lobe involvement), and T2c (bilateral involvement). A recent study questioned the existence of a true pathologic pT2b tumor. The aim of our study is to verify this question.

MATERIALS AND METHODS

The study population consisted of 224 men submitted to radical retropubic prostatectomy. The surgical specimens were histologically evaluated by complete embedding and whole-mount processing. Tumor extent was evaluated by a point-count method. The surgical specimens were staged according to the 2002 TNM staging system.

RESULTS

Using the 2002 TNM criteria, the surgical specimens were classified as pT2a, 28 (12.50%); pT2b, 0 (0%); pT2c, 138 (61.61%); pT3a, 30 (13.39%); and, pT3b, 28 (12.50%). Using the point-count method for tumor extent evaluation, the minimum and maximum total points obtained in unilateral tumors were 192 and 368 points, respectively; the most extensive unilateral tumor showed 68 positive points (less than half the minimum total point-count).

CONCLUSIONS

Using the point-count method for tumor extent, our study questions a real existence for pathologic stage pT2b tumors (unilateral tumors involving greater than one-half of one lobe).