Does HistoScanning™ predict positive results in prostate biopsy? A retrospective analysis of 1,188 sextants of the prostate

PURPOSE

The role of HistoScanning™ (HS) in prostate biopsy is still indeterminate. Existing literature is sparse and controversial. To provide more evidence according to that important clinical topic, we analyzed institutional data from the Martini-Clinic, Prostate Cancer Center, Hamburg.

METHODS

Patients who received prostate biopsy and who also received HS were included in the study cohort. A single examiner, blinded to pathological results, re-analyzed all HS data in accordance with sextants of the prostate. Each sextant was considered as an individual case. Corresponding results from biopsy and HS were analyzed. The area under the receiver-operating characteristic curve (AUC) for the prediction of a positive biopsy by HS was calculated. Furthermore, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were assessed according to different HS signal volume cutoffs (>0, >0.2 and >0.5 ml).

RESULTS

Overall, 198 men were identified and 1,188 sextants were analyzed. The AUC to predict positive biopsy results by HS was 0.58. Sensitivity, specificity, PPV and NPV for HS to predict positive biopsy results per sextant, depending on different HS signal volume cutoffs (>0, >0.2 and >0.5 ml) were 84.1, 27.7, 29.5 and 82.9 %, 60.9, 50.6, 28.8 and 79.7 %, and 40.1, 73.3, 33.1 and 78.8 %, respectively.

CONCLUSIONS

Positive HS signals do not accurately predict positive prostate biopsy results according to sextant analysis. We cannot recommend a variation of well-established random biopsy patterns or reduction of biopsy cores in accordance with HS signals at the moment.

Safe-R: a novel score, accounting for oncological safe nerve-sparing at radical prostatectomy for localized prostate cancer

OBJECTIVES

The objectives of the study were to describe a novel score (safe-R), combining information on surgical margin status (SM) and extend of nerve-sparing (NS) applicable for all patients undergoing radical prostatectomy (RP), and to test the impact of our frozen-section navigated nerve-sparing approach (NeuroSAFE) on safe-R score.

METHODS

We retrospectively analyzed 9,635 RPs performed at our center between 2002 and 2011. Of these, 47 % were conducted with NeuroSAFE. Proportions of NS and SM status were assessed. Subsequently, a score for oncological safe NS (safe-R) was developed; Safe-R was categorized as 3 (for negative SM and bilateral NS), 2 (for negative SM and unilateral NS), 1 (for negative SM without NS), and 0 (for patients with positive SM), respectively. The impact of NeuroSAFE on safe-R was analyzed by chi-square test and confirmed by multinomial logistic regression, adjusting for preoperative risk factors.

RESULTS

Applying NeuroSAFE resulted in enhanced safe-R score, indicating lower rates of positive SM and higher rates of NS, across all risk categories (all p < 0.001). For example in high-risk patients, NeuroSAFE resulted in lower proportions of safe-R 0 (27.6 vs. 33.6 %) and higher proportions of safe-R 3 (32.4 vs. 17.1 %, p < 0.001). Linkage between the NeuroSAFE approach and safe-R was confirmed after multinomial logistic adjustment for preoperative risk factors. All results were confirmed in a propensity-matched cohort (matched for preoperative risk factors and year of surgery, data not shown).

CONCLUSION

Safe-R represents a novel tool to assess and report on oncological safe nerve-sparing in RP. NeuroSAFE is associated with enhanced safe-R scores.

Incremental detection rate of prostate cancer by real-time elastography targeted biopsies in combination with a conventional 10-core biopsy in 1024 consecutive patients

OBJECTIVE

To quantify the incremental detection rate (DR) of a targeted biopsy in addition to a randomized 10-core biopsy.

PATIENTS AND METHODS

This retrospective study analysed 1024 patients who consecutively underwent a four-core real-time elastography (RTE) targeted biopsies in addition to a randomized 10-core transrectal ultrasonography (TRUS)-guided biopsy in a primary or rebiopsy setting. The overall DR, the DR of a 10-core randomized, RTE targeted biopsy and the incremental DR were calculated.

RESULTS

Overall, randomized and RTE targeted biopsy DRs (for the combination, the 10-core and the four-core RTE biopsy scheme) were 46.2% (n = 473), 39.1% (n = 400) and 29.0% (n = 297), respectively. Four-core RTE targeted biopsies detected an additional 73 patients not detected by the 10-core randomized biopsies (increase in the overall DR of 7.1%). This represented a relative increase in DR of 18.3%. The incremental DR was better in rebiopsy patients (24.8%) than in patients having their first biopsy (14.7%). Within all patients diagnosed by RTE targeted biopsy only, 34 patients harboured significant Gleason 4 or 5 prostate cancer (PCa), diagnosed by four-core RTE biopsy only. Moreover, PCa with a Gleason grade of 4 or 5 was detected by four-core RTE biopsies in 30 patients, who showed low-grade PCa ≤ Gleason 3 only in the systematic 10-core biopsy.

CONCLUSIONS

Real-time elastography targeted biopsy seems to be an appropriate method for increasing the DR of PCa. Nevertheless, RTE targeted biopsies missed a high proportion of patients with PCa and should therefore be considered as an addition to randomized biopsies.

Effect of adjuvant and salvage radiotherapy after radical prostatectomy on urinary continence

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Background: The clinical value of adjuvant (aRT) or salvage radiation (sRT) for patient treated with radical prostatectomy (RP) is currently controversially debated. In this study, we assessed the impact of aRT and sRT on long-term urinary continence. Methods: Overall, 15,901 patients who underwent RP in our center between 1992 and 2012 were analyzed. aRT within the first 6 months was performed in 734 (2.9%) patients, and sRT after 6 months in 1405 (8.8%) patients (median time 21.6 months), respectively. Continence rates were assessed annually after RP using a self-administrated questionnaire. Median follow-up was 48.4 months. Continence was defined as the use of no pads or one safety pad. Incontinence was categorized by the number of used pads. The impact of additional radiation therapy on continence results was analyzed by logistic regression analyses, the chi2-likelyhood test and propensity score matching. Results: In multivariate logistic regression analysis, adjusted for age, prostate volume, extend of nerve-sparing, year of surgery, the event of additive RT (OR=1.2, p=0.17) was not statistically relevant correlated with the long-term continence status whereas all other variables significantly correlated with urinary incontinence (p<0.01, each). The lacking correlation of RT and continence remained in a second logistic regression model, adjusted for tumor features (pT, pN, Gleason, PSA, margin-status). The timing of RT (aRT vs. sRT) was not statistically relevant correlated with the long-term continence status (OR=1.7, p=0.09; OR=1.2, p=0.5) In addition, a comparison of all patients received aRT with a propensity score based matched cohort of RP only patients (corrected for age, prostate volume, extend of nerve-sparing and year of surgery) revealed no statistical significant impact of RT on continence (p>0.05). In 248 patients, the continence status was available pre and post RT, again not showing a negative impact of RT (p>0.05). Conclusions: Additive radiation therapy after radical prostatectomy does not negatively affect urinary continence.

SPINK1 expression is tightly linked to 6q15- and 5q21-deleted ERG-fusion negative prostate cancers but unrelated to PSA recurrence

BACKGROUND

The serine peptidase inhibitor, Kazal type 1 (SPINK1) has been suggested to define an aggressive molecular subtype of ERG-fusion negative prostate cancer. It was the aim of this study to further study the clinical relevance of SPINK1 expression and its relationship with other key genomic alterations of prostate cancer.

METHODS

A tissue microarray containing more than 10,000 prostate cancers with clinical follow-up was used for immunohistochemical SPINK1 analysis. Data on ERG status as well as PTEN, 6q, 5q, and 3p deletions were available for comparison.

RESULTS

SPINK1 expression was absent in benign prostate glands and detectable in 5.9% of 9,503 interpretable prostate cancers. Presence of SPINK1 expression was markedly more frequent in ERG negative (10.4%) than in ERG positive cancers (0.3%; P < 0.0001). However, SPINK1 expression was unrelated to tumor phenotype and biochemical recurrence in all cancers and in the subgroup of ERG negative cancers. Further subgroup analyses revealed, however, that--within ERG negative cancers--SPINK1 expression was significantly linked to deletions at 6q15 (P < 0.0001) and 5q21 (P = 0.0042).

CONCLUSIONS

Our results exclude SPINK1 as a relevant prognostic prostate cancer biomarker. However, the data demonstrate that SPINK1 overexpression is tightly linked to the small subsets of 6q15- and 5q21-deleted ERG negative prostate cancers. These findings support the concept of molecularly defined subtypes of prostate cancers.

Recurrent deletion of 3p13 targets multiple tumour suppressor genes and defines a distinct subgroup of aggressive ERG fusion-positive prostate cancers

Deletion of 3p13 has been reported from about 20% of prostate cancers. The clinical significance of this alteration and the tumour suppressor gene(s) driving the deletion remain to be identified. We have mapped the 3p13 deletion locus using SNP array analysis and performed fluorescence in situ hybridization (FISH) analysis to search for associations between 3p13 deletion, prostate cancer phenotype and patient prognosis in a tissue microarray containing more than 3200 prostate cancers. SNP array analysis of 72 prostate cancers revealed a small deletion at 3p13 in 14 (19%) of the tumours, including the putative tumour suppressors FOXP1, RYBP and SHQ1. FISH analysis using FOXP1-specific probes revealed deletions in 16.5% and translocations in 1.2% of 1828 interpretable cancers. 3p13 deletions were linked to adverse features of prostate cancer, including advanced stage (p < 0.0001), high Gleason grade (p = 0.0125), and early PSA recurrence (p = 0.0015). In addition, 3p13 deletions were linked to ERG(+) cancers and to PTEN deletions (p < 0.0001 each). A subset analysis of ERG(+) tumours revealed that 3p13 deletions occurred independently from PTEN deletions (p = 0.3126), identifying tumours with 3p13 deletion as a distinct molecular subset of ERG(+) cancers. mRNA expression analysis confirmed that all 3p13 genes were down regulated by the deletion. Ectopic over-expression of FOXP1, RYBP and SHQ1 resulted in decreased colony-formation capabilities, corroborating a tumour suppressor function for all three genes. In summary, our data show that deletion of 3p13 defines a distinct and aggressive molecular subset of ERG(+) prostate cancers, which is possibly driven by inactivation of multiple tumour suppressors.

Loss of CDKN1B/p27Kip1 expression is associated with ERG fusion-negative prostate cancer, but is unrelated to patient prognosis

The cyclin-dependent kinase inhibitor p27Kip1 has been suggested as a prognostic marker in prostate cancer. The aim of this study was to determine the clinical and prognostic role of p27 expression in hormone-naive prostate cancers. A tissue microarray containing samples from 4,699 prostate cancers with attached pathological, clinical follow-up and molecular data was analyzed for nuclear p27 expression by immunohistochemistry. p27 staining was negative in 18.6%, weak in 33.5%, moderate in 28.4% and strong in 19.5% of 3,701 interpretable cancer spots. Loss of p27 immunostaining was linked to tumors of low Gleason grade (P<0.0001) and ERG fusion-negative cancers (P<0.0001). p27 levels were not associated with other parameters, including tumor stage, nodal stage, preoperative prostate-specific antigen (PSA) levels, surgical margin status and cell proliferation (as measured by the Ki67 labeling index). p27 expression was also unrelated to clinical outcome in all cancers, as well as in the subsets of ERG fusion-positive and -negative cancers. Overall, the present data demonstrated that elevated p27 expression was often unrelated to prostate cancer phenotype. Furthermore, the lack of an effect of the p27 protein levels on PSA recurrence following radical prostatectomy indicated that factors other than p27 expression are likely to be the major determinants of prostate cancer recurrence. However, a subset of ERG-negative, low-grade tumors was frequently characterized by loss of p27, suggesting a role of this alteration for the development of these tumors.

Reduced CD147 expression is linked to ERG fusion-positive prostate cancers but lacks substantial impact on PSA recurrence in patients treated by radical prostatectomy

The extracellular matrix metalloproteinase inducer CD147 has been suggested as a prognostic marker in prostate cancer. CD147 expression was analyzed by immunohistochemistry on a tissue microarray containing 11,152 prostate cancer specimens. Results were compared to tumor phenotype, biochemical recurrence, ERG status and deletions on PTEN, 3p13, 6q15 and 5q21. CD147 expression was strong in benign prostatic glands and often reduced in prostate cancers. CD147 immunostaining was found in 71.7% of 7628 interpretable cases. CD147 staining was considered strong in 34.6%, moderate in 24.3% and weak in 12.8% of cancers while 28.3% did not show any CD147 reactivity. Reduced CD147 staining was strongly associated with both TMPRSS2-ERG-rearrangement and ERG expression (p<0.0001 each). Within the subgroups of ERG positive and negative cancers, deletions of PTEN, 3p13, 6q15 and 5q21 were unrelated to the CD147 expression status. Decreased CD147 expression was significantly linked to high preoperative PSA values, high Gleason grade, advanced tumor stage (p<0.0001 each), and positive lymph node involvement (p=0.0026) in all cancers. There was a marginal, but statistically significant, association of reduced CD147 expression with early biochemical recurrence (p=0.0296). The significant reduction of CD147 expression in ERG positive prostate cancer provides further evidence for marked biological differences between "fusion type" and "non-fusion type" prostate cancer. Despite a weak association with PSA recurrence, CD147 cannot be considered a relevant prognostic biomarker.

Strong expression of the neuronal transcription factor FOXP2 is linked to an increased risk of early PSA recurrence in ERG fusion-negative cancers

BACKGROUND AND AIMS

Transcription factors of the forkhead box P (FOXP1-4) family have been implicated in various human cancer types before. The relevance and role of neuronal transcription factor FOXP2 in prostate cancer is unknown.

METHODS

A tissue microarray containing samples from more than 11 000 prostate cancers from radical prostatectomy specimens with clinical follow-up data was analysed for FOXP2 expression by immunohistochemistry. FOXP2 data were also compared with pre-existing ERG fusion (by fluorescence in situ hybridisation and immunohistochemistry) and cell proliferation (Ki67 labelling index) data.

RESULTS

There was a moderate to strong FOXP2 protein expression in basal and secretory cells of normal prostatic glands. As compared with normal cells, FOXP2 expression was lost or reduced in 25% of cancers. Strong FOXP2 expression was linked to advanced tumour stage, high Gleason score, presence of lymph node metastases and early tumour recurrence (p<0.0001; each) in ERG fusion-negative, but not in ERG fusion-positive cancers. High FOXP2 expression was linked to high Ki67 labelling index (p<0.0001) in all cancers irrespective of ERG fusion status.

CONCLUSIONS

These data demonstrate that similar high FOXP2 protein levels as in normal prostate epithelium exert a 'paradoxical' oncogenic role in 'non fusion-type' prostate cancer. It may be speculated that interaction of FOXP2 with members of pathways that are specifically activated in 'non fusion-type' cancers may be responsible for this phenomenon.

High c-MET expression is frequent but not associated with early PSA recurrence in prostate cancer

c-MET is considered a possible therapeutic target in numerous tumor types and is also a candidate regulator of response to anti-HER2 and anti-epidermal growth factor receptor (EGFR) therapy. The aim of this study was to determine the prevalence and clinical significance of c-MET expression in hormone-naïve prostate cancers. A pre-existing prostate tissue microarray (TMA) containing samples of 4,177 patients treated by radical prostatectomy was used. A total of 3,378 different prostate cancers were successfully analyzed for c-MET expression by immunohistochemistry and follow-up data were available for 4,104 patients. Membranous c-MET immunostaining was performed for 2,655 (78.6%) tumors. High c-MET protein expression was significantly associated with a high Gleason grade (P=0.0018). However, c-MET was not a prognostic marker for biochemical recurrence. c-MET levels were also not associated with other parameters, including tumor stage, nodal stage and surgical margin status. The c-MET protein is often overexpressed in prostate cancer, but has no prognostic relevance. However, the frequent presence of high levels of membranous c-MET protein in prostate cancer cells makes c-MET an attractive target for imaging and treatment.

Assessment of rates of lymph nodes and lymph node metastases in periprostatic fat pads in a consecutive cohort treated with retropubic radical prostatectomy

OBJECTIVE

To determine the rates of lymph nodes and lymph node metastases in periprostatic fat pads yielded during exposure of the anterior surface of the dorsal vein complex, puboprostatic ligaments, and endopelvic fascia during radical prostatectomy.

METHODS

Histopathologic examination was performed in 356 patients who underwent radical prostatectomy between July 2010 and September 2010 at a single institution. Separate histologic work-up of the periprostatic fat pads addressed the presence of lymph nodes and possible metastatic invasion of lymph nodes within this area. Descriptive analyses and multivariable analyses to predict the presence of lymph node metastases within these fat pads were performed.

RESULTS

Lymph nodes within periprostatic fat pads were detected in 19 (5.5%) patients. Among these patients, tumor infiltration was found in 4 (1.2%). Three of these 4 patients harbored lymph node metastases without any other lymph node metastasis during standard lymphadenectomy. No relationship was detected between the total number of lymph nodes removed and the detection of lymph nodes within periprostatic fat pads (P = .6).

CONCLUSION

Our analysis demonstrates that periprostatic fat pads harbor lymph nodes. No relationship between the presence of lymph node metastases in periprostatic fat pads and the presence of lymph node metastases in other areas was found. Similarly, no relationship exists between the presence of lymph nodes in this area and the total number of lymph nodes yielded in other lymphatic fields. Therefore, for guaranteeing precise lymph node staging, implementing routinely pathologic work-up of periprostatic fat pads yielded during radical prostatectomy should be considered.

Neurovascular structure-adjacent frozen-section examination (NeuroSAFE) increases nerve-sparing frequency and reduces positive surgical margins in open and robot-assisted laparoscopic radical prostatectomy: experience after 11,069 consecutive patients

BACKGROUND

Intraoperative frozen-section analysis allows real-time histologic assessment of surgical margins (SMs) and identification of candidates for nerve-sparing (NS) procedures.

OBJECTIVE

To examine the efficacy and oncologic safety of a systematic neurovascular structure-adjacent frozen-section examination (NeuroSAFE) during NS radical prostatectomy (RP).

DESIGN, SETTING, AND PARTICIPANTS

From January 2002 to June 2011, 11 069 consecutive RPs were performed at the University Medical Center Hamburg-Eppendorf. Of these, 5392 (49%) were conducted with NeuroSAFE.

SURGICAL PROCEDURE

Our NeuroSAFE approach included the whole laterorectal circumference of the prostate to determine the SM status of the complete neurovascular tissue-corresponding prostatic surface.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The impact of NeuroSAFE on NS frequency, SM status, and biochemical recurrence (BCR) was analyzed by chi-square test, and by Kaplan-Meier analyses in propensity score-based matched cohorts.

RESULTS AND LIMITATIONS

Positive SMs (PSMs) were detected in 1368 (25%) NeuroSAFE RPs, leading to a secondary resection of the ipsilateral neurovascular tissue. Secondary wide resection resulted in conversion to a definitive negative SM (NSM) status in 1180 (86%) patients. In NeuroSAFE RPs, frequency of NS was significantly higher (all stages: 97% vs 81%; pT2: 99% vs 92%; pT3a: 94% vs 72%; pT3b: 88% vs 40%; p<0.0001) and PSM rates were significantly lower (all stages: 15% vs 22%; pT2: 7% vs 12%; pT3a: 21% vs 32%; p<0.0001) than in the matched non-NeuroSAFE RPs. In propensity score-based comparisons, NeuroSAFE had no negative impact on BCR (pT2, p=0.06; pT3a, p=0.17, pT3b, p=0.99), and BCR-free survival of patients with conversion to NSM did not differ significantly from patients with primarily NSM (pT2, p=0.16; pT3, p=0.26). The accuracy of our NeuroSAFE approach was 97% with a false-negative rate of 2.5%. The major limitations of this study are its retrospective nature and relatively short follow-up.

CONCLUSIONS

NeuroSAFE enables real-time histologic monitoring of the oncologic safety of a NS procedure. Systematic NeuroSAFE significantly increases NS frequencies and reduces PSMs. Patients with a NeuroSAFE-detected PSM could be converted to a prognostically more favorable NSM status by secondary wide resection.