Fluorescence in situ hybridization aneuploidy as a predictor of clinical disease recurrence and prostate-specific antigen level 3 years after radical prostatectomy

Quantification of large scale DNA organization for predicting prostate cancer recurrence

This study investigates whether Genomic Organization at Large Scales (which we propose to call GOALS) as quantified via nuclear phenotype characteristics and cell sociology features (describing cell organization within tissue) collected from prostate tissue microarrays (TMAs) can separate biochemical failure from biochemical nonevidence of disease (BNED) after radical prostatectomy (RP). Of the 78 prostate cancer tissue cores collected from patients treated with RP, 16 who developed biochemical relapse (failure group) and 16 who were BNED patients (nonfailure group) were included in the analyses (36 cores from 32 patients). A section from this TMA was stained stoichiometrically for DNA using the Feulgen-Thionin methodology, and scanned with a Pannoramic MIDI scanner. Approximately 110 nuclear phenotypic features, predominately quantifying large scale DNA organization (GOALS), were extracted from each segmented nuclei. In addition, the centers of these segmented nuclei defined a Voronoi tessellation and subsequent architectural analysis. Prostate TMA core classification as biochemical failure or BNED after RP using GOALS features was conducted (a) based on cell type and cell position within the epithelium (all cells, all epithelial cells, epithelial >2 cell layers away from basement membrane) from all cores, and (b) based on epithelial cells more than two cell layers from the basement membrane using a Classifier trained on Gleason 6, 8, 9 (16 cores) only and applied to a Test set consisting of the Gleason 7 cores (20 cores). Successful core classification as biochemical failure or BNED after RP by a linear classifier was 75% using all cells, 83% using all epithelial cells, and 86% using epithelial >2 layers. Overall success of predicted classification by the linear Classifier of (b) was 87.5% using the Training Set and 80% using the Test Set. Overall success of predicted progression using Gleason score alone was 75% for Gleason >7 as failures and 69% for Gleason >6 as failures. © 2017 International Society for Advancement of Cytometry.

TMPRSS2-ERG gene fusion in prostate cancer

BACKGROUND

The TMPRSS2-ERG gene fusion is one of the most widely spread chromosomal rearrangements in carcinomas. Since its discovery, a number of studies have examined its diagnostic, prognostic and therapeutic implications for prostate cancer where suitable biomarkers are still lacking. The publication data are inconsistent. The aim of this review was to critically evaluate the current clinical impact of this gene fusion.

METHODS

The PubMed online database was used to search relevant reviews and original articles.

RESULTS

Although the TMPRSS2-ERG gene fusion appears to be a suitable diagnostic biomarker, the prognostic implications of this gene fusion are still unclear. Several new strategies for therapeutically targeting ETS fusions and their modulators have been identified and are currently being investigated.

CONCLUSION

Due to the heterogeneity of prostate cancer, the combination of several biomarkers is necessary to accurately assess the presence of prostate cancer, predict its potential clinical outcome and decide on appropriate therapy (e.g. PARP inhibitors).

Increased gene copy number of ERG on chromosome 21 but not TMPRSS2-ERG fusion predicts outcome in prostatic adenocarcinomas

The role of TMPRSS2-ERG gene fusion in prostate cancer prognostication remains controversial. We evaluated the prognostic role of TMPRSS2-ERG fusion using fluorescence in situ hybridization analysis in a case-control study nested in The Johns Hopkins retropubic radical prostatectomy cohort. In all, 10 tissue microarrays containing paired tumors and normal tissues obtained from 172 cases (recurrence) and 172 controls (non-recurrence) matched on pathological grade, stage, race/ethnicity, and age at the time of surgery were analyzed. All radical prostatectomies were performed at our institution between 1993 and 2004. Recurrence was defined as biochemical recurrence, development of clinical evidence of metastasis, or death from prostate carcinoma. Each tissue microarray spot was scored for the presence of TMPRSS2-ERG gene fusion and for ERG gene copy number gains. The odds ratio of recurrence and 95% confidence intervals were estimated from conditional logistic regression. Although the percentage of cases with fusion was slightly lower in cases than in controls (50 vs 57%), the difference was not statistically significant (P=0.20). The presence of fusion due to either deletion or split event was not associated with recurrence. Similarly, the presence of duplicated ERG deletion, duplicated ERG split, or ERG gene copy number gain with a single ERG fusion was not associated with recurrence. ERG gene polysomy without fusion was significantly associated with recurrence (odds ratio 2.0, 95% confidence interval 1.17-3.42). In summary, TMPRSS2-ERG fusion was not prognostic for recurrence after retropubic radical prostatectomy for clinically localized prostate cancer, although men with ERG gene copy number gain without fusion were twice more likely to recur.

TMPRSS2-ERG gene fusion status in minute (minimal) prostatic adenocarcinoma

Minute prostatic adenocarcinomas are considered to be of insufficient virulence. Given recent suggestions of TMPRSS2-ERG gene fusion association with aggressive prostatic adenocarcinoma, we evaluated the incidence of TMPRSS2-ERG fusion in minute prostatic adenocarcinomas. A total of 45 consecutive prostatectomies with minute adenocarcinoma were used for tissue microarray construction. A total of 63 consecutive non-minimal, Gleason Score 6 tumors, from a separate PSA Era prostatectomy tissue microarray, were used for comparison. FISH was carried out using ERG break-apart probes. Tumors were assessed for fusion by deletion (Edel) or split (Esplit), duplicated fusions and low-level copy number gain in normal ERG gene locus. Minute adenocarcinomas: Fusion was evaluable in 32/45 tumors (71%). Fifteen out of 32 (47%) tumors were positive for fusion. Six (19%) were of the Edel class and 7 (22%) were classified as combined Edel+Esplit. Non-minute adenocarcinomas (pT2): Fusion was identified in 20/30 tumors (67%). Four (13%) were of Edel class and 5 (17%) were combined Edel+Esplit. Duplicated fusions were encountered in 5 (16%) tumors. Non-minute adenocarcinomas (pT3): Fusion was identified in 19/33 (58%). Fusion was due to a deletion in 6 (18%) tumors. Seven tumors (21%) were classified as combined Edel+Esplit. One tumor showed Esplit alone. Duplicated fusions were encountered in 3 (9%) cases. The incidence of duplicated fusions was higher in non-minute adenocarcinomas (13 vs 0%; P=0.03). A trend for higher incidence of low-level copy number gain in normal ERG gene locus without fusion was noted in non-minute adenocarcinomas (10 vs 0%; P=0.07). We found a TMPRSS2-ERG fusion rate of 47% in minute adenocarcinomas. The latter is not significantly different from that of grade matched non-minute adenocarcinomas. The incidence of duplicated fusion was higher in non-minute adenocarcinomas. Our finding of comparable rate of TMPRSS2-ERG fusion in minute adenocarcinomas may argue against its value as a marker of aggressive prostate carcinoma phenotype.

Identification of patients with low-risk for aneuploidy: comparative discriminatory models using linear and machine-learning classifiers in prostate cancer

BACKGROUND

Prostate needle biopsy (PNB) ploidy status has proven utility to predict adverse outcomes after prostatectomy. We sought to develop models to predict ploidy status using clinicopathologic variables.

METHODS

We identified a cohort of 169 patients with a diagnosis of prostatic adenocarcinoma on PNB, and estimated ploidy status (determined using Feulgen stained biopsy tissue) using four predictors, including age, prebiopsy PSA, highest Gleason score (GS), and the percentage of involvement by carcinoma at the biopsy site with the highest GS (PCARBX). Logistic regression (LR), Neural Network (NN), and CART classifiers were constructed.

RESULTS

Univariate analyses revealed all four predictors to be significantly associated with ploidy status. On multivariable analyses, LR identified a 2-parameter model, including GS and PCARBX that had a significant ability to predict ploidy status with a 74% and 75% correct classification rate (CCR), respectively. Using the same variables, CART and NN yielded similar CCRs of 70.4%. Within GS = 6 cohort, the CART model classified over 90% of biopsies as diploid when patients had a PCARBX < 55% and a log(PSA) < 1.7.

CONCLUSIONS

Our study demonstrates that models using GS and PCARBX are able to predict PNB ploidy status with acceptable accuracy. While machine learning classifier-derived models yield similar accuracy as LR-derived models, the latter methodology has the distinct advantage of being applicable in future datasets to estimate case-specific predictions. This information may be useful in identifying potentially aneuploid patients, who can then be targeted for more aggressive therapy.

The 20-Yr Outcome in Patients with Well- or Moderately Differentiated Clinically Localized Prostate Cancer Diagnosed in the Pre-PSA Era: The Prognostic Value of Tumour Ploidy and Comorbidity

OBJECTIVE

This observational cohort study describes the long-term outcome of patients with clinically localized prostate cancer managed with watchful waiting, the prognostic value of tumour ploidy, and the impact of comorbidity.

METHODS

A total of 119 patients with clinically localized (T1-2) prostate cancer consecutively diagnosed from 1978 to 1982 were prospectively managed by watchful waiting, with treatment given if progression occurred.

RESULTS

Median age was 68 yr. Median observation time was 24 yr+/-6.25 (SD). Of the 112 patients who died, 42 died of prostate cancer. Disease-specific survival rates were 85% (95% CI: 77-93%), 58% (46-70%), and 32% (19-46%) at 10, 15, and 20 yr, respectively. Treatment-free survival rate was 43% (95% CI: 33-54%) at 10 yr. Patients aged 70 yr and over had a statistically significant increased risk of dying from any cause. There was a statistically significant increased risk of dying from prostate cancer for patients with nondiploid tumours.

CONCLUSION

In the present series from the pre-PSA era, watchful waiting yielded a relatively high long-term disease-specific survival rate in patients with well- or moderately differentiated clinically localized prostate cancer, and almost half were not treated 10 yr after diagnosis. Watchful waiting may be an option at least for such patients with a 10- to 15-yr life expectancy. Age of 70 yr or more predicted an increased overall mortality. High comorbidity increased the risk (although not statistically significant) for death from any cause and for death from prostate cancer. Patients with nondiploid tumours were at an increased risk to die from prostate cancer.

Prognostic factors and reporting of prostate carcinoma in radical prostatectomy and pelvic lymphadenectomy specimens

This paper, based on the activity of the Morphology-Based Prognostic Factors Committee of the 2004 World Health Organization-sponsored International Consultation, describes various methods of handling radical prostatectomy specimens for both routine clinical use and research purposes. The correlation between radical prostatectomy findings and postoperative failure is discussed in detail. This includes issues relating to pelvic lymph node involvement, detected both at the time of frozen section and in permanent sections. Issues of seminal vesicle invasion, including its definition, routes of invasion and relationship to prognosis, are covered in detail. The definition, terminology and incidence of extra-prostatic extension are elucidated, along with its prognostic significance relating to location and extent. Margins of resection are covered in terms of their definition, the etiology, incidence and sites of positive margins, the use of frozen sections to assess the margins and the relationship between margin positivity and prognosis. Issues relating to grade within the radical prostatectomy specimen are covered in depth, including novel ways of reporting Gleason grade and the concept of tertiary Gleason patterns. Tumor volume, tumor location, vascular invasion and perineural invasion are the final variables discussed relating to the prognosis of radical prostatectomy specimens. The use of multivariate analysis to predict progression is discussed, together with proposed modifications to the TNM system. Finally, biomarkers to predict progression following radical prostatectomy are described, including DNA ploidy, microvessel density, Ki-67, neuroendocrine differentiation, p53, p21, p27, Bcl-2, Her-2/neu, E-cadherin, CD44, retinoblastoma proteins, apoptotic index, androgen receptor status, expression of prostate-specific antigen and prostatic-specific acid phosphatase and nuclear morphometry.

DNA image cytometry and fluorescence in situ hybridization for noninvasive detection of urothelial tumors in voided urine

BACKGROUND

Cystoscopy and histologic examination remain the standard methods for initial tumor diagnosis and monitoring for early detection of recurrences, since the sensitivity of conventional urinary cytology for the detection of urothelial tumors in urinary specimens is low. DNA image cytometry (ICM) and fluorescence in situ hybridization (FISH) have been suggested as ancillary tools. The goal of the current study was to compare the diagnostic value of DNA image cytometry and FISH for the noninvasive detection of urothelial tumors in voided urine.

METHODS

Cytospin preparations were prepared from voided urine collected prior to the resection of 26 noninvasive (pTa) and 11 invasive (pT1-2) tumors. Specimens from 14 patients with benign prostatic hyperplasia were used as negative controls. DNA ICM was performed using the AUTOCYTE trade mark cell analytical system on Feulgen-stained cytospin specimens. The commercially available UroVysion trade mark FISH multiprobe was used to analyze chromosomes 3, 7, and 17, and 9p21.

RESULTS

The overall sensitivity of cytology improved from 24% to 54% and to 78% if supplemented by ICM or FISH, respectively. Image cytometry detected all invasive tumors (pT1-2), while FISH missed one; FISH identified 19 of 26 (73%) pTa tumors, while only 9 (35%) of these tumors were aneuploid by ICM. The results of ICM and FISH were concordant in 37 of 51 (72%) cases.

CONCLUSIONS

The current study shows that both FISH and ICM can successfully be used as supplementary methods to detect the clinically most relevant group of invasive bladder carcinomas. However, UroVysion FISH is more sensitive in the detection of pTa tumors than ICM, as it recognizes individual chromosomal alterations that frequently prevail in urothelial tumors.

Pathologic assessment of the surgical specimen

Despite the wealth of information obtained by conventional histology, long-term studies are needed to provide novel information on the correlation of pathologic findings with prognosis. Findings need to be correlated not only with PSA progression but with the more clinically important parameters of distant metastases and survival. Although conventional histology still will have a role in the evaluation of prostate cancer at radical prostatectomy and its correlation with outcome, it undoubtedly will be augmented by newer techniques. These developments must be approached critically and rationally to determine whether they provide additional prognostic information beyond that currently available using more conventional parameters.