[The usefulness of Ki67 expression in the biopsy specimens, to predict the biochemical progresion of the prostate cancer after radical prostatectomy]

Apalutamide and autophagy inhibition in a xenograft mouse model of human prostate cancer

Background

Apalutamide (APA) is a next-generation androgen receptor antagonist for the treatment of advanced prostate cancer. We have previously shown that upregulation of autophagy is one of the mechanisms by which prostate cancer (PC) cells survive APA anti-tumor treatment in vitro. Therefore, we investigated the characteristics of the autophagic response to APA treatment, alone and in combination with autophagy inhibition, in an in vivo model.

Methods

Tumor cells were injected into previously castrated nude mice. Four groups of mice bearing LNCaP xenografts were treated with daily intraperitoneal (i.p.) injections of vehicle (control), APA (10 mg/kg), APA (10 mg/kg) + Chl (Chloroquine, 10 mg/kg) or Chl (10 mg/kg). The animals of each treatment group (3/treatment) were kept for the duration of 2 and 3 weeks. At the end of the experiments, the animals were sacrificed and all samples assessed for tumor weight and size, histological analysis, immunoblotting (WES) and immunofluorescence.

Results

The tumor weight was significantly reduced in mice treated with APA + Chl (203.2 ± 5.0, SEM, P = 0.0066) compared to vehicle control (380.4 ± 37.0). Importantly, the combined treatment showed a higher impact on tumor weight than APA (320.4 ± 45.5) or Chl (337.9 ± 35) alone. The mice treated with the combination of APA + Chl exhibited a reduced expression of ATG5 (autophagy-related five protein), Beclin 1 and LC3 punctuations and an increase in P62 as visualized by immunofluorescence and WES. In addition, Ki-67 nuclear staining was detected in all samples however reduced in APA + Chl (58%) compared to vehicle control (100%). The reduction in Ki-67 protein was associated with an increase in caspase 3 and endothelial CD31 protein expression.

Conclusion

These data demonstrate that a treatment with APA + Chl leads to reduced autophagy levels and to tumor suppression compared to the APA monotherapy. Hence, the increased antitumor effect of APA in combination with autophagy inhibitors might provide a new therapeutic approach potentially translatable to patients.

Prognostic role of Ki-67 score in localized prostate cancer: A systematic review and meta-analysis

BACKGROUND

Ki-67 for quantifying tumor proliferation is widely used. In localized prostate cancer (PCa), despite a suggested predictive role of Ki-67 for outcomes after therapies, it has not been incorporated into clinical practice. Herein, we conduct a systematic review and meta-analysis of the literature reporting the association of Ki-67 and disease outcomes in PCa treated radically.

METHODS

Medline and EMBASE databases were searched without date or language restrictions, using "KI67" and "prostate cancer" MeSH terms. Studies reporting Ki-67 association with clinical outcomes (disease-free survival [DFS], biochemical failure-free survival, rate of distant metastases [DM], disease-specific survival [DSS], or overall survival [OS], or all of these) in patients with PCa managed actively were included, and relevant data extracted by 2 independent reviewers. Odds ratios (OR) were weighted and pooled in a meta-analysis using Mantel-Haenszel random-effect modeling.

RESULTS

Twenty-one studies comprising 5,419 patients met eligibility for analysis, and 67.6% of patients had low Ki-67. Mean Ki-67 was 6.14%. High Ki-67 was strongly associated with worse clinical outcomes. DFS was better in those patients with low Ki-67 at 5 and 10 years (OR = 0.32, 95% CI: 0.23-0.44, P<0.00001; OR = 0.31, 95% CI: 0.20-0.48, P<0.00001). Similarly, low Ki-67 was related to improved DSS at 5 and 10 years (OR = 0.15, 95% CI: 0.10-0.21, P<0.00001; OR = 0.16, 95% CI: 0.06-0.40, P<0.00001). Association between low Ki-67 scores with improved OS (OR = 0.47; 95% CI: 0.37-0.61; P<0.00001) and high Ki-67 scores with DM at 5 years (OR = 4.07; 95% CI: 2.52-6.58; P<0.00001) was consistently observed.

CONCLUSIONS

High Ki-67 expression in localized PCa is a factor of poor prognosis for DSS, biochemical failure-free survival, DFS, DM, and OS after curative-intent treatments. Incorporation into clinical routine of this widely available and standardized biomarker should be strongly considered.

Gelsolin-like actin-capping protein is associated with patient prognosis, cellular apoptosis and proliferation in prostate cancer

AIM

To investigate the role of gelsolin-like actin-capping protein (CapG) in prostate cancer (PCa).

MATERIALS & METHODS

CapG expression and its correlation with clinicopathological characters and patient prognosis were analyzed in 76 cases of PCa by immunohistochemistry and qRT-PCR. Then, the influence of CapG downregulation on cell apoptosis and proliferation were assessed.

RESULTS

CapG expression in PCa was significantly higher compared with those in matched adjacent noncancerous prostate tissues, and significantly correlated with clinicopathological characters. Survival analysis indicated that CapG could be an independent prognostic factor in PCa. Moreover, CapG depletion significantly affected cellular proliferation and apoptosis by regulating Caspase 6/Caspase 9/Bcl-2/p-Akt/Akt signaling pathway.

CONCLUSION

CapG, as a potential biomarker in PCa, is associated with patient prognosis, cellular apoptosis and proliferation.

Survival predictors in patients with prostate adenocarcinoma with hormonal blockade

Ki-67 index and clinical-pathological factors such as the Gleason score and the presence of neuroendocrine differentiation have been used for predicting survival in patients with prostate cancer. We examined prostate tissue from 45 patients with advanced prostate cancer who were treated with maximal androgen blockade and analysed their cancer-specific survival (CSS). We assessed the Gleason index, performed an immunohistochemical analysis of Ki-67 (MIB-1) and determined the presence of neuroendocrine differentiation (chromogranin A). A survival study was conducted using Kaplan-Meier curves (log-rank test) and a Cox regression analysis. Twenty-four patients (53.3%) died from the disease, with a mean follow-up of 68.7±7.7 months (56.6% CSS at 5 years and 31.8% at 10 years). In the univariate analysis, survival was associated with an interquartile distribution of Ki-67 (0-5, 6-12%, 13-25%, >25%; log-rank, p=0.01), Gleason 5 (total index 9-10; log-rank, p=0.002) and the presence of metastases during the diagnosis (M1; log-rank, p=0.004) but not to cT category (T3-T4; log-rank, p=0.26) or neuroendocrine differentiation (immunohistochemically positive tumour cell nests; log-rank, p=0.46). The multivariate analysis revealed that a Ki-67 index ≤12% (HR, 0.22; p=0.0009) and the absence of metastases (M0) during diagnosis (HR, 0.17; p=0.0002) were protective factors in this population. In conclusion, Ki-67 proliferation index and the lack of metastases at diagnosis predict CSS in patients with advanced prostate cancer who undergo hormonal blockade. Neuroendocrine differentiation in tumour tissue had no prognostic value in this study.

Survival analysis of patients with biochemical relapse after radical prostatectomy treated with androgen deprivation: Castration-resistance influential factors

INTRODUCTION

We evaluate the prognosis of patients with biochemical recurrence (BCR) treated with androgen deprivation therapy (ADT) and to determine the influential factors to castration resistance (CR) and death.

METHODS

From a series of 1310 patients with T1-T2 prostate cancer treated with radical prostatectomy between 1989 and 2012, 371 had BCR. Patients with lymph node involvement were excluded. We analyzed only the 159 treated with salvage ADT. At the end of the study, 77 (48%) had developed CR.

RESULTS

The median follow-up to CR was 9.2 years. The CR-resistant free survival (RFS) was 76 ± 3%, 62 ± 3% and 43 ± 9% in 5, 10 and 15 years, respectively. The RFS median time was 14 years. In the multivariate study, the prostate-specific antigen (PSA) doubling time (PSA-DT) was <6 months (p = 0.01) (hazard ratio [HR] 3; 95% confidence interval [CI] 1.4-6.8, p = 0.007); seminal vesicle involvement (HR 3.1; 95% CI 1.5-6.2, p = 0.01) and PSA velocity in ng/mL/year (HR 1.3; 95% CI 1.1-1.5, p = 0.002) with better cut-off points of 0.84 ng/mL/year (p = 0.04) (HR 4; 95% CI 1.7-9.4, p = 0.001) were influential variables. Specific survival (SS) at 5, 10 and 15 years since surgery was 96 ± 1, 85 ± 2 and 76 ± 4, respectively. The time of CR to death was 30 ± 6% at 5 years, with the median at 3.2 years. In the multivariate only Ki 67 (HR 1.04; 95% CI 1.005-1.08, p = 0.02) had an independent influence.

CONCLUSIONS

In BCR patients treated with ADT, the median to CR was 14 years. PSA-DT <6 months, PSA velocity (ng/mL/year) and seminal vesicle involvement were influential variables. From the CR, the median time to death was 3.2 years. Ki-67 marker was an independent influence.

Prognostic significance of neuroendocrine differentiation in prostate adenocarcinoma

Much progress has been made toward an understanding of the development and progression of prostate cancer (PC) and the factors that drive the development of androgen independence. Neuroendocrine (NE) cells may provide an intriguing link between NE cell differentiation (NED) and tumor progression in PC. NED in PC generally confers a more aggressive clinical behavior and less favorable prognosis than conventional PC. In this article, we review the known functions of NE cells in PC and discuss the current knowledge on stimulation of cancer proliferation, invasion, apoptosis resistance, serum and immunohistochemical markers, and the prognostic significance of NED in human PC.

[Time-influencing factors for biochemical progression following radical prostatectomy]

INTRODUCTION

We assessed the time-influencing clinical-pathological factors for biochemical progression of an equal series of patients from a single institution.

MATERIALS AND METHODS

Retrospective analysis of 278 patients with biochemical progression following prostatectomy. We considered biochemical progression to be PSA>0.4 ng/ml. We performed the trial using the Cox model (univariate and multivariate) and using the Student's t-test to compare averages.

RESULTS

With a mean follow-up of 4 (±3 DE) years, the univariate study showed a mean until progression for the Gleason score 2-6 in the biopsy of 824 days and 543 for the Gleason score 7-10 (p=0.003). For negative surgical margins, the mean was 920 days and 545 for positive margins (p=0.0001). In the case of a Gleason score 2-7 in the specimen, the mean was 806 days and 501 for a Gleason score 8-10 (p=0.001). Lastly, the mean for the cases with Ki-67 negative in the specimen (< 10%) was 649 days and 345 for Ki-67 positive (> 10%) (p=0.003). In the multivariate study, Ki-67 (OR 1.028; IC 95% 1-1.01; p=0.0001) and Gleason score 8-10 (OR 1.62; IC 95% 1.5-2.45; p=0.026) in the specimen, and initial PSA >10 ng/ml (OR 1.02; IC 95% 1.01-1.04; p=0.0001) were independent variables. Using these variables, we designed a predictive model with three groups. The time until the progression of each group was 1,081, 551 and 218 days respectively.

CONCLUSION

The Gleason score 7-10 in the prostate biopsy, the presence of Ki-67, the positive margins and the Gleason score 8-10 in the specimen, and the initial PSA > 10 ng/ml are time-influencing factors until biochemical progression. Pathological Gleason score 8-10, PSA > 10 ng/ml and Ki-67 are independent factors.

Ki-67 and outcome in clinically localised prostate cancer: analysis of conservatively treated prostate cancer patients from the Trans-Atlantic Prostate Group study

Treatment decisions after diagnosis of clinically localised prostate cancer are difficult due to variability in tumour behaviour. We therefore examined one of the most promising biomarkers in prostate cancer, Ki-67, in a cohort of 808 patients diagnosed with prostate cancer between 1990 and 1996 and treated conservatively. Ki-67 expression was assessed immunohistochemically, in two laboratories, by two different scoring methods and the results compared with cancer-specific and overall survival. The power of the biomarker was compared with Gleason score and initial serum prostate-specific antigen (PSA). Both methods showed that Ki-67 provided additional prognostic information beyond that available from Gleason score and PSA: for the semi-quantitative method, Δχ² (1 d.f.)=24.6 (P<0.0001), overall survival χ²=20.5 (P<0.0001), and for the quantitative method, Δχ² (1 d.f.)=15.1 (P=0.0001), overall survival χ²=10.85 (P=0.001). Ki-67 is a powerful biomarker in localised prostate cancer and adds to a model predicting the need for radical or conservative therapy. As it is already in widespread use in routine pathology, it is confirmed as the most promising biomarker to be applied into routine practice.

Expression of p27((Kip1)), cyclin D3 and Ki67 in BPH, prostate cancer and hormone-treated prostate cancer cells

p27((Kip1)), cyclin D3 and Ki67 are the markers of DNA damage and cell proliferation. The goal of the current study was to analyze expression of the markers in benign and malignant prostate cancer tissues. Activity of p27((Kip1)), cyclin D3 and Ki67 was immunohistochemically evaluated in different cells of BPH, prostate cancer (PCa) and hormonally treated prostate cancer (HTPCa) tissues. The tissue samples were derived by means of TURP or radical prostatectomy. Intensity of the expression was compared between the groups, and association was sought with clinical parameters. Total expression of p27((Kip1)) was significantly higher in BPH as compared with PCa. Epithelial marker expression was higher in HTPCa than in PCa. Intensity of the expression in epithelial, vascular and ductal cells was negatively associated with the tumor stage and Gleason grades. Total Ki67 activity was positively correlated with patient age and serum PSA level. There was significantly higher expression in PCa and hormone-escaped PCa (HEPCa) as compared with BPH. Epithelial and vascular marker expression was positively associated with tumor stage and Gleason grades. There was a positive correlation between cyclin D3 and serum PSA level. With the increase of Gleason grades, cyclin D3 expression increased significantly. Expression of p27((Kip1)) negatively correlated with Ki67 and cyclin D3, while the latter two markers correlated positively. p27((Kip1)) is down-regulated, whereas Ki67 and cyclin D3 are up-regulated in PCa. Intensity of the markers' expression is associated with tumor stage and grades. Hormonotherapy of PCa causes activation of p27((Kip1)). HEPCa is characterized by increased Ki67 expression.

Prognostic factors in prostate cancer

Prognostic factors in organ confined prostate cancer will reflect survival after surgical radical prostatectomy. Gleason score, tumour volume, surgical margins and Ki-67 index have the most significant prognosticators. Also the origins from the transitional zone, p53 status in cancer tissue, stage, and aneuploidy have shown prognostic significance. Progression-associated features include Gleason score, stage, and capsular invasion, but PSA is also highly significant. Progression can also be predicted with biological markers (E-cadherin, microvessel density, and aneuploidy) with high level of significance. Other prognostic features of clinical or PSA-associated progression include age, IGF-1, p27, and Ki-67. In patients who were treated with radiotherapy the survival was potentially predictable with age, race and p53, but available research on other markers is limited. The most significant published survival-associated prognosticators of prostate cancer with extension outside prostate are microvessel density and total blood PSA. However, survival can potentially be predicted by other markers like androgen receptor, and Ki-67-positive cell fraction. In advanced prostate cancer nuclear morphometry and Gleason score are the most highly significant progression-associated prognosticators. In conclusion, Gleason score, capsular invasion, blood PSA, stage, and aneuploidy are the best markers of progression in organ confined disease. Other biological markers are less important. In advanced disease Gleason score and nuclear morphometry can be used as predictors of progression. Compound prognostic factors based on combinations of single prognosticators, or on gene expression profiles (tested by DNA arrays) are promising, but clinically relevant data is still lacking.