The role of transrectal ultrasound in the diagnosis of prostate cancer: new contributions

Imaging Recommendations for Diagnosis, Staging, and Management of Prostate Cancer

The Prostate Carcinoma Guidelines Panel have formulated these guidelines to assist medical professionals in the evidence-based management of prostate cancer. These have been formulated by a panel consisting of Indian multidisciplinary group of radiologists, uro-oncologists, urologists, radiation oncologists, medical oncologists, and pathologists. These recommendations present the best evidence available to the clinicians; however, using these recommendations will not always result in the best outcome. They aid in decision making for individual patients; however, these will never replace clinical expertise when making treatment decisions. Taking personal values and preferences or individual circumstances of patients into account is necessary for final treatment decision. Guidelines are not mandatory and should not to be referred as a legal standard of care.

A New Framework for Precise Identification of Prostatic Adenocarcinoma

Prostate cancer, which is also known as prostatic adenocarcinoma, is an unconstrained growth of epithelial cells in the prostate and has become one of the leading causes of cancer-related death worldwide. The survival of patients with prostate cancer relies on detection at an early, treatable stage. In this paper, we introduce a new comprehensive framework to precisely differentiate between malignant and benign prostate cancer. This framework proposes a noninvasive computer-aided diagnosis system that integrates two imaging modalities of MR (diffusion-weighted (DW) and T2-weighted (T2W)). For the first time, it utilizes the combination of functional features represented by apparent diffusion coefficient (ADC) maps estimated from DW-MRI for the whole prostate in combination with texture features with its first- and second-order representations, extracted from T2W-MRIs of the whole prostate, and shape features represented by spherical harmonics constructed for the lesion inside the prostate and integrated with PSA screening results. The dataset presented in the paper includes 80 biopsy confirmed patients, with a mean age of 65.7 years (43 benign prostatic hyperplasia, 37 prostatic carcinomas). Experiments were conducted using different well-known machine learning approaches including support vector machines (SVM), random forests (RF), decision trees (DT), and linear discriminant analysis (LDA) classification models to study the impact of different feature sets that lead to better identification of prostatic adenocarcinoma. Using a leave-one-out cross-validation approach, the diagnostic results obtained using the SVM classification model along with the combined feature set after applying feature selection (88.75% accuracy, 81.08% sensitivity, 95.35% specificity, and 0.8821 AUC) indicated that the system’s performance, after integrating and reducing different types of feature sets, obtained an enhanced diagnostic performance compared with each individual feature set and other machine learning classifiers. In addition, the developed diagnostic system provided consistent diagnostic performance using 10-fold and 5-fold cross-validation approaches, which confirms the reliability, generalization ability, and robustness of the developed system.

Assessment of the value of the different variants of abnormal digital rectal examination finding in predicting carcinoma of the prostate: a preliminary report of a two-center study

Background

Digital rectal examination is a veritable tool for the clinical diagnosis and screening for carcinoma of the prostate. This study aims to assess the value of the different variables which constitute abnormal digital rectal examination (DRE) findings.

Results

Following ethical approval, one hundred and thirty-one men met the inclusion criteria and were enrolled in the study. The peak incidence of abnormal DRE finding was in the 8th decade of life, while the PPV was 66.5%. Of the total, 44 (33.5%) were nodular hyperplasia, 12 (9.2%) were prostate intra-epithelia neoplasia, while 75 (57.3%) were adenocarcinoma. With a positive predictive value (PPV) of 73.3%, a hard nodular feel was the only abnormal DRE finding that independently and significantly predicted the risk of prostatic adenocarcinoma. A suspicious nodule and obliterated median groove had PPV of 23.1% and lobar asymmetry, 0%. There was a statistically significant correlation (P = 0.005) between DRE findings and histology, between PSA and histology (P = 0.000) and between the size of the prostate and PSA value (P = 0.021). The mean size of the prostate was 101.2 g, standard deviation 92.11783, maximum 648 g and minimum 13.6 g.

Conclusion

Most of the variants of abnormal DRE findings do not sufficiently predict the risk of adenocarcinoma on their own. They need to be in combination with other DRE findings or a raised PSA to significantly predict adenocarcinoma.

The role of multiparametric resonance and biopsy in prostate cancer detection: comparison with definitive histological report after laparoscopic/robotic radical prostatectomy

Purpose

Magnetic Resonance Imaging (MRI) targeted biopsy increases overall detection rates and decreases the risk of clinically insignificant PCa detection. The aim of this retrospective study is to compare concordance rates regarding side of lesion and Gleason Score at fusion targeted/systematic biopsy and MRI with the definitive histologic report of prostatectomy specimen.

Methods

115 patients underwent multiparametric (mp) MRI and successively fusion targeted/systematic biopsy. 107 patients, with a positive biopsy for PCa, further underwent laparoscopic/robotic radical prostatectomy. We compared surgical histologic report with biopsy histologic report for side of lesion and Gleason Score. We further compared PIRADS score at mpMRI with Gleason Score of both histologic reports.

Results

Concordance rate for mpMRI lesion side was 74% compared to biopsy and 52.3% compared to surgical histologic report (p < 0.0001). Fusion targeted/systematic biopsy reported a concordance rate with surgical histologic report of 67.3% for side of the lesion, while Gleason Score was concordant for 73.6% for clinically significant cancer (Gleason Score ≥ 7) (p < 0.0001). PIRADS score ≥ 3 was further associated with clinically significant cancer at surgical histologic report in 92.4% of cases (p = 0.359).

Conclusion

Multiparametric MRI of the prostate reaches a good and improvable accuracy in the detection of suspicious PCa before biopsy. A combined approach of fusion targeted and systematic biopsy could further increase the overall accuracy in PCa diagnosis, especially in biopsy-naïve patients, reaching concordance rates with definitive histologic report up to 52.3% and 85.5%.

Advances in prostate cancer imaging

Many exciting advances in medical imaging have been made in recent years that will alter the way we diagnose, stage, and treat patients with prostate cancer. Multiparametric magnetic resonance imaging (MRI) is emerging as the main modality for prostate cancer imaging. Contrast-enhanced ultrasound and shear wave elastography may be strong alternatives in patients who cannot undergo MRI. Prostate-specific membrane antigen-directed positron emission tomography/computed tomography has proven to be valuable in the primary staging of high-risk disease and for detecting disease in patients with biochemical recurrence. As more studies continue to emerge, it is becoming clear that the standard algorithm for diagnosing and staging prostate cancer will undergo significant changes in the near future.

The use of long non-coding RNAs as prognostic biomarkers and therapeutic targets in prostate cancer

Prostate cancer is the most common cancer in men and the second leading cause of cancer-related deaths. The most used biomarker to detect prostate cancer is Prostate Specific Antigen (PSA), whose levels are measured in serum. However, it has been recently established that molecular markers of cancer should not be based solely on genes and proteins but should also reflect other genomic traits; long non-coding RNAs (lncRNAs) serve this purpose. lncRNAs are transcripts of >200 bases that do not encode proteins and that have been shown to display abnormal expression profiles in different types of cancer. Experimental studies have highlighted lncRNAs as potential biomarkers for prognoses and treatments in patients with different types of cancer, including prostate cancer, where the PCA3 lncRNA is currently used as a diagnostic tool and management strategy. With the development of genomic technologies, particularly next-generation sequencing (NGS), several other lncRNAs have been linked to prostate cancer and are currently under validation for their medical use. In this review, we will discuss different strategies for the discovery of novel lncRNAs that can be evaluated as prognostic biomarkers, the clinical impact of these lncRNAs and how lncRNAs can be used as potential therapeutic targets.

Percutaneous stent placement for the treatment of malignant biliary obstruction: nitinol versus elgiloy stents

Objective

This study aimed to compare two self-expanding stents, a nitinol stent and an elgiloy stent, both placed percutaneously, in terms of their efficacy in palliating inoperable malignant biliary obstruction.

Materials and Methods

We retrospectively investigated 99 patients with unresectable malignant biliary obstruction treated with percutaneous placement of a self-expanding metallic stent at our institution between May 2007 and January 2010. Serum bilirubin and liver enzyme levels were measured before and 30 days after stenting. For all procedures using elgiloy or nitinol stents, stent occlusion and patient survival rates were calculated using Kaplan-Meyer analysis.

Results

All of the patients showed clinical improvement after stent placement, with no difference between the two groups. In both groups, the occlusion-free survival rate was 67% at 30 days, 37% at 90 days, 25% at 180 days, and 10% at 360 days, with no significant difference in relation to the type of stent.

Conclusion

The two stents evaluated showed comparable efficacy for the percutaneous treatment of unresectable biliary malignancy, with good clinical results.

Long non-coding RNA ATB promotes growth and epithelial-mesenchymal transition and predicts poor prognosis in human prostate carcinoma

Long non-coding RNAs (lncRNAs) have been identified to be critical mediators in various tumors associated with cancer progression. Long non-coding RNA activated by TGF-β (lncRNA-ATB) is a stimulator of epithelial-mesenchymal transition (EMT) and serves as a novel prognostic biomarker for hepatocellular carcinoma. However, the biological role and clinical significance of lncRNA-ATB in human prostate cancer have yet to be fully elucidated. The present study was designed to explore the expression of lncRNA-ATB in human prostate cancer patients and the role of lncRNA-ATB in prostate cancer cells. We showed that lncRNA-ATB expression was significantly upregulated in tumor tissues in patients with prostate cancer in comparison with adjacent non-tumor tissues. Further analysis indicted that high lncRNA-ATB expression may be an independent prognostic factor for biochemical recurrence (BCR)-free survival in prostate cancer patients. Overexpression of lncRNA-ATB promoted, and knockdown of lncRNA-ATB inhibited the growth of prostate cancer cells via regulations of cell cycle regulatory protein expression levels. In addition, lncRNA-ATB stimulated epithelial-mesenchymal transition (EMT) associated with ZEB1 and ZNF217 expression levels via ERK and PI3K/AKT signaling pathways. These results indicated that lncRNA-ATB may be considered as a new predictor in the clinical prognosis of patients with prostate cancer. Overexpression of lncRNA-ATB exerts mitogenic and EMT effects of prostate cancer via activation of ERK and PI3K/AKT signaling pathways.