Are localized prostate cancer biomarkers useful in the clinical practice?

Genomics in active surveillance and post-prostatectomy patients: A review of when and how to use effectively

PURPOSE OF REVIEW

Prostate cancer (PCa) represents a significant health burden globally, ranking as the most diagnosed cancer among men and a leading cause of cancer-related mortality. Conventional treatment methods such as radiation therapy or radical prostatectomy have significant side effects which often impact quality of life. As our understanding of the natural history and progression of PCa has evolved, so has the evolution of management options.

RECENT FINDINGS

Active surveillance (AS) has become an increasingly favored approach to the management of very low, low, and properly selected favorable intermediate risk PCa. AS permits ongoing observation and postpones intervention until definitive treatment is required. There are, however, challenges with selecting patients for AS, which further emphasizes the need for more precise tools to better risk stratify patients and choose candidates more accurately. Tissue-based biomarkers, such as ProMark, Prolaris, GPS (formerly Oncotype DX), and Decipher, are valuable because they improve the accuracy of patient selection for AS and offer important information on the prognosis and severity of disease. By enabling patients to be categorized according to their risk profiles, these biomarkers help physicians and patients make better informed treatment choices and lower the possibility of overtreatment. Even with their potential, further standardization and validation of these biomarkers is required to guarantee their broad clinical utility. Active surveillance has emerged as a preferred strategy for managing low-risk prostate cancer, and tissue-based biomarkers play a crucial role in refining patient selection and risk stratification. Standardization and validation of these biomarkers are essential to ensure their widespread clinical use and optimize patient outcomes.

Proteomic-based stratification of intermediate-risk prostate cancer patients

Gleason grading is an important prognostic indicator for prostate adenocarcinoma and is crucial for patient treatment decisions. However, intermediate-risk patients diagnosed in the Gleason grade group (GG) 2 and GG3 can harbour either aggressive or non-aggressive disease, resulting in under- or overtreatment of a significant number of patients. Here, we performed proteomic, differential expression, machine learning, and survival analyses for 1,348 matched tumour and benign sample runs from 278 patients. Three proteins (F5, TMEM126B, and EARS2) were identified as candidate biomarkers in patients with biochemical recurrence. Multivariate Cox regression yielded 18 proteins, from which a risk score was constructed to dichotomize prostate cancer patients into low- and high-risk groups. This 18-protein signature is prognostic for the risk of biochemical recurrence and completely independent of the intermediate GG. Our results suggest that markers generated by computational proteomic profiling have the potential for clinical applications including integration into prostate cancer management.

Urinary Biomarkers and Point-of-Care Urinalysis Devices for Early Diagnosis and Management of Disease: A Review

Biosensing and microfluidics technologies are transforming diagnostic medicine by accurately detecting biomolecules in biological samples. Urine is a promising biological fluid for diagnostics due to its noninvasive collection and wide range of diagnostic biomarkers. Point-of-care urinalysis, which integrates biosensing and microfluidics, has the potential to bring affordable and rapid diagnostics into the home to continuing monitoring, but challenges still remain. As such, this review aims to provide an overview of biomarkers that are or could be used to diagnose and monitor diseases, including cancer, cardiovascular diseases, kidney diseases, and neurodegenerative disorders, such as Alzheimer’s disease. Additionally, the different materials and techniques for the fabrication of microfluidic structures along with the biosensing technologies often used to detect and quantify biological molecules and organisms are reviewed. Ultimately, this review discusses the current state of point-of-care urinalysis devices and highlights the potential of these technologies to improve patient outcomes. Traditional point-of-care urinalysis devices require the manual collection of urine, which may be unpleasant, cumbersome, or prone to errors. To overcome this issue, the toilet itself can be used as an alternative specimen collection and urinalysis device. This review then presents several smart toilet systems and incorporated sanitary devices for this purpose.

Molecular biomarkers in the context of focal therapy for prostate cancer: recommendations of a Delphi Consensus from the Focal Therapy Society

BACKGROUND

Focal therapy (FT) for prostate cancer (PCa) is promising. However, long-term oncological results are awaited and there is no consensus on follow-up strategies. Molecular biomarkers (MB) may be useful in selecting, treating and following up men undergoing FT, though there is limited evidence in this field to guide practice. We aimed to conduct a consensus meeting, endorsed by the Focal Therapy Society, amongst a large group of experts, to understand the potential utility of MB in FT for localized PCa.

METHODS

A 38-item questionnaire was built following a literature search. The authors then performed three rounds of a Delphi Consensus using DelphiManager, using the GRADE grid scoring system, followed by a face-to-face expert meeting. Three areas of interest were identified and covered concerning MB for FT, 1) the current/present role; 2) the potential/future role; 3) the recommended features for future studies. Consensus was defined using a 70% agreement threshold.

RESULTS

Of 95 invited experts, 42 (44.2%) completed the three Delphi rounds. Twenty-four items reached a consensus and they were then approved at the meeting involving (N.=15) experts. Fourteen items reached a consensus on uncertainty, or they did not reach a consensus. They were re-discussed, resulting in a consensus (N.=3), a consensus on a partial agreement (N.=1), and a consensus on uncertainty (N.=10). A final list of statements were derived from the approved and discussed items, with the addition of three generated statements, to provide guidance regarding MB in the context of FT for localized PCa. Research efforts in this field should be considered a priority.

CONCLUSIONS

The present study detailed an initial consensus on the use of MB in FT for PCa. This is until evidence becomes available on the subject.

Reclassification prediction of first-year protocol biopsy on active surveillance of prostate cancer by p2PSA-related parameters: from PRIAS-JAPAN

BACKGROUND

There is no useful predictive marker for reclassification on active surveillance. Thus, we aimed to investigate thresholds of [-2] proPSA (p2PSA)-related parameters to predict reclassification of the first-year protocol biopsy (1-year PBx) and evaluate the influence of clinical decision-making.

METHODS

This was an observational, prospective cohort study conducted at 19 Japanese institutes. The inclusion criteria included clinical stage T1c/T2, prostate-specific antigen (PSA) levels ≤10 ng/mL, PSA density <0.2 ng/ml/cc, one or two positive biopsy cores, and Gleason score (GS) ≤6 (GS ≦7 for patients aged ≥70 years) at diagnostic biopsy. All participants were required to receive a blood-sampling test on a protocol visit at inclusion and at the 1-year PBx. PSA and PSA isoforms (free PSA, p2PSA) were measured, and parameters (%free PSA, %p2PSA, phi) were calculated. Multivariable logistic regression models were used to predict the reclassification risk. To assess the predictive power and thresholds for reclassification, we plotted Receiver Operating Characteristic (ROC) curves. Decision curve analysis (DCA) was used to evaluate the variables that yielded a net clinical benefit.

RESULTS

A total of 135 patients were included, and 36 patients were reclassified on the 1-year PBx. Multivariate analyses showed that %p2PSA and phi at inclusion and p2PSA, %p2PSA, and phi before the 1-year PBx were significant predictors of reclassification at the 1-year PBx. The ROC analysis showed an optimal cutoff point, sensitivity, and specificity of %p2PSA and phi before the 1-year PBx of 1.64, 86%, 49% and 35.92, 89%, 47%, respectively. The DCA showed that phi before the 1-year PBx had the highest net benefit. The study limitation was its single-arm observational design.

CONCLUSIONS

%p2PSA and phi before the 1-year PBx had a good prediction power. phi is the most useful indicator for clinical decision-making on active surveillance.

TRIAL REGISTRATION

This study is registered atthe Japan Trial Register with ID UMIN000009876 ( https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000011573 ).

Integrating Serum Biomarkers into Prediction Models for Biochemical Recurrence Following Radical Prostatectomy

This study undertook to predict biochemical recurrence (BCR) in prostate cancer patients after radical prostatectomy using serum biomarkers and clinical features. Three radical prostatectomy cohorts were used to build and validate a model of clinical variables and serum biomarkers to predict BCR. The Cox proportional hazard model with stepwise selection technique was used to develop the model. Model evaluation was quantified by the AUC, calibration, and decision curve analysis. Cross-validation techniques were used to prevent overfitting in the Irish training cohort, and the Austrian and Norwegian independent cohorts were used as validation cohorts. The integration of serum biomarkers with the clinical variables (AUC = 0.695) improved significantly the predictive ability of BCR compared to the clinical variables (AUC = 0.604) or biomarkers alone (AUC = 0.573). This model was well calibrated and demonstrated a significant improvement in the predictive ability in the Austrian and Norwegian validation cohorts (AUC of 0.724 and 0.606), compared to the clinical model (AUC of 0.665 and 0.511). This study shows that the pre-operative biomarker PEDF can improve the accuracy of the clinical factors to predict BCR. This model can be employed prior to treatment and could improve clinical decision making, impacting on patients' outcomes and quality of life.

Decreased levels of cathepsin Z mRNA expressed by immune blood cells: diagnostic and prognostic implications in prostate cancer

Cathepsin Z (CTSZ) is a cysteine protease responsible for the adhesion and migration of both immune and tumor cells. Due to its dual role, we hypothesized that the site of CTSZ expression could be determinant of the pro- or anti-tumorigenic effects of this enzyme. To test this hypothesis, we analyzed CTSZ expression data in healthy and tumor tissues by bioinformatics and evaluated the expression levels of CTSZ mRNA in the blood cells of prostate cancer (PCa) patients by qRT-PCR compared with healthy subjects, evaluating its diagnostic and prognostic implications for this type of cancer. Immune cells present in the blood of healthy patients overexpress CTSZ. In PCa, we found decreased CTSZ mRNA levels in blood cells, 75% lower than in healthy subjects, that diminished even more during biochemical relapse. CTSZ mRNA in the blood cells had an area under the curve for PCa diagnosis of 0.832, with a 93.3% specificity, and a positive likelihood ratio of 9.4. The site of CTSZ mRNA expression is fundamental to determine its final role as a protective determinant in PCa, such as CTSZ mRNA in the blood cells, or a malignant determinant, such as found for CTSZ expressed in high levels by different types of primary and metastatic tumors. Low CTSZ mRNA expression in the total blood is a possible PCa marker complementary to prostate-specific antigen (PSA) for biopsy decisions, with the potential to eliminate unnecessary biopsies.

Effect of targeted prophylaxis with rectal swab on complications after prostate biopsy: prospective randomized study

BACKGROUND

For diagnosis of prostate cancer, prostate biopsy accompanied by TRUS is the current method applied today.

AIM

The aim of this study was to compare targeted antibiotic prophylaxis, chosen according to rectal swab results before the procedure, with routinely administered prophylaxis and to investigate the effect on infective complications.

METHODS

The study included 140 patients with 12-quadrant prostate biopsy accompanied by TRUS in our hospital from 2018 to 2020. The first group had antibiotherapy prophylaxis administered according to the results of rectal swabs before the procedure. The second group had routine ciprofloxacin prophylaxis administered. Patients were followed prospectively for 1 month after the procedure.

RESULTS

When the mean age, systemic diseases and distribution in both groups are examined, there was no significant difference observed. Fever (> 38.5 °C) was observed in 3 patients in the rectal swab group (4.3%), while it was identified in 10 people in the control group (14.1%) (p = 0.047). Major complications were observed in 3 people in the rectal swab group (4.3%) and in 7 people in the control group (9.9%) (p = 0.012).

CONCLUSIONS

The results of the study identified that routine administration of targeted antibiotic prophylaxis may be more effective in preventing infective complications compared to standard prophylaxis. Targeted prophylaxis is recommended for risky patients in the guidelines. However, the lack of difference between the groups in terms of age and comorbidities supports the need to administer targeted prophylaxis not just to risky patients but as well as routine practice.

Proteomic Tissue-Based Classifier for Early Prediction of Prostate Cancer Progression

Although ~40% of screen-detected prostate cancers (PCa) are indolent, advanced-stage PCa is a lethal disease with 5-year survival rates around 29%. Identification of biomarkers for early detection of aggressive disease is a key challenge. Starting with 52 candidate biomarkers, selected from existing PCa genomics datasets and known PCa driver genes, we used targeted mass spectrometry to quantify proteins that significantly differed in primary tumors from PCa patients treated with radical prostatectomy (RP) across three study outcomes: (i) metastasis ≥1-year post-RP, (ii) biochemical recurrence ≥1-year post-RP, and (iii) no progression after ≥10 years post-RP. Sixteen proteins that differed significantly in an initial set of 105 samples were evaluated in the entire cohort (n = 338). A five-protein classifier which combined FOLH1, KLK3, TGFB1, SPARC, and CAMKK2 with existing clinical and pathological standard of care variables demonstrated significant improvement in predicting distant metastasis, achieving an area under the receiver-operating characteristic curve of 0.92 (0.86, 0.99, p = 0.001) and a negative predictive value of 92% in the training/testing analysis. This classifier has the potential to stratify patients based on risk of aggressive, metastatic PCa that will require early intervention compared to low risk patients who could be managed through active surveillance.

Expansile cribriform Gleason pattern 4 has histopathologic and molecular features of aggressiveness and greater risk of biochemical failure compared to glomerulation Gleason pattern 4

BACKGROUND

Molecular testing of prostate cancer biopsies with Gleason pattern 4 suggests the expansile cribriform pattern is more aggressive than the glomerulation pattern. These two extreme patterns have not been compared at prostatectomy. We hypothesized that at prostatectomy the expansile cribriform pattern would be associated with histopathologic and molecular features of aggressiveness and with greater risk of biochemical recurrence (BCR) than the glomerulation pattern.

METHODS

In a retrospective cohort study, radical prostatectomy reports with expansile cribriform pattern or glomerulation pattern were analyzed for percentage of total pattern 4, extraprostatic extension (EPE), positive lymph nodes, seminal vesicle invasion (SVI), and intraductal carcinoma (IDC). Cases with pattern 5 or with both expansile cribriform and glomerulations patterns present were excluded. The electronic medical record was reviewed for BCR-free survival and for Decipher test results.

RESULTS

Of 1020 radical prostatectomies from July 2015 to July 2018, 110 (11%) had either expansile cribriform or glomerulation pattern present. The expansile cribriform group was associated with more histopathologic features of aggressiveness, with higher average total percentage pattern 4 (43.7 vs 27.0, P = .002), a trend of greater extensive EPE (32.7% vs 17.2%, P = .06), a trend toward statistical significance of higher rate of SVI (11.5% vs 3.4%, P = .1), greater positive lymph nodes (9.6% vs 0%, P = .02), and a higher percentage of cases with or suspicious for IDC (23.1% vs 8.6%, P = .04). The risk of BCR was 4.4 (1.3-15.4) fold greater for the expansile cribriform group vs the glomerulations group (P = .02). For the 38 patients who underwent Decipher testing, the expansile cribriform group had a high-risk assay category mean score whereas the glomerulations group had an average risk assay category mean score (0.61 vs 0.47, P = .02).

CONCLUSIONS

In a comparison of prostatectomy cases with expansile cribriform pattern to those with glomerulation pattern, the expansile cribriform pattern was associated with more histopathologic features of aggressiveness, greater risk of biochemical failure, and higher scores with a molecular classifier (Decipher) test. These findings underscore the importance of reporting the types of pattern 4 and supports the argument that men with expansile cribriform likely require more aggressive management.

Search for Novel Diagnostic Biomarkers of Prostate Inflammation-Related Disorders: Role of Transglutaminase Isoforms as Potential Candidates

Investigations on prostate inflammation-related disorders, including acute and chronic prostatitis, chronic pelvic pain syndrome, benign prostate hyperplasia (BPH), and prostate cancer (PCa), are still ongoing to find new, accurate, and noninvasive biomarkers for a differential diagnosis of those pathological conditions sharing some common macroscopic features. Moreover, an ideal biomarker should be useful for risk assessment of prostate inflammation progression to more severe disorders, like BPH or PCa, as well as for monitoring of treatment response and prognosis establishment in carcinoma cases. Recent literature evidence highlighted that changes in the expression of transglutaminases, enzymes that catalyze transamidation reactions leading to posttranslational modifications of soluble proteins, occur in prostate inflammation-related disorders. This review focuses on the role specifically played by transglutaminases 4 (TG4) and 2 (TG2) and suggests that both isoenzymes hold a potential to be included in the list of candidates as novel diagnostic biomarkers for the above-cited prostate pathological conditions.