Early prostate-specific antigen changes and the diagnosis and prognosis of prostate cancer

Clinical study of multifactorial diagnosis in prostate biopsy

PURPOSE

To study the feasibility of using an artificial intelligence (AI) algorithm for the diagnosis of clinically significant prostate cancer (csPCa) on multiparametric MRI (mpMRI) in combination with conventional clinical information.

METHODS

A retrospective study cohort with 505 patients was collected, with complete information on age (≤60, 60-80, and >80 years), PSA (≤4, 4-10, and >10 ng/dL), and pathology results. The patients with ISUP group >2 were classified as csPCa, and the patients with ISUP = 1 or no evidence of prostate cancer were classified as non-csPCa. The diagnosis of mpMRI was made by experienced radiologists following the prostate imaging reporting and data system (PIRADS ≤ 2, PIRADS = 3, and PIRADS > 3). The mpMRI images were processed by a homemade AI algorithm, and the AI results were obtained as positive or negative for csPCa. Two logistic regression models were fitted, with pathological findings as the dependent variable, that is, a conventional model and an AI model. The conventional model used age, PSA, and PIRADS as the independent variables. The AI model took the AI result and the abovementioned clinical information as the independent variables. The predicted probability of the patients from the conventional model and the AI model were used to test the prediction efficacy of the models. The DeLong test was performed to compare differences in the area under the receiver operating characteristic (ROC) area under the curve (AUC) between the conventional model and the AI model.

RESULTS

In total, 505 patients were included in the study; 280 were diagnosed with csPCa, and 225 were non-csPCa. The median age was 72.0 (67.0, 76.0) years, with a median PSA value of 13.0 (7.46, 27.5) ng/dL. Statically significant differences were found in age, PSA, PIRADS score and AI results between the csPCa and non-csPCa groups (all p < 0.001). In the multivariable regression models, all the variables were independently associated with csPCa. The conventional model (R2  = 0.361) and the AI model (R2  = 0.474) were compared with analysis of variance (ANOVA) and showed statistically significant differences (χ2  = 63.695, p < 0.001). The AUC of the ROC curve for the conventional model was 0.782 (95% confidence interval [CI]: 0.742-0.823), which was less than the AUC of the AI model with statistical significance (0.849 [95% CI: 0.815-0.883], p < 0.001).

CONCLUSION

In combination with routine clinical information, such as age, PSA, and PIRADS category, adding information from the AI algorithm based on mpMRI could improve the diagnosis of csPCa.

Correlation between prostate-specific antigen and four renal function-associated parameters in different ethnicities in southwest China

A limited number of studies have investigated the significance of cystatin C, creatinine, uric acid and urea in prostate cancer. The present study aimed to explore the correlation between these molecules and total prostate-specific antigen (tPSA) levels using big data from patients of different Chinese ethnicities. Patients undergoing physical examination at the Medical Examination Center of West China Hospital (Chengdu, China) between January 2010 and May 2019 were retrospectively included. A χ² test or Fisher's test and Kruskal-Wallis rank-sum test were used to compare categorical and continuous variables. Pearson's correlation coefficients (r) with 95% CI were also determined to assess the correlation between tPSA and cystatin, uric acid, creatinine and urea in the entire patient population and in different ethnicities. A total of 253,281 male patients were included and their mean age was 47.83±14.28 years. The mean tPSA level of these patients was 1.15±1.88 ng/ml. The mean levels of the renal function-associated parameters cystatin C, uric acid, creatinine and urea were 0.91±0.19, 388.02±77.37, 83.94±55.89 and 5.23±1.23 ng/ml, respectively. In the total patient population, urea (r=0.0774, P<0.0001), creatinine (r=0.0219, P<0.0001) and cystatin (r=0.1513, P<0.0001) were slightly positively correlated with tPSA, whereas uric acid was negatively correlated with tPSA (r=-0.0307, P<0.0001). Subgroup analyses generally yielded consistent results; however, a stronger correlation was noted between cystatin C and tPSA for the Mongolian ethnicity (r=0.6572, P<0.0001) and between creatinine and tPSA for the Yi ethnicity (r=0.6125, P<0.0001). In conclusion, the present study used data from a large population to reveal a generally significant and slightly positive correlation between tPSA and cystatin C levels among the 10 most common ethnicities in China. Subgroup analyses indicated that the tPSA level was moderately positively correlated with the creatinine level for the Mongolian and Yi ethnicities and the cystatin C level was moderately positively correlated with tPSA for the Mongolian ethnicity. Future studies are required to confirm and expand the present results.

A Nomogram Based on a TRUS Five-Grade Scoring System for the Prediction of Prostate Cancer and High Grade Prostate Cancer at Initial TRUS-Guided Biopsy

Purpose: To evaluate the efficacy of transrectal ultrasound five-grade scoring system (TRUS-5) in predicting prostate cancer (PCa) and high grade PCa (HGPCa), compared with TRUS two-grade scoring system (TRUS-2), and establish a TRUS-5 based nomogram for the prediction of PCa and HGPCa at initial biopsy (IPBx).

Methods: Data were collected from 862 men who underwent initial TRUS-guided 12-core prostate biopsy. Age, prostate-specific antigen (PSA), percent free PSA, digital rectal examination (DRE), prostate volume (PV), PSA density (PSAD) and TRUS findings were included in the analysis. For TRUS-5, the probability of PCa was quantified on a scale from 1 (benign) to 5 (malignant). TRUS-2 used the grades “normal” and “suspicious”. After univariate and multivariate logistic regression analyses, nomogram models were developed and internally validated based on independent predictors to predict the probability of PCa and HGPCa.

Results: Overall PCa was detected in 42% (362/862) with 26.22% (226/862) showing HGPCa. TRUS-5 significantly outperformed TRUS-2 for the risk prediction of PCa and HGPCa (area under the receiver operating characteristic curve [AUC]: 0.787 vs. 0.694 for PCa, 0.841 vs. 0.713 for HGPCa, P<0.05). The TRUS-5 based nomogram showed higher AUCs (0.905 for PCa, 0.903 for HGPCa) than PSA alone, clinical base model, the TRUS-2 based model, and other predictive models (P<0.05).

Conclusions: TRUS-5 represents a better imaging predictor than TRUS-2 for PCa and HGPCa. Our TRUS-5 based nomogram models performed well for the prediction of PCa and HGPCa at IPBx, which may help to make the decision to biopsy.

The Role of Sarcosine, Uracil, and Kynurenic Acid Metabolism in Urine for Diagnosis and Progression Monitoring of Prostate Cancer

The aim of this pilot study is to evaluate sarcosine, uracil, and kynurenic acid in urine as potential biomarkers in prostate cancer detection and progression monitoring. Sarcosine, uracil, and kynurenic acid were measured in urine samples of 32 prostate cancer patients prior to radical prostatectomy, 101 patients with increased prostate-specific antigen prior to ultrasonographically-guided prostatic biopsy collected before and after prostatic massage, and 15 healthy volunteers (controls). The results were related to histopathologic data, Gleason score, and PSA (Prostate Specific Antigen). Metabolites were measured after analysis of urine samples with Ultra-High Performance Liquid Chromatography coupled to tandem mass spectrometry (UPLC-MS/MS) instrumentation. Multivariate, nonparametric statistical tests including receiver operating characteristics analyses, one-way analysis of variance (Kruskal–Wallis test), parametric statistical analysis, and Pearson correlation, were performed to evaluate diagnostic performance. Decreased median sarcosine and kynurenic acid and increased uracil concentrations were observed for patients with prostate cancer compared to participants without malignancy. Results showed that there was no correlation between the concentration of the studied metabolites and the cancer grade (Gleason score <7 vs. ≥7) and the age of the patients. Evaluation of biomarkers by ROC (Receiving Operating Characteristics) curve analysis showed that differentiation of prostate cancer patients from participants without malignancy was not enhanced by sarcosine or uracil levels in urine. In contrast to total PSA values, kynurenic acid was found a promising biomarker for the detection of prostate cancer particularly in cases where collection of urine samples was performed after prostatic massage. Sarcosine and uracil in urine samples of patients with prostate cancer were not found as significant biomarkers for the diagnosis of prostate cancer. None of the three metabolites can be used reliably for monitoring the progress of the disease.

Whole blood mRNA in prostate cancer reveals a four-gene androgen regulated panel

Due to increased sensitivity, the expression of circulating nucleotides is rapidly gaining popularity in cancer diagnosis. Whole blood mRNA has been used in studies on a number of cancers, most notably two separate studies that used whole blood mRNA to define non-overlapping signatures of prostate cancer that has become castration independent. Prostate cancer is known to rely on androgens for initial growth, and there is increasing evidence on the importance of the androgen axis in advanced disease. Using whole blood mRNA samples from patients with prostate cancer, we have identified the four-gene panel of FAM129A, MME, KRT7 and SOD2 in circulating mRNA that are differentially expressed in a discovery cohort of metastatic samples. Validation of these genes at the mRNA and protein level was undertaken in additional cohorts defined by risk of relapse following surgery and hormone status. All the four genes were downregulated at the mRNA level in the circulation and in primary tissue, but this was not always reflected in tissue protein expression. MME demonstrated significant differences in the hormone cohorts, whereas FAM129A is downregulated at the mRNA level but is raised at the protein level in tumours. Using published ChIP-seq data, we have demonstrated that this may be due to AR binding at the FAM129A and MME loci in multiple cell lines. These data suggest that whole blood mRNA of androgen-regulated genes has the potential to be used for diagnosis and monitoring of prostate cancer.

Predictors of pathological upgrading in low-risk prostate cancer patients without hypointense lesions on an apparent diffusion coefficient map of multiparametric magnetic resonance imaging

PURPOSE

To examine the clinicopathological features and identify the predictors of pathological upgrading in low-risk prostate cancer (PCa) patients without hypointense lesions on the apparent diffusion coefficient (ADC) map calculated from multiparametric magnetic resonance imaging.

METHODS

We reviewed the medical records of 1905 PCa patients who underwent radical prostatectomy between 2007 and 2015. All ADC images were graded using the five-grade Likert scale; the positive hypointense lesions were graded 4-5. We analyzed 256 patients with low-risk classifications according to D'Amico criteria. Patients were classified into two groups according to the pathologic upgrading in the surgical specimens. The predictive factors for pathologic upgrading were evaluated using a multivariate logistic regression analysis.

RESULTS

In 256 patients with low-risk PCa, the percentage of positive cores [odds ratio (OR) 1.09; 95 % confidence interval (CI) 1.02-1.16], the percentage of cancer in the positive cores (OR 1.07, 95 % CI 1.03-1.12), and the presence of hypointensity on an ADC map (OR 2.28; 95 % CI 1.23-4.22) were independent predictors of pathologic upgrading. Notably, 138 of low-risk patients (53.9 %) had no hypointense lesions on an ADC map. Of these 138 patients, the percentage of positive cores (OR 1.09; 95 % CI 1.01-1.18) and the percentage of cancer in the positive cores (OR 1.06; 95 % CI 1.01-1.12) remained independent predictors of pathologic upgrading.

CONCLUSIONS

In low-risk PCa patients without hypointense lesions on an ADC map, biopsy-related parameters such as the percentage of positive cores and the percentage of cancer in the positive cores were independent predictors of pathological upgrading following radical prostatectomy.

A Review of Imaging Methods for Prostate Cancer Detection

Imaging is playing an increasingly important role in the detection of prostate cancer (PCa). This review summarizes the key imaging modalities-multiparametric ultrasound (US), multiparametric magnetic resonance imaging (MRI), MRI-US fusion imaging, and positron emission tomography (PET) imaging-used in the diagnosis and localization of PCa. Emphasis is laid on the biological and functional characteristics of tumors that rationalize the use of a specific imaging technique. Changes to anatomical architecture of tissue can be detected by anatomical grayscale US and T2-weighted MRI. Tumors are known to progress through angiogenesis-a fact exploited by Doppler and contrast-enhanced US and dynamic contrast-enhanced MRI. The increased cellular density of tumors is targeted by elastography and diffusion-weighted MRI. PET imaging employs several different radionuclides to target the metabolic and cellular activities during tumor growth. Results from studies using these various imaging techniques are discussed and compared.

Optimization of amine-rich multilayer thin films for the capture and quantification of prostate-specific antigen

It is demonstrated that poly(allylamine hydrochloride)/poly(styrenesulfonate) (PAH/SPS) multilayer films can be successfully tailored for the capture and detection of small biomolecules in dilute concentrations. Based on in vitro results, these films could be potentially applied for rapid and high-throughput diagnosis of dilute biomarkers in serum or tissue. PAH presents functional amino groups that can be further reacted with desired chemistries in order to create customizable and specific surfaces for biomolecule capture. A variety of film assembly characteristics were tested (pH, molecular weight of PAH, and ionic strength) to tune the biotinylation and swelling behavior of these films to maximize detection capabilities. The resultant optimized biotinylated PAH/SPS 9.3/9.3 system was utilized in conjunction with quantum dots (Qdots) to capture and detect a dilute biomarker for prostate cancer, prostate-specific antigen (PSA). Compared to previous work, our system presents a good sensitivity for PSA detection within the clinically relevant range of 0.4-100 ng/mL.

N-acetyl-L-aspartyl-L-glutamate peptidase-like 2 is overexpressed in cancer and promotes a pro-migratory and pro-metastatic phenotype

N-acetyl-L-aspartyl-L-glutamate peptidase-like 2 (NAALADL2) is a member of the glutamate carboxypeptidase II family, best characterized by prostate-specific membrane antigen (PSMA/NAALAD1). Using immunohistochemistry (IHC), we have shown overexpression of NAALADL2 in colon and prostate tumours when compared with benign tissue. In prostate cancer, NAALADL2 expression was associated with stage and Grade, as well as circulating mRNA levels of the NAALADL2 gene. Overexpression of NAALADL2 was shown to predict poor survival following radical prostatectomy. In contrast to PSMA/NAALAD1, NAALADL2 was localized at the basal cell surface where it promotes adhesion to extracellular matrix proteins. Using stable knockdown and overexpression cell lines, we have demonstrated NAALADL2-dependent changes in cell migration, invasion and colony-forming potential. Expression arrays of the knockdown and overexpression cell lines have identified nine genes that co-expressed with NAALADL2, which included membrane proteins and genes known to be androgen regulated, including the prostate cancer biomarkers AGR2 and SPON2. Androgen regulation was confirmed in a number of these genes, although NAALADL2 itself was not found to be androgen regulated. NAALADL2 was also found to regulate levels of Ser133 phosphorylated C-AMP-binding protein (CREB), a master regulator of a number of cellular processes involved in cancer development and progression. In combination, these data suggest that changes in expression of NAALADL2 can impact upon a number of pro-oncogenic pathways and processes, making it a useful biomarker for both diagnosis and prognosis.

Prostate-specific antigen and other serum and urine markers in prostate cancer

Prostate-specific antigen (PSA) is one of the most widely used tumor markers, and strongly correlates with the risk of harboring from prostate cancer (PCa). This risk is visible already several years in advance but PSA has severe limitations for PCa detection with its low specificity and low negative predictive value. There is an urgent need for new biomarkers especially to detect clinically significant and aggressive PCa. From all PSA-based markers, the FDA-approved Prostate Health Index (phi) shows improved specificity over percent free and total PSA. Other serum kallikreins or sarcosine in serum or urine show more diverging data. In urine, the FDA-approved prostate cancer gene 3 (PCA3) has also proven its utility in the detection and management of early PCa. However, some aspects on its correlation with aggressiveness and the low sensitivity at very high values have to be re-examined. The detection of a fusion of the androgen regulated TMPRSS2 gene with the ERG oncogene (from the ETS family), which acts as transcription factor gene, in tissue of ~50% of all PCa patients was one milestone in PCa research. When combining the urinary assays for TMPRSS2:ERG and PCA3, an improved accuracy for PCa detection is visible. PCA3 and phi as the best available PCa biomarkers show an equal performance in direct comparisons.

Tumour markers and kidney function: a systematic review

Tumour markers represent useful tools in diagnosis and clinical management of patients with cancer, because they are easy to use, minimally invasive, and easily measured in either blood or urine. Unfortunately, such an ideal marker, as yet, does not exist. Different pathological states may increase the level of a tumour marker in the absence of any neoplasia. Alternatively, low levels of tumour markers could be also found in the presence of neoplasias. We aimed at reviewing studies currently available in the literature examining the association between tumour markers and different renal impairment conditions. Each tumour marker was found to be differently influenced by these criteria; additionally we revealed in many cases a lack of available published data.

Aberrant PSA glycosylation--a sweet predictor of prostate cancer

Prostate cancer--the most commonly diagnosed cancer in men worldwide--can have a substantial effect on quality of life, regardless of the route the cancer takes. The serum PSA assay is the current gold standard option for diagnosing prostate cancer. However, a growing body of evidence suggests that PSA screening for prostate cancer results in extensive overdiagnosis and overtreatment. It is increasingly evident that the potential harm from overdiagnosis (in terms of unnecessary biopsies) must be weighed against the benefit derived from the early detection and treatment of potentially fatal prostate cancers. Rapid screening methods have been used to analyse glycosylation patterns on glycoproteins in large cohorts of patients, enabling the identification of a new generation of disease biomarkers. Changes to the expression status of certain glycan structures are now widely thought to be common features of tumour progression. In light of this development, much research has focused on the potential role of altered PSA glycosylation patterns in discriminating between significant and insignificant prostate cancers, with the aim of developing a more reliable diagnostic tool than the current serum PSA test.

Risk stratification in prostate cancer screening

Screening for prostate cancer is a controversial topic within the field of urology. The US Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial did not demonstrate any difference in prostate-cancer-related mortality rates between men screened annually rather than on an 'opportunistic' basis. However, in the world's largest trial to date--the European Randomised Study of Screening for Prostate Cancer--screening every 2-4 years was associated with a 21% reduction in prostate-cancer-related mortality rate after 11 years. Citing the uncertain ratio between potential harm and potential benefit, the US Preventive Services Task Force recently recommended against serum PSA screening. Although this ratio has yet to be elucidated, PSA testing--and early tumour detection--is undoubtedly beneficial for some individuals. Instead of adopting a 'one size fits all' approach, physicians are likely to perform personalized risk assessment to minimize the risk of negative consequences, such as anxiety, unnecessary testing and biopsies, overdiagnosis, and overtreatment. The PSA test needs to be combined with other predictive factors or be used in a more thoughtful way to identify men at risk of symptomatic or life-threatening cancer, without overdiagnosing indolent disease. A risk-adapted approach is needed, whereby PSA testing is tailored to individual risk.

A prospective study of total and ionized serum calcium and time to fatal prostate cancer

BACKGROUND

Higher levels of total and ionized serum calcium have been shown to predict fatal prostate cancer in prospective studies. Because the follow-up time in these studies was relatively short, these associations could reflect the effect of clinically significant but occult prostate tumors on serum calcium levels. If this were true, prostate cancer mortality rates among men with higher levels of serum calcium should be higher during the early follow-up period and should decline thereafter.

METHODS

We tested this hypothesis by estimating the relative risk of death from prostate cancer in the National Health and Nutrition Examination Survey III for incremental increases in total and ionized serum calcium using Cox proportional hazards regression with time-dependent effects.

RESULTS

Forty-nine (49) fatal prostate cancers occurred over 204 months of follow-up and 1,069,327 person-months of observation. Men with higher total serum calcium and higher serum ionized calcium had increased risks of fatal prostate cancer during the first 96 months of follow-up [Relative Hazard (RH) = 1.50 per 0.1 mmol/L total serum calcium, 95% confidence interval (CI) = 1.04-2.17; RH = 1.72 per 0.05 mmol/L ionized calcium, 95% CI = 1.11-2.66]. Evidence of an association between total and ionized serum calcium and prostate cancer deaths was not significant after 96 months.

CONCLUSIONS

Our analyses support the hypothesis that the elevated risk for fatal prostate cancer observed in men with high serum calcium is because of the presence of extant, but occult prostate cancer.

IMPACT

These findings have implications for the potential use of serum calcium in the detection of clinically significant prostate cancer.

Effect of CYP17 and PSA gene polymorphisms on prostate cancer risk and circulating PSA levels in the Slovak population

Cytochrome P-450c17α (CYP17) and prostate-specific antigen (PSA) genes, which are involved in the androgen metabolism cascade, have been studied as possible candidates for genetic influences on prostate cancer development. Contradictory results prompted us to evaluate the frequencies of polymorphisms in the CYP17 and PSA genes as well as the association between these genetic variants and serum PSA levels in prostate cancer patients and men routinely screened for prostate cancer with PSA in the Slovak male population. The CYP17 and PSA polymorphisms were determined by the PCR-RFLP analysis in 197 Caucasian prostate cancer patients and 256 Caucasian controls. We did not find any association between the CYP17 and PSA genotypes and prostate cancer risk overall, or by grade. Also the total serum PSA levels in the cases with the AG or AA genotype were not significantly higher than in the men with the GG genotype (P > 0.05). Our study did not provide support for the hypothesized relationship between CYP17 and PSA gene polymorphisms and prostate cancer in the Slovak male population.

Chemically modified non-antimicrobial tetracyclines are multifunctional drugs against advanced cancers

Metastatic cancers account for more than 90% of cancer mortality. The metastasis of all cancers is critically mediated by enzymes that degrade extracellular matrix. Aggressive tumors are characterized by an imbalance between enzymes that degrade ECM and endogenous inhibitors of the enzymes. Matrix metalloproteinases (MMPs) make up the majority of ECM degrading enzymes implicated in cancer metastasis. The potent MMP inhibitory activities of tetracyclines, especially their chemically modified analogs, combined with their relatively well tolerated pharmacological profile, led several researchers to investigate their anticancer potential in a variety of cancers, including melanoma, lung, breast and prostate cancers. Chemically modified non-antibiotic tetracyclines (CMTs or COL) were tested using tumors of prostate, breast and melanomas. Some of these CMTs, notably, CMT-3 and CMT-308 significantly inhibited not only invasive potential and MMP activity, but also inhibited cell proliferation by inducing cell cycle arrest and apoptosis. CMT-3 and CMT-308 were significantly more potent than doxycycline or minocycline in inhibiting tumor cell-derived MMPs and inducing apoptosis in vitro and in vivo. CMT-3 (COL-3) showed potent inhibition of tumor growth in xenografts and in bone metastatic models of prostate cancer. Similar results were also reported in melanoma and breast cancer models. The mechanism by which CMTs kill tumor cells is via generation of hydroxyl free radicals ([OH](-)) which permeate and depolarize mitochondria, which in turn activates caspase mediated apoptosis. Analysis of tumor tissues from CMT-3 treated rats demonstrated reduction in angiogenesis and increase in apoptosis; both emerged as mechanisms of CMT action. These observations led to testing the efficacy of CMT-3 in human clinical trials against several types of cancer with significant outcomes, which are described in the next chapter of this issue.

Late onset hypogonadism, sexuality and fertility

The numerous and varying effects of androgen deficiency in males cause an array of symptoms and complaints any of which can be the trigger for a medical consultation. It is, therefore, important to consider the possibility of late onset hypogonadism (LOH) in a patient who is presenting with any such symptoms. This review describes LOH and the current guidelines for its treatment and management. Also discussed are the normal changes undergone by men as they age and the effects that are expected due to this change. The relationship between LOH and its effects on both sexuality and fertility are also considered.