Prostate-specific antigen 1.5-4.0 ng/mL: a diagnostic challenge and danger zone

Prostate Cancer Foundation Screening Guidelines for Black Men in the United States

BACKGROUND

In the United States, Black men are at highest risk for being diagnosed with and dying from prostate cancer. Given this disparity, we examined relevant data to establish clinical prostate-specific antigen (PSA) screening guidelines for Black men in the United States.

METHODS

A comprehensive literature search identified 1848 unique publications for screening. Of those screened, 287 studies were selected for full-text review, and 264 were considered relevant and form the basis for these guidelines. The numbers were reported according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines.

RESULTS

Three randomized controlled trials provided Level 1 evidence that regular PSA screening of men 50 to 74 years of age of average risk reduced metastasis and prostate cancer death at 16 to 22 years of follow-up. The best available evidence specifically for Black men comes from observational and modeling studies that consider age to obtain a baseline PSA, frequency of testing, and age when screening should end. Cohort studies suggest that discussions about baseline PSA testing between Black men and their clinicians should begin in the early 40s, and data from modeling studies indicate prostate cancer develops 3 to 9 years earlier in Black men compared with non-Black men. Lowering the age for baseline PSA testing to 40 to 45 years of age from 50 to 55 years of age, followed by regular screening until 70 years of age (informed by PSA values and health factors), could reduce prostate cancer mortality in Black men (approximately 30% relative risk reduction) without substantially increasing overdiagnosis.

CONCLUSIONS

These guidelines recommend that Black men should obtain information about PSA screening for prostate cancer. Among Black men who elect screening, baseline PSA testing should occur between ages 40 and 45. Depending on PSA value and health status, annual screening should be strongly considered. (Supported by the Prostate Cancer Foundation.).

Initial Longitudinal Outcomes of Risk-Stratified Men in Their Forties Screened for Prostate Cancer Following Implementation of a Baseline Prostate-Specific Antigen

PURPOSE

Prostate cancer (PCa) screening can lead to potential over-diagnosis/over-treatment of indolent cancers. There is a need to optimize practices to better risk-stratify patients. We examined initial longitudinal outcomes of mid-life men with an elevated baseline prostate-specific antigen (PSA) following initiation of a novel screening program within a system-wide network.

MATERIALS AND METHODS

We assessed our primary care network patients ages 40 to 49 years with a PSA measured following implementation of an electronic health record screening algorithm from 2/2/2017-2/21/2018. The multidisciplinary algorithm was developed taking factors including age, race, family history, and PSA into consideration to provide a personalized approach to urology referral to be used with shared decision-making. Outcomes of men with PSA ≥1.5 ng/mL were evaluated through 7/2021. Statistical analyses identified factors associated with PCa detection. Clinically significant PCa (csPCa) was defined as Gleason Grade Group (GGG) ≥2 or GGG1 with PSA ≥10 ng/mL.

RESULTS

The study cohort contained 564 patients, with 330 (58.5%) referred to urology for elevated PSA. Forty-nine (8.7%) underwent biopsy; of these, 20 (40.8%) returned with PCa. Eleven (2.0% of total cohort and 55% of PCa diagnoses) had csPCa. Early referral timing (odds ratio [OR], 4.58) and higher PSA (OR, 1.07) were significantly associated with PCa at biopsy on multivariable analysis (both p<0.05), while other risk factors were not. Referred patients had higher mean PSAs (2.97 vs. 1.98, p=0.001).

CONCLUSIONS

Preliminary outcomes following implementation of a multidisciplinary screening algorithm identified PCa in a small, important percentage of men in their forties. These results provide insight into baseline PSA measurement to provide early risk stratification and detection of csPCa in patients with otherwise extended life expectancy. Further follow-up is needed to possibly determine the prognostic significance of such mid-life screening and optimize primary care physician-urologist coordination.

Ethnic differences in prostate-specific antigen levels in men without prostate cancer: a systematic review

INTRODUCTION

Black men are twice as likely to be diagnosed with prostate cancer than White men. Raised prostate-specific antigen (PSA) levels can indicate an increased risk of prostate cancer, however it is not known whether PSA levels differ for men of different ethnic groups.

METHODS

PubMed and Embase were searched to identify studies that reported levels of PSA for men of at least two ethnic groups without a prostate cancer diagnosis or symptoms suggestive of prostate cancer. An adaptation of the Newcastle-Ottawa scale was used to assess risk of bias and study quality. Findings were stratified into the following broad ethnic groups: White, Black, Asian, Hispanic, and Other. Data were analysed in a narrative synthesis due to the heterogeneity of reported PSA measures and methods in the included studies.

RESULTS

A total of 654 197 males from 13 studies were included. By ethnicity, this included 536 201 White (82%), 38 287 Black (6%), 38 232 Asian (6%), 18 029 Pacific Island (3%), 13 614 Maori (2%), 8 885 Hispanic (1%), and 949 Other (<1%) men aged ≥40 years old. Black men had higher PSA levels than White men, and Hispanic men had similar levels to White men and lower levels than Black men.

CONCLUSIONS

Black men without prostate cancer have higher PSA levels than White or Hispanic men, which reflects the higher rates of prostate cancer diagnosis in Black men. Despite that, the diagnostic accuracy of PSA for prostate cancer for men of different ethnic groups is unknown, and current guidance for PSA test interpretation does not account for ethnicity. Future research needs to determine whether Black men are diagnosed with similar rates of clinically significant prostate cancer to White men, or whether raised PSA levels are contributing to overdiagnosis of prostate cancer in Black men.

Aggregation-Induced Emission Luminogen-Based Dual-Mode Enzyme-Linked Immunosorbent Assay for Ultrasensitive Detection of Cancer Biomarkers in a Broad Concentration Range

The enzyme-linked immunosorbent assay (ELISA) is one of the most commonly used methods for measuring antibodies and antigens in biological samples. However, developing new ELISAs with high detection sensitivity and broad detection dynamic ranges without resorting to complicated signal processing and equipment setups remains a challenge. In this work, we report a strategy to simultaneously improve the detection sensitivity and broaden the dynamic range by replacing the chromogenic reagents used in traditional ELISAs with an aggregation-induced emission luminogen (AIEgen). The developed AIE-ELISA could generate complementary absorbance and fluorescence signals with a linear detection range of 1.6-25,000 pg/mL. The application of this dual-mode AIE-ELISA in the detection of the prostate-specific antigen (PSA) realized a limit of detection of 1.3 pg/mL (3.78 × 10^-14 M) and dynamic range improvement of approximately 2 orders of magnitude compared to a single-mode ELISA, which enabled it to discriminate a minor PSA difference in a patient's serum. The simpler experimental operation, faster enzyme response speed, and better photostability of AIEgen than the traditional chromogenic reagents used in ELISAs showed that our developed AIE-ELISA holds great potential in the fields of immunoassay, immunohistochemistry, and immunocytochemistry.

Investigation on core-fucosylated prostate-specific antigen as a refined biomarker for differentiation of benign prostate hyperplasia and prostate cancer of different aggressiveness

Prostate cancer represents a major cause of cancer death in men worldwide. Novel non-invasive methods are still required for differentiation of non-aggressive from aggressive tumors. Recently, changes in prostate-specific antigen glycosylation pattern, such as core-fucosylation, have been described in prostate cancer. The objective of this study was to evaluate whether the core-fucosylation determinant of serum prostate-specific antigen may serve as refined marker for differentiation between benign prostate hyperplasia and prostate cancer or identification of aggressive prostate cancer. A previously developed liquid chromatography-mass spectrometry/mass spectrometry-based strategy was used for multiplex analysis of core-fucosylated prostate-specific antigen (fuc-PSA) and total prostate-specific antigen levels in sera from 50 benign prostate hyperplasia and 100 prostate cancer patients of different aggressiveness (Gleason scores, 5-10) covering the critical gray area (2-10 ng/mL). For identification of aggressive prostate cancer, the ratio of fuc-PSA to total prostate-specific antigen (%-fuc-PSA) yielded a 5%-8% increase in the area under the curve (0.60) compared to the currently used total prostate-specific antigen (area under the curve = 0.52) and %-free prostate-specific antigen (area under the curve = 0.55) tests. However, our data showed that aggressive prostate cancer (Gleason score > 6) and non-aggressive prostate cancer (Gleason score ≤ 6) could not significantly (p-value = 0.08) be differentiated by usage of %-fuc-PSA. In addition, both non-standardized fuc-PSA and standardized %-fuc-PSA had no diagnostic value for differentiation of benign prostate hyperplasia from prostate cancer. The %-fuc-PSA serum levels could not improve the differentiation of non-aggressive and aggressive prostate cancer compared to conventional diagnostic prostate cancer markers. Still, it is unclear whether these limitations come from the biomarker, the used patient cohort, or the imprecision of the applied method itself. Therefore, %-fuc-PSA should be further investigated, especially by more precise methods whether it could be clinically used in prostate cancer diagnosis.

Evaluation of an Aggressive Prostate Biopsy Strategy in Men Younger than 50 Years

PURPOSE

Longitudinal cohort studies and guidelines demonstrate that prostate specific antigen 1 ng/ml or greater in younger patients confers an increased risk of delayed prostate cancer death. At our institution we have used an aggressive biopsy strategy in younger patients with prostate specific antigen 1 ng/ml or greater. Our objective was to determine the proportion of detected cancer and specifically clinically significant cancer by this strategy.

MATERIALS AND METHODS

The prostate biopsy database at Princess Margaret Cancer Centre was queried for patients younger than 50 years who underwent a first prostate biopsy between 2000 and 2016. We included only patients who underwent prostate biopsy due to prostate specific antigen 1 ng/ml or greater and those with a suspicious digital rectal examination, a positive family history or a suspicious lesion on transrectal ultrasound. All clinical and pathological parameters were analyzed. Patients were stratified according to specific prostate specific antigen values. Multivariable logistic regression was performed to ascertain predictors of any prostate cancer diagnosis and of clinically significant prostate cancer.

RESULTS

Of the 199 patients who met study inclusion criteria 37 (19%) were diagnosed with prostate cancer and 8 (22%) had a Gleason score of 7 or greater. Of those diagnosed with prostate cancer 25 (68%) had prostate specific antigen 1.5 ng/ml or greater and all men with a Gleason score of 7 or greater had prostate specific antigen 1.5 ng/ml or greater. Notably 19 patients (51%) had prostate cancer exceeding the Epstein criteria for active surveillance. Factors predicting prostate cancer included a positive family history, rising prostate specific antigen and lower prostate volume.

CONCLUSIONS

Our results justify adopting an aggressive prostate biopsy strategy in men younger than 50 years with prostate specific antigen 1.5 ng/ml or greater while patients with prostate specific antigen less than 1.5 ng/ml are unlikely to have significant cancer. Special attention should be given to patients with a smaller prostate and a positive family history.

Clarifying the PSA grey zone: The management of patients with a borderline PSA

INTRODUCTION

Prostate specific antigen is a marker for prostate cancer and a key diagnostic tool, yet when to refer patients with a borderline PSA is currently unclear. This review describes how to assess a patient with borderline PSA and provides an algorithm for management.

METHODS

Current literature on reference values, factors affecting PSA, indications for referral, non-invasive investigations and the role of MRI were reviewed. Medline and EMBASE were searched using MeSH terms.

RESULTS

The literature suggests that a PSA of over 1.5 ng/mL should be used as a cut-off to consider further testing for all age groups. There is strong evidence to show that adjuncts are useful when interpreting PSA results, most notably percentage free PSA and proPSA. Considerable weighting should also be given to the ERSPC risk calculator when deciding when to refer. Multi-parametric MRI is valuable in closely examining suspicious lesions to reduce the number of negative biopsies. MRI fusion biopsy (TRUS, transrectal ultrasonography or transperineal) should be considered over standard TRUS biopsy to detect more clinically significant disease.

CONCLUSIONS

Management of borderline PSA is not straightforward. A cut-off of 1.5 ng/mL should be used in conjunction with digital rectal exam, risk calculation and PSA adjuncts. Imaging and biopsy should utilise mpMRI to achieve improved diagnosis of clinically significant prostate cancer, with fewer unnecessary investigations.

A panel of DNA methylation markers reveals extensive methylation in histologically benign prostate biopsy cores from cancer patients

BACKGROUND

Men with a negative first prostate biopsy will undergo one or more additional biopsies if they remain at high suspicion of prostate cancer. To date, there are no diagnostic tests capable of identifying patients at risk for a positive diagnosis with the predictive power needed to eliminate unnecessary repeat biopsies. Efforts to develop clinical tests using the epigenetic signature of cores recovered from first biopsies have been limited to a few markers and lack the sensitivity and specificity needed for widespread clinical adoption.

METHODS

We developed methylation-specific quantitative polymerase chain reaction assays for a panel of 24 markers that are preferentially methylated in prostate cancer. We modified the bisulfite conversion conditions to allow the integration of the methylation information from multiple markers. We determined the methylation status of the 24 markers in 213 prostate biopsy cores from 104 patients, 37 prostate cancer patients and 67 controls. We performed logistic regression on combinations of markers as well as the entire panel of 24 markers to identify the best candidates for a diagnostic test.

RESULTS

The marker panel differentiated between cancer cores and benign cores from non-cancer patients with 100% sensitivity and 97% specificity. Furthermore, the panel detected significant methylation in benign cores from prostate cancer patients that was not present in controls. Using methylation of 5 out of 24 to define a cancer case, the analysis of a single benign biopsy core identified 62% of prostate cancer patients undergoing repeat biopsies. ROC curve analysis showed that markers commonly methylated in benign cores from cancer patients are the best candidates for a diagnostic test. The results suggest that 5 to 10 markers will be needed to achieve optimal predictive power.

CONCLUSIONS

This study shows that epigenetic field effects differ significantly between cancer patients and controls. Their detection in benign biopsy cores can form the basis of diagnostic tests to identify patients in need of repeat biopsies, reducing the cost of continued PCA screening by up to 40%. They could also be used to identify prostate cancer patients with low grade disease who are likely candidates for active surveillance or focal therapy.

The clinic-pathological characteristics of prostate cancer in an Irish subpopulation with a serum PSA less than 4.0ng/ml

Background:

Prostate specific antigen (PSA) has been used as a biomarker for prostate cancer for the last 20 years. Traditionally, a serum PSA <4 ng/ml has been used as a general cut-off between normal and abnormal readings. There is evidence to demonstrate that men with a normal serum PSA can develop prostate cancer. The aim of this study was to investigate the clinico-pathological features of prostate cancer in a non-screened Irish cohort with serum PSA <4 ng/ml.

Methods:

A retrospective analysis was performed of all patients who underwent radical retropubic prostatectomy (RRP) in a tertiary referral unit over a 10-year period (2000–2010). Clinico-pathological characteristics were collated including those from trans-rectal ultrasound-guided (TRUS) prostate biopsies and radical prostatectomy specimens.

Results:

Between 2000 and 2010, 651 men underwent an RRP, with 43 (6.6%) having a serum PSA <4 ng/ml. The median PSA was 3.2 ng/ml (range 0.8–4.0). Nineteen (44.2%) had palpable disease on direct rectal examination (DRE). Following prostatectomy, 28 (65.12%) had Gleason 6 disease, 14 (32.56%) had Gleason 7 disease and one (2.32%) had Gleason 8 disease. Five (11.63%) patients were upgraded from TRUS biopsy to final histopathology. Six (13.95%) patients had pathological evidence of extracapsular extension on final pathology. Three (6.98%) patients experienced biochemical recurrence and received salvage radiation therapy after a median time of 24 months. The median follow-up was 106 months (range 36–158). Twenty (46.51%) patients had a first-degree family history of prostate cancer.

Conclusions:

A PSA cut-off of 4 ng/ml has commonly been used in the detection of prostate cancer. Our study emphasizes that this cut-off is inappropriate and that no specific level of PSA can be used. Management decisions need to be individualized based on index of suspicion with concomitant counselling and rectal examination.

Cumulative probability of prostate cancer detection in biopsy according to free/total PSA ratio in men with total PSA levels of 2.1-10.0 ng/ml at population screening

PURPOSE

The aim of this study was to investigate the cumulative probability of prostate cancer detection according to free/total prostate-specific antigen (PSA) ratio in men with PSA levels of 2.1-10.0 ng/ml and also likelihood of detecting clinically insignificant prostate cancer in population-based screening.

METHODS

A total of 1,277 men aged between 55 and 69 years with total PSA (tPSA) levels of 2.1-10.0 ng/ml screened in population screening in Kanazawa city and underwent systematic transrectal ultrasonography-guided prostate biopsy between 2000 and 2011 were enrolled. The cumulative probability of prostate cancer detection in biopsy according to age, serum tPSA, and free-to-total PSA (f/t PSA) ratio was investigated. The clinicopathological features of screening-detected prostate cancer were also investigated.

RESULTS

Of the 1,277 subjects in the study population, 320 (25.0 %) were diagnosed with prostate cancer during the observation period. The probabilities of prostate cancer detection at 3 years were 64.5, 41.2, 28.5, and 14.3 % for the men with f/t PSA ratio ≤0.08, 0.09-0.13, 0.14-0.22, and ≥0.23, respectively; the differences in probabilities of prostate cancer detection among men with different f/t PSA ratios were statistically significant. Among 320 patients, 84 (26.3 %) had favorable clinicopathological features that made them suitable for active surveillance. The f/t PSA ratio in unfavorable cancer patients was significantly lower that that in favorable cancer patients.

CONCLUSION

The present study demonstrated that the f/t PSA ratio was a strong predictor of future cancer detection and unfavorable cancerous features in prostate biopsy in men with total PSA levels of 2.1-10.0 ng/ml at population screening.

Comparison of oncologic outcomes after radical prostatectomy in men diagnosed with prostate cancer with PSA levels below and above 4 ng/mL

PURPOSE

To assess whether the PSA level (threshold 4 ng/mL) is a prognostic factor in biochemical recurrence-free survival in men with prostate cancer (PCa) with an initial PSA level <10 ng/mL who underwent robotic-assisted laparoscopic radical prostatectomy (RARLP).

METHODS

We prospectively recruited data for consecutive patients treated by RARLP for PCa with an initial PSA level below 10 ng/mL between 2003 and 2011 at our institution. We divided the population into two groups: patients with a PSA level below 4 ng/mL (G1; n = 53) and patients with a PSA level between 4 and 10 ng/mL (G2; n = 371). Biochemical recurrence was defined as a single increase in PSA greater than 0.2 ng/mL after surgery. Multivariate analysis was used to assess prognostic factors of recurrence-free survival.

RESULTS

Overall, 424 patients were included, and the median age was 62 (58-67) years. The median PSA was 5.8 ng/mL (4.8-7.7 ng/mL). Overall, 6 patients from G1 and 34 patients from G2 experienced a biochemical recurrence. Overall, the 5-year recurrence-free survival rate was 86.6 %. The PSA level at diagnosis (under or over 4 ng/mL) was not significantly linked to recurrence-free survival (HR = 0.59, p = 0.25). However, positive margins and a Gleason score >7 on the specimen were significantly linked to recurrence-free survival with respective hazard ratios of 4.30 (p < 0.0001) and 6.18 (p < 0.0001), respectively.

CONCLUSION

A PSA level <4 ng/mL alone appears to be obsolete as a cut-off to define a population of men likely to have indolent disease.

Long-term oncological outcomes of men undergoing radical prostatectomy with preoperative prostate-specific antigen <2.5 ng/ml and 2.5-4 ng/ml

OBJECTIVES

Prostate-specific antigen (PSA) screening has increased the detection of small, organ-confined tumors, and studies suggest that these patients may have favorable outcomes following radical prostatectomy (RP). To date, there are limited data available on the outcomes of patients diagnosed with low PSA (≤ 4 ng/ml) who underwent RP. This study aimed to evaluate long-term oncological outcomes of patients undergoing RP with preoperative PSA <2.5 and 2.5-4 ng/ml compared with PSA 4.1-10 ng/ml.

MATERIALS AND METHODS

Data were analyzed from 3,621 men who underwent RP between 1988 and 2010 at our institution. Patients were stratified into 3 PSA groups: <2.5 ng/ml (n = 280), 2.5-4 ng/ml (n = 563), and 4.1-10 ng/ml (n = 2,778). Patient and disease characteristics were compared. Overall, biochemical disease-free (bDFS), and PCa-specific survivals were analyzed and compared between the groups. Multivariable analyses were conducted using proportional hazards model.

RESULTS

Compared with the 4.1-10 ng/ml PSA group, Gleason score >7, extracapsular extension, and non-organ-confined disease were less common in patients with PSA ≤ 4 ng/ml (all P < 0.001). The incidence of organ-confined disease was similar between the PSA < 2.5 and 2.5-4 ng/ml groups while perineural invasion (P = 0.050) and Gleason score ≥ 7 (P = 0.026) were more common in the 2.5-4 ng/ml PSA group. Estimated 10-year overall and PCa-specific survivals were comparable across all PSA groups, whereas bDFS was significantly lower in PSA 4.1-10 group (P < 0.001). bDFS was not statistically different between PSA <2.5 and 2.5-4 groups (P = 0.300). 10-year bDFS were 59.0%, 70.1%, and 76.4% in PSA 4.1-10, 2.5-4, and <2.5, respectively. For the PSA ≤ 4 ng/ml groups, age, race, margin status, pathologic stage, but not PSA were independent predictors of bDFS, whereas age, pathologic Gleason, and biochemical recurrence were associated with overall survival.

CONCLUSIONS

Long-term oncological outcomes (overall, bDFS, PCa-specific survivals) of patients presenting with low PSA (≤ 4 ng/ml) were excellent in this study. Compared with PSA 4.1-10 ng/ml, patients presenting with PSA ≤ 4 ng/ml had better bDFS outcomes. However, there was no difference in long-term outcomes between PSA <2.5 and 2.5-4 ng/ml.

Optimal baseline prostate-specific antigen level to distinguish risk of prostate cancer in healthy men between 40 and 69 years of age

The present study evaluated optimal baseline prostate-specific antigen (PSA) level at different ages in order to determine the risk of developing prostate cancer (CaP). We analyzed 6,651 Korean men, aged 40-69 yr. The serum PSA levels for these men were measured at one institute from 2000 to 2004 and were determined to be between 0-4 ng/mL. Patients were divided into 4 groups of 25th-percentile intervals, based on initial PSA level. Of these, the group with an increased risk was selected, and the optimal value was determined by the maximal area under a receiver-operating characteristic curve within the selected group. The risk of CaP diagnosis was evaluated by Cox regression. The mean follow-up period was 8.3 yr. CaP was detected in 27 of the 6,651 subjects. CaP detection rate was increased according to age. The optimal PSA value to distinguish the risk of CaP was 2.0 ng/mL for 50- to 69-yr-olds. Patients with a baseline PSA level greater than the optimal value had a 27.78 fold increase in the prostate cancer risk. Baseline PSA values are useful for determining the risk of developing CaP in Korean men for 50- and 69-yr-old. We suggest that PSA testing intervals be modified based on their baseline PSA levels.