Prostate cancer UK's Risk Checker: help or hindrance to PSA testing policy?

BACKGROUND

The UK has an informed choice prostate cancer testing policy, where the PSA blood test is available for free to any man aged 50 or over who request it and has been informed of the harms and benefits. This leads to differences in PSA testing rates which can exacerbate health inequalities.

AIM

To assess whether Prostate Cancer UK's Risk Checker helps men at risk of prostate cancer make an informed choice about the PSA test.

DESIGN & SETTING

Mixed methods study, UK.

METHOD

1,181 men at risk, their partners, and clinical experts participated in surveys, focus groups, and 1:1 interviews. Data on risk checker completions by sociodemographic factors were analysed over time. Data from GP practices that sent the Risk Checker to their patients were collected and analysed for service monitoring purposes.

RESULTS

There was a strong assumption that testing must be good, and therefore a need to emphasise the pros and cons of the test and that having it was the patient's decision. Men believed their GP would invite them for PSA testing. 80% of men who completed the risk checker had at least one prostate cancer risk factor. Average time they interacted with the information in the tool was 9 minutes 28 seconds. 75.7% felt the tool had equipped them to make an informed choice.

CONCLUSION

Online decision-making tools like the Risk Checker can help reach men at high risk of prostate cancer and support them in making an informed choice about the PSA test.

Prostate tumor markers: diagnosis, prognosis and management

Prostate cancer (PCA) is the second most common type of cancer in the world. Nevertheless, diagnosis is still based on nonspecific methods, or invasive methods which makes clinical decision and diagnosis difficult, generating risk of both underdiagnosis and overdiagnosis. Given the high prevalence, morbidity and mortality of PCA, new strategies are needed for its diagnosis. A review of the literature on available biomarkers for PCA was performed, using the following terms: prostate cancer AND marker OR biomarker. The search was carried out in Pubmed, Science Direct, Web of Science and Clinical Trial. A total of 35 articles were used, and PHI (Prostate Health Index) and the 4Kscore tests were identified as the best well-established serum markers. These tests are based on the evaluation of expression levels of several molecules. For analysis of urine samples, Progensa, ExoDXProstate, and Mi Prostate Score Urine Test are available. All these tests have the potential to help diagnosis, avoiding unnecessary biopsies, but they are used only in association with digital rectal examination and PSA level data. The search for biomarkers that can help in the diagnosis and therapeutic management of PCA is still in its initial phase, requiring more efforts for an effective clinical application.

Knowledge and Awareness of Screening for Prostate Cancer Risk Factors and Symptoms Among the General Population in Tabuk City, Saudi Arabia

Background Early-stage prostate cancer may not show any signs. Digital rectal examination and the prostate-specific antigen test are frequently used in the screening for prostate cancer. The objective of this research is to assess the knowledge and awareness of screening prostate cancer among males in Tabuk, Saudi Arabia. Methodology A cross-sectional study was performed among Saudi males in Tabuk City. A structured interviewing technique based on a questionnaire was used based on the objectives and research questions. Data were collected by well-trained data collectors from the general population in Tabuk City who were randomly chosen in proportion to the city's population density. A multivariate logistic regression analysis was done to evaluate the variables related to knowledge and awareness in this study. Results This questionnaire was completed by a total of 417 male participants. In the studied group, 86.8% of participants had heard about prostate cancer through friends (59%), TV/radio/newspaper (53.24%), and other health services (41.49%). In addition, around 67.6% of participants knew about the prostate cancer screening test. In addition, 32.4% of participants had no prior knowledge of prostate cancer or a screening test. Conclusions There was a good level of awareness and attitude toward screening methods for prostate cancer (54.7%). Aside from having good knowledge regarding prostate cancer symptoms among males in Tabuk City, all participants with regard to demographic distribution showed a significant level of good knowledge and awareness of screening prostate cancer methods and the necessity of performing regular prostate examinations.

Prevalence of Cardiovascular Risk Factors in Saudi Patients With Psoriatic Arthritis: A Single-Center Retrospective Cohort Study

Background Psoriatic arthritis (PsA) is an extremely heterogeneous disease with numerous articular phenotypes and extra-articular manifestations. It is common for patients with PsA to have coexisting medical conditions. In recent studies, PsA patients were found to have a greater prevalence of cardiovascular risk factors when compared to non-PsA groups. Objectives This study aimed to describe the prevalence of cardiovascular risk factors among Saudi psoriatic arthritis patients treated at King Abdulaziz Medical City (KAMC), Riyadh. Methods A hundred and twenty-six patients with psoriatic arthritis diagnoses were enrolled in this study. Patients who were 18-years-old or older, had PsA diagnosed by a rheumatologist, and met the Classification Criteria for Psoriatic Arthritis (CASPAR) criteria were included in the study population. Patients were excluded from the study if they were younger than 18, did not fulfill the CASPAR criteria, did not have a documented diagnosis by a rheumatologist, or had been diagnosed with any type of joint arthritis in the past. In this retrospective cohort article, we investigated the frequency of risk factors for cardiovascular disease such as [hypertension (HTN), dyslipidemia (DLP), diabetes mellitus (DM), obesity, and coronary heart disease (CHD)] and non-established risk factors such as [HbA1C, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP)]. SPSS version 12.0 for Windows (SPSS Inc.) was used for statistical analysis. The threshold for statistical significance was set at 5%. Results A hundred and twenty-six PsA patients were enrolled in this study, 30 (24%) had PsA for less than two years (early), and 96 (76%) had PsA for more than two years (established). When the analysis was performed, the mean age was 47.5 years, and the mean age at diagnosis of PsA was 42.4 years. Of them, 89 (71%) were female while 37 (29%) were male. Established PsA patients were significantly older at the time of analysis than early PsA patients (49.2 vs. 41.8 years; P= 0.007). Furthermore, established PsA patients had a longer duration of PsA than those with early PsA (6.3 vs. 1.5 years; P= <0.001). The most frequently reported comorbidity was obesity (61%) followed by DLP (43%), HTN (34%), DM (30%), and CHD (11%). CV comorbidities did not differ between subgroups. However, patients with established PsA had a higher prevalence of DLP, especially females. Additionally, patients with early PsA had greater rates of HTN than those with established PsA, and patients with early PsA were more likely to have CHD. Conclusion This study confirms that PsA is linked with cardiovascular (CV) morbidity. When evaluating PsA, future studies should take these CV conditions into consideration.

Prevalence and Clinical Predictors of Psoriatic Arthritis in Saudi Patients With Psoriasis: A Single-Center Retrospective Cohort Study

Background Among psoriatic patients, psoriatic arthritis is the most common and most impactful comorbidity. In most cases, it occurs after the onset of psoriasis. Detecting and treating it early is crucial for rheumatologists and dermatologists. Objectives The study aimed to determine the prevalence of psoriatic arthritis among recognized cases of psoriasis, as well as to determine the clinical features of psoriasis that are linked to a greater prevalence of psoriatic arthritis at King Abdulaziz Medical City (KAMC), Riyadh. Methods A retrospective cohort study of 487 psoriatic patients diagnosed between 2015 and 2023 was conducted at KAMC, Riyadh. The study included subjects aged 18 years or older with a psoriasis diagnosis documented by a dermatologist and a psoriatic arthritis diagnosis documented by a rheumatologist based on the Classification Criteria for Psoriatic Arthritis (CASPAR). Patients younger than 18 years, diagnosed with psoriatic arthritis concurrently with psoriasis, or within 90 days of psoriasis diagnosis, or who lack a documented diagnosis of psoriasis by a dermatologist were excluded. The study evaluated demographic data and medical variables concerning psoriasis (age at onset, type of psoriasis, site of psoriasis, and nail dystrophy) and psoriatic arthritis. SPSS Statistics version 25 (IBM Corp., Armonk, NY) was used to conduct statistical analysis. The p-value of 0.05 was used to evaluate statistical significance. Results Overall, 487 patients had psoriasis in this study. Of these, 49 (10%) were diagnosed with psoriatic arthritis. The mean ± standard deviation of the age of the psoriasis group was 41.7 ± 15.6 years, with 264 (54.2%) females and 223 (44.8%) males. The clinical features of psoriasis that were linked to a greater frequency of psoriatic arthritis in our study included female gender (71.4%), plaque psoriasis (95.9%), psoriatic lesions involving the extremities (75%), scalp (42.9%), and trunk (36.7%), nail dystrophy (28.6%), as well as the involvement of three or more sites (40.8%) at the time of their initial diagnosis of psoriasis. Conclusion Our study indicated that 10% of Saudi patients with psoriasis had psoriatic arthritis. Moreover, the present study shows that patients with greater psoriatic lesions at initial presentation are more likely to develop psoriatic arthritis.

Characterization of Google Search Volumes and Trends From 2004 to 2021 for Diagnosis and Treatment of Locally Advanced Prostate Cancer

Introduction and objective The purpose of this study is to better characterize at which point during the course of diagnosis and treatment of locally advanced prostate cancer the internet is utilized and to evaluate the search trends over time. Methods Monthly Google Trends data were collected from 2004 to 2021 for prostate cancer-specific terms. Temporal trends were analyzed by comparing average search volume indexes (aSVI) and analysis with joinpoint software of six-month percent change (6mPC). Chloropleths were created for geographic pattern comparisons. Results Search terms associated with interventions demonstrated the highest aSVI with terms such as "prostate biopsy" (aSVI: 33.59), "prostatectomy" (aSVI: 31.6), and "prostate radiation" (aSVI: 16.45). Terms associated with treatment side effects increased at a high rate with "radiation side effects" (21.4 6mPC, p<0.05) and "prostatectomy side effects" (14.4 6mPC, p<0.05). Prostate-specific antigen (PSA)-related search terms demonstrated a strong positive trend on joinpoint analysis with search terms "What is PSA?" (8.9 6mPC, p<0.05), and "What is normal PSA?" (15.1, p<0.05). Geographic patterns demonstrated higher search volumes in regard to screening and diagnostic terms in the northeast, while the southern regions demonstrated relatively higher search volumes for treatment and interventions. Conclusions The internet continues to be a growing part of the dynamics of prostate cancer management with more men utilizing the internet each year to help understand their diagnosis. Specifically, we found that the internet is used more for searches pertaining to PSA, procedures, and interventions affecting the quality of life.

Lutetium-177 Prostate-Specific Membrane Antigen-617 Treatment in Metastatic Castration-Resistant Prostate Adenocarcinoma: Results of Single-Center Experience

OBJECTIVE

Lutetium-177 prostate-specific membrane antigen-617 is a novel alternative therapeutic option in metastatic castration-resistant prostate cancer, especially useful for patients who do not respond to standard therapy methods. The aim of this study was to define the efficacy and safety profile of lutetium-177 prostate- specific membrane antigen-617 treatment in a group of patients with metastatic castration-resistant prostate cancer.

MATERIALS AND METHODS

Study group included 34 men with metastatic castration-resistant prostate cancer (median, 69.6 ± 7.7 years) who were treated with lutetium-177 prostate-specific membrane antigen-617 therapy (22/34; 4 courses, 12/34; 2 courses). Patients were evaluated by physical examination, Eastern coop- erative oncology group performance status, gallium-68 prostate-specific membrane antigen positron emis- sion tomography/computed tomography, brief pain inventory-short form questionnaire, biochemical tests, and complete blood counts. Treatment response and adverse effects were examined by brief pain inventory scores, SUVmax values, biochemical tests, and complete blood counts. Independent variables were analyzed statistically (significance; P < .05).

RESULTS

The Eastern cooperative oncology group performance was grade 0 in 5/34 (14.7%), grade 1 in 25/34 (73.5%), and grade 2 in 4/34 (11.8%) patients. Distribution of patient numbers according to brief pain inven- tory scores (score: <1, scores: 1-4, and scores: 5-10) was 2, 10 and 22 at the beginning, 6, 16 and 12 after the second course, and 10, 10 and 2 after the fourth course of treatment, respectively. Serum prostate-specific antigen decreased in 15 of 22 patients (68%) (P < .05). Before and after the treatment, we found a substan- tial decrease in SUVmax values (22.3 vs. 11.8, P < .001) and brief pain inventory scores (score ≥ 5; 22/34 pts vs. 0/22 pts). The counts of white blood cells (P < .05), hemoglobin (P < .05), and thrombocytes (P = .001) were all significantly lower at the conclusion of the therapy. The most important adverse events were severe leukopenia (1/34 pts; 2.29 × 103/μL) and thrombocytopenia (3/34 pts; 32 000, 36 000, 32 000 106/L). Q1 Conclusion: We found that lutetium-177 prostate-specific membrane antigen-617 therapy is a promising treatment method for metastatic castration-resistant prostate cancer patients who are unresponsive to conventional therapy, according to our biochemical, positron emission tomography/computed tomography, and pain score outcomes.

An Interesting Case of Prostate Cancer Presenting With Colonic Metastasis

Prostate cancer is common cancer that grows slowly and tends to metastasize to bones, lungs, and the liver. Most malignancies have established patterns in presentation, localization, and organs where they metastasize. We are presenting a case of a 60-year-old man who presented with abdominal pain and, on further investigation, was found to have polyps in the colon, a flat rectal mass with eccentric thickening of the rectum, a moderately enlarged prostate, and multiple liver masses suggestive of metastasis. It was initially thought to be colorectal cancer with metastasis but was eventually diagnosed as a stage IV prostate adenocarcinoma with metastases to the liver and rectum. It is very unusual for prostate cancer to present with distal metastasis to the liver and rectum, as in this case.

Characteristics of prostate biopsy in patients under the dutasteride treatment

We performed a retrospective study to clarify the characteristics of prostate biopsies in patients treated with dutasteride, a benign prostate hyperplasia treatment drug that inhibits 5α-reductase. We studied the digital clinical data of 677 patients, including 96 cases treated with dutasteride, with suspected localized prostate cancer. All patients underwent transrectal ultrasonography-guided prostate biopsy between 2014 and 2017 in our department. A propensity score matching analysis was performed based on prostate-specific antigen (PSA) (calculated as double the PSA value for the dutasteride group) and age. Ninety-six patients in each of the dutasteride and control groups were assessed and their characteristics were compared. The characteristics of the patients in the dutasteride and control groups were well balanced by matching. There were fewer prostate cancer-positive patients in the dutasteride group. When comparing only the prostate cancer-positive patients in each group, there were significantly more cases of high-grade cancers and abnormal magnetic resonance imaging (MRI) findings in the dutasteride group. In the dutasteride group, abnormal MRI findings and advanced age were significant predictors of high grade cancer. This study shows the characteristics of prostate biopsies in patients treated with dutasteride and indicates that patients on dutasteride with advanced age and abnormal MRI findings should undergo prostate biopsy.

Response to [ 177 Lu]Lu-PSMA radioligand therapy in metastatic castration-resistant prostate cancer patients presenting with only lymph node metastases

OBJECTIVE

[ 177 Lu]Lu-PSMA radioligand therapy (PSMA-RLT) is a promising therapy for patients with metastatic castration-resistant prostate cancer (mCRPC) and offers a survival benefit particularly to patients with only lymph node metastases. We therefore sought to evaluate the clinical outcome of this therapy in such a cohort.

METHODS

Of all prostate cancer patients admitted to our department between September 2015 and March 2019 to receive 1-4 courses of PSMA-RLT (each course consisted of three cycles of highly standardized PSMA-RLT every 4 weeks), only 10 consecutive men were found to have nodal metastases only and were analyzed retrospectively.

RESULTS

Nine out of 10 patients responded to their first PSMA-RLT course with a mean prostate-specific antigen (PSA) decline of 71.8 ± 25.2%, seven of them demonstrated a PSA decline of ≥50%. Collectively, seven of eight patients responded to further PSMA-RLT courses with a total PSA reduction of 59.8 ± 30.0%, five of which showed a PSA reduction of ≥50%. One patient experienced complete remission. Median progression-free survival was 85 weeks (range 14-255 weeks) and median overall survival was not reached during the median observation time of 209 weeks (30-298 weeks). Univariate Cox-regression identified initial PSA decline as the only predictive parameter for progression-free survival ( P = 0.047).

CONCLUSION

mCRPC patients with only lymph node metastases showed favorable survival and excellent response to PSMA-RLT, leading to transient partial remission of the disease in most of them.

Effect of a novel technique of posterior reconstruction of pubourethralis on 'early' return of continence after robot assisted radical prostatectomy (RARP): A comparative study

OBJECTIVE

To study the effect of a novel technique of posterior reconstruction of pubourethralis on early return of continence after robot assisted radical prostatectomy (RARP).

MATERIALS AND METHODS

The study included 206 patients of organ confined prostate cancer managed at our centre between March 2014 and December 2018.The patients were randomly distributed into two comparable groups with respect to age, height, weight and BMI, with 100 patients in control and 106 patients in study group. After standard excision of the specimen, the posterior reconstruction in the form of Rocco stitch was done in control group while in addition to Rocco stitch pubourethralis was approximated posteriorly in midline at the proposed site of vesicourethral anastomosis in study group. Continence was defined as the need to use 0-1 pad in 24 h. The data was collected on day 0, 3, 7, 15, 30, 90 and 180 after removal of catheter.

RESULTS

At day zero, 3,7, 15, 30, 90 and 180 days after catheter removal continence rates (⩽1 pad usage per day) were observed to be 18.8% versus 0%, 22.6% versus 0%, 50.9% versus 5%, 72.6% versus 20%, 84.9 versus 32%, 97.1% versus 83%, and 97.1% versus 91% in the study and control group respectively.

CONCLUSION

Despite small number of patients in this study the results with respect to early return of continence are encouraging in the reconstruction group and there by in favour of this technique .Furthermore the technique is easily reproducible and may be seen as one more additional step to be applied in order to enhance the recovery of continence after RARP. However it is necessary to further validate the efficacy of this procedure through multicenteric controlled trials.

Does the Distance of the Tumor from the Surgical Margin Affect Biochemical Recurrence in Patients with Pathological Organ-Confined Prostate Cancer?

OBJECTIVE

To investigate the effect of the distance between tumor and surgical margin on biochemical recurrence in patients with organ-confined prostate cancer.

MATERIAL AND METHOD

The data of 208 patients, who underwent radical prostatectomy between 2012-2018, were retrospectively analyzed. The surgical margin status of 147 pathologically organ-confined patients was categorized as positive, close ( < 1mm) and negative. Surgical margin status and parameters affecting biochemical recurrence were examined. Furthermore, multivariate analysis was done to determine the parameters associated with biochemical recurrence.

RESULTS

Biochemical recurrence was detected in 21 (14.2%) of 147 patients. 38 (27.9%) men had negative surgical margins, 68 (46.2%) had close surgical margins and 41 (25.9%) had positive surgical margins. Tumor volume and ISUP grade were found to be statistically significant for positive surgical margin and close surgical margin patients compared to negative surgical margin patients. Close surgical margin was not statistically associated with biochemical recurrence. Preoperative high PSA (p < 0.001) and positive surgical margin (p=0.021) were independent risk factors for biochemical recurrence.

CONCLUSION

According to our results, it is not necessary to include the presence of a close surgical margin in the pathology reports in patients with pathological organ-confined tumors and negative surgical margins.

A Comparative Study: Has MRI-guided Fusion Prostate Biopsy Changed the Prostate-specific Antigen Gray-zone Range?

Objective

The gray-zone prostate-specific antigen (PSA) range is accepted to be 4-10 ng/ml and is considered to vary according to age. We aimed to investigate whether fusion prostate biopsy (FPB), which has been reported to have relatively higher cancer detection rates, has an effect on gray-zone PSA cut-off value.

Material and methods

This retrospective study included patients that underwent standard prostate biopsy (SPB) or multiparametric magnetic resonance imaging (MpMRI)-guided FPB (SPB+ targeted biopsy). All the patients included in the study were detected with a Prostate Imaging Reporting and Data System (PI-RADS) ≥3 lesion on MpMRI (the FPB group only). The demographics, clinical characteristics, and histopathological diagnoses were recorded for each patient.

Results

A total of 1,628 patients comprising 1,208 patients in the SPB group and 420 patients in the FPB group were included in the study. The mean PSA level was 9.75±6.68 ng/ml in the FBP group and 10.46±6.46 ng/ml in the SPB group (p=0.053). Prostate cancer (PCa) detection rate was significantly higher in the FPB group as compared to the SPB group (42.4% vs. 36.4%). The PSA cut-off value for PCa was 9.75 ng/ml (sensitivity and specificity, 81%) in the SPB group and was 7.55 ng/ml (sensitivity and specificity, 81% and 84%, respectively) in the FPB group. In the FPB group, the cancer detection rate among the patients with a PSA level of 7.55-10.00 ng/ml was 56.1%.

Conclusion

The results indicated that the introduction of FPB into clinical practice, which has relatively higher cancer detection rates, has further lowered the upper limit for gray-zone PSA.

Improving the detection rate of prostate cancer in the gray zone of PI-RADS v2 and serum tPSA by using prostate-specific antigen-age volume

To improve the detection of prostate cancer (PCa) by combining the Prostate Imaging Reporting and Data System version 2 (PI-RADS v2) and prostate-specific antigen-age volume (PSA-AV), especially among those in gray zone with PI-RADS v2 score 3 or serum total prostate-specific antigen (tPSA) 4 to 10 ng/mL.The 357 patients were enrolled in this study. The PI-RADS v2 scoring system was used to represent characteristics on multiparametric magnetic resonance imaging (mpMRI). PI-RADS v2 score 3 or tPSA 4 to 10 ng/mL were defined as the gray zone in detecting PCa. The formula equates to the patient age multiplied by the prostate volume, which is divided by the tPSA level. Univariate and multivariate analyses were done to ascertain significant predictors of prostate cancer.In all, 174 (48.7%) were benign prostatic hyperplasia, 183 (51.3%) had PCa. The results showed that PI-RADS v2, tPSA, and PSA-AV were significant independent predictors of prostate cancer. PI-RADS v2 score ≥4 could detect PCa with rate of 82.1%. Serum tPSA ≥10 ng/mL could detect PCa with rate of 66.2%, PSA density (PSAD) ≥0.15 ng/mL/cc with rate of 62.8%, and PSA-AV ≤250 with rate of 83.5%. Combining with PSA-AV ≤250, patients those with tPSA 4 to 10 ng/mL could improve the detection from 36.0% up to 81%, those with PI-RADS v2 score 3 from 28.6% up to 60.0%.PI-RADS v2 and PSA-AV are faithful variables for detecting PCa. And for patients, those in gray zones of PI-RADS v2 and tPSA, PSA-AV can improve detection rate of PCa.

Prostate Cancer Metastatic to the Peritoneum: A Road Less Traveled by a Common Malignancy

A 70-year-old Indian male with a history of a Gleason 7 (3+4) prostate cancer presented with abdominal ascites. Imaging was remarkable for peritoneal carcinomatosis as well as possible metastases to the bladder and seminal vesicle. Given the atypical pattern of presentation, further investigation was performed with studies of the ascites fluid. Cytology from the ascites fluid returned consistent with malignant cells of prostatic origin. His treatment course included androgen deprivation therapy (ADT), docetaxel, abiraterone, and cabazitaxel. He had eventual progression and worsening of his disease and performance status and was transitioned to hospice. This case demonstrated the importance of pursuing a thorough diagnostic evaluation, when faced with a rare presentation of a common malignancy. Furthermore, it illustrated the challenges incurred when tailoring standard regimens to best address the needs of the whole patient and not simply their disease.

Male Oncology Research and Education program for men at high risk for prostate cancer

Three groups of men are at high risk of developing prostate cancer: men with a strong family history of prostate cancer, men of West African or Caribbean ancestry, and men with a germline pathogenic variant in a prostate cancer-associated gene. Despite the fact that those men constitute a significant portion of the male population in North America, few recommendations for prostate cancer screening specific to them have been developed. For men at general population risk for prostate cancer, screening based on prostate-specific antigen (psa) has remained controversial despite the abundance of literature on the topic. As a result, recommendations made by major screening authorities are inconsistent (ranging from no psa screening to baseline psa screening at age 45), allowing physicians to pick and choose how to screen their patients. The Male Oncology Research and Education (more) program is an observational research program that serves as an academic platform for multiple research foci. For its participants, serum and dna are biobanked, medical information is collected, and contact for relevant research-related opportunities is maintained. This research program is paired with a specialized clinic called the more clinic, where men at high risk are regularly screened for prostate cancer in a standard approach that includes physical examination and serum psa measurement. In this article, we describe the goals, participant accrual to date, and projects specific to this unique program.

Value of free/total prostate-specific antigen (f/t PSA) ratios for prostate cancer detection in patients with total serum prostate-specific antigen between 4 and 10 ng/mL: A meta-analysis

BACKGROUND

Prostate carcinoma is a common disease that occurs in men over 50 years old. Many studies have explored the effect of free/total prostate-specific antigen (f/t PSA) ratio in monitoring prostate cancer. We conducted a meta-analysis to identify the accuracy of the f/t PSA ratio in the diagnosis of prostate cancer in patients who have PSA levels of 4 to 10 ng/mL.

METHODS

Databases searched included PubMed and OVID databases, from inception to March 2017, after a systematical review, sensitivity, specificity, and other measures of accuracy of the f/t PSA ratio in the diagnosis of prostate cancer were pooled. We used summary receiver operating characteristic curves to summarize overall test performance.

RESULTS

Fifteen case-control studies from 14 articles were identified. The results indicated that the sensitivity of the f/t PSA ratio in the diagnosis of prostate cancer ranged from 0.5 to 0.94 (pooled sensitivity 0.70, 95% CI: 0.67-0.72), whereas its specificity ranged from 0.31 to 0.93 (pooled specificity 0.55, 95% CI: 0.57-0.60). The positive likelihood ratio was 1.85 (95% CI: 1.56-2.20), negative likelihood ratio was 0.42 (95% CI: 0.34-0.53), and diagnostic odds ratio was 4.81 (9.53% CI: 3.33-6.94).

CONCLUSIONS

The f/t PSA ratio determination has a low sensitivity and specificity for the diagnosis of prostate cancer; it would not be useful for the diagnosis of prostate cancer by itself. The results of f/t PSA ratio measurements should refer to the clinical manifestations and the results of conventional tests such as biopsies.

PSA declines and survival in patients with metastatic castration-resistant prostate cancer treated with enzalutamide: A retrospective case-report study

RATIONALE

PSA responses have been associated with a survival benefit in patients treated with enzalutamide in retrospective analyses.

PATIENT CONCERNS

However the prognostic value of PSA declines in highly pretreated patients receiving enzalutamide remains to be defined.

DIAGNOSES AND INTERVENTATIONS

Medical records of patients with documented mCRPC treated with enzalutamide between September 2011 and August 2016 were reviewed at multiple participating centers and assessed for overall survival (OS), PSA variations, and other variables of interest. Univariable and multivariable analyses were conducted.

OUTCOMES

A total of 129 patients received enzalutamide. PSA response rates (>50% PSA declines) were 58/119 (48.7%), 58/115 (50.4%), 54/110 (49.1%), and 47/91 (51.7%) at weeks 4, 8, 12, and 16, respectively. Having a PSA response was a statistically significant prognostic factor of improved OS at 8 and 12 weeks in univariable analysis, whereas it was significant at 12 weeks in the multivariable analysis. Patients treated with enzalutamide had a median OS of 7.8 months.

LESSONS

Our study supports the prognostic value of PSA declines in heavily treated patients receiving enzalutamide.

The role of prostate cancer biomarkers in undiagnosed men

PURPOSE OF REVIEW

This article intends to review biomarkers derived from blood, urine, and tissue that can aid in the diagnosis of prostate cancer (PCa).

RECENT FINDINGS

PCa screening requires tools that complement prostate-specific antigen (PSA) with a higher specificity for clinically significant disease. Novel blood biomarkers, such as the Prostate Health Index (phi) and 4Kscore, utilize isoforms of PSA to more accurately predict high-grade PCa than traditional tools such as PSA and the percentage free-to-total PSA. Several gene products associated with PCa can be detected in the urine through commercially available assays. PCa antigen 3 (PCA3), though approved for repeat biopsy decisions, appears inferior to other biomarkers such as phi for identifying aggressive disease. However, combinations of PCA3 with other urine assays have shown promising results. One tissue-based hypermethylation test, named ConfirmMDx, can also be used to determine the need for repeat biopsy in men with a prior negative biopsy.

SUMMARY

Several biomarkers have been developed to aid in the screening and diagnosis of PCa. Such tests are often indicated in men with moderately elevated PSA or history of a prior negative biopsy. Their use facilitates reduction of unnecessary biopsies without sacrificing the early diagnosis of clinically significant PCa.

Detection of candidate biomarkers of prostate cancer progression in serum: a depletion-free 3D LC/MS quantitative proteomics pilot study

BACKGROUND

Prostate cancer (PCa) is the most common male cancer in the United Kingdom and we aimed to identify clinically relevant biomarkers corresponding to stage progression of the disease.

METHODS

We used enhanced proteomic profiling of PCa progression using iTRAQ 3D LC mass spectrometry on high-quality serum samples to identify biomarkers of PCa.

RESULTS

We identified >1000 proteins. Following specific inclusion/exclusion criteria we targeted seven proteins of which two were validated by ELISA and six potentially interacted forming an 'interactome' with only a single protein linking each marker. This network also includes accepted cancer markers, such as TNF, STAT3, NF-κB and IL6.

CONCLUSIONS

Our linked and interrelated biomarker network highlights the potential utility of six of our seven markers as a panel for diagnosing PCa and, critically, in determining the stage of the disease. Our validation analysis of the MS-identified proteins found that SAA alongside KLK3 may improve categorisation of PCa than by KLK3 alone, and that TSR1, although not significant in this model, might also be a clinically relevant biomarker.

Beyond prostate-specific antigen: utilizing novel strategies to screen men for prostate cancer

PURPOSE OF REVIEW

The purpose of this article is to review blood and urine tests that are currently available and under investigation for a role in prostate cancer screening and detection.

RECENT FINDINGS

Compared with total prostate-specific antigen (PSA) alone, its combination with percentage free-to-total PSA contributes greater specificity for prostate cancer, and is a component of two newer blood tests called the 4kScore and Prostate Health Index. All three tests improve the prediction of high-grade disease and are commercially available options to aid in initial or repeat prostate biopsy decisions. PCA3 is a urinary marker that is currently available for repeat prostate biopsy decisions. Although PCA3 alone has inferior prediction of clinically significant disease and requires collection of urine after digital rectal examination, it may be combined with other clinical variables or other urine markers like TMPRSS2:ERG to improve performance. Little data are available to support a role for single nucleotide polymorphisms or other investigational markers in early detection.

SUMMARY

Several commercially available blood and urine tests have been shown to improve specificity of PSA for high-grade prostate cancer. Use of such tests would decrease unnecessary biopsy and overdiagnosis of indolent disease. Biopsy of men with moderately elevated PSA without use of such a reflex test should be discouraged.

The Memorial Sloan Kettering Cancer Center Recommendations for Prostate Cancer Screening

The Memorial Sloan Kettering Cancer Center (MSKCC) recommendations on prostate cancer screening were developed in response to three limitations of previous screening guidelines: insufficient evidence base, failure to link screening with treatment, and lack of risk stratification. The objective of the recommendations is to provide a schema for prostate cancer screening that maximizes the benefits, in terms of reduction in prostate cancer-specific mortality, and minimizes the harms, in terms of overdiagnosis and overtreatment. We recommend the following schema for men choosing to be screened following informed decision-making: starting at age 45, prostate-specific antigen (PSA) without digital rectal examination. If PSA ≥ 3 ng/mL: consider prostate biopsy; if PSA ≥ 1 but < 3 ng/mL: return for PSA testing every 2-4 years; if PSA < 1 ng/mL: return for PSA testing at 6-10 years. PSA testing should end at age 60 for men with PSA ≤ 1 ng/ mL; at 70, unless a man is very healthy and has a higher than average PSA; at 75 for all men. The decision to biopsy a man with a PSA > 3 ng/mL should be based on a variety of factors including repeat blood draw for confirmatory testing of the PSA level, digital rectal examination results, and workup for benign disease. Additional reflex tests in blood such as a free-to-total PSA ratio, the Prostate Health Index, or 4Kscore, or urinary testing of PCA3, can also be informative in some patients. The best evidence suggests that more restricted indication for prostate biopsy and a more focused approach to pursue screening in men at highest risk of lethal cancer would retain most of the mortality benefits of aggressive screening schema, while importantly reducing harms from overdetection and overtreatment.

Stereotactic Body Radiotherapy for Clinically Localized Prostate Cancer: Toxicity and Biochemical Disease-Free Outcomes from a Multi-Institutional Patient Registry

Objectives: To report on initial patient characteristics, treatment practices, toxicity, and early biochemical disease-free survival (bDFS) of localized prostate cancer treated with stereotactic body radiotherapy (SBRT) and enrolled in the RSSearch^® Patient Registry.

Methods: A retrospective analysis was conducted on patients with clinically localized prostate cancer enrolled in RSSearch^® from June 2006 - January 2015. Patients were classified as low-risk (PSA ≤ 10 ng/ml, T1c-T2a, Gleason score ≤ 6), intermediate-risk (PSA 10.1 - 20 ng/ml, T2b-T2c, or Gleason 7), or high-risk (PSA > 20 ng/ml, T3 or Gleason ≥ 8). Toxicity was reported using Common Toxicity Criteria for Adverse Events, version 3. Biochemical failure was assessed using the Phoenix definition (nadir + 2 ng/ml). The Kaplan-Meier analysis was used to calculate bDFS and association of patient and tumor characteristics with the use of SBRT.

Results: Four hundred thirty-seven patients (189 low, 215 intermediate, and 33 high-risk) at a median of 69 years (range: 48-88) received SBRT at 17 centers. Seventy-eight percent of patients received 36.25 Gy/5 fractions, 13% received 37 Gy/5 fractions, 6% received 35 Gy/5 fractions, 3% received 38 Gy/4 fractions, and 5% received a boost dose of 19.5-29 Gy following external beam radiation therapy. Median follow-up was 20 months (range: 1–64 months). Genitourinary (GU) and gastrointestinal (GI) toxicities were minimal, with no acute or late Grade 3+ GU or GI toxicity. Late Grade 1 and 2 urinary frequency was 25% and 8%. Late Grade 1 and 2 proctitis was 3% and 2%. Median PSA decreased from 5.8 ng/ml (range: 0.3-43) to 0.88, 0.4, and 0.3 ng/ml at one, two, and three years. Two-year bDFS for all patients was 96.1%. Two-year bDFS was 99.0%, 94.5%, and 89.8% for low, intermediate, and high-risk patients (p < 0.0001). Two-year bDFS was 99.2%, 93.2%, and 90.4% for Gleason ≤ 6, Gleason 7, and Gleason ≥ 8 (p < 0.0001). Two-year bDFS was 96.4%, 97.2%, and 62.5% for PSA ≤ 10 ng/ml, PSA 10.1 - 20 ng/ml, and PSA > 20 ng/ml (p < 0.0001). Clinical T Stage was not significantly associated with bDFS. 

Conclusions: Early disease outcomes of SBRT for the treatment of clinically localized prostate cancer from a multicenter patient registry compare favorably with reports from single institutions. Acute and late GU and GI toxicities were minimal, and PSA response to SBRT was highly encouraging. Continued accrual and follow-up will be necessary to confirm long-term results.

Prostate-specific antigen-based screening: controversy and guidelines

Although prostate-specific antigen (PSA) screening has improved the detection of prostate cancer, allowing for stage migration to less advanced disease, the precise mortality benefit of early detection is unclear. This is in part due to a discrepancy between the two large randomized controlled trials comparing PSA screening to usual care. The European Randomized Study of Screening for Prostate Cancer (ERSPC) found a survival benefit to screening, while the United States Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial did not. Furthermore, the benefit of immediate surgical intervention for screen-detected prostate cancer is unclear, as the results superficially differ between the two large randomized controlled trials comparing prostatectomy to observation. The Prostate Cancer Intervention Versus Observation Trial (PIVOT) found no survival benefit for prostatectomy in PSA screened U.S. men, while the Scandinavian Prostate Cancer Group Study Number Four (SPCG-4) found a survival benefit for prostatectomy in clinically diagnosed prostate cancer. As a result of the controversy surrounding PSA screening and subsequent prostate cancer treatment, guidelines vary widely by organization.

Prognostic Factors for Prostate Cancer Endpoints Following Biochemical Failure: A Review of the Literature

PURPOSE

In the setting of biochemical failure (BCF) following primary treatment for prostate cancer, additional discrimination between clinically significant and non-clinically significant biochemical recurrence is critical in defining robust surrogate endpoints for prostate cancer and guiding salvage management decisions. We reviewed the literature to determine which prognostic factors are most significant for predicting prostate cancer-specific survival (PCSS), metastases-free survival (MFS), and/or overall survival (OS) after BCF.

MATERIALS AND METHODS

A search of PubMed from 1980 to 2013 yielded 999 studies that examined prognostic factors predictive for PCSS, MFS, and/or OS in prostate cancer patients with BCF following primary treatment. Eligibility criteria for inclusion were: 1) examined a prostate cancer population in the setting of BCF without overt clinical relapse following primary treatment with radical prostatectomy or radiotherapy; 2) based analyses on patient parameters obtained prior to the initiation of salvage therapies; and 3) determined clinical prognostic factors that were significant prognostic measures for at least one of three clinically relevant endpoints: OS, PCS, or MFS.

RESULTS

Nineteen eligible studies reported on 8,040 patients that experienced BCF from 1981-2013. The initial primary therapy was variable: radical prostatectomy alone (n=8), radiotherapy alone (n=4), radiotherapy/radical prostatectomy ± adjuvant therapy (n=5), and multiple treatment arms (n=2). There was also heterogeneity in which outcomes were assessed: PCSS (n=14), MFS (n=7), and OS (n=5). The prognostic factors most commonly found to be significant on multivariate analyses were PSA doubling time (PSADT), time to biochemical failure (TTBF), pathological Gleason score (pGS), and age.  

CONCLUSIONS

Risk stratification in prostate cancer post-BCF is challenging because of limited predictive modeling that can determine which patients will optimally benefit from salvage therapy. Our systematic literature review has identified PSADT, TTBF, pGS, and age as the leading prognostic factors for the prediction of PCSS, MFS, and OS after BCF. We plan to leverage the Canadian ProCaRS database to perform predictive modeling using the putative findings in the present study in order to propose potential evidence-based surrogate endpoints for prostate cancer in the setting of BCF.

High placenta-specific 1/low prostate-specific antigen expression pattern in high-grade prostate adenocarcinoma

BACKGROUND

The scarcity of effective therapeutic approaches for prostate cancer (PCa) has encouraged steadily growing interest for the identification of novel antigenic targets. Placenta-specific 1 (PLAC1) is a novel cancer-testis antigen with reported ectopic expression in a variety of tumors and cancer cell lines. The purpose of the present study was to investigate for the first time the differential expression of PLAC1 in PCa tissues.

METHODS

We investigated the differential expression of PLAC1 in PCa, high-grade prostatic intraepithelial neoplasia (HPIN), benign prostatic hyperplasia (BPH), and nonneoplastic/nonhyperplastic prostate tissues using microarray-based immunohistochemistry (n = 227). The correlation of PLAC1 expression with certain clinicopathological parameters and expression of prostate-specific antigen (PSA), as a prostate epithelial cell differentiation marker, were investigated.

RESULTS

Placenta-specific 1 (PLAC1) expression was increased in a stepwise manner from BPH to PCa, which expressed highest levels of this molecule, while in a majority of normal tissues, PLAC1 expression was not detected. Moreover, PLAC1 expression was positively associated with Gleason score (p ≤ 0.001). Interestingly, there was a negative correlation between PLAC1 and PSA expression in patients with PCa and HPIN (p ≤ 0.01). Increment of PLAC1 expression increased the odds of PCa and HPIN diagnosis (OR 49.45, 95 % CI for OR 16.17-151.25).

CONCLUSION

Our findings on differential expression of PLAC1 in PCa plus its positive association with Gleason score and negative correlation with PSA expression highlight the potential usefulness of PLAC1 for targeted PC therapy especially for patients with advanced disease.

Correlation between frequencies of blood monocytic myeloid-derived suppressor cells, regulatory T cells and negative prognostic markers in patients with castration-resistant metastatic prostate cancer

Myeloid-derived suppressor cells (MDSC) are believed to play a role in immune suppression and subsequent failure of T cells to mount an efficient anti-tumor response, by employing both direct T-cell inhibition as well as induction of regulatory T cells (Tregs). Investigating the frequency and function of immune suppressive cell subsets in the peripheral blood of 41 patients with prostate cancer (PC) and 36 healthy donors (HD) showed a significant increase in circulating CD14(+) HLA-DR(low/neg) monocytic MDSC (M-MDSC) and Tregs in patients with PC compared to HD. Furthermore, M-MDSC frequencies correlated positively with Treg levels. In vitro proliferation assay with autologous T cells confirmed M-MDSC-mediated T-cell suppression, and intracellular staining of immune suppressive enzyme iNOS revealed a higher expression in M-MDSC from patients with PC. Increased frequencies of M-MDSC correlated with known negative prognostic markers in patients with PC including elevated levels of lactate dehydrogenase and prostate-specific antigen. Accordingly, high levels of M-MDSC were associated with a shorter median overall survival. Our data strongly suggest that M-MDSC, possibly along with Tregs, play a role in establishing an immune suppressive environment in patients with PC. Moreover, correlation of M-MDSC frequency with known prognostic markers and the observed impact on OS could reflect a possible role in tumor progression. Further insight into the generation and function of MDSC and their interplay with Tregs and other cell types may suggest ways to tackle their induction and/or function to improve immunological tumor control.

A dual-reporter, diagnostic vector for prostate cancer detection and tumor imaging

Detection of prostate-specific antigen (PSA) as a screening strategy for prostate cancer is limited by the inability of the PSA test to differentiate between malignant cancer and benign hyperplasia. Here, we report the use of a cancer-specific promoter, inhibition of differentiation-1 (Id1), to drive a dual-reporter system (Ad5/3-Id1-SEAP-Id1-mCherry) designed for detection of prostate cancer using a blood-based reporter-secreted embryonic alkaline phosphatase (SEAP) and tumor visualization using a fluorescent reporter protein, mCherry. In human prostate tumors, Id1 levels are correlated with increased Gleason grade and disease progression. To evaluate the performance of the dual-reporter system, a prostate cell panel with varying aggressive phenotypes was tested. Following infection with the Ad5/3-Id1-SEAP-Id1-mCherry vector, expression of the SEAP and mCherry reporters was shown to increase with increasing levels of cellular Id1. No correlation was observed between Id1 and PSA. To evaluate in vivo performance, flank tumors were grown in athymic male mice using three prostate cancer cell lines. Following intra-tumoral injection of the vector, tumors formed by cells with high Id1 had the greatest reporter expression. Interestingly, tumors with the lowest levels of Id1 and reporter expression produced the greatest amounts of PSA. These data support the use of Ad5/3-Id1-SEAP-Id1-mCherry as a predictor of prostate cancer malignancy and as a strategy for tumor localization.

Prevention and early detection of prostate cancer

Prostate cancer is a common malignancy in men and the worldwide burden of this disease is rising. Lifestyle modifications such as smoking cessation, exercise, and weight control offer opportunities to reduce the risk of developing prostate cancer. Early detection of prostate cancer by prostate-specific antigen (PSA) screening is controversial, but changes in the PSA threshold, frequency of screening, and the use of other biomarkers have the potential to minimise the overdiagnosis associated with PSA screening. Several new biomarkers for individuals with raised PSA concentrations or those diagnosed with prostate cancer are likely to identify individuals who can be spared aggressive treatment. Several pharmacological agents such as 5α-reductase inhibitors and aspirin could prevent development of prostate cancer. In this Review, we discuss the present evidence and research questions regarding prevention, early detection of prostate cancer, and management of men either at high risk of prostate cancer or diagnosed with low-grade prostate cancer.

Empirical estimates of prostate cancer overdiagnosis by age and prostate-specific antigen

BACKGROUND

Prostate cancer screening depends on a careful balance of benefits, in terms of reduced prostate cancer mortality, and harms, in terms of overdiagnosis and overtreatment. We aimed to estimate the effect on overdiagnosis of restricting prostate specific antigen (PSA) testing by age and baseline PSA.

METHODS

Estimates of the effects of age on overdiagnosis were based on population based incidence data from the US Surveillance, Epidemiology and End Results database. To investigate the relationship between PSA and overdiagnosis, we used two separate cohorts subject to PSA testing in clinical trials (n = 1,577 and n = 1,197) and a population-based cohort of Swedish men not subject to PSA-screening followed for 25 years (n = 1,162).

RESULTS

If PSA testing had been restricted to younger men, the number of excess cases associated with the introduction of PSA in the US would have been reduced by 85%, 68% and 42% for age cut-offs of 60, 65 and 70, respectively. The risk that a man with screen-detected cancer at age 60 would not subsequently lead to prostate cancer morbidity or mortality decreased exponentially as PSA approached conventional biopsy thresholds. For PSAs below 1 ng/ml, the risk of a positive biopsy is 65 (95% CI 18.2, 72.9) times greater than subsequent prostate cancer mortality.

CONCLUSIONS

Prostate cancer overdiagnosis has a strong relationship to age and PSA level. Restricting screening in men over 60 to those with PSA above median (>1 ng/ml) and screening men over 70 only in selected circumstances would importantly reduce overdiagnosis and change the ratio of benefits to harms of PSA-screening.

Galectin-3: a possible complementary marker to the PSA blood test

The prostate-specific antigen (PSA) test has served as a blood marker of prostate cancer (PCa), and for monitoring recurrence/metastasis in patients after therapeutic intervention. However, the applicability/reliability of the PSA test was recently questioned as it is not without challenges, in particular in men who have PCa without an elevated PSA (false negative), or in men who are disease-free with elevated levels of PSA (false positive). Galectin-3 is a tumor-associated protein; present in the seminal fluid and is a substrate for the PSA enzyme e.g., a chymotrypsin-like serine protease. We hypothesized that the cleavage status and level of galectin-3 in the prostate tissue and sera are associated with PCa. Thus, we compared galectin-3 levels obtained from sera of non-cancer urology patients to those of metastatic PCa patients. The data were confirmed by analyzing PCa tissue arrays. Here, we report that galectin-3 levels in the sera of patients with metastatic PCa were uniformly higher as compared to the non-cancer patient controls. The data suggest that galectin-3 serum level may be a useful serum complementary marker to the PSA blood test to be used for initial and follow-up PSA complimentary diagnostic/prognostic tool for recurrence in PCa patients.

Counterpoint: Prostate-specific antigen velocity is not of value for early detection of cancer

Firm evidence shows that prostate-specific antigen (PSA) velocity is statistically associated with many prostate cancer outcomes, including those related to early detection. However, the clinical use of a marker depends on clinical and statistical significance. Before PSA velocity is used to inform decisions such as whether to perform a biopsy, evidence should be clear that doing so would improve clinical outcome. A systematic review on PSA velocity found that almost no studies had evaluated whether PSA velocity aids in clinical decision-making. Since that time, several reports have indicated that including PSA in a statistical model alongside standard predictors (eg, PSA, digital rectal examination) does not improve predictive accuracy. Specifically, performing a biopsy on men with high PSA velocity in the absence of other indications, as recommended by the NCCN Clinical Practice Guidelines in Oncology for Prostate Cancer Early Detection, would lead to many millions of unnecessary biopsies, without a corresponding number of aggressive cancers being detected. Advocates of PSA velocity have been reduced to citing a single article claiming that PSA velocity aids in clinical decision-making. The article involves selective reporting of an unusual subgroup analysis based on an extremely limited number of events. This is not to say that, in clinical practice, urologists should ignore prior PSA values: clinical judgment can be aided by careful longitudinal evaluation of PSA changes, interpreted in the context of symptoms and treatments. However, the literature clearly shows that simplistic application of PSA velocity cutoffs is not of value for early detection of prostate cancer.

Prostate cancer specific survival in the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial

BACKGROUND

The prostate component of the Prostate, Lung, Colorectal, and Ovarian (PLCO) randomized screening trial demonstrated no mortality effect of screening. Here we analyze prostate cancer specific survival in PLCO and its relation to screening.

METHODS

76,693 men aged 55-74 were randomized to usual care (n = 38,350) or intervention (n = 38,343). Intervention arm men received annual prostate-specific antigen (6 years) and digital rectal exam (4 years). Men were followed for cancer diagnosis and mortality through 13 years. Medical record abstractors confirmed prostate cancer diagnoses, stage and grade. Prostate-specific survival in PLCO cases was analyzed using Kaplan-Meier analysis and proportional hazards modeling. We utilized data from the Surveillance, Epidemiology and End Results (SEER) program to compute expected survival in PLCO and compared this to observed.

RESULTS

There was no significant difference in prostate-specific survival rates between arms; 10 year survival rates were 94.7% (intervention, n = 4250 cases) versus 93.5% (usual care, n = 3815 cases). Within the intervention arm, cases never screened in PLCO had lower 10 year survival rates (82%) than screen detected or interval (following a negative screen) cases, both around 95.5%. The ratio of observed to expected 10 year prostate-specific death (1-survival) rates was 0.59 (95% CI: 0.51-0.68) for all PLCO cases, 0.66 (95% CI: 0.51-0.81) for Gleason 5-7 cases and 1.07 (95% CI: 0.87-1.3) for Gleason 8-10 cases.

CONCLUSION

Prostate cancer specific survival in PLCO was comparable across arms and significantly better than expected based on nationwide population data. How much of the better survival is due to a healthy volunteer effect and to lead-time and overdiagnosis biases is not readily determinable.

Crystallization and preliminary X-ray diffraction analysis of PsaA, the adhesive pilin subunit that forms the pH 6 antigen on the surface of Yersinia pestis

Yersinia pestis has been responsible for a number of high-mortality epidemics throughout human history. Like all other bacterial infections, the pathogenesis of Y. pestis begins with the attachment of bacteria to the surface of host cells. At least five surface proteins from Y. pestis have been shown to interact with host cells. Psa, the pH 6 antigen, is one of them and is deployed on the surface of bacteria as thin flexible fibrils that are the result of the polymerization of a single PsaA pilin subunit. Here, the crystallization of recombinant donor-strand complemented PsaA by the hanging-drop vapor-diffusion method is reported. X-ray diffraction data sets were collected to 1.9 Å resolution from a native crystal and to 1.5 Å resolution from a bromide-derivatized crystal. These crystals displayed the symmetry of the orthorhombic space group P222(1), with unit-cell parameters a = 26.3, b = 54.6, c = 102.1 Å. Initial phases were derived from single isomorphous replacement with anomalous scattering experiments, resulting in an electron-density map that showed a single molecule in the crystallographic asymmetric unit. Sequence assignment was aided by residues binding to bromide ions of the heavy-atom derivative.

Trypsin-like proteolytic contamination of commercially available psa purified from human seminal fluid

BACKGROUND

Prostate-Specific Antigen (PSA) is a serine protease whose expression is maintained in all stages of prostate cancer. A role for PSA in the pathobiology for prostate cancer has not been firmly established. Experimental studies to date support a role for PSA through mechanisms such as release or processing of growth factors and degradation of the extracellular matrix. Exposure of prostate cancer cells to exogenous PSA also results in gene expression changes. These in vitro and biochemical assays rely on the use of commercially available PSA. Contamination of these commercial preparations can significantly impact the results of these in vitro studies.

METHODS

We characterized PSA and trypsin-like activity of PSA preparations obtained from three commercial sources: Calbiochem, Fitzgerald, and AbD Serotec. Silver stained gels were used to compare the purity of each preparation and mass spectrometry was performed to characterize contaminating proteases.

RESULTS

PSA activity varied between PSA preparations with AbD Serotec PSA having highest degree of activity. Significant trypsin-like activity, which was inhibited by aprotinin, was observed in PSA preparations from Calbiochem and Fitzgerald, but not AbD Serotec. These former two PSA preparations also contained the greatest degree of non-PSA contaminants by silver stain and mass spectrometry.

CONCLUSIONS

Commercially available preparations of PSA contain contaminating proteins, including trypsin-like protease activity, that could potentially complicate the interpretation of results obtained from in vitro studies assessing PSA proteolysis of potential protein substrates and effects of PSA on gene expression.

Prospective evaluation of 18F-NaF and 18F-FDG PET/CT in detection of occult metastatic disease in biochemical recurrence of prostate cancer

PURPOSE

This study aimed to perform a prospective evaluation of 18F-NaF and 18F-FDG PET/CT in the detection of occult metastatic disease in men with prostate cancer and biochemical relapse.

METHODS

Thirty-seven men with prostate-specific antigen (PSA) relapse (median, 3.2 ng/mL; range, 0.5-40.2 ng/mL) after definitive therapy for localized prostate cancer [26 radical prostatectomy (RP), 11 external beam radiation therapy] and negative conventional imaging underwent 18F-FDG and 18F-NaF PET/CT on 2 separate days within the same week. Studies were interpreted by 2 experienced radiologists in consensus for abnormal uptake suspicious for metastatic disease. The reference standard was a combination of imaging and clinical follow-up. Rank of PSA values for positive and negative PET/CT was compared using analysis of variance adjusting for primary therapy. Association between PSA and scan positivity in patients with RP was evaluated using Wilcoxon rank sum test.

RESULTS

Result of the 18F-FDG PET/CT scan was positive for nodal disease in 2 patients. True-positive detection rate for occult osseous metastases by 18F-NaF PET/CT was 16.2%. Median PSA levels for positive versus negative PET/CT scans were 4.4 and 2.9 ng/mL, respectively, with the difference marginally significant in prostatectomized men (P=0.072). Percentages of patients with either 18F-NaF- or 18F-FDG-positive PET/CT in RP and external beam radiation therapy were 10% (n=10) and undefined (n=0) for a PSA of 2 ng/mL or less, 29% (n=7) and 50% (n=2) for PSA greater than 2 ng/mL but 4 ng/mL or less, 60% (n=5) and 40% (n=5) for PSA greater than 4 ng/mL but 10 ng/mL or less, and 25% (n=4) and 25% (n=4) for PSA greater than 10 ng/mL, respectively.

CONCLUSIONS

In biochemical relapse of prostate cancer, 18 F-NaF PET/CT is useful in the detection of occult osseous metastases, whereas the yield of 18F-FDG PET/CT is relatively limited. 18F-NaF PET/CT positivity tends to associate with increasing PSA level in prostatectomized men and may occur in lower PSA ranges than conventionally recognized.

Importance of prostate volume in the European Randomised Study of Screening for Prostate Cancer (ERSPC) risk calculators: results from the prostate biopsy collaborative group

OBJECTIVES

To compare the predictive performance and potential clinical usefulness of risk calculators of the European Randomized Study of Screening for Prostate Cancer (ERSPC RC) with and without information on prostate volume.

METHODS

We studied 6 cohorts (5 European and 1 US) with a total of 15,300 men, all biopsied and with pre-biopsy TRUS measurements of prostate volume. Volume was categorized into 3 categories (25, 40, and 60 cc), to reflect use of digital rectal examination (DRE) for volume assessment. Risks of prostate cancer were calculated according to a ERSPC DRE-based RC (including PSA, DRE, prior biopsy, and prostate volume) and a PSA + DRE model (including PSA, DRE, and prior biopsy). Missing data on prostate volume were completed by single imputation. Risk predictions were evaluated with respect to calibration (graphically), discrimination (AUC curve), and clinical usefulness (net benefit, graphically assessed in decision curves).

RESULTS

The AUCs of the ERSPC DRE-based RC ranged from 0.61 to 0.77 and were substantially larger than the AUCs of a model based on only PSA + DRE (ranging from 0.56 to 0.72) in each of the 6 cohorts. The ERSPC DRE-based RC provided net benefit over performing a prostate biopsy on the basis of PSA and DRE outcome in five of the six cohorts.

CONCLUSIONS

Identifying men at increased risk for having a biopsy detectable prostate cancer should consider multiple factors, including an estimate of prostate volume.

Regulation of human osteoclast development by dendritic cell-specific transmembrane protein (DC-STAMP)

Osteoclasts (OC) are bone-resorbing, multinucleated cells that are generated via fusion of OC precursors (OCP). The frequency of OCP is elevated in patients with erosive inflammatory arthritis and metabolic bone diseases. Although many cytokines and cell surface receptors are known to participate in osteoclastogenesis, the molecular mechanisms underlying the regulation of this cellular transformation are poorly understood. Herein, we focused our studies on the dendritic cell-specific transmembrane protein (DC-STAMP), a seven-pass transmembrane receptor-like protein known to be essential for cell-to-cell fusion during osteoclastogenesis. We identified an immunoreceptor tyrosine-based inhibitory motif (ITIM) in the cytoplasmic tail of DC-STAMP, and developed an anti-DC-STAMP monoclonal antibody 1A2 that detected DC-STAMP expression on human tumor giant cells, blocked OC formation in vitro, and distinguished four patterns of human PBMC with a positive correlation to OC potential. In freshly isolated monocytes, DC-STAMP(high) cells produced a higher number of OC in culture than DC-STAMP(low) cells and the surface expression of DC-STAMP gradually declined during osteoclastogenesis. Importantly, we showed that DC-STAMP is phosphorylated on its tyrosine residues and physically interacts with SHP-1 and CD16, an SH2-domain-containing tyrosine phosphatase and an ITAM-associated protein, respectively. Taken together, these data show that DC-STAMP is a potential OCP biomarker in inflammatory arthritis. Moreover, in addition to its effect on cell fusion, DC-STAMP dynamically regulates cell signaling during osteoclastogenesis.

Enzymatically active prostate-specific antigen promotes growth of human prostate cancers

BACKGROUND

Prostate specific antigen (PSA) is the best-known member of the kallikrein-related peptidase family, with an established role as a prostatic disease biomarker. Although it is produced at high levels by all stages of prostate cancer, it is uncertain if PSA plays a role in prostate cancer initiation and progression. We decided to investigate the impact of PSA and its enzymatic activity on tumor cell growth rates.

METHODS

A gene-specific shRNA lentiviral construct reduced endogenous PSA expression in the LNCaP human prostate cancer cell line. Resulting changes in growth rates in vitro and in vivo were determined. Using a mass spectroscopy-based approach, alterations to the LNCaP proteome due to reduced PSA were measured. Finally, to evaluate the importance of PSA's proteolytic activity, the PSA-null Du145 human prostate cancer cell line was engineered to express either enzymatically inactive pro-PSA (WT) or a furin-activated variant (FR) with high enzymatic activity. The resulting clones were evaluated for PSA-induced changes in growth rates in vivo and in vitro.

RESULTS

Lowered PSA levels dramatically reduced LNCaP growth rates. Expressing active PSA (FR), but not the inactive WT variant, conferred a growth advantage on Du145 cells. Proteomics analysis revealed global changes to the LNCaP proteome as a result of reduced PSA expression.

CONCLUSIONS

These studies demonstrate the importance of PSA to prostate cancer cell growth. We also show that the enzymatic activity of PSA confers an enhanced growth rate to human prostate cancer cells, suggesting a causal role in prostate cancer progression.

Active surveillance for prostate cancer: patient selection and management

Screening for prostate cancer using prostate-specific antigen (PSA) has been appealing. However, the significant associated decline in prostate cancer mortality comes at the cost of a very high rate of diagnosis, and many patients with indolent, non-life-threatening cancer are exposed to the risk of significant side effects from radical treatment. Most men with favourable-risk prostate cancer are not destined to die of their disease, even in the absence of treatment. The challenge is to identify the subset that harbour more aggressive disease early enough that curative therapy is still a possibility, thereby allowing the others to enjoy improved quality of life, free from the side effects of treatment. This article reviews current research into active surveillance in favourable-risk disease and some of the issues that arise when prostate cancer is monitored rather than being treated immediately.

Androgen-induced PSA expression requires not only activation of AR but also endogenous IGF-I or IGF-I/PI3K/Akt signaling in human prostate cancer epithelial cells

BACKGROUND

Prostate cancer (PrCa) risk is positively associated with levels of insulin-like growth factor I (IGF-I) and prostate specific antigen (PSA), both androgen receptor (AR) signaling target genes in PrCa cells. Although activated AR is required for androgen-induction of expression of both genes, effects of the IGF-I signaling pathways on the androgen-induction of PSA have not been studied.

METHODS

Human prostate stromal and epithelial cancer cells were treated alone or in coculture with steroid hormone and/or inhibitors. Gene or protein expression was analyzed by real time RT-PCR or Western blotting of lysates, nuclear extracts, or immunoprecipitated products.

RESULTS

In PrCa epithelial cells, endogenous IGF-I, significantly induced by R1881, was required for R1881-induction of PSA. Increased IGF-I correlated with accumulation of cytoplasmic dephospho β-catenin (CPDP β-catenin), a co-activator of AR signaling. Exogenous IGF-I enhanced R1881-induced PSA and accumulation of CPDP β-catenin in LAPC-4 cells. Functional depletion of IGF-I or IGF-I receptor diminished PSA induction. Induction of IGF-I reached a plateau while PSA consecutively increased. Inhibiting PI3K abolished R1881-induced Akt phosphorylation, CPDP and nuclear β-catenin and nuclear association of AR/β-catenin, consequently abrogating R1881-induced expression of IGF-I and/or PSA.

CONCLUSIONS

By integrating androgen, IGF-I and β-catenin signaling pathways, these data reveal that androgen-induced PSA expression requires activation of AR and endogenous IGF-I or IGF-I/PI3K/Akt signaling, suggesting a positive feedback cycle for increased production of PSA associated with PrCa.

Stearoyl CoA desaturase (SCD) facilitates proliferation of prostate cancer cells through enhancement of androgen receptor transactivation

Stearoyl-CoA desaturase (SCD), the rate-limiting enzyme in the biosynthesis of monounsaturated fatty acids, is highly expressed in prostate cancer although the SCD protein has been known to be rapidly turned over by proteolytic cleavage. The present data demonstrate that SCD can promote proliferation of androgen receptor (AR)-positive LNCaP prostate cancer cells and enhance dihydrotestosterone (DHT)-induced AR transcriptional activity, resulting in increased expression of prostate-specific antigen (PSA) and kallikrein-related peptidase 2 (KLK2). Interestingly, among the previously reported SCD-derived peptides produced by proteolytic cleavage of SCD, a peptide spanning amino acids 130-162 of SCD (SCD-CoRNR) contained the CoRNR box motif (LFLII) and enhanced AR transcriptional activity. In contrast, a mutant SCD-CoRNR in which Leu136 was replaced by Ala had no effect on AR transcriptional activity. Moreover, SCD-CoRNR directly interacted with AR and inhibited RIP140 suppression of AR transactivation. Knockdown of the SCD gene by SCD microRNA suppressed AR transactivation with decreased cell proliferation, suggesting that SCD may regulate the proliferation of LNCaP cells via modulation of AR transcriptional activity. Moreover, ectopic expression of SCD in LNCaP cells facilitated LNCaP tumor formation and growth in nude mice. Together, the data indicate that SCD plays a key role in the regulation of AR transcriptional activity in prostate cancer cells.

The associations between statin use and prostate cancer screening, prostate size, high-grade prostatic intraepithelial neoplasia (PIN), and prostate cancer

OBJECTIVE

Prior studies report statins may reduce the risk of advanced prostate cancer. This study investigates the association between statin use and the likelihood of having a PSA or DRE test, blood PSA levels, prostate volume, and the severity of lower urinary tract symptoms. We also describe the association between statin use and prostate cancer and high-grade prostatic intraepithelial neoplasia (PIN) before and after controlling for prostate cancer screening indices associated with statin use.

METHODS

The Nashville Men's Health Study used a multicenter, rapid recruitment protocol to collect clinical, biologic, behavioral, and body measurement data from 2,148 men 40 years or older scheduled for diagnostic prostate biopsy. Medication use and other data were ascertained by research survey, clinical interview, and chart review.

RESULTS

Approximately 37% of participants were taking a statin. Statin use was significantly associated with a 12% lower PSA levels and 8% smaller prostate volume after controlling for age, race, BMI, WHR, aspirin use, and other comorbidity. Simvastatin was more strongly associated with prostate volume, while atorvastatin was associated with PSA. Statin use was marginally associated with increasing PSA test frequency among men with undiagnosed cancer. Statin use was not associated with the frequency or results of digital rectal exams, lower urinary tract symptom severity, high-grade (Gleason > 6) prostate cancer (OR = 0.95 (0.73, 1.24)), low-grade (Gleason = 6) prostate cancer (OR = 1.11 (0.86, 1.42)) or PIN (OR = 0.82, (0.57, 1.17)). Additional control for the number of prior PSA tests, PSA levels, and prostate volume did not alter these results.

CONCLUSION

These results suggest selective referral for biopsy associated with statin use is an essential element to address in further understanding the potential for statins to prevent prostate cancer.

Body mass index adjusted prostate-specific antigen and its application for prostate cancer screening

OBJECTIVES

The prostate cancer prevention trial (PCPT) prostate cancer risk calculator was developed to aid physicians in counseling men for consideration of prostate biopsy based on prostate-specific antigen (PSA) and other clinical risk factors. This study investigated the role of body mass index (BMI) in this assessment.

MATERIALS AND METHODS

BMI category was defined as < 25 (under/normal weight), 25.0-29.9 (overweight), 30.0-34.9 (obese [OB] I), 35.0-39.9 (OB II), and ≥ 40 (OB III). BMI-adjusted PSA for a man was determined by multiplying his PSA to the ratio of the geometrical mean of PSA for BMI < 25 to the geometrical mean of PSA for his BMI category. Operating characteristics of PSA and BMI-adjusted PSA were compared with PCPT risks using area underneath the receiver operating characteristic curve (AUC). Statistical tests of differences between AUCs for different diagnostic tests were performed with the nonparametric U-statistic method.

RESULTS

BMI-adjusted PSA equaled to unadjusted PSA multiplying 1.09, 1.20, 1.50, and 1.71 for men in overweight, OBI, OBII, and OBIII categories, respectively. The AUC for BMI-adjusted PSA values (0.84) did not differ from PSA; that of the PCPT calculator with BMI-adjusted PSA (0.87) did not differ from the calculator with PSA. Of 2816 men with a PSA less than or equal to 2.5 ng/mL who did not undergo biopsy, 126 (4.5%) would have a BMI-adjusted PSA exceeding 2.5 ng/mL.

CONCLUSIONS

Because of lower levels of PSA, overweight and obese men may have diminished cancer detection opportunities when undergoing PSA-based screening.

Correlation between serum prostate-specific antigen and cancer volume in prostate glands of different sizes

OBJECTIVES

To further evaluate the relationship of prostate-specific antigen (PSA) with prostate size and tumor volume in a contemporary surgical series. Although early studies showed a strong correlation between PSA and tumor volume, it has been suggested that PSA is no longer a valid marker for prostate cancer and only correlates with prostate size.

METHODS

From 2003 to 2009, 1234 men with data on prostate weight and total tumor volume underwent radical prostatectomy by a single surgeon. Prostate size was classified into tertiles: small (≤ 41.2 g), medium (41.3-54.5 g), and large (≥ 54.6 g). Pearson correlation coefficients were used to examine the relationship of PSA with prostate size and tumor volume across different prostate sizes.

RESULTS

Median preoperative PSA was 4.9 ng/mL (standard deviation ± 4.6), mean prostate size was 51.7 g, and mean tumor volume was 5.6 cm(3). PSA had a significant correlation with prostate size only at a prostate weight ≥ 54.6 g (P = .02). Regardless of prostate size, PSA had a more robust significant correlation with tumor volume than with prostate size (all P < .0001).

CONCLUSIONS

PSA was significantly correlated with prostate size only in the largest prostate glands, but was significantly associated with tumor volume in small, medium, or large prostates. Thus, PSA continues to be a better marker for tumor volume than for prostate size.

Effect of aspirin, other NSAIDs, and statins on PSA and PSA velocity

BACKGROUND

Aspirin, other non-steroidal anti-inflammatory drugs (NSAIDs), and statins have been associated with lower risk of prostate cancer and its progression, though results have been inconsistent.

METHODS

Data from 140 men with prostate cancer enrolled in a Phase 2 clinical trial of selenium to prevent prostate cancer progression were analyzed to determine association between aspirin, other NSAIDs, or statin use with baseline serum prostate-specific antigen (PSA) levels and PSA velocity (rate of PSA change over time) using repeated measures over an average follow-up time of 3.2 years. Multiple linear regression and mixed effects models were used to model the association of medication use with PSA at baseline and with PSA velocity, respectively.

RESULTS

Baseline PSA levels were significantly lower in aspirin users compared to non-users (5.17 ng/ml vs. 7.58 ng/ml, P = 0.001). This association was statistically significant in never smokers (aspirin users vs. non-users: 4.19 ng/ml vs. 8.24 ng/ml, P = 0.004) but not in ever smokers (aspirin users vs. non-users: 5.52 ng/ml vs. 7.3 ng/ml, P = 0.101). Statin and other NSAID use was not associated with baseline PSA. Aspirin, statin, or other NSAID use at baseline demonstrated a non-significant negative association with PSA velocity.

CONCLUSION

These findings support an effect of aspirin use on PSA, particularly among never smokers. However, they do not suggest a protective effect on the disease and support previous findings that aspirin use may mask accurate measurement of PSA warranting consideration of washout procedures prior to testing.

Partners in crime: deregulation of AR activity and androgen synthesis in prostate cancer

Prostate cancer remains a leading cause of cancer death, as there are no durable means to treat advanced disease. Treatment of non-organ-confined prostate cancer hinges on its androgen dependence. First-line therapeutic strategies suppress androgen receptor (AR) activity, via androgen ablation and direct AR antagonists, whereas initially effective, incurable, 'castration-resistant' tumors arise as a result of resurgent AR activity. Alterations of AR and/or associated regulatory networks are known to restore receptor activity and support resultant therapy-resistant tumor progression. However, recent evidence also reveals an unexpected contribution of the AR ligand, indicating that alterations in pathways controlling androgen synthesis support castration-resistant AR activity. In this report, the mechanisms underlying the lethal pairing of AR deregulation and aberrant androgen synthesis in prostate cancer progression will be discussed.

A prospective, multicenter, National Cancer Institute Early Detection Research Network study of [-2]proPSA: improving prostate cancer detection and correlating with cancer aggressiveness

BACKGROUND

The free prostate-specific antigen (PSA) isoform, [-2]proPSA, has been shown to be associated with prostate cancer. The study objective was to characterize the clinical utility of serum [-2]proPSA for prostate cancer detection and assess its association with aggressive disease.

METHODS

From among 669 subjects in a prospective prostate cancer detection study at four National Cancer Institute Early Detection Research Network clinical validation centers, 566 were eligible. Serum PSA, free PSA, and [-2]proPSA were measured (Beckman Coulter Access 2 Analyzer).

RESULTS

Two hundred and forty-five (43%) of the 566 participants had prostate cancer on biopsy. At 70% specificity, the sensitivity of %[-2]proPSA ([-2]proPSA/fPSA) was 54% [95% confidence interval (CI), 48-61%; null hypothesis, 40%]. Including %[-2]proPSA in a multivariate prediction model incorporating PSA and %fPSA improved the performance (P<0.01). In the 2 to 4 ng/mL PSA range, %[-2]proPSA outperformed %fPSA (receiver operator characteristic-areas under the curve, 0.73 versus 0.61; P=0.01). At 80% sensitivity, %[-2]proPSA had significantly higher specificity (51.6%; 95% CI, 41.2-61.8%) than PSA (29.9%; 95% CI, 21.0-40.0%) and %fPSA (28.9%; 95% CI, 20.1-39.0%). In the 2 to 10 ng/mL PSA range, a multivariate model had significant improvement (area under the curve, 0.76) over individual PSA forms (P<0.01 to <0.0001). At 80% sensitivity, the specificity of %[-2]proPSA (44.9%; 95% CI, 38.4-51.5%) was significantly higher than PSA (30.8%; 95% CI, 24.9-37.1%) and relatively higher than %fPSA (34.6%; 95% CI, 28.5-41.4%). %[-2]proPSA increased with increasing Gleason score (P<0.001) and was higher in aggressive cancers (P=0.03).

CONCLUSIONS

In this prospective study, %[-2]proPSA showed potential clinical utility for improving prostate cancer detection and was related to the risk of aggressive disease.

IMPACT

The addition of %[-2]proPSA could affect the early detection of prostate cancer.

Study of matrix metalloproteinases and their inhibitors in prostate cancer

BACKGROUND

Extracellular matrix metalloproteases (MMPs) have raised an extraordinary interest in cancer research because of their potential role in basal membrane and extracellular matrix degradation, consequently facilitating tumour invasion and metastases development.

METHODS

An immunohistochemical study was performed using tissue arrays and specific antibodies against MMPs 1, 2, 7, 9, 11, 13, 14, and their tissue inhibitors, TIMPs 1, 2 and 3. More than 2600 determinations on cancer specimens from 133 patients with clinically localised prostate carcinoma, 20 patients with prostatic intraepithelial neoplasia and 50 patients with benign prostate hyperplasia and controls, were performed.

RESULTS

When compared with benign pathologies, prostate carcinomas had higher expression of all MMPs and TIMPs. Dendogram shows a first-order division of tumours into two distinct MMPs/TIMPs molecular profiles, one of them with high MMPs/TIMs expression profile (n=70; 52.6%). Tumours with high expression of MMP-11 or -13, or cluster thereof, were significantly associated with higher probability of biochemical recurrence.

CONCLUSION

The expression of MMPs and TIMPs seems to have an important role in the molecular biology of prostate carcinomas, and their expression by tumours may be of clinical interest to used as indicators of tumour aggressiveness.

PSA and body composition by dual X-ray absorptiometry (DXA) in NHANES

BACKGROUND

Obese men are at higher risk for advanced prostate cancer and have a poorer prognosis following treatment. Several studies also report that obese men have lower blood PSA levels, suggesting that obesity may be interfering with the ability to detect early-stage prostate cancer.

METHODS

Dual X-ray absorptiometry (DXA) is considered a gold-standard measurement of body composition. We investigated the association between PSA levels and body composition measured by DXA among 1,360 men participating in NHANES (2001-2004), a representative sample of the U.S. male population.

RESULTS

After controlling for age, race, and other factors, PSA concentration was approximately 15% lower for men with the highest level of total mass, lean mass, fat mass, trunk lean mass, and trunk fat mass (all P for trend <0.05). We then multiplied PSA concentration by estimated plasma volume to calculate the amount of PSA in circulation (i.e., PSA mass). Total body fat mass and fat mass located in the body trunk were not significantly associated with PSA mass, however, PSA mass was approximately 10-15% higher across low versus high categories of total body lean mass and bone mineral content (all P-trend <0.05).

CONCLUSION

Our results using DXA to measure body composition confirm that a greater body mass, not just fat mass, is associated with a lower PSA concentration. This is consistent with PSA hemodilution within men with a higher body mass index. The separate associations between measured lean and fat mass on calculated PSA mass require further investigation.