Should Men with Serum Prostate-Specific Antigen ≤4 ng/ml and Normal Digital Rectal Examination Undergo a Prostate Biopsy?

Molecular MR Imaging of Prostate Cancer

This review summarizes recent developments regarding molecular imaging markers for magnetic resonance imaging (MRI) of prostate cancer (PCa). Currently, the clinical standard includes MR imaging using unspecific gadolinium-based contrast agents. Specific molecular probes for the diagnosis of PCa could improve the molecular characterization of the tumor in a non-invasive examination. Furthermore, molecular probes could enable targeted therapies to suppress tumor growth or reduce the tumor size.

Semen AMACR protein as a novel method for detecting prostate cancer

BACKGROUND

Alpha methylacyl A coenzyme racemase (AMACR) has shown to be an excellent immunohistological biomarker for prostate cancer (CaP). Given the connection between prostate and urethra, we hypothesized that semen ejaculate would be an ideal specimen for detection of CaP specific biomarkers, such as AMACR. This study explores the detection of semen AMACR protein in men with and without CaP.

METHODS

Semen ejaculates from 28 biopsy proven CaP patients prior to radical prostatectomy and 15 age-comparable controls were analyzed. An indirect sandwich ELISA chemiluminescence assay was used to detect semen AMACR, PSA, and Matriptase proteins. Tissue AMACR protein was quantified in 12 corresponding prostatectomy specimens using automated quantitative analysis (AQUA).

RESULTS

Semen AMACR protein was detected in 23 of 28 (82%) CaP patients and 23 of 24 (96%) CaP patients with significant tumor volume (>0.5 cc or 0.3 g). Among the 5 cancer patients with undetectable semen AMACR, 4 patients had small tumor volumes (<1% or 0.3 g). Semen AMACR protein was also detected in 7 of 15 (47%) control noncancer patients. Using 76 ng/ml as a cutoff value, 20 of 28 (71%) patients and 20 of 24 (83%) patients with significant tumor volume were positive for semen AMACR protein, whereas only 5 of 15 (33%) age-comparable controls were positive. AMACR levels degrade with time.

CONCLUSIONS

This is the first study to demonstrate that AMACR protein is detectable in semen ejaculate. The higher AMACR levels detected in cancer patients suggests that semen AMACR protein may be useful as a noninvasive test for prostate cancer. Further validation is warranted.

Comparison of pathological and biochemical outcomes after radical prostatectomy in Korean patients with serum PSA ranges

The aim of this study was to assess surgical outcome at radical prostatectomy (RP) in Korean men with a serum prostate-specific antigen (PSA) level of 2.5 to 3.0 ng/mL and compared with those of patients who had a PSA level of 3.0-4.0 and 4.0-10.0 ng/mL. We retrospectively compared clinico-pathological characteristics and biochemical recurrence (BCR) risk in patients with PSA level of 2.5-3.0 (group 1, n = 92, 5.7%), 3.0-4.0 (group 2, n = 283, 17.5%), or 4.0-10.0 ng/mL (group 3, n = 1,242, 76.8%) who underwent RP between 1995 and 2013. The pathologic characteristics including Gleason score, pathologic stage, and percentage of significant cancer in group 1 were similar to those in group 2 and group 3. Furthermore, pathological upgrading and upstaging were found in 23 (30.7%) and 10 (14.7%) in group 1, 84 (33.9%) and 19 (8.8%) in group 2, and 321 (32.8%) and 113 (12.8%) in group 3, respectively, with no significant differences among the three groups (all P > 0.05). In multivariate analysis, PSA grouping was not an independent predictor of BCR. Within the population with PSA lower than 10 ng/mL, substratification of PSA is not a significant predictor for upgrading, upstaging, or adverse prognosis.

Usefulness of diffusion-weighted magnetic resonance imaging in the diagnosis of prostate cancer

RATIONALE AND OBJECTIVES

The aim of this study was to evaluate the diagnostic accuracy of diffusion-weighted magnetic resonance imaging (DWI) in prostate cancer.

MATERIALS AND METHODS

The MEDLINE, Embase, CANCERLIT, and Cochrane Library databases were searched for studies published from January 2001 to August 2011 evaluating the diagnostic performance of DWI in detecting prostate carcinoma. Sensitivities and specificities were determined across studies, and summary receiver-operating characteristic curves were constructed using hierarchical regression models.

RESULTS

Sixteen studies (18 subsets) with a total of 852 patients were included. Six studies (seven subsets) examining men with pathologically confirmed prostate cancer (260 patients) had pooled sensitivity and specificity of 0.88 (95% confidence interval [CI], 0.76-0.95) and 0.84 (95% CI, 0.76-0.90), respectively. Compared to patients at high risk for clinically relevant cancer, sensitivity was higher in low-risk patients (0.94 [95% CI, 0.89-0.97] vs 0.62 [95% CI, 0.54-0.70], P < .05), but specificity was lower (0.86 [95% CI, 0.72-0.94] vs 0.89 [95% CI, 0.83-0.93], P < .05). Ten studies (11 subsets) examining patients with suspected prostate cancer (592 patients) had pooled sensitivity and specificity of 0.76 (95% CI, 0.68-0.84) and 0.86 (95% CI, 0.79-0.91). Sensitivity was lower in high-risk patients (0.74 [95% CI, 0.57-0.87] vs 0.78 [95% CI, 0.70-0.84], P > .05), but specificity was higher (0.92 [95% CI, 0.89-0.94] vs 0.78 [95% CI, 0.70-0.84], P < .05).

CONCLUSIONS

A limited number of small studies suggest that DWI could be a rule-in test for high-risk patients. Further prospective studies including larger populations are necessary to confirm the actual value of DWI in this field.

Effect of Prostate Biopsy Hemorrhage on MRDW and MRS Imaging

Purpose

To retrospectively evaluate the effect of post-prostate-biopsy hemorrhage on the interpretation of magnetic resonance diffusion-weighted (MRDW) and magnetic resonance spectroscopic (MRS) imaging in the detection of prostate cancer. We also investigated the optimal timing for magnetic resonance examination after prostate biopsy.

Materials and Methods

We reviewed the records of 135 men. All patients underwent prostate magnetic resonance imaging (MRI). The prostate was divided into eight regions according to the biopsy site. Subsequently, we measured hemorrhage on apparent diffusion coefficient (ADC) values and (choline+creatinine)/citrate ([Cho+Cr]/Cit) ratios in the same regions on the MRI. We investigated the effect of hemorrhage at ADC values and (Cho+Cr)/Cit ratios on MRI and the relationship between prostate biopsy results and MRI findings.

Results

The mean patient age was 68.7 years and the mean time between biopsy and MRI was 23.5 days. The total hemorrhagic score demonstrated no significant associations with intervals from biopsy to MRI. Higher hemorrhagic scores were associated with higher ADC values, prostate cancer, and noncancer groups, respectively (p<0.001). ADC values were lower in tumors than in normal tissue (p<0.001), and ADC values were inversely correlated with tumor Gleason score in biopsy cores (p<0.001). However, (Cho+Cr)/Cit ratios did not exhibit any association with prostate biopsy results and hemorrhage.

Conclusions

Hemorrhage had no significant associations with the interval from biopsy to MRI. ADC values may help to detect prostate cancer and predict the aggressiveness of cancer; however, it is important to consider the bias effect of hemorrhage on the interpretation of MRDW imaging given that hemorrhage affects ADC values.

Life events, cortisol and levels of prostate specific antigen: a story of synergism

BACKGROUND

Previous studies have tested the relationship between stressful life events (LE) and cancer onset, but inconsistent results have been found. One possibility is that the LE-cancer relation may depend on other biological factors pertinent to stress and cancer.

METHODS

This study examined the relationship between LE and prostate specific antigen (PSA) levels, a tumor marker, and whether cortisol mediates or moderates a LE-PSA relationship. During a voluntary screening for prostate cancer risk, 139 men (mean age=57.3 years) were assessed with the Holmes and Rahe questionnaire about their LE during the past 1-5 years, and their PSA and serum cortisol levels were measured.

RESULTS

LE and cortisol alone were unrelated to PSA. However, statistically controlling for age, body mass index and the ratio of triglycerides to HDL cholesterol, we found evidence for a synergistic interaction between LE and cortisol. Among men with low cortisol, number of LE were inversely and significantly correlated with PSA (r=-0.265, p<0.05), while in men with high cortisol, number of LE were positively and significantly correlated with PSA (r=0.344, p<0.01). These results more consistently stemmed from the effects of uncontrollable LE. Similar results were found, using a clinically significant PSA cut-off.

CONCLUSIONS

These results suggest considering the joint effects of psychosocial and biological factors in relation to possible cancer risk, where the hypothalamic pituitary adrenal axis may moderate stress-cancer risk associations.

VEGF and prostatic cancer: a systematic review

Elevated vascular endothelial growth factor (VEGF) blood concentration reflects its prostatic production, making this a potentially interesting tumour marker to support the decision of submitting a patient for prostatic biopsy. The objective was to review systematically the evidence on the role of VEGF blood concentration in prostate cancer detection. Published studies addressing the relation between serum or plasma VEGF levels and prostate cancer were identified by searching Pubmed, ISI Web of Knowledge, SCOPUS and LILACS up to January 2010, and reviewed following a standardized protocol. Three studies reported higher plasma VEGF (pg/ml) in patients with localized prostate cancer than in healthy controls (7.0 vs. 0.0, 9.9 vs. 2.2, and 210 vs. 26.5, P<0.01), and two showed higher serum VEGF (pg/ml) in prostate cancer patients than in patients with benign prostate hypertrophy (518.9 vs. 267.9, P<0.001; no specific values, P<0.05). In one study, serum VEGF was significantly lower in healthy controls than in patients with benign prostate hypertrophy, localized or metastatic prostate cancer. The three studies that used controls with previous suspicion of prostatic cancer but a negative biopsy reported non-statistically significant difference in VEGF serum levels (pg/ml) between controls and localized prostate cancer patients (241 vs. 206; 69.5 vs. 55; 215.2 vs. 266.4). Higher VEGF plasma levels are observed in prostatic cancer patients compared with healthy controls, but serum levels do not appear to be useful in differentiating benign from malignant prostatic disease using, as controls, individuals with high risk of prostate cancer and negative biopsy.

Incidence of insignificant prostate cancer using free/total PSA: results of a case-finding protocol on 14,453 patients

To evaluate prostate cancer (PCa) detection and incidence of pathologically insignificant PCa (pIPCa) tumour using percent-free PSA (%f-PSA) in patients with total PSA ≤ 10 ng ml(-1). From February 2002 to October 2009, 14,453 patients (median 60.5 years) were enrolled in a case-finding protocol for the early diagnosis of PCa. Indications to biopsy were suspicious digital rectal examination; PSA >10 ng ml(-1); PSA ≤ 2.5 ng ml(-1), included between 2.6-4 and 4.1-10 ng ml(-1) with %f-PSA <15, <20 and <25%, respectively. A median of 18 and 26 cores in case of primary and repeated biopsy were determined; 2123 men underwent prostate biopsy, of whom 1589 (74.8%) had a PSA ≤ 10 ng ml(-1). A PCa was found in 777 (36.6%) and in 35 (23.3%) patients at primary and repeated biopsy: 459 and 26 men had PSA ≤ 10 ng ml(-1) and 419 and 26 patients underwent surgery, respectively, 244 (58.3%) and 18 (69.2%) had an organ-confined PCa with a pIPCa incidence equal to 1.4 and 7.7%, respectively. Cancer detection rate of 28.8% in patients with PSA ≤ 10 ng ml(-1) associated with a low incidence of pIPCa should induce to introduce %f-PSA in screening programmes to reduce the risk of overdiagnosis.

Detection rates of nonpalpable prostate cancer in Korean men with prostate-specific antigen levels between 2.5 and 4.0 ng/mL

OBJECTIVE

To evaluate the detection rate and pathology of cancer in Korean men with low levels of prostate-specific antigen (PSA), 2.5-4.0 ng/mL.

METHODS

We examined 1097 patients with PSA level of 2.5-10.0 ng/mL, who underwent transrectal ultrasonography-guided prostate needle biopsies between January 2008 and March 2009. Of the 1097 biopsy patients, 815 met our criteria of benign findings by digital rectal examination and the absence of cancerous lesions by TRUS. Clinical characteristics and detection rates of prostate cancer, as well as the pathology of specimens obtained by needle biopsies and prostatectomies, were evaluated in these patients.

RESULTS

Of the 815 patients, 349 had group 1 (PSA level, 2.5-4.0 ng/mL) and 466 had group 2 (PSA level, 4.0-10.0 ng/mL). The percentage of patients diagnosed with prostate cancer was not statistically different between the 2 groups (21.8% in group 1, and 20.2% in group 2). In group 1, 70.7% of patients had a pathologic Gleason score of 7 or higher and 91.4% had organ-confined tumors (pT2). The pathologic characteristics, including Gleason score, pathologic stage, and percentage of insignificant cancer were similar in prostatectomy specimens between group 1 and group 2.

CONCLUSIONS

Detection rates of nonpalpable prostate cancer in Korean men were 21.8% in group 1 and 20.2% in group 2 without statistically significant difference. Pathologic characteristics of prostatectomy specimens also were similar between group 1 and group 2. These results suggest that a lower PSA level might be considered as an indication for prostate biopsy.

High-b-value diffusion-weighted imaging at 3 T to detect prostate cancer: comparisons between b values of 1,000 and 2,000 s/mm2

OBJECTIVE

The objective of our study was to investigate the diagnostic performance of 3-T MRI of the prostate using diffusion-weighted imaging (DWI) with high b values (1,000 and 2,000 s/mm2) and a phased-array coil in predicting localized prostate cancer.

MATERIALS AND METHODS

Forty-eight patients underwent single-shot echo-planar DWI at 3 T, followed by radical prostatectomy. DWI was performed at high b values of 1,000 and 2,000 s/mm2. Apparent diffusion coefficient (ADC) maps were analyzed by visual and quantitative assessment for tumor and benign tissue in the peripheral and transition zones. The visual and quantitative results of ADC maps obtained at b values of 1,000 and 2,000 s/mm2 were compared with the histopathologic findings.

RESULTS

To predict localized prostate cancer, the sensitivity of ADC maps obtained at a b value of 1,000 versus 2,000 s/mm2 was 88% and 71%, respectively, and the accuracy was 89% and 86% (p<0.01). The mean ADC values of tumors in both the peripheral and transition zones were significantly lower than those of benign tissues at both b values of 1,000 and 2,000 s/mm2 (p<0.001).

CONCLUSION

Prostate DWI performed at 3 T using high b values was able to improve differentiation of tumors from benign tissue. DWI performed using a b value of 1,000 s/mm2 was more sensitive and more accurate in predicting localized prostate cancer than DWI performed using a b value of 2,000 s/mm2.

[Incidence of locally invasive prostate cancer in patients with intermediate values of prostate-specific antigen]

BACKGROUND/AIM

Feasibility of radical prostatectomy (RP) in patients with locally invasive prostate cancer (PC) is assessed by the standard parameters such as the stage of the disease, serum prostate-specific antigen (PSA) and bioptic Gleason grade (GG). Intermediate values of PSA are important in predicting the local confines of the tumor, but can also be detected in more than 30% of patients with locally advanced PC. The aim of this study was to find out the incidence of locally advanced PC in the patients with intermediate serum PSA in whom RP had been performed.

METHODS

We used the biopsy cores and the tissue obtained after RP from 46 patients who had intermidiate PSA values which were defined as PSA from 2.6-10 ng/ml. In all the patients classical regional lymphadenectomy was performed. In all the patients, preoperative stage was determined according to the Partin tables (PT) from 2001.

RESULTS

In 52, 17% of the patients biopsy GG was < or = 6, while it was 7 in 47.83% of the patients. Clinically localized disease (cT2b) was found in 86.96% of patients; other 13.04% of the patients had locally advanced PC. After RP, the incidence of localized PC was 47.83%, while the advanced disease was found in 52.17%. Metastasis in one or two regional lymph nodes (N1) was found in 10.87% of the patients with the advanced PC. According to PT, the expected incidence of positive lymph nodes should have been 8% for pT3 stage. Positive correlation between the assumed N1 stage according to PT and N1 stage in our radical prostatectomies was statistically significant (p = 0.012).

CONCLUSION

In more than 50% of patients with intermediate values of PSA locally advanced disease can be expected after RP. The use of the Partin tables have an important predictive value in assessing the local confines of the cancer and metastasis in regional lymph nodes.