M1 prostate cancer with a serum level of prostate-specific antigen less than 10 ng/mL

BACKGROUND: M1 prostate cancer, which is invasive, is usually associated with a serum level of prostate-specific antigen (PSA) greater than 10 ng/mL, but cases are occurring where the serum PSA level is less than this. The present study investigated the clinical and pathologic characteristics of these cases of M1 prostate cancer. METHODS: Between April 1989 and March 1998, 167 cases of M1 prostate cancer were diagnosed by transrectal needle biopsy and eight of these with a serum PSA level less than 10 ng/mL were investigated. The patients' ages ranged from 57 to 79 years (median, 73) and the serum PSA levels ranged from less than 4.0 to 9.8 ng/mL. In all cases except one, the distal metastasis was to bones only. All cases had received hormonal therapy as the initial therapy. Immunostaining of PSA, chromogranin A, neuron-specific enolase, carcinoembryonic antigen and vimentin were performed in five of the eight cases. RESULTS: Four cases were poorly differentiated, two were undifferentiated, one was a mixture of poorly differentiated and undifferentiated and one case was moderately differentiated. Of the five cases in the immunohistochemical study, three cases with an undifferentiated carcinoma component showed negative staining reactions for PSA and all cases were positive for carcinoembryonic antigen. Four of the patients died of prostate cancer. In two of these four cases, hormonal therapy was ineffective, but systemic chemotherapy and irradiation therapy had been moderately effective. The overall 3-year survival rate was 33.3%. CONCLUSIONS: The cases of M1 prostate cancer with a serum PSA less than 10 ng/mL are almost always poorly differentiated or undifferentiated and have a poor prognosis compared with the usual M1 prostate cancer. Because hormonal therapy is ineffective in these cases, systemic chemotherapy and irradiation therapy should be chosen as the initial therapy.     

Prostate cancer detection by prostate biopsy among Japanese with prostate-specific antigen below 4.0 ng/ml

The cases of prostate cancer diagnosed at our hospital after the introduction of transrectal ultrasound-guided prostate biopsy were analyzed to ascertain the cancer detection rate among individuals with a prostate-specific antigen (PSA) below 4.0 ng/ml and to assess the pathological characteristics of the prostatectomy specimens. During the period from January 1997 to December 2003, 1,167 individuals received prostate biopsies at our hospital. Before March 2003, the PSA cut-off level for biopsy was set at 4.0 ng/ml, but a biopsy was sometimes performed if a rectal examination revealed abnormalities or the patient desired a biopsy with a PSA below 4.0 ng/ml. After April 2003, all individuals with a PSA over 3.1 ng/ml were biopsied. The results of the prostate biopsy and the pathology data on radical prostatectomy specimens were compared between individuals with a PSA below 4.0 ng/ml and those with a PSA of 4.1-10 ng/ml. The prostate cancer detection rate among individuals with a PSA between 3.1 and 4.0 ng/ml was 19.4% (12/62) before March 2003 and 15.6% (7/45) after April 2003. The number of cancer-positive core was significantly lower among individuals with a PSA below 4.0 ng/ml. On prostatectomy specimens the percentage of surgical margin positive cases was significantly higher among individuals with a PSA below 4.0ng/ml (17 cases) than those with a PSA of 4.1-10 ng/ml (67 cases), although there was no significant difference between these two groups in terms of the pathological stage and Gleason score. Our results indicate that the prostate cancer detection rate is also high among Japanese men with a PSA below 4.0 ng/ml. The biopsy results and pathological features for prostate cancer with a PSA below 4.0 ng/ml did not differ markedly from prostate cancer with a PSA in the gray zone (4.1-10.0 ng/ml).     

Complexed prostate specific antigen (PSA) reduces unnecessary prostate biopsies in the 2.6-4.0 ng/mL range of total PSA

OBJECTIVE: To compare the performance of complexed prostate-specific antigen (cPSA) to total PSA (tPSA) and percentage free PSA (f/tPSA) in the diagnosis of prostate cancer for the tPSA range 2.6-4.0 ng/mL. PATIENTS AND METHODS: Consecutive men scheduled for prostate biopsy were enrolled prospectively at 14 different sites in two multicentre studies in Europe and the USA. Serum obtained before biopsy was tested with the ACS:180 and Immuno 1 tPSA and cPSA assays (Bayer Diagnostics, Tarrytown, NY, USA) and the Access fPSA and tPSA assays (Beckman, Inc., San Diego, CA, USA). Receiver operating characteristics (ROC) curves were generated to compare the diagnostic performance of tPSA, cPSA and f/tPSA. RESULTS: Of 316 men with a tPSA of 2.6-4.0 ng/mL, 82 (26%) were diagnosed with prostate cancer on biopsy. ROC analysis of all 316 men showed an area under the curve (AUC) for cPSA of 0.63, significantly greater than the AUC for tPSA of 0.56 (P = 0.008). At a sensitivity of 95%, threshold values of 2.3 ng/mL for cPSA and 2.73 ng/mL for tPSA provided specificities of 20.1% and 9.8%, respectively. f/tPSA was only available for 205 of the 316 (65%) men and the AUC for cPSA was 0.63, and did not significantly differ from the f/tPSA AUC of 0.64 (P = 0.58). CONCLUSIONS: As a single test, cPSA provides improved specificity over tPSA and comparable specificity to f/tPSA for detecting prostate cancer, and may reduce the number of unnecessary prostate biopsies in the 2.6-4.0 ng/mL tPSA range.     

Characterizing prostatic adenocarcinomas in men with a serum prostate specific antigen level of < 4.0 ng/mL

OBJECTIVE: To characterize prostate cancer in men undergoing radical prostatectomy who have a prostate-specific antigen (PSA) level of < 4.0 ng/mL, hypothesizing that a low PSA is not caused by diminished tumour production of PSA, nor does it signify clinically insignificant disease. PATIENTS AND METHODS: Seventy-nine men (mean age 59.3 years, range 43-77) with a PSA level of < 4.0 ng/mL were identified from 702 who had a radical prostatectomy between 1994 and 2000. Demographic and clinical data were analysed; pathological specimens were evaluated by routine haematoxylin and eosin staining and immunohistochemistry with anti-PSA antibody, for both pathological staging and grading, and for the presence of PSA production. Tumours were classified as 'clinically insignificant' if the tumour volume was < 0.5 mL and the Gleason score < 7. RESULTS: The mean (SD, range) preoperative PSA level was 3.04 (0.85, 0.8-3.8) ng/mL Indications for biopsy included an abnormal digital rectal examination (61%), a PSA velocity of > 0.75 ng/mL/year (12%), a strong family history of prostate cancer (3%), obstructive urinary symptoms (2%), or no obvious indication (23%). Thirty-eight (48%) tumours were clinically insignificant. Of 41 clinically significant cancers, 13 had a final Gleason score of > or = 7, 20 had extraprostatic extension and 11 had a tumour volume of > or = 10 mL Of the 79 prostate cancer specimens 78 stained strongly for PSA; the exception was a Gleason 9 tumour. With a mean (range) follow-up of 3.5 (0.18-6) years only one patient had a biochemical recurrence (PSA > or = 0.1 ng/mL). CONCLUSIONS: Most prostate cancers in men with a PSA level of < 4.0 ng/mL are clinically significant and PSA-producing. Many of these tumours are high-grade, high-volume and extraprostatic. We are currently exploring factors to explain why serum PSA is not elevated in these men, including tumour location, pattern of invasion and microvessel density.     

Evaluation of proprostate specific antigen for early detection of prostate cancer in men with a total prostate specific antigen range of 4.0 to 10.0 ng/ml

PURPOSE: In contemporary screening populations a major drawback of prostate specific antigen (PSA) is its relative lack of specificity, especially in the range of 4 to 10 ng/ml, where prostate cancer is found 25% of the time. ProPSA is a derivative of free PSA (fPSA) consisting of the truncated forms (eg [-2]proPSA, [-4]proPSA or the full-length [-7]proPSA). There is increasing evidence that proPSA is associated preferentially with prostate cancer. The objective of this study was to determine whether proPSA can influence the detection of early prostate cancer. MATERIALS AND METHODS: Archival serum samples obtained from 93 men who underwent a systematic 12-core prostate biopsy (total PSA range 4.0 to 10.0 ng/ml) were assayed for percent free PSA, total PSA and the 3 forms of proPSA (Hybritech Tandem Assays Beckman Coulter Access, Beckman Coulter, Inc., Brea, California). Free PSA, the cumulative sum of individual proPSA forms ([-2], [-4] and [-7], or sum-proPSA) and derivatives were determined. Of the 93 men assessed 41 (44%) had evidence of prostate cancer (76% Gleason 5/6, 19% Gleason 7 and 5% Gleason 8). Prostate volume was measured at systematic 12-core biopsy for the detection of prostate cancer. Results were analyzed using univariate and multivariate logistic regression (LR) nonparametric statistical methods. RESULTS: Using univariate LR, fPSA, percent fPSA (%fPSA), percent sum-proPSA and prostate volume significantly (p <0.05) differentiated men with prostate cancer from those with benign disease. However, applying stepwise backward multivariate LR, total PSA, %fPSA and sum-proPSA were retained and generated a receiver operator characteristic curve with an area under the curve of 76.6%. At 90% sensitivity these 3 variables collectively achieved a specificity of 44% for the detection of prostate cancer. Individually, the 3 retained variables had a specificity of 23% (total PSA), 33% (%fPSA) and 13% (sum-proPSA). CONCLUSIONS: Sum-proPSA, total PSA and %fPSA in combination improve the specificity of early prostate cancer detection in men with a total PSA of 4 to 10 ng/ml compared with the results of individual PSA molecular forms measured.     

Complexed prostate-specific antigen improvement in detecting prostate cancer

This article presents the current reports of complexed prostate-specific antigen (PSA) aimed for the enhancement of prostate cancer detection. Further studies are needed to ascertain the variability of complexed PSA. Comparisons of percent free PSA, potential additive value of a1 -antichymotripsin-bound PSA (PSA-ACT) and Bayer complexed PSA (cPSA) remains controversial in men with intermediate elevated total PSA concentration. Volume-referenced complexed PSA (PSA-ACT and cPSA) can enhance prostate cancer detection. Preliminary results show that PSA-α₂ -macrobloblin (PSA-α₂M) and PSA-α₁ -protease inhibitor (PSA-API) are promising assays for improving cancer detection.     

Prostate cancer detection among men with prostate specific antigen levels of 2.5 to 4.0 ng/ml in a Japanese urological referral population

PURPOSE: Prostate cancer detection at levels of 2.5 to 4.0 ng/ml in a Japanese urological referral population has not been elucidated. The purpose of this study is to investigate the cancer detection rate and clinical relevance of prostate cancer in this PSA range. MATERIALS AND METHODS: All urological patients 70 years or younger tested for prostate cancer were studied. There were 550, 97, 112 and 52 patients with a PSA of less than 2.5, 2.5 to 4.0, 4.1 to 10.0 and more than 10.0 ng/ml, respectively. Transrectal 10-core prostate biopsy was performed in 80 (82%) of the 97 patients with a PSA of 2.5 to 4.0 ng/ml and 102 (91%) of the 112 patients with a PSA of 4.1 to 10.0 ng/ml. RESULTS: Cancer detection rates in patients who underwent biopsy were 26.3% and 34.3% at PSA levels 2.5 to 4.0 and 4.1 to 10.0 ng/ml, respectively. High grade cancers with Gleason score 7 or more were found in 19.0% and 22.9% of patients with cancer with PSA 2.5 to 4.0 and 4.1 to 10.0 ng/ml, respectively. No significant difference was found between the 2 groups in pathological findings on biopsy, including percent positive cores (16.7% vs 20.0%, p = 0.10), maximum cancer length (25.0% vs 30.0%, p = 0.28) and maximum percent cancer length (2.0 vs 3.0 mm, p = 0.17). CONCLUSIONS: Japanese urological referral patients develop prostate cancer quite commonly even if their serum PSA levels are 2.5 to 4.0 ng/ml. Since these cancer cases include high grade, clinically significant cancer, prostate biopsy might be considered at least for selected cases in this PSA range.     

The incidence of prostate cancer in a screening population with a serum prostate specific antigen between 2.5 and 4.0 ng/ml: relation to biopsy strategy

PURPOSE: It has recently been suggested that the diagnostic threshold for the prostate specific antigen (PSA) assay be lowered to enhance prostate cancer detection. A 22% incidence of prostate cancer has been reported in men with PSA between 2.5 and 4.0 ng/ml. We designed a study to confirm this observation. MATERIALS AND METHODS: Men who participated in our free early detection program and who had serum PSA between 2.5 and 4.0 ng/ml were asked to undergo prostate biopsy. Of 268 eligible men 151 (56%) agreed to participate in this free trial. All men underwent biopsy using an 11-core multisite directed biopsy scheme. All biopsy cores were color coded for location specificity and examined by 1 pathologist. RESULTS: Cancer was identified in 24.5% (37 of 151) of the men biopsied. The median age of men with cancer was 62 years (range 43 to 74). Conventional systematic sextant biopsies, which accounted for 6 of the 11 cores, detected 73.0% (27 of 37) of the cancers and the alternate site biopsies identified the remaining 10. Gleason score was 6 in 25 men, 3 + 4 in 5, 4 + 3 in 4 and 8 or greater in 3 (median Gleason score 6). There were 14 men who had 1 core positive for cancer, 9 had 2 and 14 had more than 2 (median number of positive cores 2). Of the 14 men with 1 positive core 11 had a less than 3 mm focus of cancer and 8 had only a positive alternate site biopsy. There were 11 cases of abnormal results on digital rectal examination, 5 of which were cancer, and 31 cases of abnormal results on ultrasonography, 13 of which were cancer. Median biological variability in PSA was +/-15% (range 0.4% to 440.0%). CONCLUSIONS: We found a significant incidence of cancer (24.5%, 37 of 51) in men with serum PSA between 2.5 and 4.0 ng/ml. In our study 67.6% of the detected cancers were significant based on the biopsy data. If the PSA threshold is lowered the conventional systematic sextant technique may be preferable to an extended strategy.     

Early detection of prostate cancer in Germany: a study using digital rectal examination and 4.0 ng/ml prostate-specific antigen as cutoff

OBJECTIVE: While international screening studies for prostate cancer are by now almost reaching the estimated number of recruitments mandatory for the necessary power to investigate an effect on mortality of prostate cancer, no statistical figures on the detection of prostate cancer in Germany - apart from historical data before the use of prostate-specific antigen (PSA) are available. In order to generate a database and to investigate the diagnostic efficacy of the primarily practice-based urological care system, a case finding study designed as a nationwide longitudinal early detection trial was initiated. METHODS: In one week in November 1997, 963 urologists prospectively examined 11,644 men between 45 and 75 years of age by digital rectal examination (DRE) and PSA with 4.0 ng/ml as cutoff. Data of family history and physical examination were collected by questionnaire. At this time participants were not aware of their PSA value. PSA was determined in the study center. Indication for sextant biopsy was a PSA value above 4.0 ng/ml or a suspicious lesion on DRE. Any indicated biopsy not performed had to be clarified. In a second questionnaire results of prostate biopsy, treatment and tumor status were documented. RESULTS: The mean age of the study population was 62 years (median 62). The PSA median was 1.4 ng/ml with 82.8% presenting with < 4.0 ng/ml, 12.8% with 4-10 ng/ml and 4.4% with >10 ng/ml. From 1,115 men (47.7%) biopsied, 262 cancers were detected resulting in a detection rate of 23.5%. While 399 men refused biopsy, further investigation was not recommended in 387 men by their urologist, because prostatitis or benign hyperplasia was thought to be the cause for elevated PSA. From the 143 patients undergoing radical prostatectomy, 93 (65%) cancers were organ confined. T(1c) cancers with elevated PSA > 10 ng/ml could be treated with curative intent in 44% only. The positive predictive value (PPV) was estimated to be 16% for DRE alone (14/90), 17% for PSA alone (143/819) and 51% for the combination of both (105/206). In that cohort, use of age-adjusted PSA values and PSA density increased the PPV of PSA testing nonsignificantly. CONCLUSIONS: Significant higher PPV indicated that utilizing a combination of both DRE and PSA is most effective in the early detection of prostate cancer. Unnecessary biopsies can be avoided using either age-adjusted PSA value or PSA density, but the PPV is not significantly changed and potentially curable cancer is missed in up to 25%. Given the substantial variability of the diagnostic approach despite the study design, uniform guidelines are necessary to ensure countrywide sufficient screening.     

Comparison of two investigative assays for the complexed prostate-specific antigen in total prostate-specific antigen between 4.1 and 10.0 ng/mL

OBJECTIVES: To determine the ability of complexed prostate-specific antigen (cPSA) levels to diagnose prostate cancer. METHODS: Between September 1998 and March 1999, cPSA levels in 182 consecutive patients with an abnormal digital rectal examination (DRE) or a total PSA (tPSA; Tandem-R assay) level greater than 4.1 ng/mL were examined. Levels of cPSA were measured by the Markit-M PSA-ACT (alpha(1)-antichymotrypsin) assay (cPSA-MM) and Bayer Immuno 1 complexed PSA assay (cPSA-BI). Free PSA (fPSA) was measured by the Tandem-R free PSA assay. RESULTS: Of the 140 patients with tPSA between 4.1 and 10.0 ng/mL, 116 were histologically confirmed as having benign tissue; the remaining 24 were diagnosed with prostate cancer. To ensure a 92% sensitivity of cancer detection, a cutoff value for the tPSA, cPSA-MM, and cPSA-BI assays of 4.8 ng/mL, 2.7 ng/mL, and 4.6 ng/mL, respectively, was determined. The percentage of negative biopsies prevented at these cutoff (ie, specificity) values was 14%, 23%, and 24%. No significant differences among these three assays were found. At 92% sensitivity, the cutoff value for the fPSA/tPSA, fPSA/cPSA-MM, and fPSA/cPSA-BI ratios was 18%, 27%, and 18%, respectively. The specificity was 35%, 49%, and 51%. No significant differences were found among these three fPSA ratios. Significant differences were noted between tPSA and the fPSA/cPSA-MM ratio and between tPSA and the fPSA/cPSA-BI ratio. No differences were seen among the other PSA parameters. CONCLUSIONS: No difference in the ability of cPSA levels to distinguish prostate cancer and noncancer was observed between cPSA-MM and cPSA-BI or between their fPSA ratios. Only the fPSA/cPSA-MM and fPSA/cPSA-BI ratios provided significantly enhanced diagnostic performance compared with tPSA.     

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

Study Type – Prognosis (inception cohort) Level of Evidence 1b What’s known on the subject? and What does the study add? Large population screening trials like the ERSPC, PCPT and PLCO have noted that men with seemingly low PSA (even as low as 0.5 ng/dL) still can have prostate cancer. Despite these findings, PSA is still predominantly used as a current indicator for possible presence of prostate cancer rather than also serving as a prognostic marker. This study examines a larger number of men in a diverse US population to determine the prognostic value of a man’s baseline or first PSA.

OBJECTIVES

? To assess the value of a PSA threshold of 1.5 ng/mL as a predictor of increased prostate cancer risk over a four‐year period based on a man’s first PSA test, including racial differences. ? To review the risk of progression of benign prostatic hyperplasia (BPH) based on a similar PSA threshold.

PATIENTS AND METHODS

? A retrospective review involving 21 502 men from a large Midwestern health system was performed. ? Men at least 40 years old with baseline PSA values between 0 and 4.0 ng/mL and at least four years of follow‐up after initial PSA test were included. ? Optimal PSA threshold and predictive value of PSA for development of prostate cancer were calculated.

RESULTS

? Prostate cancer rates were 15‐fold higher in patients with PSA ≥1.5 ng/mL vs patients with PSA <1.5 ng/mL (7.85% vs 0.51%). ? African American patients with baseline PSA <1.5 ng/mL faced prostate cancer rates similar to the whole study population (0.54% vs 0.51%, respectively), while African American patients with PSA 1.5–4.0 ng/mL faced a 19‐fold increase in prostate cancer.

CONCLUSION

? Both Caucasian and African American men with baseline PSA values between 1.5 and 4.0 ng/mL are at increased risk for future prostate cancer compared with those who have an initial PSA value below the 1.5 ng/mL threshold. ? Based on a growing body of literature and this analysis, it is recommended that a first PSA test threshold of 1.5 ng/mL and above, or somewhere between 1.5 and 4.0 ng/mL, represent the Early‐Warning PSA Zone (EWP Zone). ? This should serve to inform patients and clinicians alike to future clinical activities with respect to prostate cancer and BPH.     

Volume-adjusted prostate-specific antigen (PSA) variables in detecting impalpable prostate cancer in men with PSA levels of 2-4 ng/mL: transabdominal measurement makes a significant contribution

OBJECTIVE: To examine whether prostate-specific antigen (PSA) levels adjusted according to prostate volume improve prostate cancer detection using transrected biopsies in men with PSA levels of 2-4 ng/mL, and benign findings on a digital rectal examination (DRE). PATIENTS AND METHODS: Men aged < or = 79 years and with serum PSA levels of 2-4 ng/mL and normal DRE findings were prospectively enrolled. Eligible patients were recommended for transrectal prostate biopsies after measuring prostate volumes with transrectal (TRUS) and transabdominal (TAUS) ultrasonography, and transition zone volumes with TRUS. In addition to PSA levels and the free-to-total PSA ratio, volume-adjusted PSA levels, PSA densities determined by TRUS (PSAD(TRUS)), and TAUS (PSAD(TAUS)), and PSA transition zone densities (PSATzD) were compared using receiver operating characteristic analysis. RESULTS: Prostate cancer was diagnosed in 31 (22%) of the 139 men who had prostate biopsies. The area under the curve (AUC) of PSAD(TRUS) (0.796) and PSATzD (0.792) was similar and significantly greater than that of PSA (AUC 0.588) and the free-to-total PSA ratio (AUC 0.658). PSAD(TAUS) was a significantly better indicator of prostate cancer than PSA levels alone (P = 0.043). CONCLUSION: As predictors of prostate cancer, there were no significant differences between PSAD(TRUS) and PSATzD. Although PSAD(TAUS) was worse than PSA variables adjusted by total and transition zone prostate volumes determined by TRUS, it was a better predictor than the PSA value alone in men with a low PSA level. These results indicate that TAUS is worthwhile where the routine use of TRUS before biopsy is difficult.     

Tumour markers for managing men who present with metastatic prostate cancer and serum prostate-specific antigen levels of <10 ng/mL

OBJECTIVE: To define immunohistochemical features of the primary cancers that might help in the differential diagnosis and monitoring of treatment in men presenting with metastatic prostate cancer and low serum levels of prostate-specific antigen (PSA), who can be difficult to diagnose and manage. PATIENTS AND METHODS: Paraffin blocks of prostate biopsies were obtained for 33 patients presenting with untreated metastatic prostate cancer and serum PSA levels of <10 ng/mL. Sections were immunostained for PSA, prostatic acid phosphatase (PAP), prostate-specific membrane antigen (PSMA), androgen receptor (AR), chromogranin A and CD 56. RESULTS: The combined Gleason scores were 8-10 in 25 men (76%) and 6 or 7 in the other eight (24%). Morphologically, there were no neuroendocrine features. PSA immunostaining was equivocal in 12 (36%) cases and in a further 19 (58%) was strong but focal and could be missed on biopsy sampling. PSMA was expressed in 90% of cases, and staining was widely distributed in nine of the 12 in which PSA staining was equivocal. There was strong AR expression in 30 (91%) cases and it was present in areas where PSA was absent. CONCLUSION: In this patient group, immunohistochemical assessments of PSMA and AR are potentially useful as diagnostic markers.