Longitudinal Evaluation of Prostate-Specific Antigen Levels in Men With and Without Prostate Disease

Watchful waiting as a treatment option for localized prostate cancer in the PSA era

The incidence rate of early-stage prostate cancer has dramatically increased since the introduction of the widespread use of PSA testing in developed countries, including Japan. With the downward stage migration there has been much interest in the concept of watchful waiting not only for elderly patients with a life expectancy of less than 10 years but also in younger patients with good social and sexual activity. The results of a recent randomized comparison between radical prostatectomy and watchful waiting for localized disease indicated comparable overall survival but superiority of surgery in disease-specific survival. The predictive value of clinico-pathological parameters including biopsy features and serum PSA seems insufficient to predict tumor growth potential. Our ongoing prospective study is aimed at clarifying whether PSA doubling time assessment for 6 months in patients with favorable biopsy features can be a good indicator for further watchful waiting or immediate aggressive treatment without any survival disadvantage.

Prostate specific antigen density. Is there a role for this parameter when screening for prostate cancer?

The objective of this paper is to validate prostate specific antigen (PSA) density (PSAD) routine use to enhance PSA specificity in men with normal digital rectal examination and intermediate PSA values. It is a retrospective study of 235 men from a prostate cancer (PCa) screening program. All of them presented PSA values between 4 and 10 ng/ml, normal digital rectal examination, and a transrectal ultrasound (TRUS) guided biopsy available (PSA>/=4 ng/ml as the sole criterion for biopsy). Multivariate analysis failed to demonstrate higher PSAD values in men with PCa. PSAD cutoff points higher than 0.07 ng/ml per cc were considered as unacceptable, with less than 95% sensitivity. When a cutoff point of 0.15 was considered, as many as 30.6% of the cancers were missed. In conclusion we cannot recommend the use of this parameter for the above mentioned purpose.Prostate Cancer and Prostatic Diseases (2001) 4, 146-149.

The Proportion of Prostate-specific Antigen (PSA) Complexed to α1-Antichymotrypsin Improves the Discrimination between Prostate Cancer and Benign Prostatic Hyperplasia in Men with a Total PSA of 10 to 30 μg/L

Background: The aim of this study was to assess the diagnostic accuracy of the proportion of prostate-specific antigen (PSA) complexed to α1-antichymotrypsin (PSA-α1ACT:PSA ratio) in the differential diagnosis of prostate cancer (CaP) and benign prostatic hyperplasia (BPH) in men with total PSA of 10–30 μg/L.

Methods: We used our immunoassays (ELISAs) for total PSA and PSA-α1ACT complex to study 146 men. In 123, total PSA was between 10 and 20 μg/L; 66 of these had CaP and 57 BPH. In 23 men, total PSA was between 20 and 30 μg/L; 14 of these had CaP and 9 BPH. We calculated the area under the ROC curves (AUC) for total PSA, PSA-α1ACT complex, and PSA-α1ACT:PSA ratio, and determined the cutoff points that gave sensitivities approaching 100%.

Results: In the total PSA range between 10 and 20 μg/L, the AUC was significantly higher for the PSA-α1ACT:PSA ratio (0.850) than for total PSA (0.507) and PSA-α1ACT complex (0.710; P <0.0001). A cutoff ratio of 0.62 would have permitted diagnosis of all 66 patients with CaP (100% sensitivity) and avoided 19% of unnecessary biopsies (11 of 57 patients). In the total PSA range between 20 and 30 μg/L, the AUC for the PSA-α1ACT:PSA ratio (0.980; 95% confidence interval, 0.82–0.99) was greater than the AUC for total PSA (0.750; 95% confidence interval, 0.51–0.89; P = 0.042). In this range, a cutoff point of 0.64 would have permitted the correct diagnosis of all 14 patients with CaP and 6 of the 9 with BPH.

Conclusions: The diagnostic accuracy of the PSA-α1ACT:PSA ratio persists at high total PSA concentrations, increasing the specificity of total PSA. Prospective studies with large numbers of patients are needed to assess whether the ratio of PSA-α1ACT to total PSA is a useful tool to avoid unnecessary prostatic biopsy in patients with a total PSA >10 μg/L.

Relationship between prostate volume, prostate-specific antigen nadir, and biochemical control

PURPOSE

In patients treated with definitive three-dimensional conformal radiotherapy (3D-CRT) for localized prostatic adenocarcinoma, we sought to evaluate the relationship between pretreatment prostate gland volume and posttreatment prostate-specific antigen (PSA) nadir, as well as the relationship of prostate volume and PSA nadir with biochemical control (bNED). Two subgroups were studied: favorable (PSA <10 ng/mL, Gleason score 2-6, and T1-T2A) and unfavorable (one or more: PSA >/=10 ng/mL, Gleason score 7-10, T2B-T3).

MATERIALS AND METHODS

A total of 655 men (n = 271 favorable and 384 unfavorable) were treated with 3D-CRT alone between May 1989 and November 1997. All patients had information on prostate volume and a minimum follow-up of 24 months (median 56, range 24-126). Of the 655 men, 481 (n = 230 favorable and 251 unfavorable) remained bNED at time of analysis, with biochemical failure defined in accordance with the American Society for Therapeutic Radiology and Oncology consensus definition. Factors analyzed for predictors of bNED included pretreatment prostate volume, posttreatment PSA nadir, pretreatment PSA, palpation T stage, Gleason score, center of the prostate dose, and perineural invasion (PNI). We also analyzed pretreatment prostate volume and its correlation to prognostic factors. For bNED patients, the relationship between PSA nadir and prostate volume was evaluated.

RESULTS

On multivariate analysis, prostate volume (p = 0.04) and palpation T stage (p = 0.02) were the only predictors of biochemical failure in the favorable group. On multivariate analysis of the unfavorable group, pretreatment PSA (p <0.0001), Gleason score (p = 0.02), palpation T stage (p = 0.009), and radiation dose (p <0.0001) correlated with biochemical failure, and prostate volume and PNI did not. For all 481 bNED patients, a positive correlation between pretreatment volume and PSA nadir was demonstrated (p <0.0001). Subgroup analysis of the favorable and unfavorable patients also demonstrated a positive correlation between prostate volume and PSA nadir (p = 0.003 and p = 0.0002, respectively). Using multiple regression analysis, the following were found to be predictive of PSA nadir in all bNED patients: prostate volume (p <0.0001), pretreatment PSA (p <0.0001), palpation T stage (p = 0.0002), and radiation dose (p = 0.0034). Gleason score and PNI were not predictive. For the favorable group, palpation T stage (p = 0.0006), pretreatment PSA (p = 0.0083), prostate volume (p = 0.0186), and Gleason score (p = 0.0592) were predictive of PSA nadir, and PNI and radiation dose were not predictive. In the unfavorable group, prostate volume (p = 0.0024), radiation dose (p = 0.0039), pretreatment PSA (p = 0.0182), and palpation T stage (p = 0.0296) were predictive of PSA nadir, and Gleason score and PNI were not predictive.

CONCLUSION

This report is the first demonstration that prostate volume is predictive of PSA nadir for patients who are bNED in both favorable and unfavorable subgroups. PSA nadir did not correlate with bNED status in the favorable patients, but it was strongly predictive in the unfavorable patients. Prostate gland volume was also predictive of bNED failure in the favorable but not the unfavorable group.

Comparative evaluation of total PSA, free/total PSA, and complexed PSA in prostate cancer detection

OBJECTIVES

To compare the performance of prostate-specific antigen (PSA), the free/total PSA (F/T PSA) ratio, and complexed PSA (cPSA) in prostate cancer detection.

METHODS

Five hundred thirty-five patients evaluated at the UROMED prostate cancer detection clinic had total PSA, free PSA, and cPSA measured before undergoing transrectal ultrasonography and sextant prostate biopsies. A direct comparison was performed between the different PSA assays to evaluate their ability to detect prostate cancer.

RESULTS

Of the 535 patients evaluated, 38.1% had prostate cancer detected. The mean age of the entire population was 63.6 years (range 35 to 86). Abnormal digital rectal examination findings were present in 33.4% of the patients. The mean and median values of PSA and cPSA were significantly higher and the F/T PSA ratio was lower in patients with prostate cancer. The F/T PSA ratio performed better than either cPSA or total PSA. A higher specificity was observed with the F/T PSA ratio than with cPSA using either the entire patient population or subsets of patients with PSA levels between 4.0 and 10 ng/mL or 4.0 to 6.0 ng/mL.

CONCLUSIONS

The use of the F/T PSA ratio offers improved prostate cancer detection compared with either cPSA or total PSA.

Promoting informed decision making about prostate cancer screening

Because prostate cancer screening with prostate specific antigen is controversial, informed consent is recommended. Physicians are encouraged to discuss facts about prostate specific antigen with patients and to supplement such discussions with informational brochures or videotapes.

Correlation of initial PSA level and biopsy features with PSA-doubling time in early stage prostate cancers in Japanese men

OBJECTIVE

To distinguish good candidates for watchful waiting from those who need immediate treatment in localized prostate cancer.

METHODS

Prostate specific antigen (PSA)-doubling time (DT) was calculated by a log-linear regression model for 78 patients with clinically localized prostate cancer (T1c: 47, T2a: 6, T2b: 21, and T3: 4) under surveillance. Median observation period was 37.5 months. The first 1-year PSA-DT was compared with the overall PSA-DT in 41 patients who had been under surveillance for more than 3 years.

RESULTS

There was significant difference in the PSA-DT distribution between a pooled group of T1c and T2a and a group of T2b and T3 patients (median 58.8 versus 33.3 months, P = 0.0052). A combination of three parameters consisting of initial PSA level less than 10 ng/ml, WHO grade 1, one or two positive core per six to eight systematic biopsy cores with 50% or less cancer involvement significantly correlated with PSA-DT distribution in the T1c plus T2a group (P = 0.0034). The first year assessment of PSA-DT was identical to the overall assessment in 48.8%, 2 years or more in 36.6%, while it was 2 years or less (possibly over-estimated) in 14.6%.

CONCLUSION

PSA-DT can be predictable to some extent with the initial PSA level and biopsy features in early stage prostate cancers. Prospective study is needed to clarify whether temporary observation together with PSA-DT estimation is a safe strategy and is complementary to clinico-pathological parameters at diagnosis.

Separation methods applicable to prostate cancer diagnosis and monitoring therapy

During the last decade, significant research has been conducted using prostate-specific antigen (PSA) in the basic and clinical sciences and many advances have occurred in the clinical use of PSA for detecting and monitoring prostate cancer (PCa). Separation methods including gel-permeation chromatography, isoelectric focusing, lectin-affinity chromatography, polyacrylamide gel electrophoresis and high-performance liquid chromatography have made significant contributions to the discovery and identification of different molecular forms of PSA. Furthermore, the measurement of free and total PSA has improved the ability of PSA to detect early PCa. However, unnecessary biopsies are still needed for men with slightly elevated PSA values. On the other hand, PSA is not adequate for staging newly diagnosed PCa and prognosticating the course in individual cases. The possible application of separation methods in the basic science of prostate cancer may be associated with identification of more cancer-specific forms of PSA and discoveries of other serum proteins useful not only for detecting, but also for staging and prognosticating PCa. Such novel markers might lead to a better understanding of PCa aggressiveness and to developments in the clinical field of treatment.

[Analysis of the use of prostate specific antigen (PSA) in a health area of the Community of Madrid]

OBJECTIVES

To approach the local extent of PSA-use, and to check its yield in terms of prostate cancer (PC) detection.

METHODS

All PSA-test records (1997-1999) were reviewed and testing rates calculated per 1000 person-years. Detection rate (PC) was also estimated and referred to our PC prevalence study using the odds ratio as instrument for comparison.

RESULTS

Testing rate in the general population was 21.6/1000 person-years. PC detection rate was 1.76% (1.28 inside the prevalence study). For every CP detected in the general population with a PSA ranging 4-10 ng/ml, 2.39 (OR = 2.39) were detected in the prevalence study (OR = 4.48 for the PSA range > 10 ng/ml).

CONCLUSIONS

PSA-testing in our setting is high. PC detection rates were lower than expected.

The role of molecular forms of prostate-specific antigen (PSA or hK3) and of human glandular kallikrein 2 (hK2) in the diagnosis and monitoring of prostate cancer and in extra-prostatic disease

Prostate-specific antigen (PSA or hK3) is a glandular kallikrein with abundant expression in the prostate that is widely used to detect and monitor prostate cancer (PCa), although the serum level is frequently elevated also in benign and inflammatory prostatic diseases. PSA testing is useful for early detection of localized PCa and for the detection of disease recurrence after treatment. However, PSA has failed to accurately estimate cancer volume and preoperative staging. There is no PSA level in serum that definitively distinguishes men with benign conditions from those with prostate cancer, although PCa is rare in men with PSA levels in serum < 2.0 ng/ml. This prompted searches for enhancing parameters to combine with PSA testing, such as PSA density, PSA velocity, and age-specific reference ranges. Due to the protease structure, PSA occurs in different molecular forms in serum and their concentrations vary according to the type of prostatic disease. Human glandular kallikrein 2 (hK2) is very similar to PSA, but expressed at higher levels in prostate adenocarcinoma than in normal prostate epithelium. Blood testing for hK2 combined with different PSA forms improves discrimination of men with benign prostatic disease from those with prostate cancer. Many data have also been reported on the extra-prostatic expression of both PSA and hK2, and it is now believed that they may both have functions in tissues outside the prostate.

A multicenter clinical trial on the use of alpha1-antichymotrypsin-prostate-specific antigen in prostate cancer diagnosis

BACKGROUND

The aim was to evaluate the clinical performance of alpha(1)-antichymotrypsin prostate-specific antigen (PSA-ACT) for early diagnosis of prostate cancer (PCa) in a multicenter trial.

METHODS

Three hundred sixty-seven white men with PCa and 290 with benign prostatic hyperplasia (BPH) with tPSA concentrations between 2 and 20 microg/L were analyzed. The Elecsys system 2010 (Roche Diagnostics, Germany) was used for determination of total PSA (tPSA) and free PSA (fPSA). The PSA-ACT test was a prototype assay used on the ES system (Roche Diagnostics).

RESULTS

The median concentrations of tPSA (PCa: 8.43 microg/L vs. BPH: 6.60 microg/L) and PSA-ACT (8.30 microg/L vs. 6.46 microg/L) were significantly different, respectively. The median ratios of fPSA/tPSA (PCa: 12% vs. BPH: 16%) and PSA-ACT/tPSA (98% vs. 95%) were significantly different. Receiver operating characteristics (ROC) analysis for discrimination between PCa and BPH (tPSA between 2 and 20 microg/L) was performed with 252 matched pairs and showed that the area under the curve (AUC) of the ratio fPSA/tPSA (0.66) was significantly different from tPSA (0.50) and PSA-ACT (0.52). PSA-ACT alone or the ratio PSA-ACT/tPSA (0.56) were not significantly different from tPSA. For tPSA between 4 and 10 microg/L (n = 145 pairs), the AUC of the ratio fPSA/tPSA (0.65) was significantly higher than tPSA (0.50) and PSA-ACT (0.54). Significant differences between tPSA and PSA-ACT or PSA-ACT/tPSA (0.56) were not found.

CONCLUSIONS

The determination of PSA-ACT as well as the PSA-ACT/tPSA ratio did not improve the diagnostic impact in patients undergoing evaluation for PCa compared to fPSA/tPSA ratio.

[Factors affecting the PSA:alpha 1 antichymotrypsin/total PSA ratio]

OBJECTIVES

To evaluate the influence of several factors, including age, prostate volume, total PSA (PSA-T), clinical stage and Gleason on the PSA:alpha 1ACT/PSA-T (C/T) ratio.

MATERIAL AND METHODS

Using in-house assays, we measured plasma levels of PSA-T and PSA:alpha 1ACT complex in 622 patients with benign prostate hyperplasia (BPH) (455 with hystological confirmation and 167 with clinical evidence of absence of malignance) and in 255 patients with prostate cancer (CaP), and determined the correlation between different parameters.

RESULTS

In BPH patients, PSA-T and PSA:alpha 1ACT significantly increased with age. There was a positive correlation between age and PSA-T (r = 0.161, p < 0.0001) and PSA:alpha 1ACT (r = 0.141, p = 0.001). In contrast, the C/T ratio remained constant and below 70% in all decades. Similar results were obtained in CaP patients. In BPH patients, there was a positive correlation between prostate volume and PSA-T and PSA:alpha 1ACT, but not with the C/T ratio. In CaP patients, however, there was a negative correlation between prostate volume and the C/T ratio. An excellent correlation was found between PSA-T and PSA:alpha 1ACT, and a good correlation between PSA-T and the C/T ratio and between PSA:alpha 1ACT and C/T ratio. A multiple regression analysis showed that, in HBP and CaP patients, PSA-T and PSA:alpha 1ACT complex were the only parameters that significantly and independently influenced the C/T ratio.

CONCLUSIONS

The C/T ratio is independent of age, prostate volume, Gleason and clinical stage. Therefore, these factors need not to be considered when using the C/T ratio.

Transrectal ultrasound and biopsy in the early diagnosis of prostate cancer

BACKGROUND

Historically, the prostate was evaluated for cancer by simple digital rectal examination, and biopsy to obtain a tissue diagnosis of cancer was performed blindly. The advent of ultrasound technology offered a new way to evaluate the prostate, and biopsy techniques were soon developed to incorporate ultrasound guidance.

METHODS

The authors review the role of transrectal ultrasound (TRUS) of the prostate and ultrasound-guided biopsy of the prostate in the diagnosis of prostate cancer. These techniques are traced from their origins to the current standards of care, with attention paid to developments and controversies in recent literature.

RESULTS

Early experience with TRUS led to the description of "classic" sonographic findings of prostate cancer. To obtain a tissue diagnosis of cancer, these regions were initially targeted in ultrasound-guided biopsies. Concomitant with the development of TRUS, though, was the development of the prostate-specific antigen (PSA) assay. Over the past decade, there has been a profound stage migration due to earlier detection of prostate cancer. Most patients now diagnosed with prostate cancer have no palpable abnormality or specific sonographic findings. In response, ultrasound-guided biopsies have become more systematic, rather than lesion-specific, in nature.

CONCLUSIONS

TRUS continues to play an important role in the evaluation of the prostate when malignancy is suspected. Although the optimal method of prostate biopsy is controversial, ultrasound is critical in ensuring accurate sampling of the gland.

Prostate cancer: screening and early detection

BACKGROUND

Despite more than a decade of prostate-specific antigen (PSA)-based screening, the proven impact of screening on mortality due to prostate cancer continues to be controversial.

METHODS

A literature review of issues pertaining to the epidemiology, screening, early detection, and mortality as they relate to prostate cancer was conducted. Included in the review are PSA refinements, controversies of screening, and organization guidelines. Finally, recent reports of mortality rates in the post-PSA era are presented for discussion.

RESULTS

Prostate cancer mortality rates have begun to decline for the first time since statistics have been recorded. The recent decline in age-adjusted mortality rates from prostate cancer is significant, and this decline appears to be earlier than would have been predicted. This finding, coupled with the dramatic decline in metastatic disease, implies that PSA-based screening may be responsible for a significant portion of this improvement in mortality.

CONCLUSIONS

The cost of prostate cancer screening appears to be acceptable. Randomized studies of PSA-based screening are currently ongoing, although the results may not be available for a decade. Currently, the best evidence is derived from population-based studies that appear to show a benefit to prostate cancer screening.

[Role of PSA velocity in the detection of prostate cancer. A study of 986 males]

OBJECTIVE

To analyze the role of PSA velocity (PSAV) in the detection of prostate cancer (Pca) when compared to other valid alternatives.

PATIENTS AND METHODS

From a Pca screening program, 986 men were evaluated in two visits (601 of them agreed for a third visit). Serum PSA was performed in every visit (PSA1, PSA2 and PSA3). All Pca diagnosed after PSA1 were excluded. Criteria for biopsy (PSA2 and PSA3) were PSA > 4 ng/ml, or PSAV > 0.7 ng/ml/year. Diagnostic performance of PSAV was compared with other options (PSA alone, DRE, and PSA density -PSAD-).

RESULTS

Median age was 57 years. Median interval between visits were 679 days and 852.5 days respectively. During PSA2, 122 biopsies were indicated (91 performed). After PSA3, 78 were indicated and 24 done. This great proportion of not biopsied men was due to refusal. Seven Pca were detected during PSA2, and 5 during PSA3. Sensitivity of PSAV (two draws) was 0.86, specificity 0.95, missed 1 cancer of 7 and needed 7.5 biopsies per cancer. When three PSA samples available, PSAV missed 2 cancers of 5, and 2.7 biopsies per cancer needed. PSA alone detected 86% of the cancers, multiplying by 2 the number of biopsies needed. Not DRE, nor PSAD improved the diagnostic performance of PSAV when combined with this parameter.

CONCLUSIONS

Diagnostic performance of PSAV was found to be unacceptable in our hands. The need for a third biopsy in these studies make them difficult to reproduce. Validation of PSAV is a difficult task to achieve, we think its role remains questioned.

Prostate Cancer - Old Problems and New Approaches. (Part II. Diagnostic and Prognostic Markers, Pathology and Biological Aspects)

Diagnostic and prognostic markers for prostatic cancer (PCa) include conventional protein markers (e.g., PAP, PSA, PSMA, PIP, OA-519, Ki-67, PCNA, TF, collagenase, and TIMP 1), angiogenesis indicator (e.g., factor VIII), neuroendocrine differentiation status, adhesion molecules (E-cadherin, integrin), bone matrix degrading products (e.g., ICPT), as well as molecular markers (e.g., PSA, PSMA, p53, 12-LOX, and MSI). Currently, only PSA is used clinically for early diagnosis and monitoring of PCa. The histological differential diagnosis of prostatic adenocarcinoma includes normal tissues such as Cowper's gland, paraganglion tissue and seminal vesicle or ejaculatory duct as well as pathological conditions such as atypical adenomatous hyperplasia, atrophy, basal cell hyperplasia and sclerosing adenosis. A common PCa is characterized by a remarkable heterogeneity in terms of its differentiation, microscopic growth patterns and biological aggressiveness. Most PCa are multifocal with signi ficant variations in tumor grade between anatomically separated tumor foci. The Gleason grading system which recognizes five major grades defined by patterns of neoplastic growth has gained almost uniform acceptance. In predicting the biologic behavior of PCa clinical and pathological stages are used as the major prognostic indicators. Among the cell proliferation and death regulators androgens are critical survival factors for normal prostate epithelial cells as well as for the androgen-dependent human prostatic cancer cells. The androgen ablation has been shown to increase the apoptotic index in prostatic cancer patients and castration also promotes apoptotic death of human prostate carcinoma grown in mice. The progression of PCa, similarly to other malignancies, is a multistep process, accompanied by genetic and epigenetic changes, involving phenomenons as adhesion, invasion and angiogenesis (without prostate specific features).

Volume-weighted mean nuclear volume predicts tumor biology of clinically organ-confined prostate cancer

BACKGROUND

Estimates of volume-weighted mean nuclear volume (MNV) are the only means by which unbiased estimates of three-dimensional parameters can be obtained from a single two-dimensional section, with stereological methods. The present study was conducted to elucidate the role of MNV in predicting tumor biology for patients treated with radical prostatectomy.

METHODS

A retrospective prognostic study of 71 patients with T1/T2 disease, treated with radical prostatectomy alone, was performed. MNV was estimated using biopsy specimens based on a stereological method, and was compared with other preoperative clinical variables. For patients with prostate-specific antigen (PSA) failure, we determined the correlation of MNV with PSA doubling time (PSA DT) which was calculated using PSA values obtained with an ultrasensitive assay.

RESULTS

Mean MNVs for pathologically organ-confined and non-organ-confined tumors were 198.9 and 236.3 microm3, respectively; this difference was significant (P = 0.0364). Univariate analysis showed that PSA, MNV, and Gleason score were significant predictors of prognosis (P = 0.0126, 0.0148, and 0.0375, respectively). Multivariate analysis revealed that MNV and preoperative PSA were powerful independent predictors of prognosis (P = 0.0160 and P = 0.0147, respectively), but the Gleason score was not correlated with prognosis (P = 0.4120). For patients with PSA failure, PSA DT was significantly correlated with MNV (r = -0.597, P = 0.0099). When these patients were classified using median PSA DT at 6 months into two groups, MNV was significantly greater in PSA rapid-riser group than in the slow-riser group (P = 0.0008), but no differences were observed between these groups in PSA, the Gleason score, or cancer volume.

CONCLUSIONS

The findings of the present study suggest that MNV is a powerful predictor of PSA failure for patients with clinically organ-confined disease treated with radical prostatectomy. More importantly, they suggest that MNV can be a useful new parameter for prediction of tumor biology for patients with PSA failure after radical prostatectomy.

Evaluation of a rapid qualitative prostate specific antigen assay, the One Step PSA(TM) test

Recently, highly sensitive prostate specific antigen (PSA) kits have been developed and reported to be useful for the early identification of a chemical relapse. However, if the measurement time was short and the cost low, such an assay kit should be sufficient for cancer screening when dealing with a large number of samples. The One Step PSA test uses an immunochromatographic method to qualitatively, not quantitatively, judge a positive or negative result. We confirmed the sensitivity of the kit using purified PSA. Serum specimens from 147 men with or without prostate diseases were tested using the kit. PSA concentration of each serum specimen was independently measured by a quantitative ACS-PSA2 EIA kit (Chiron, cut-off: 2.1 ng/ml). The sensitivity of this kit was determined to be 4 ng/ml. All 33 samples with a value of greater than 4 ng/ml were clearly positive. Of the 94 samples with values less than 4 ng/ml, nine were judged as positive. The remaining 85 cases were judged as completely negative. These results indicate that the sensitivity of the One Step PSA test is 100% and the specificity is 90.4%. Tests using this kit can be easily performed at outpatient clinics or elsewhere. This kit is useful for initial cancer screening, because results can be obtained within 15 min and at a cost lower than that of ordinary PSA kits.

Prostate-specific antigen

Serum prostate-specific antigen (PSA) measurements are the most useful serum biomarker to aid in early prostate cancer detection, clinical staging and therapeutic monitoring. Although the optimal use of PSA testing remains controversial, population based studies suggest that PSA screening reduces prostate cancer mortality. Customizing screening protocols based on individual risk factors and PSA level may be a useful approach to reduce overall costs incurred by widespread PSA testing. Lowering PSA cut-offs (i.e., from 4.0 ng/ml to 2.5 ng/ml) may reduce advanced stage prostate cancer, and the use of different PSA derivatives and PSA forms may reduce 'unnecessary' biopsies in some men. In addition to prostate cancer, manipulation and benign diseases of the prostate falsely elevate serum PSA levels. In contemporary clinical practice, PSA testing plays an important role in prostate cancer diagnosis and treatment.

Design of the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial

The objectives of the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial are to determine in screenees ages 55-74 at entry whether screening with flexible sigmoidoscopy (60-cm sigmoidoscope) can reduce mortality from colorectal cancer, whether screening with chest X-ray can reduce mortality from lung cancer, whether screening men with digital rectal examination (DRE) plus serum prostate-specific antigen (PSA) can reduce mortality from prostate cancer, and whether screening women with CA125 and transvaginal ultrasound (TVU) can reduce mortality from ovarian cancer. Secondary objectives are to assess screening variables other than mortality for each of the interventions including sensitivity, specificity, and positive predictive value; to assess incidence, stage, and survival of cancer cases; and to investigate biologic and/or prognostic characterizations of tumor tissue and biochemical products as intermediate endpoints. The design is a multicenter, two-armed, randomized trial with 37,000 females and 37,000 males in each of the two arms. In the intervention arm, the PSA and CA125 tests are performed at entry, then annually for 5 years. The DRE, TVU, and chest X-ray exams are performed at entry and then annually for 3 years. Sigmoidoscopy is performed at entry and then at the 5-year point. Participants in the control arm follow their usual medical care practices. Participants will be followed for at least 13 years from randomization to ascertain all cancers of the prostate, lung, colorectum, and ovary, as well as deaths from all causes. A pilot phase was undertaken to assess the randomization, screening, and data collection procedures of the trial and to estimate design parameters such as compliance and contamination levels. This paper describes eligibility, consent, and other design features of the trial, randomization and screening procedures, and an outline of the follow-up procedures. Sample-size calculations are reported, and a data analysis plan is presented.

Pathologic findings and prostate specific antigen outcome after radical prostatectomy for patients diagnosed on the basis of a single microscopic focus of prostate carcinoma with a gleason score </= 7

BACKGROUND

Whether patients who are diagnosed on the basis of a single microscopic focus of prostate carcinoma with a Gleason score </= 7 (micro PC) have potentially life-threatening disease if they are not treated is unknown.

METHODS

Pathologic findings and prostate specific antigen (PSA) outcome after radical prostatectomy (RP) for men who were diagnosed with micro PC were determined. Of 917 patients who were managed with RP during 1989-1999 at the Brigham and Women's Hospital, 66 patients (7%) were diagnosed on the basis of micro PC. Pathologic stage, tumor grade, tumor volume, margin status, and PSA outcome were investigated and are reported. Estimates of PSA outcome were calculated using the actuarial method of Kaplan and Meier. Pairwise comparisons were made using the log rank test.

RESULTS

The finding of micro PC at biopsy was associated with macroscopic disease (involving at least half of a single lobe) in 92% of the patients in this series. Although these men had favorable pathologic findings (94% had organ confined disease, 89% had negative tumor margins, and 79% had a prostatectomy Gleason score </= 6), approximately 10% of the patients failed biochemically within 5 years after RP.

CONCLUSIONS

The finding of micro PC at biopsy should not be used as a surrogate for clinically insignificant disease.

Using the free-to-total prostate-specific antigen ratio to detect prostate cancer in men with nonspecific elevations of prostate-specific antigen levels

BACKGROUND

Prostate-specific antigen (PSA) levels between 4.0 to 10.0 ng/ml have poor specificity in prostate cancer screening, leading to unnecessary biopsies.

OBJECTIVE

To determine whether the free-to-total PSA ratio (F/T PSA) improved the diagnostic accuracy of these nonspecific PSA levels.

MEASUREMENTS AND MAIN RESULTS

MEDLINE searchedwas from 1986 to 1997. Additional studies were identified from article bibliographies and by searching urology journals. Two investigators independently identified English-language studies providing F/T PSA ratio test-operating characteristics data on > or = 10 cancer patients with PSA values between 2.0 and 10.0 ng/ml. Twenty-one of 90 retrieved studies met selection criteria. Two investigators independently extracted data on methodology and diagnostic performance. Investigator-selected cut points for the optimal F/T PSA ratio had a median likelihood ratio of 1.76 (interquartile range, 1.40 to 2.11) for a positive test and 0.27 (0.20 to 0.40) for a negative test. Assuming a 25% pretest probability of cancer, the posttest probabilities were 37% following a positive test and 8% following a negative test. The summary receiver operating characteristic curve showed that maintaining test sensitivity above 90% was associated with false positive rates of 60% to 90%. Methodologic problems limited the validity and generalizability of the literature.

CONCLUSIONS

A negative test reduced the posttest probability of cancer to approximately 10%. However, patients may find that this probability is not low enough to avoid undergoing prostate biopsy. The optimal F/T PSA ratio cut point and precise estimates for test specificity still need to be determined.

[Usefulness of the percentage of free prostatic specific antigen in the differential diagnosis between benign prostatic hyperplasia and prostate cancer]

BACKGROUND

PSA (prostatic specific antigen) is the most used tumor marker to monitor prostate cancer (PC). It is an acceptably sensitive test. Molecular forms of PSA give a chance to improve its specificity. We have evaluated the usefulness of the ratio free PSA/total PSA (f-PSA/t-PSA%) to diagnose prostate cancer, in the range between 4 and 20 ng/ml; i.e. the interval in which values overlap for patients with PC and benign prostatic hyperplasia (BPH) in our environment.

PATIENTS AND METHODS

Prospective study on 269 patients, 73 with PC and 196 with BPH. Both t-PSA and f-PSA were determined using microparticles enzyme immune assay (MEIA) with AXSYM (Abbott) analyzer.

RESULTS

Statistically significant differences were evidenced in f-PSA/t-PSA% for patients with PC vs. BPH; but that did not happen for t-PSA values. Sensitivity and specificity values were established for different cut-off points. ROC curve analysis proved diagnostic efficacy was better for f-PSA/t-PSA% than for t-PSA.

CONCLUSIONS

f-PSA/t-PSA percentage is a useful tool for the differential diagnosis between PC and BPH. A ratio lower than 12% selects a population with high risk of cancer. A percentage over 18% is useful to avoid or delay the indication of biopsy.

[Prostatic rebiopsy. Prognosis factors of the anatomopathologic result]

The indications for repeat prostate needle biopsy after a previous biopsy are not defined. We examined 107 prostate biopsies (in 98 patients) without a diagnosis of malignancy, which we repeat. Carcinoma was detected in 31 patients (31.6%). We didn't find statistic relationship between the repeat biopsy's outcome and: interval between biopsy and repeat biopsy, PSA value, PSA density (biopsy), PSAD of the transitional area (PSAD ad., on repeat biopsy). We found relationship with: prostatic weight (p = 0.002 on the biopsy, p = 0.0002 on the repeat biopsy), volume of the transitional area (p = 0.02 on the biopsy, p = 0.0001 on the repeat biopsy), PSA value (p = 0.02, on the repeat biopsy), PSAD ad. (p = 0.002, on the repeat biopsy), and with PSA velocity (p = 0.008). We only found clinic usefulness for the PSA velocity: patients with PSA velocity greater than 1 ng/ml/year are at high risk for prostate carcinoma on the repeat biopsy, specially in small prostates.