The prostate specific antigen era in the United States is over for prostate cancer: what happened in the last 20 years?

Using prostate-specific antigen screening and nomograms to assess risk and predict outcomes in the management of prostate cancer

We review the role of prostate-specific antigen (PSA) and the importance of patient education in the management of prostate cancer, based on discussions held at a European symposium on managing prostate cancer. Although PSA is the most widely used serum marker for detecting prostate cancer and for monitoring treatment responses, its use as a diagnostic marker is controversial due to concerns of over-diagnosis and low specificity. PSA isoforms, as well as PSA doubling time, might improve the specificity for earlier prostate cancer detection and can be used as surrogate markers for treatment efficacy. Patients can differ considerably in the importance they place on health-related quality of life aspects and fear of cancer progression. Consequently, there needs to be active, educated discussion of risk and outcomes between physicians and patients. Risk assessment tools, e.g. validated nomograms, enable clinicians to improve their decision analysis and form the basis for subsequent discussion of treatment options between the physician and patient, thereby enabling informed consent and appropriate decision-making.

Plasma levels of trefoil factors are increased in patients with advanced prostate cancer

PURPOSE

Through cDNA array analyses and immunohistochemistry on tissue microarrays, trefoil factor 3 (TFF3) was recently shown to be overexpressed in prostate cancer. The purpose of this study was to test the feasibility of using the levels of trefoil factors as a plasma marker for prostate cancer.

EXPERIMENTAL DESIGN

In 79 patients with prostate cancer, 23 patients with benign prostatic hyperplasia, and 44 healthy individuals plasma TFF1, TFF2, and TFF3 were determined with ELISAs and compared with clinical stage and prostate-specific antigen (PSA) values. Plasma levels of TFF were compared with the immunohistochemical expression of TFF and chromogranin A in 30 prostate cancer tissue samples.

RESULTS

Patients with advanced prostate cancer had significantly higher plasma concentrations of TFF1, TFF2, and TFF3 (P < 0.01) compared with patients with localized disease. Using a cutoff of 200 pmol/L, the sensitivity and specificity of plasma TFF3 in differentiating between patients with localized and advanced disease was 74% (59-85%) and 81% (66-91%). Plasma levels of TFF3 were highest in patients with bone metastases (P = 0.008). Patients with serum PSA >10 microg/L had significantly higher plasma TFF3 values than patients with serum PSA <10 microg/L (P = 0.03) and TFF3 levels were higher in patients with Gleason sums of > or = 7 (P = 0.02). Expression of TFF1 and TFF3 determined by immunohistochemistry was increased in patients with prostate cancer but did not correlate with plasma trefoil factor values.

CONCLUSIONS

Plasma levels of trefoil factors are increased in patients with advanced prostate cancer. Prospective studies are needed to confirm the predictive utility of trefoil factors in prostate cancer.

Preoperative serum prostate specific antigen remains a significant prognostic variable in predicting biochemical failure after radical prostatectomy

PURPOSE

Multiple investigators have argued that PSA may no longer be an accurate marker of prostate cancer biology. We determined whether the impact of PSA in predicting biochemical failure after radical prostatectomy has changed since the beginning of the PSA era.

MATERIALS AND METHODS

A total of 1,246 patients were identified from the Columbia University Comprehensive Urological Oncology Database who underwent radical prostatectomy by 1 of 3 surgeons between 1988 and 2003. Cox proportional hazards models were fit to the data to estimate the impact of PSA (logPSA) in predicting BCF (PSA 0.2 ng/ml or greater). To determine if the predictive impact of PSA changed over time, patients were classified based on year of surgery, and an interaction term between PSA and time was included. Finally concordance indexes were estimated to determine if the predictive ability of PSA has changed over time.

RESULTS

In a Cox model including PSA, year of surgery and a year/PSA interaction term, the impact of PSA appears to change over time (p = 0.002). However, when correcting for the effects of stage and grade there was no significant change in the impact of PSA. In addition, concordance analysis indicated that the predictive ability of PSA has remained constant throughout the PSA era (0.65, 0.66 and 0.64 for each period, respectively).

CONCLUSIONS

This study demonstrates that the predictive ability of PSA as a cancer outcomes biomarker has not changed significantly since the beginning of the PSA era. Despite suggestions to the contrary, PSA remains an important variable in predicting risk of BCF after RP.

Prevalence of Prostate Specific Antigen Testing for Prostate Cancer in Elderly Men

PURPOSE

We investigated the prevalence and outcome of PSA testing for prostate cancer screening or diagnosis in elderly men 75 years or older at our academic medical center.

MATERIALS AND METHODS

A cross-sectional study design was used to identify all men 75 years or older who underwent a PSA test through the family medicine or internal medicine service at our institution between January 1, 1998 and June 30, 2004. All patients with a suspected (PSA less than 0.1 ng/ml) or confirmed prior diagnosis of prostate cancer were excluded. The prevalence of PSA testing was then compared to that in younger age groups (45 to 54, 55 to 64 and 65 to 74 years). We then examined the frequency and nature of further evaluation and treatment performed in men following the PSA test.

RESULTS

The 8,787 male patients who were 75 years or older generated a total of 82,672 visits in the 5.5-year period. Of these patients 505 (5.7%) underwent at least 1 PSA test. The prevalence of PSA testing in the younger age groups was 10.3% (1,769 of 17,175) in patients 45 to 54 years old, 14.9% (2,052 of 13,772) in those 55 to 64 years old and 11.8% (1,258 of 10,661) in those 65 to 74 years old (chi-square test p <0.001). Of these patients 98 of 343 (28.6%) with PSA between 0.1 and 4 ng/ml were referred to a urologist at our institution and 3 underwent biopsy. None had a prostate cancer diagnosis. Of the 162 patients with PSA more than 4 ng/ml 84 (51.9%) were referred to a urologist. Only 10 of the 84 patients (11.9%) who were referred to a urologist underwent prostate biopsy. Six of the 10 men (60%) were diagnosed with prostate cancer, including 1 with a Gleason 6 tumor, 1 with a Gleason 7 tumor and 4 who were found to have tumors with a Gleason score of 8 or greater. All patients received androgen deprivation therapy, except 1 who received local external beam radiation therapy. An additional patient was diagnosed by biopsy of a vertebral lesion and he received hormone therapy. At a median followup of 51 months (range 28 to 72) 4 of 7 men (57%) were alive with disease.

CONCLUSIONS

PSA testing for prostate cancer screening and diagnosis appear to decrease with advancing age. A small but significant proportion of men who are 75 years or older continue to undergo PSA testing. Abnormal PSA results do not always result in further evaluation and therapy for prostate cancer in elderly men. The establishment of firm guideline recommendations regarding PSA testing and further evaluation for prostate cancer in elderly men, perhaps based on individualized geriatric assessment, may be helpful.

Prostate cancer detection strategies

Prostate cancer is the most common malignancy in men and, as a result, there has been a nationwide emphasis on screening and detection. With the widespread use of the prostate-specific antigen (PSA), prostate cancer screening effectively detects localized prostate cancer. However, recent reports have identified a significant proportion of prostate cancer in men with low PSA levels. Many of these cancers are higher-grade malignancies. Consequently, PSA may function more effectively as a screening tool when applied over a continuum that is associated with degree of risk, rather than a binary measure. Other markers are currently being investigated. Ideally, a marker will identify the malignancy that is a clinical threat, thereby avoiding intervention for indolent disease. Prevention strategies may be employed for higher-risk patients, and these strategies eventually may be tailored to genetic or other risks.

Shift of tumor features in patients with clinically localized prostate cancer undergoing radical prostatectomy since the beginning of the PSA era

AIM

To analyze trends of clinical and tumor characteristics over a 12-year period since the beginning of the prostate-specific antigen (PSA) era in a consecutive series of radical prostatectomies.

PATIENTS AND METHODS

Between 1993 and 2004 a consecutive series of 1351 patients underwent radical prostatectomy for clinically localized prostate cancer (PC) in a single institution. Clinical and histopathological information was entered into our computer database and analyzed for changes over time.

RESULTS

The annual frequency of surgical interventions increased from 43 to 160 (272%) during the observation period (r = 0.930; p < 0.01). The detection of PC based solely on pathological PSA levels rose impressively from 7% to 70% (r = 0.986; p < 0.01). The rates of organ-confined disease also increased significantly from 47% to 79% (r = 0.774; p < 0.01). Stage pT3a decreased somewhat from 28% to 18% (r = -0.389; n.s.) whereas pT3b decreased significantly from 26% to 3% (r = -0.729; p < 0.01).

CONCLUSION

During the 12-year period, PC was increasingly detected on the basis of a pathological PSA level only and shifted significantly to more organ-confined stages. With a time delay, these findings are consistent with trends observed in large centers in the USA.

The predictive value of PSA in diagnosis of prostate cancer in non screened population

INTRODUCTION

[corrected] PSA is the most important tumor marker in all solid tumor, indispensable in the management of prostate cancer. Screening for prostate cancer is still not recomended, although performed in many countries, which introduced questions about the usefulnes of PSA in detection of prostate cancer. The PSA treshold has also been changed, the value of PSA derivatives revised. Whether such changes are applicable in non scrrened population is questionable. Aim of this study was to evaluate the predictive value of PSA, free/ total PSA and PSA density in our non screened population.

PATIENTS AND METHODS

TRUS guided prostate biopsy was performed in 579 patients. The number of cores was 6-12. Mean age of the patients was 67.5 years (30-90). PSA was ranging from 0.41 to 2250 (mean 38.6 ng/ml, median: 11.95, SD 140,45). Digitorectal examination was considered positive in 351 patients. Free PSA was measured in 352 patients with the index ranging from 0.02 to 0.88 (mean free/total PSA: 0.14, median: 0.13). The volume of the prostate was measured in all patients according the prostate ellipsoid model, and PSA density calculated according to the formula PSA/PV. Patients were stratified in 6 groups according to PSA value (I: PSA ng/ml, II: PSA 2.5-4, III: PSA 4-10, IV: PSA 10-20, V: PSA: 20 to 50, Group 6: PSA 50).

RESULTS

Non homogenicity of the patients can be seen through the wide range of PSA which was from 0.4 to 2025). Prostate cancer was diagnosed in 233 pts (40.2%). As expected, the probability of detecting cancer was raised with PSA (p), and was extremely rare in pts with PSA below 4 ng/ml. PSA, free/total PSA, volume of the prostate and PSA density were significantly different according to the presence of cancer. Most of our patients had PSA between 4 and 20 ng/ml. Predictive value of PSA was 20.6% for pts with PSA from 4 to 10 and 32.7% for those with PSA from 10 to 20 ng/ml. Sensitivity, specificity, positive and negative predictive values for different cut off's of PSA (4, 10 and 20) was performed. The best results were obtained for PSA cut off of 10 ng/ml. In the group of patient with PSA, PSA density more reliable than free/total PSA index.

CONCLUSION

PSA is still valuable marker for detection of prostate cancer in our non screened population. According to our results PSA treshold should not be lowered below 4 ng/ml. PSA density is a reliable PSA derivative, free/total PSA index having less importance in pts with PSA below 20 ng/ml.

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

The clinical significance of a prostate cancer (PCa) cannot be determined solely by tumor volume (< or =0.5 cm(3)), as small tumors of higher Gleason grade and tumors occurring in younger men may become clinically significant even though the initial volume at diagnosis is small. A certain number of these minimal cancers are likely to remain clinically insignificant; however, it is unpredictable how many can progress beyond the curable stage by the time there is a rise in serum prostate-specific antigen (PSA) values. Compared to clinically detected PCa, PCa detected exclusively by PSA screening (clinical stage T1c) are less likely to be advanced but no more likely to be insignificant in terms of volume, pathologic stage, and Gleason pattern. Only 10-15% of PSA-detected cancers have the features of PCa found at autopsy or in cystoprostatectomy specimens. Actually, 25-30% of PCa are detected with PSA values between 2.5 and 4 ng/ml, and most of these cancers are clinically significant. Evidence from both retrospective and longitudinal studies has shown that the risk of a PCa is dependent on the patient's age and the initial serum PSA. This allows an individualized approach to PCa screening programs, and PSA cutoff values for biopsy indication may be lowered in selected patients.

Active surveillance with selective delayed intervention for favorable risk prostate cancer

Good risk prostate cancer, defined as a Gleason score of < or = 6, prostate-specific antigen (PSA) <10, and T1c-T2a, now constitutes 50% of newly diagnosed prostate cancer. Recent data from the Prostate Cancer Prevention Trial, Stamey data set on PSA-prostate cancer correlations, and the Surveillance, Epidemiology, and End Results database make it very clear that a policy of PSA screening with biopsy for those patients in whom PSA is increased results in the diagnosis, and radical treatment, of a very large proportion of men who do not have life-threatening prostate cancer. Most men with good risk prostate cancer have indolent and slow growing disease. The challenge is to identify those patients who are unlikely to have significant progression, while offering radical therapy to those who are at risk. The approach to favorable risk prostate cancer described in this article uses estimation of PSA doubling time (DT) and repeat biopsy to stratify patients according to the risk of progression. Patients who select this approach are treated initially with active surveillance. Those patients who have a PSA DT of < or = 3 years (based on a minimum of 3 determinations over 6 months) are offered radical intervention. The remaining patients are closely monitored with serial PSA and periodic prostate repeat biopsy at 1, 4, 7, and 10 years. In one series of 299 patients treated in this way, 65% remained free of treatment at 8 years. The prostate cancer specific survival using this approach was 99.3% at 8 years. The majority of patients in this study remain on surveillance. Active surveillance with selective delayed intervention based on PSA DT is a practical middle ground between radical therapy for all, which results in over-treatment of patients with indolent disease, and watchful waiting with palliative therapy only, which results in under-treatment of those with aggressive disease.

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.

Decision making in prostate-specific antigen screening National Health Interview Survey, 2000

BACKGROUND

The net benefits and harms of prostate cancer screening with the prostate-specific antigen (PSA) test are uncertain, and professional organizations recommend that physicians discuss these uncertainties with patients before initiating screening. Using a nationally representative sample of men reporting past PSA screening, we aimed to determine the extent to which screening was initiated by physicians and preceded by physician-patient discussions.

METHODS

Cross-sectional analysis of data from the 2000 National Health Interview Survey; 2,676 men aged 40 and older underwent PSA screening and met study inclusion criteria. We analyzed the proportions of men for whom PSA screening was (1) was initiated by the physician versus the patient, and (2) preceded by discussions about the test's advantages and disadvantages.

RESULTS

Overall, 74% (95% CI=71.8-76.0) of recipients reported that PSA screening was initiated by their physician, and the proportion increased with advancing age, declining health status, lack of family history of prostate cancer, presence of a usual source of medical care, and non-Hispanic ethnicity. Sixty-five percent (95% CI=63.1-67.1) of screening recipients reported prescreening discussions with their physicians. Discussions were more common with physician-initiated screening than with patient-initiated screening, and among patients reporting a usual source of medical care, non-blue-collar occupation, and black race.

CONCLUSIONS

Among U.S. men receiving PSA screening, screening is usually initiated by physicians, frequently in men relatively less likely to benefit from it, and often without prior discussion of the test's advantages and disadvantages. Further examination of the PSA decision-making process among screened and unscreened men is warranted.

Metabolic fingerprinting in disease diagnosis: biomedical applications of infrared and Raman spectroscopy

The ability to diagnose the early onset of disease, rapidly, non-invasively and unequivocally has multiple benefits. These include the early intervention of therapeutic strategies leading to a reduction in morbidity and mortality, and the releasing of economic resources within overburdened health care systems. Some of the routine clinical tests currently in use are known to be unsuitable or unreliable. In addition, these often rely on single disease markers which are inappropriate when multiple factors are involved. Many diseases are a result of metabolic disorders, therefore it is logical to measure metabolism directly. One of the strategies employed by the emergent science of metabolomics is metabolic fingerprinting; which involves rapid, high-throughput global analysis to discriminate between samples of different biological status or origin. This review focuses on a selective number of recent studies where metabolic fingerprinting has been forwarded as a potential tool for disease diagnosis using infrared and Raman spectroscopies.

Contemporary issues in the diagnosis of prostate cancer for the radiologist

Prostate cancer diagnostic techniques have improved considerably in recent years, but they must yet be optimised to ensure cancer detection at a potentially curable stage. Arrangements for prostate biopsy vary throughout Europe, and prostate biopsy may be undertaken by urologists or radiologists. This review discusses current issues relevant for radiologists involved in the detection of early prostate cancer. Prostate biopsy should be based on a systematic approach involving 8-12 cores obtained with peri-prostatic infiltration of local anaesthetic. Quality issues being considered by the United Kingdom Prostate Cancer Risk Management Programme are discussed.

[Screening for prostate cancer: arguments "against"]

Prostate cancer screening is controversial since PSA assay has been made available. Screening supporters consider that early diagnosis allows better and less aggressive treatment. These arguments lie on longitudinal cohort studies without controls. Randomized studies are required to assess the correlation between screening and mortality lowering. Two studies are being performed and their results will be available within three or four years. Consequently, the validity of screening is unknown. Nevertheless, the analysis of various parameters demonstrates that the reduction of cancer mortality related to screening is low. According to these data and as recommended by health institutions prostate cancer screening is not required. At the present time, detection asked by the patient himself remains the good attitude between negligence and excessive attitude.

A Novel Serum Marker, Total Prostate Secretory Protein of 94 Amino Acids, Improves Prostate Cancer Detection and Helps Identify High Grade Cancers at Diagnosis

PURPOSE

New biomarkers for prostate cancer are needed. We determined whether a novel serum marker, total PSP94 can be used to accomplish these goals.

MATERIALS AND METHODS

We conducted a case-control study of 1,212 men with no previous history of prostate cancer and who underwent a prostate biopsy from 1998 to 2000 because of an increased PSA or an abnormal DRE. Serum PSP94 levels were assessed using a sandwich enzyme-linked immunosorbent assay technique. Cases were patients with prostate cancer, and controls were patients who had no evidence of cancer. Multivariate logistic regression analysis was used to determine whether or not PSP94 levels improved the predictive value for prostate cancer.

RESULTS

Of the 1,212 men 596 (49.2%) had cancer detected. The median PSP94 level was significantly lower among cases (2.60 ng/ml) than among controls (3.40 ng/ml, p <0.0001). The adjusted odds ratios for the presence of prostate cancer for patients with the lowest quartile of PSP94, compared to patients in the highest quartile was 2.70 (95% CI 1.8 - 4.0, p <0.0001). Among a subgroup of 649 men in whom PSA had a low predictive value (PSA less than 20 ng/ml, normal DRE and less than 70 years), 260 (40.1%) were found to have cancer. In this subgroup total PSP94 levels helped discriminate between patients with high grade disease (Gleason score 8 or more, median 1.90 ng/ml), moderate grade disease (Gleason score 7, median 2.34 ng/ml) and low grade disease (Gleason score 6 or less, median 2.60 ng/ml, p = 0.007). PSA and the FTPSA were not able to distinguish between patients with different grades in this group.

CONCLUSIONS

Patients with low total PSP94 levels had a high probability for having prostate cancer detected at biopsy. The total PSP94 level was able to help identify patients with high grade disease among a subset of patients in whom PSA and FTPSA are least informative.

Role of prostate biopsy schemes in accurate prediction of Gleason scores

OBJECTIVES

To determine whether improved prostate sampling by the extended biopsy scheme also improves the accuracy of the biopsy Gleason score (bGS). Because most prostate cancer cases are now detected at an early stage with a low prostate-specific antigen level, the bGS may be the most important factor in therapeutic decision-making. Sextant biopsy schemes had poor correlation with prostatectomy Gleason scores. Extended prostate biopsies have replaced the sextant scheme because of the former's greater cancer detection rate.

METHODS

We identified 426 patients whose biopsy and prostatectomy specimens were reviewed at our center. To minimize the effect of stage migration, all patients before 1997 were excluded. Of the 426 included patients, 221 men had undergone sextant biopsy and 205 men extended biopsy before prostatectomy. The rate of grading concordance and the effect of different variables on the concordance rate was determined.

RESULTS

The overall accuracy of the extended and sextant schemes was 68% and 48% (P <0.001), respectively. Upgrading of the bGS was significantly less likely with the extended scheme (17% versus 41%, P <0.001). The sextant biopsy was more likely to be upgraded for a bGS of 6 or less (44% versus 25%, P <0.002) and a bGS of 7 (14% versus 3%, P <0.02). On multivariate analysis, the biopsy scheme was the only independent predictor of accurate Gleason scoring (P <0.001) and age, prostate-specific antigen level, digital rectal examination findings, prostate size, clinical stage, and number of positive cores were not.

CONCLUSIONS

The use of an extended prostate biopsy scheme significantly improves the correlation between the bGS and prostatectomy Gleason score and reduces the risk of upgrading to a worse Gleason group at prostatectomy.

[Validity of digital rectal examination in the era of prostate specific antigen]

OBJECTIVE

To determine the presence of a possible correlation between prostate specific antigen (PSA) and the findings from digital rectal examination (DRE) in patients with prostate cancer or benign prostatic hyperplasia.

DESIGN

Retrospective, longitudinal, and observational study of diagnostic tests.

SETTING

Gregorio Marañón Hospital, Madrid, Spain.

PARTICIPANTS

It included 706 patients with a PSA in the range 4.1-20 ng/mL, studied owing to suspected prostate cancer localised using DRE and transrectal ultrasound, in whom randomised prostate biopsies were performed.

MAIN MEASUREMENTS

Total PSA and free/total PSA ratio and DRE normal or suspicious were studied as main variables. The outcome variable was the diagnosis of prostatic cancer by biopsy.

RESULTS

With a detection of cancer of 28.2%, there were no statistically significant differences in the PSA or free/total PSA ratio mean values between patients with or without suspicious DRE. The analysis using ROC curves (with a 95% confidence interval) between both groups of patients found the same sensitivity of 95% with a similar specificity of 6% and 10%, respectively, for a PSA of 4.8 ng/mL.

CONCLUSIONS

In the PSA range of 4.1-20 ng/mL, the findings of DRE appeared as a variable unrelated to the increase in PSA or the free/total PSA ratio and, therefore are not indicative of a lesser or greater volume of a tumour producing PSA. The performing of this examination could be considered as optional.

The Detection and Potential Economic Value of Complexed Prostate Specific Antigen as a First Line Test

PURPOSE

Prostate cancer detection is subject to a number of variables that can lead to unnecessary biopsies and associated costs. Measuring cPSA has been proposed as an alternative to tPSA for the early detection of prostate cancer.

MATERIALS AND METHODS

Between November 1998 and April 2000, 1,362 men underwent transrectal ultrasound guided biopsies at 7 institutions. Of 1,243 evaluable men 467 with tPSA between 2.5 and 6.0 ng/ml, and normal digital rectal examination were analyzed. Statistical analysis used to compare cancer detection rates between PSA assays was performed using the Mann-Whitney U test. A separate group of 2,807 men who participated in a free cancer detection program was used to determine the current tPSA distribution and assess the economic impact of cPSA.

RESULTS

Cancer was detected in 31.5% of the men (147 of 467) with tPSA between 2.5 and 6.0 ng/ml. Using a 2.2 ng/ml cPSA cutoff point detected 93.9% of cancers and would have avoided 20.3% of unnecessary biopsies in men with tPSA between 2.5 and 4.0 ng/ml. A 2.2 ng/ml cPSA cutoff point achieved an 11.9% overall decrease in the number of unnecessary biopsies in the tPSA range of 2.5 to 6.0 ng/ml with accompanying 98% sensitivity. The decrease in unnecessary biopsies is potentially associated with substantial health care cost savings.

CONCLUSIONS

In the clinically relevant sensitivity ranges a 2.2 ng/ml cPSA cutoff point decreases the number of unnecessary biopsies and maintains higher specificity than a tPSA threshold of 2.5 ng/ml, illustrating the potential value of cPSA as a first line diagnostic test.

Prostate Specific Antigen Remains an Independent Predictor of Cancer at Prostate Biopsy in Black American Men But Not in White Men: Results from a Consecutive Series of 914 Men

PURPOSE

Black American men may be at increased risk for prostate cancer but differences in prebiopsy parameters between black and white men have not been fully examined. Therefore, we identified the prebiopsy parameters that may be predictive of prostate cancer in black and white men.

MATERIALS AND METHODS

From January 2000 to July 2004, 914 consecutive men undergoing prostate needle biopsy were prospectively examined by a single urologist. Urinary symptoms were measured by AUASS. Prebiopsy parameters recorded were PSA, free PSA, DRE, age, race, biopsy history, prostate volume, TRUS lesion and AUASS.

RESULTS

Prostate biopsy was performed in 914 men with a mean age of 63.9 years. Mean PSA in the entire cohort was 11.2 ng/ml (median 5.8). Abnormal TRUS and abnormal DRE were found in 37% and 52% of men, respectively. Mean AUASS was 9.6. The overall positive biopsy rate was 37%. In black and white men the positive biopsy rate was 44% and 34%, respectively. Analysis of AUASS indicated that 47% of patients had low symptom scores (less than 7), 39% had moderate scores (8 to 19) and 14% had severe scores (20 to 35). Multivariate analysis revealed that PSA was an independent predictor of positive biopsy in black but not in white men (p = 0.001 and 0.79, respectively). Multivariate analysis also showed that race alone was an independent predictor of positive prostate biopsy (p = 0.013).

CONCLUSIONS

PSA remains an independent predictor of positive prostate biopsy on multivariate analysis. Other independent predictors are black race, age, low AUASS, prostate volume, abnormal DRE, no previous biopsy and abnormal TRUS. In the black group low AUASS, PSA, no previous biopsy and DRE were unique independent predictors, while in the white group age and abnormal TRUS were unique predictors.

Classification and Regression Tree Analysis for the Prediction of Aggressive Prostate Cancer on Biopsy

PURPOSE

Prostate cancer screening allows early cancer detection but not all patients benefit from subsequent therapy. Thus, identifying patients who are likely to harbor aggressive cancer could significantly decrease the number of prostate biopsies performed.

MATERIALS AND METHODS

Data were collected on 1,563 consecutive referred men with serum PSA 10 ng/ml or less who underwent an initial prostate biopsy. Predictors of aggressive cancer (Gleason sum 7 or greater) were identified using CART analysis. Model building was done in a randomly selected training set (70% of the data) and validation was completed using the remaining data.

RESULTS

Cancer was detected in 406 men (26.1%). Gleason 7 or greater cancer was found in 130 men (8.3%). CART created a decision tree that identified certain groups at risk for aggressive cancer, namely 1) PSAD greater than 0.165 ng/ml/cc, and 2) PSAD greater than 0.058 to 0.165 ng/ml/cc or less, age greater than 57.5 years and prostate volume greater than 22.7 cc. The incidence of aggressive prostate cancer was 1.1% when PSAD was 0.058 ng/ml/cc or less in the validation set. The sensitivity and specificity of CART for identifying men with aggressive cancer were 100% and 31.8% for model building data, and 91.5% and 33.5% for the validation data set, respectively.

CONCLUSIONS

CART identified groups at risk for aggressive prostate cancer. Application of this CART could decrease unnecessary biopsies by 33.5% when only a diagnosis of high grade prostate cancer would lead to subsequent therapy.

Does PSA Velocity Predict Prostate Cancer in Pre-Screened Populations?

PSA-driven screening has been applied to a large part of the male population in many countries. An elevated PSA in secondary screens may indicate benign enlargement of the prostate rather than prostate cancer. In such cases the yearly rate of increase of PSA (PSA velocity [PSAV]) may improve the test characteristics of PSA.

MATERIALS AND METHODS

Data from the European Randomized Study of Screening for Prostate Cancer Rotterdam are used to study the issue. Relative sensitivity, relative specificity, and positive predictive value (PPV) are calculated. Logistic regression analysis is used to compare odds ratios for positive biopsies. The relationship between PSAV and parameters of tumour aggressiveness is investigated.

RESULTS

Five hundred eighty-eight consecutive participants were identified who presented at their first screening with PSA values <4.0 and who progressed to PSA values >4.0 ng/ml four years later. None were biopsied in round one, all were biopsied in round two. Relative sensitivity and specificity depend strongly on PSAV cut-offs of 0.25-1.0 ng/ml/yr. The use of PSAV cut-offs does not improve the PPV of the PSA cut-off of 4.0 ng/ml, nor do any of the PSAV cut-offs improve the odds ratio for identifying prostate cancer with respect to the cut-off value of 4.0 ng/ml. The rate of aggressive cancers seems to increase with increasing PSAV.

CONCLUSIONS

PSAV does not improve the detection characteristics of a PSA cut-off of 4.0 ng/ml in secondary screening after four years.

Brief report: physicians and their personal prostate cancer-screening practices with prostate-specific antigen. A national survey

BACKGROUND

There is inconclusive evidence that prostate cancer screening with prostate-specific antigen (PSA) reduces mortality. Although PSA testing is widespread, it is unknown how many physicians have taken the PSA test themselves.

OBJECTIVE

To determine the prevalence of PSA testing among physicians.

DESIGN

Cross-sectional survey.

SUBJECTS

A nationwide stratified random sample of urologists (response rate 61%, n=247), Internists (response rate 51%, n=273), and family physicians (response rate 64%, n=249) were surveyed by mail in 2000. After excluding female respondents and men who either reported a positive history of prostate cancer or did not respond to that query, there were 146 urologists, 96 Internists, and 118 family physicians.

MEASUREMENTS

Whether physicians had undergone prostate cancer screening with PSA.

RESULTS

Eighty-seven percent (155/178) of male physicians aged, 50 and older and 21% (31/150) of white male physicians under age 50 reported having had a PSA test. More urologists than nonurologists in both age groups reported having had a screening PSA test.

CONCLUSION

Most physicians aged 50 and older report undergoing PSA testing. This may reflect a belief in its efficacy and contribute to its widespread use.

Pathological Characteristics of Prostate Cancer Detected Through Prostate Specific Antigen Based Screening

PURPOSE

Since the introduction of PSA testing for CaP, there has been an increase in CaP detection. However, it is uncertain to what extent clinically insignificant tumors are being diagnosed and treated. In a large, community based population we determined the pathological characteristics of screening detected cancers.

MATERIALS AND METHODS

From 1989 to 2001, 35,661 men were enrolled in a longitudinal prostate cancer screening study. Data were available on 3,492 of the 3,568 men (98%) diagnosed with CaP during this study period. Radical prostatectomy was performed in 2,254 men (63%). Clinical stage, Gleason score and pathological analysis were recorded and analyzed in the context of preoperative PSA, digital rectal examination findings, PSA velocity and the year of cancer detection.

RESULTS

CaP was detected in 10% of men. Virtually all cases were clinically localized (99.8%) and approximately 70% treated with radical prostatectomy were pathologically organ confined disease. Fewer than 10% of tumors would be considered clinically insignificant based on 2 previously published pathological criteria.

CONCLUSIONS

Compared to the high prevalence of CaP found in autopsy studies there is a lower detection rate using current screening protocols. Although the outcomes are unknown if these tumors had been left untreated, the majority met pathological criteria for significant cancer.

Application of surface-enhanced laser desorption/ionization time-of-flight-based serum proteomic array technique for the early diagnosis of prostate cancer

AIM

To identify the serum biomarkers of prostate cancer (PCa) by protein chip and bioinformatics.

METHODS

Serum samples from 83 PCa patients and 95 healthy men were taken from a mass screening in Changchun, China. Protein profiling was carried out using surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS). The data of spectra were analyzed using two bioinformatics tools.

RESULTS

Eighteen serum differential proteins were identified in the PCa group compared with the control group (P < 0.01). There were four proteins at the higher serum level and 14 proteins at the lower serum level in the PCa group. A decision tree classification algorithm that used an eight-protein mass pattern was developed to correctly classify the samples. A sensitivity of 92.0% and a specificity of 96.7% for the study group were obtained by comparing the PCa and control groups.

CONCLUSION

We identified new serum biomarkers of PCa. SELDI-TOF MS coupled with a decision tree classification algorithm will provide a highly accurate and innovative approach for the early diagnosis of PCa.

Regulatory objectivity and the generation and management of evidence in medicine

The evolution of Western medicine since World War II has resulted in the emergence of new practices based on the direct interaction of biology and medicine. The post-war realignment of biology and medicine has been accompanied by the emergence of a new type of objectivity, regulatory objectivity, that is based on the systematic recourse to the collective production of evidence. Unlike forms of objectivity that emerged in earlier eras, regulatory objectivity consistently results in the production of conventions, sometimes tacit and unintentional but most often arrived at through concerted programs of action. These actions incorporate unprecedented levels of reflexivity, in the sense that biomedical practitioners in their debates and discussions take into account the conventional dimension of their endeavors. The conventions produced by regulatory objectivity create the conditions for a clinical objectivity that relies on the existence of entities and protocols produced and maintained far outside the intimate encounter between doctor and patient. By establishing endogenous forms of regulation, regulatory objectivity operates on a different plane and in a different mode from those suggested by analysts who treat all regulation as a form of rationalization imposed upon medicine from without.

N-cadherin switching occurs in high Gleason grade prostate cancer

BACKGROUND

The inappropriate expression of non-epithelial N-(neural) cadherin by epithelial cells, called cadherin switching, has been suggested to play a role in prostate cancer (PC) progression. We explored the role of N-cadherin as a biomarker in PC by correlating the expression with clinical parameters.

METHODS

Two pathologists blinded to patients' history independently reviewed and scored the intensity and extent of staining of N-cadherin expression in 44 randomly selected radical prostatectomy specimens. The expression was correlated with total Gleason grade, individual Gleason patterns, tumor stage, and preoperative serum prostate specific antigen (PSA) levels and P-values < 0.05 were considered statistically significant.

RESULTS

Of the 44 PC specimens, 14 (32%), 23 (52%), 7 (16%) consisted of Gleason grade 5-6, 7, and 8-10, respectively and 20/44 (45%) demonstrated N-cadherin expression. N-cadherin was expressed in 1/14 (7%) of Gleason 5-6 compared to 15/23 (65%) of Gleason grade 7, and 4/7 (57%) of Gleason grade 8-10, demonstrating a significant correlation between N-cadherin switching and higher Gleason grade (P = 0.001). While only about a third of primary or secondary Gleason pattern 3 demonstrated N-cadherin expression, a majority of Gleason patterns of > or = 4 expressed N-cadherin (P > 0.05), further suggesting that N-cadherin switching occurs with higher Gleason pattern. However, N-cadherin expression did not significantly correlate with preoperative serum PSA levels or tumor stage in our study cohort.

CONCLUSIONS

We have demonstrated for the first time that N-cadherin switching occurs in higher grade PC and correlates significantly with increasing Gleason patterns. N-cadherin may be as a useful biomarker of aggressive PC.

Does year of radical prostatectomy independently predict outcome in prostate cancer?

OBJECTIVES

To examine how the biochemical outcomes after radical prostatectomy (RP) have changed in the prostate-specific antigen (PSA) era when controlling for the effects of other prognostic variables. Since the beginning of the PSA era, the presentation, treatment, and therapeutic outcomes of prostate cancer have evolved.

METHODS

We reviewed the Columbia University Comprehensive Urologic Oncology Database and identified 1319 patients who had undergone RP without adjuvant therapy, performed by three surgeons, between 1988 and 2003 (minimal follow-up of 12 months). Univariate Cox proportional hazards models were used to determine which variables affect the hazard of biochemical failure (BCF), defined as a PSA level of 0.2 ng/mL or greater on at least two occasions, after RP. Multivariate analysis, controlling for the effects of other prognostic variables, was used to determine the effect that the year of surgery had on hazard of BCF.

RESULTS

Univariate analysis confirmed the importance of the year of surgery, preoperative PSA level, pathologic stage, Gleason sum, and surgical margin status in estimating the hazard of BCF (P <0.001). Age at surgery did not have a statistically significant effect. A multivariate Cox model showed that the year of surgery had a highly significant impact on the hazard of BCF even when controlling for PSA, stage, Gleason sum, and surgical margin status.

CONCLUSIONS

Patients undergoing RP in more recent years are at significantly less risk of BCF compared with patients who underwent surgery earlier in the PSA era, even when controlling for the effects of other prognostic variables. The factors that account for this change in outcomes over time have yet to be identified.

Making Sense of Prostate Specific Antigen: Improving its Predictive Value in Patients Undergoing Prostate Biopsy

PURPOSE

The clinical usefulness of PSA for prostate cancer screening is unclear, although the test remains in common use. New methods to interpret PSA are needed.

MATERIALS AND METHODS

We examined a cohort of 2,637 men who underwent prostate biopsies for abnormal DRE or PSA between 1999 and 2004. Using risk factors for prostate cancer, including patient age, ethnicity, family history of prostate cancer, previous negative biopsy, voiding symptoms and prostate volume, we developed risk groups for prostate cancer using recursive partitioning modeling independent of PSA or DRE. We then compared prostate cancer probabilities by PSA ranges by risk group.

RESULTS

Of the 2,637 men 1,282 (48.6%) had prostate cancer. Age, ethnicity, family history, previous negative biopsy and prostate volume were predictive for cancer. We constructed 6 risk groups by combining these factors and created tables to assign patients to these groups. Independent of PSA and DRE the probability of cancer ranged from 15% in patients in group 1 to 78% in patients in group 6 (p <0.0001). By adding PSA and DRE to each risk group prostate cancer probabilities were refined from 0% to 100%. Patients in the higher risk groups also had higher grade cancer (p <0.0001).

CONCLUSIONS

We generated 6 risk groups based on simple risk factors for prostate cancer. When used in the right context and patient, PSA is highly accurate for predicting prostate cancer and permitting rational decision making in patients with abnormal PSA.

Cancer de la prostate : les aspects cliniques, biologiques et histopathologiques utiles au radiologue

Medical imaging has an important role in the diagnosis and treatment options of prostate cancer (TRUS guided biopsies, MRI). The knowledge of the different types of cancers, their preferred topography, imaging features, extension pattern, and also the important items that may help the surgical procedure (or any other treatment) are as many crucial key points for optimal management of patients.

Sensitivity and detection rate of a 12-core trans-perineal prostate biopsy: preliminary report

OBJECTIVES

The various prostate biopsy methods are usually compared in terms of the diagnosis rate of prostate cancer. However, the prevalence of cancer in patients with a negative prostatic biopsy is not usually known. We determined the sensitivity and detection rate of 12-core transperineal biopsies in patients not previously investigated for prostate cancer.

METHODS

We performed prostate biopsy in 63 patients (median age 67 years) before radical cystoprostatectomy for high-grade bladder cancer. We then assessed the relationships between biopsy result, prostate cancer in the surgical specimen, and other variables.

RESULTS

17.2% of patients had a positive biopsy and 54% had prostate cancer on definitive histology. Biopsy sensitivity was 32.3% overall, 75% for clinically significant cancers, and 11% for non-significant cancers. Median PSA was 1.2ng/ml, PSA levels did not correlate with the presence of prostate cancer, the presence of clinically significant cancer, bioptic diagnosis, or prostate volume. Age correlated with risk of cancer.

CONCLUSIONS

According to autopsy series, the prevalence of prostate cancer is greater than 50% in males older than 60, yet low PSA levels do not reliably indicate disease absence. The sensitivity of double sextant biopsy is unsatisfactory overall (32%), but acceptable (75%) for diagnosing clinically significant cancer.

Pre-operative percent free PSA predicts clinical outcomes in patients treated with radical prostatectomy with total PSA levels below 10 ng/ml

INTRODUCTION

To evaluate the association of total prostate specific antigen (T-PSA) and percent free PSA (%F-PSA) with prostate cancer outcomes in patients treated with radical prostatectomy (RP).

METHODS

Pre-operative serum levels of T-PSA and F-PSA were prospectively measured in 402 consecutive patients treated with RP for clinically localized prostate cancer who had T-PSA levels below 10 ng/ml.

RESULTS

T-PSA was not associated with any prostate cancer characteristics or outcomes. Lower %F-PSA was significantly associated with higher percent positive biopsy cores, extracapsular extension, seminal vesicle involvement, lympho-vascular invasion, perineural invasion, positive surgical margins, and higher pathologic Gleason sum. When adjusted for the effects of standard pre-operative features, lower %F-PSA significantly predicted non-organ confined disease, seminal vesicle involvement, lympho-vascular invasion, and biochemical progression. %F-PSA did not retain its association with biochemical progression after adjusting for the effects of standard post-operative features. Based on data from 22 patients with biochemical progression, lower %F-PSA was correlated with shorter T-PSA doubling time after biochemical progression (rho = 0.681, p = 0.010). %F-PSA was lower in patients who failed salvage radiation therapy (p = 0.031) and in patients who developed distant cancer metastases compared to patients who did not (p < 0.001).

CONCLUSIONS

Pre-operative T-PSA is not associated with prostate cancer outcomes after RP when levels are below 10 ng/ml. In contrast, pre-operative %F-PSA is associated with adverse pathologic features, biochemical progression, and features of aggressive disease progression in patients treated with RP and T-PSA levels below 10 ng/ml. %F-PSA may improve pre-operative predictive models for predicting clinical outcomes of patients diagnosed with prostate cancer nowadays.

THE RELATIONSHIP BETWEEN TUMOR VOLUME AND THE NUMBER OF POSITIVE CORES IN MEN UNDERGOING MULTISITE EXTENDED BIOPSY: IMPLICATION FOR EXPECTANT MANAGEMENT

PURPOSE

We assessed the relationship between the number of positive cores obtained at extended biopsy and tumor volume in radical prostatectomy specimens as a tool for predicting the biological significance of prostate cancer from biopsy data.

MATERIALS AND METHODS

The study group included 207 men who were treated with radical prostatectomy without neoadjuvant therapy at our cancer center. All patients were diagnosed by systematic extended biopsy (10 or 11 cores) performed between 1997 and 2003. The variables analyzed were patient age, prostate specific antigen, clinical stage, biopsy Gleason score, maximum tumor length in a core, greatest percent of tumor in a core, total tumor length, total percent of tumor in all cores, positive core location, initial or repeat biopsy and prostate volume in subgroups based on the number of positive cores, that is group 1-1, group 2-2 and group 3-3 or more cores. Bivariate correlation analysis and multiple logistic regression analysis were used to determine the predictors of insignificant cancer.

RESULTS

The number of positive cores was significantly related to total tumor volume (r = 0.433, p <0.001). Insignificant prostate cancer (volume less than 0.5 cc and Gleason score 6 or less) was found in 21.7% of patients (45 of 207). The incidence of insignificant cancer was 42.5% (31 of 73 patients) in group 1, 16.4% (10 of 61) in group 2 and 5.5% (4 of 73) in group 3. There was a significant difference in the incidence of insignificant cancer among the subgroups (group 1 vs 2 p <0.001, group 1 vs 3 p <0.0001 and group 2 vs 3 p <0.05). The best model for predicting insignificant cancer in group 1 was the combination of tumor length less than 2 mm, Gleason score 3 + 4 or less and prostate volume greater than 50 cc with 83.9% sensitivity (26 of 31 patients) and 61.9% specificity (26 of 42).

CONCLUSIONS

The probability of insignificant cancer was directly related to the number of positive cores. Tumor length in a core, Gleason score and prostate volume significantly enhanced the prediction model for insignificant cancer in men with 1 positive core who underwent extended biopsy.

USE OF 2.6 NG/ML PROSTATE SPECIFIC ANTIGEN PROMPT FOR BIOPSY IN MEN OLDER THAN 60 YEARS

PURPOSE

Since the United States Food and Drug Administration approved the prostate specific antigen (PSA) blood test as an aid to early prostate cancer detection, using a cutoff of 4.0 ng/ml in 1994, this cutoff has been widely adopted to recommend prostate biopsy. There has been recent investigation into lowering the PSA prompt for biopsy, especially in men younger than 60 years. We determined how a lower cutoff would perform in men older than 60 years.

MATERIALS AND METHODS

From a prostate cancer screening study we studied 782 consecutive men who underwent prostate biopsy for PSA greater than 2.5 ng/ml or suspicious digital rectal examination. Biopsy results were evaluated as a function of patient age.

RESULTS

Clinical and pathological characteristics of cancers detected in the PSA range 2.6 to 4.0 ng/ml were similar regardless of patient age. Overall PSA between 2.6 and 4.0 ng/ml was associated with a cancer detection rate of 16.2% using a sextant biopsy technique. PSA velocity was similar in men with prostate cancer in all age groups.

CONCLUSIONS

More than 15% of men with PSA 2.6 to 4.0 ng/ml who are 40 years or older have prostate cancer detected with sextant needle biopsies. PSA velocity, tumor stage, Gleason grade and tumor volume were similar in all age groups.

PSA testing: an evolving relationship with prostate cancer screening

PSA testing has made prostate cancer screening a reality for men in many parts of the world, but its benefit for men's health continues to be debated. In men exposed to PSA testing, there has been a well-documented change in the presentation of prostate cancer with a shift towards earlier pathological stage, not without justifiable concern about over-diagnosis by prostate biopsy. Increasingly, men now diagnosed with early stage cancer have previous PSA exposure and are selected for biopsy based on PSA change in relation to cutoff values. Some recent observations suggest that PSA may no longer be an effective marker for early stage tumours, with PSA elevation failing to discriminate tumour-specific characteristics from benign gland enlargement. Traditionally, variation in pathological stage of clinically localised prostate cancer at diagnosis has related to clinical stage, PSA and biopsy Gleason grade, but with distinctions based upon these three assessments declining and an increasing proportion of organ-confined tumours at presentation, new methods of cancer detection and prognostic assessment are now required. Molecular technologies hold great promise in this respect, and in the future biomarker signatures are likely to overshadow total PSA for guiding early diagnosis and prognostic assessment. While arguments about prostate screening will continue, owing not least to its feasibility, future debate is likely to focus increasingly on technological advances and molecular profiling of these notoriously heterogeneous tumours.

Active Surveillance for Prostate Cancer: For Whom?

Prostate-specific antigen (PSA) –based prostate cancer screening results in the diagnosis of prostate cancer in many men who are not destined to have clinical progression during their lifetime. Good-risk prostate cancer, defined as a Gleason score of 6 or less, PSA < 10, and T1c to T2a, now constitutes 50% of newly diagnosed prostate cancer. In most of these patients, the disease is indolent and slow growing. The challenge is to identify those patients who are unlikely to experience significant progression while offering radical therapy to those who are at risk. The approach to favorable-risk prostate cancer described in this article uses estimation of PSA doubling time (PSA DT) to stratify patients according to the risk of progression. Patients who select this approach are managed initially with active surveillance. Those who have a PSA DT of 3 years or less (based on a minimum of three determinations over 6 months) are offered radical intervention. The remainder are closely monitored with serial PSA and periodic prostate rebiopsies (at 2, 5, and 10 years). In this series of 299 patients, the median DT was 7 years. Forty-two percent had a PSA DT > 10 years, and 20% had a PSA DT > 100 years. The majority of patients on this study remain under surveillance. The approach of active surveillance with selective delayed intervention based on PSA DT represents a practical compromise between radical therapy for all (which results in overtreatment for patients with indolent disease) and watchful waiting with palliative therapy only (which results in undertreatment for those with aggressive disease).