Frequency Of Prostate-specific Antigen Testing Research Articles

Ethnic and socio-economic disparities in prostate cancer screening: lessons from New Zealand.

To investigate the presence of ethnic and socio-economic disparities in prostate cancer (PCa) screening and identify its impact on cancer outcomes. From January 2008 to December 2017, all men in the Northern region of New Zealand who had a prostate-specific antigen (PSA) test performed in the community were identified from the electronic laboratory reports database. Asymptomatic men, with no known diagnosis of PCa, were included. Variables collected were age, ethnicity, social deprivation, medical therapy, PSA test information and cancer data. Disparities were investigated by comparing the frequency of PSA testing, proportions of men screened, and rates of cancer detection, between Māori (indigenous) and non-Māori ethnic groups. The study cohort included 248 491 men, who each received approximately 3.45 PSA tests over the 10-year study period. Māori men were less likely to be tested compared to non-Māori men (25.4% vs 46.1% of the total aged-matched region population; P < 0.001). Moreover, they received less frequent PSA testing irrespective of their deprivation status (mean difference of 0.97 PSA tests per person; P < 0.001). The higher testing frequency in non-Māori men was associated with increased PCa diagnosis rates. Nevertheless, cancers detected in Māori men were 73% more likely to be of high grade (Gleason 8 or above), compared to those in non-Māori men. There were significant ethnic disparities in PCa screening rates in the Northern region of New Zealand. Māori men, regardless of other demographic factors, were disproportionately affected. The difference in the rates of screening by ethnicity had influenced the incidence and clinical significance of the diagnosed cancers.

Association Between Antidiabetic Medications and Prostate-Specific Antigen Levels and Biopsy Results

Diabetic men appear to have a lower risk of prostate cancer. Whether antidiabetic medications are protective or potentially mask prostate cancer by lowering prostate-specific antigen (PSA) levels is unclear. To examine the associations of antidiabetic medication use with (1) PSA levels, (2) frequency of PSA testing, (3) receipt of biopsy following elevated PSA results, and (4) prostate cancer detection at biopsy. Population-based cohort study using data from the Stockholm PSA and Biopsy Register. Participants were all prostate cancer-free men aged 40 to 79 years residing in Stockholm County, Sweden, between January 1, 2006, and December 31, 2015. Data were analyzed from November 2018 to March 2019. One or more prescription for metformin, sulfonylurea, or insulin, as recorded in Sweden's National Prescribed Drug Register. Levels of PSA following first exposure to antidiabetic medications were assessed using multivariable linear regression. Frequency of PSA testing was assessed via multivariable Poisson regression. Biopsy following elevated PSA (≥3.0 ng/mL) and prostate cancer detection at biopsy were assessed via multivariable logistic regression. The cohort of 564 666 men (median [range] age, 65 [40-79] years) consisted of 4583 men initially exposed to metformin, 1104 exposed to sulfonylurea, and 978 exposed to insulin who were age matched with unexposed men (1:5). Exposed men had lower median (interquartile range) PSA levels before starting antidiabetic medications compared with unexposed men (1.2 [0.7-2.5] vs 1.6 [0.8-3.2] ng/mL). After accounting for baseline differences, PSA levels did not vary from those of unexposed men following exposure to antidiabetic medications. Frequency of PSA testing was higher for those receiving metformin (rate ratio, 1.07; 95% CI, 1.06-1.09) and sulfonylurea (rate ratio, 1.06; 95% CI, 1.03-1.08) but was lower for those receiving insulin (rate ratio, 0.79; 95% CI, 0.77- 0.81). Likelihood of biopsy after elevated PSA was lower among men receiving metformin (odds ratio, 0.87; 95% CI, 0.80-0.96) and insulin (odds ratio, 0.83; 95% CI, 0.74-0.93). There were no differences in prostate cancer detection at biopsy, regardless of PSA levels that triggered the biopsy. This study's findings do not support the hypothesis that the inverse association between diabetes and prostate cancer is mediated through antidiabetic medications lowering PSA levels to mask prostate cancer. They do suggest potential detection bias due to fewer biopsies among men receiving antidiabetic medications, which may explain the lower prostate cancer risk in men with diabetes.

MP25-10 DECLINE IN PROSTATE SPECIFIC ANTIGEN SCREENING AMONG PRIMARY CARE PHYSICIANS IN RESPONSE TO UNITED STATES PREVENTATIVE SERVICES TASK FORCE RECOMMENDATIONS

INTRODUCTION AND OBJECTIVES: The United States Preventative Services Task Force (USPSTF) controversially recommended against prostate specific antigen (PSA) screening in its guideline released in October of 2011. Previous studies of national screening rates have found a significant decrease in PSA screening after the release of the USPSTF recommendations, however these are limited by their reliance on patient self report. The National Ambulatory Medical Care Survey (NAMCS) is a conducted annually by the Centers for Disease Control and Prevention (CDC), and collects data on PSA screening from records of medical visits. In this study, we aim to determine the frequency of PSA testing by primary care physicians before and after release of the USPSTF guidelines. METHODS: NAMCS is based on a sample of visits to nonfederal, office-based physicians. The basic sampling unit for the NAMCS is the physician-patient visit. All analysis was performed in accordance with NCHS recommendations accounting for the complex survey design, and Pearson0s chi-squared test was used for all statistical comparisons. RESULTS: In men over forty seeing their primary care doctor for preventative care, the rate of PSA testing by year is shown in Figure 1. Comparing the years prior to the release of the USPSTF guideline and 2012, the rate of testing decreased from 28.3% (95% CI 25.2% to 31.5%) to 15.6% (95% CI 11.8% to 20.4%, p<0.001). The rate of testing by age is shown in Figure 2. The American Urological Association currently recommends joint decision-making in deciding on screening in men aged 55 to 69. The rate of screening among these men decreased from 33.0% (95% CI 29.4% to 36.8%) in 2002-2010 to 18.7% (95% CI 13.8% to 24.9%) in 2012 (p<0.001). CONCLUSIONS: Office-based prostate cancer screening decreased 45% after the release of the 2012 USPSTF guideline. This report, combined with results from other sources, suggest that the use of PSA screening is rapidly declining in primary care practice. Source of Funding: None

Association of sociodemographic factors and prostate-specific antigen (PSA) testing

ObjectivesThere are conflicting recommendations regarding the use of prostate specific antigen (PSA) as a screening test. Integral to this debate is an understanding of who is currently being tested. The purpose of this study was to provide a detailed account of PSA testing practices in a major Canadian city (Calgary, Alberta) and to identify variables that may affect access to the PSA test. Design and methodsPSA test counts were retrieved from Calgary Laboratory Services' Laboratory Information System from January 1, 2011 to December 31, 2011. A total of 75,914 individual PSA tests were included in our analysis. The frequency of PSA testing was plotted onto a dissemination area map of Calgary using ArcGIS software. Associations with sociodemographic variables were tested using Poisson regression. ResultsThe median PSA value was 0.93μg/L and the median age at collection was 58years. Forty-three percent of men aged 60–69 received a PSA test. Visible minority status ‘Black’ (P=0.0002) and Métis status (P=0.0075) were associated with lower PSA testing frequencies, while median household income (P=<0.0001) and university education (P=<0.0001) were associated with higher PSA testing frequencies. ConclusionThere are areas in Calgary which are significantly over or under tested relative to the mean. The amount of PSA testing in men <50years of age is increasing, which is contrary to PSA testing guidelines.

Population-based assessment of prostate-specific antigen testing for prostate cancer in the elderly

ObjectivesTo perform a population-based analysis to characterize the effect of prostate-specific antigen (PSA) testing on oncologic outcomes in men diagnosed with prostate cancer. Materials and methodsWe used the Surveillance, Epidemiology, and End Results–Medicare–linked data to identify 98,883 men diagnosed with prostate cancer from 1996 to 2007. We stratified frequency of PSA testing as none, 1 to 2, 3 to 5, and≥6 tests in the 5 years before prostate cancer diagnosis. We used propensity scoring methods to assess the effect of frequency of PSA testing on likelihood of (1) metastases at diagnosis and (2) overall mortality and prostate cancer–specific mortality. ResultsIn adjusted analyses, the likelihood of being diagnosed with metastatic prostate cancer decreased with greater frequency of PSA testing (none, 10.6; 1–2, 8.3; 3–5, 3.7; and≥6, 2.5 events per 100 person years, P<0.001). Additionally, greater frequency of PSA testing was associated with improved overall survival and prostate cancer–specific survival (P<0.001 for both). ConclusionsGreater frequency of PSA testing in men 70 years of age or older in the 5 years before prostate cancer diagnosis is associated with lower likelihood of being diagnosed with metastatic prostate cancer and improved overall and prostate cancer–specific survival.

The impact of reducing the frequency of prostate specific antigen (PSA) testing among men on active surveillance for prostate cancer.

5092 Background: Active surveillance is a management strategy for men with low risk prostate cancer. Most surveillance regimens include routine PSA assessments, typically performed q 3 mos, although recent studies have questioned the utility of short-term PSA kinetics. Moreover, frequent PSA assessments may be associated with repeated intervals of anxiety around the time of testing, decreasing overall quality of life and potentially leading to avoidable interventions. We hypothesized that PSA assessment q 6 mos rather than q 3 mos would yield similar PSA kinetics calculations. Methods: We analyzed data from the Prostate Active Surveillance Study (PASS), a prospective, multicenter cohort accruing data and biospecimens from men on surveillance at 9 sites across North America. In PASS, PSAs are measured q 3 mos, with high completeness of data. We included data from men who had at least 5 PSA assessments after diagnosis, separated by ≥6 months (most had 10 PSAs separated by 3 months). PSA doubling time (PSADT) was calculated as ln(2) divided by the slope of a regression line drawn through the 5 PSAs. PSADT3 and PSADT6 were defined as the PSADT calculated from q 3 mos and q 6 mos data, respectively; for PSADT6, PSAs between each 6-month measurement were ignored. In each case, PSADT of 0-3 years defined progression, and PSADT &gt; 3 years or declining PSA defined non-progression. Results: 161 men had sufficient PSA followup for analysis. 133 had no progression by either PSADT3 or PSADT6, and 16 progressed by both PSADT calculations. 4 and 8 men, respectively, progressed only by the PSADT3 or PSADT6 calculation but not by the other calculation. The κ score for agreement of progression ascertainment between PSADT3 and PSADT6 was 0.68, and McNemar’s test indicated no statistically significant difference between the two assessments (p=0.39). Conclusions: Calculating PSADT using 6-month rather than 3-month PSA assessments does not significantly change ascertainment of PSA progression in men on surveillance. Our finding suggests that surveillance protocols may reduce the frequency of PSA testing, potentially reducing unnecessary biopsy procedures and patient anxiety due to more frequent PSA measurements.

The Utility of Prostate-Specific Antigen Screening and Prostate Cancer Treatment in Elderly Patients

Screening and treatment of prostate cancer remain controversial, particularly for elderly men. Since the previous United States Preventive Services Task Force recommendation in 2008 against prostate-specific antigen (PSA) screening after age 75 years, there has not been a substantial reduction in the frequency of PSA testing in this age group. A substantial proportion of elderly men are overdiagnosed and overtreated. On the other hand, men aged >75 years have more aggressive disease. Although screening has questionable benefit for elderly men with significant comorbidities, healthy men >75 years may benefit from definitive therapy. This review discusses prostate cancer screening and management decisions for elderly men, including the use of nomograms and predictive tools for life expectancy.

Prostate‐specific antigen testing in older men in the USA: data from the behavioral risk factor surveillance system

To examine the frequency of PSA testing in men aged ≥75 years before and after the 2008 US Preventive Services Task Force (USPSTF) recommendation to stop prostate-specific antigen (PSA) screening at age 75. Data were obtained from the Behavioral Risk Factor Surveillance System (BRFSS) surveys completed in 2006, 2008 and 2010. Men aged ≥ 76 years at the time of survey and without a prostate cancer diagnosis were included in the study. The percentage of men who had a PSA test in the year before the survey was computed separately for survey years 2006, 2008 and 2010. The estimated percentages of men with a PSA test in the year before the survey were 60% (95% CI: 58-62%), based on 9033 respondents interviewed in 2006, 63% (95% CI: 62-65%), based on 12,063 respondents interviewed in 2008, and 60% (95% CI: 59-61%), based on 14,782 respondents interviewed in 2010. No substantial reduction in the frequency of PSA testing was observed in the BRFSS 2010 survey data compared with the earlier years, suggesting that the USPSTF 2008 recommendation had no major impact on the frequency of PSA testing in older men in the USA.

Clinical evaluation of a novel method for the measurement of prostate‐specific antigen, AccuPSATM, as a predictor of 5‐year biochemical recurrence‐free survival after radical prostatectomy: results of a pilot study

Study Type - Diagnostic (validating cohort) Level of Evidence 1b What's known on the subject? and What does the study add? Nadir Ultrasensitive PSA levels has some value for predicting BCR following RD. AccuPSA assays lower limit of PSA quantification of <0.01 pg/ml greatly enhances sensitivity and specificity of nadir PSA to predict BCR following RP. Our pilot study shows an AccuPSA of 3 pg/ml has a sensitory and specificity of 100% and 75% respectively for predicting 5 year BCR following RP. OBJECTIVES • To conduct a proof of concept study to evaluate a novel digital single molecule immunoassay (AccuPSA(TM) ) that detects prostate-specific antigen (PSA) a thousandfold more sensitively than current PSA detection methods. • To determine the ability of the AccuPSA(TM) assay to predict 5-year biochemical recurrence (BCR)-free survival after radical prostatectomy (RP). PATIENTS AND METHODS • A total of 31 frozen serum specimens were obtained from specimen logs maintained at New York University Langone Medical Center and the Johns Hopkins University School of Medicine on men who had undergone RP. Those men without evidence of BCR had a minimum of 5 years' PSA follow-up. • In all cases, preoperative and pathological information were available, as was a serum specimen 3-6 months after RP, with a PSA level of <0.1 ng/mL measured by conventional PSA methods at the time of serum collection. • Specimens were tested using the AccuPSA(TM) method. • A Cox proportional hazard model and Kaplan-Meier analysis were used to determine whether AccuPSA(TM) predicted the risk of BCR. RESULTS • Overall, 11/31 (35.5%) men developed BCR. • Mean AccuPSA(TM) nadir levels were significantly different (P < 0.001) between the non-BCR group (2.27 pg/mL) and the BCR group (46.99 pg/mL). • Using a multivariate Cox proportional hazard model, AccuPSA(TM) nadir level was a significant predictor of BCR-free survival (P < 0.01). • Kaplan-Meier analysis of up to 5 years follow-up showed that 100% of men with AccuPSA(TM) nadir values <3 pg/mL did not develop BCR, whereas 62.5% of men with values >3 pg/mL developed BCR (P= 0.00024). • The sensitivity, specificity, positive predictive value and negative predictive value of the AccuPSA(TM) method was 100%, 75%, 69% and 100%, respectively. CONCLUSIONS • AccuPSA(TM) assay predicts 5-year BCR- free survival after RP. • Identifying a reliable predictor of BCR soon after RP has important implications for frequency of PSA testing, selection of candidates for adjuvant therapy, and reassuring a large subset of men that they are not at risk of recurrence. • Larger studies are needed to validate these findings.

438 NATIONAL TRENDS IN THE USE OF PROSTATE-SPECIFIC ANTIGEN TESTING AMONG PRIMARY CARE PHYSICIANS IN THE UNITED STATES FROM 1997 TO 2008

You have accessJournal of UrologyGeneral & Epidemiological Trends & Socioeconomics: Practice Patterns, Cost Effectiveness1 Apr 2011438 NATIONAL TRENDS IN THE USE OF PROSTATE-SPECIFIC ANTIGEN TESTING AMONG PRIMARY CARE PHYSICIANS IN THE UNITED STATES FROM 1997 TO 2008 Sandip Prasad, G. Caleb Alexander, and Scott Eggener Sandip PrasadSandip Prasad Chicago, IL More articles by this author , G. Caleb AlexanderG. Caleb Alexander Chicago, IL More articles by this author , and Scott EggenerScott Eggener Chicago, IL More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2011.02.529AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES The role of prostate-specific antigen (PSA)-based prostate cancer screening remains uncertain and national guidelines offer differing recommendations to providers. We examined the rate and predictors of PSA testing by primary care providers (PCPs) in the United States to assess for trends in utilization patterns. METHODS Using the National Ambulatory Medical Care Survey from 1997 to 2008, we examined the frequency of PSA testing by PCPs among men 40 years or older from without prostate cancer. RESULTS Annual PSA use increased from an estimated 5.3 million tests (5.7% of all visits) in 1997 to 12.4 million tests (11.5% of all visits) in 2008, representing an annual increase of approximately 6.5% (Figure, p<0.01 for trend). After adjusting for year, race, comorbidities and census region, testing was more likely among non-Hispanics (odds ratio [OR] 1.19, 95% confidence intervals [CI] 1.05–1.34) and older men, with the odds of testing highest among men aged 60–69 (OR 2.32, 95% CI 1.88–2.85) (Table). Testing was also greater among patients seen by allopathic providers (OR 1.32, 95% CI 1.10–1.61) and those living in urban areas (OR 1.33, 95% CI 1.05–1.67). Men with Medicare (OR 0.80, 95% CI 0.68–0.95) and Medicaid (OR 0.42, 95% CI 0.29–0.60) were less likely than those with private insurance to receive testing. No differences in PSA utilization were noted by census region, comorbidity, or race. Multivariate logistic regression model for receiving a PSA test during a patient visit to a PCP in the United States, 1997–2008 Estimated office visits (millions) % of total estimated % of office visits OR 95% CI All patients 1,166 8.2 Year (continuous) 1.05 1.02–1.07 AGE (years) 40–49 288 24.7 5.1 REF 50–59 300 25.8 9.6 1.91 1.58–2.30 60–69 255 21.9 11.0 2.32 1.88–2.85 70–74 114 9.8 8.5 1.87 1.44–2.43 75–85 163 14.0 6.9 1.53 1.16–2.00 <>85 45 3.9 5.3 1.11 0.74–1.68 ETHNICITY Hispanic 93 8.9 6.9 REF Non-hispanic 949 91.1 8.6 1.19 1.05–1.34 RACE White 1,003 86.1 8.2 REF Black 107 9.2 8.0 0.98 0.77–1.24 Other 55 4.7 8.1 1.0 0.66–1.50 COMORBIDITY INDEX (1) 0 760 65.2 7.8 REF 1 337 28.9 8.9 1.13 0.99–1.29 2 64 5.5 9 1.13 0.87–1.47 3 4 0.3 7.9 1.0 0.36–2.58 GEOGRAPHIC LOCATION Rural 231 19.8 6.5 REF Urban 935 80.2 8.6 1.33 1.05–1.67 CENSUS REGION Northeast 226 19.4 8.3 REF Midwest 271 23.2 8.7 1.09 0.86–1.38 South 419 35.9 7.7 0.91 0.73–1.14 West 251 21.5 8.2 0.99 0.75–1.29 INSURANCE Private 603 51.7 9.2 REF Medicare 369 31.6 7.8 0.80 0.68–0.95 Medicaid 53 4.6 4.1 0.42 0.29–0.60 Other (including self-insured) 140 12.0 6.3 0.72 0.55–0.94 PROVIDER Osteopathic physician 138 11.9 6.6 REF Allopathic physician 1027 88.1 8.4 1.32 1.10–1.61 (1) Chronic Condition Indicator index CONCLUSIONS In a nationally representative sample from 1997 to 2008, the rate of office-based PSA testing by primary care providers doubled and was associated with definable demographic factors. There was no association between comorbidity and PSA testing, although rates of testing in elderly men persisted. The impact of increasing rates of PSA testing on prostate cancer diagnosis and mortality remain unknown, especially in elderly men and those with multiple comorbidities who are unlikely to benefit from screening. © 2011 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 185Issue 4SApril 2011Page: e177-e178 Advertisement Copyright & Permissions© 2011 by American Urological Association Education and Research, Inc.MetricsAuthor Information Sandip Prasad Chicago, IL More articles by this author G. Caleb Alexander Chicago, IL More articles by this author Scott Eggener Chicago, IL More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

The Importance of Serum Prostate-specific Antigen Testing Frequency in Assessing Biochemical and Clinical Failure After Prostate Cancer Treatment

To assess the relationship between prostate-specific antigen (PSA) testing frequency and biochemical failure (bF) and clinical failure (cF). The records of 5616 patients with low-, intermediate-, or high-risk prostate cancer treated (brachytherapy, external beam radiotherapy, or surgery) between 1996 and 2007 were reviewed. Factors influencing bF and cF were recorded including age, initial PSA, androgen deprivation, race, clinical stage, biopsy Gleason score, and the frequency of follow-up PSA testing. Univariate and multivariate analyses were performed to assess the effect of these factors on bF and cF. Sensitivity and specificity were calculated to determine the optimal frequency of PSA testing. The median follow-up is 45 months. The median number of PSA tests per year before the occurrence of bF and cF is 1.9 for both endpoints. The multivariate analysis of factors significantly associated with bF and cF demonstrate that PSA frequency, initial PSA, clinical stage, and biopsy Gleason score are independently predictive of outcome. PSA testing achieves the best sensitivity and specificity when 2 PSA tests are drawn per year for both bF (sensitivity = 66.3%, specificity = 58.0%) and cF (sensitivity = 75.1%, specificity = 60.3%). The frequency of PSA testing is strongly associated with the detection of bF and cF. Because it is a variable that can be controlled, PSA testing frequency should be standardized to minimize spurious conclusions from studies with bF and cF endpoints. The sensitivity and specificity can be optimized by obtaining 2 PSA tests per year.

Racial Disparities in Access to Care for Men in a Public Assistance Program for Prostate Cancer

California's IMPACT program provides all its enrollees with health insurance and social service resources. We hypothesized that racial/ethnic disparities in access to care might be attenuated among men served by this program. Our objective was to evaluate racial/ethnic differences in health services utilization and patient-reported health care outcomes among disadvantaged men in a prostate cancer public-assistance program, and to identify modifiable factors that might explain persistent disparities in this health care setting. We performed a retrospective cohort study of 357 low-income men enrolled in IMPACT from 2001 through 2005. We evaluated realized access to care with two health services utilization measures: (1) use of emergency department care without hospitalization and, (2) frequency of prostate-specific antigen testing. We also measured two patient-experience outcomes: (1) satisfaction with care received from IMPACT, and (2) confidence in IMPACT care providers. We observed significant bivariate associations between race/ethnicity and patient-experience outcomes (P<0.05), but not utilization measures. In multivariable models, Hispanic men were more likely than white men to report complete satisfaction with health care received in IMPACT (adjusted OR=5.15, 95% CI 1.17-22.6); however, the association between race/ethnicity and satisfaction was not statistically significant (P=0.11). Language preference and self-efficacy in patient-physician interactions are potentially-modifiable predictors of patient-experience outcomes. We observed no racial/ethnic disparities in health services utilization among disadvantaged men served by a disease-specific public assistance program. The greater satisfaction and confidence among Hispanic men are explained by modifiable variables that suggest avenues for improvement.

Cancer de la prostate. Diagnostic et bilan d'extension

The discovery and the use of serum prostate specific antigen (PSA) has considerably improved the diagnosis of prostate cancer during the past 20 years. Before PSA era, early diagnosis was only based on the digital rectal examination (DRE) of which the Limitations have been evidenced; over half of the tumours diagnosed by such means had already spread out of the prostate and were incurable. Assessment of serum PSA has allowed the diagnosis to be made at an earlier stage of the disease, curable by current treatments. Whichever the diagnostic tools, transrectal ultrasound (TRUS) prostatic biopsies remain necessary for diagnosis ascertainment, taking into account the low specificity of PSA assessment. The feasibility of a diagnosis at an early and curable stage of the disease has logically resulted in screening procedures aimed at reducing the high mortality related to prostate cancer. The numerous publications on prostate cancer screening provide precise information on the accuracy of available diagnostic means (PSA, DRE, TRUS, combined PSA and DRE), on the characteristics of screened tumours (stage and differentiation), and also on the population of men likely to benefit from the screening (age at beginning and end of the screening, frequency of PSA testing, identification of the men with ethnic and/or genetic predisposition). In those early diagnosed prostate cancers, the assessment of loco-regional cancer extension (extracapsular and/or, microscopic nodal involvement), remains unsatisfactory because no imaging technique (ultrasonography, CT scan, MRI,...) allows visualising the tumour itself or microscopic metastases. Nevertheless, the combination of multiple parameters such as DRE data, PSA level, biopsy data and tumour differentiation helps approaching with an increasing precision (nomograms) the true pathologic stage of the disease. Such advances allow distinguishing, among the very heterogeneous group of prostate cancers, tumours that differ from one to another in terms of disease stage, progression and prognosis, which is helpful for the determination of an adapted therapeutic strategy.

Cancer de la prostate. Diagnostic et bilan d'extension

The discovery and the use of serum prostate specific antigen (PSA) has considerably improved the diagnosis of prostate cancer during the past 20 years. Before PSA era, early diagnosis was only based on the digital rectal examination (DRE) of which the limitations have been evidenced; over half of the tumours diagnosed by such means had already spread out of the prostate and were incurable. Assessment of serum PSA has allowed the diagnosis to be made at an earlier stage of the disease, curable by current treatments. Whichever the diagnostic tools, transrectal ultrasound (TRUS) prostatic biopsies remain necessary for diagnosis ascertainment, taking into account the low specificity of PSA assessment. The feasibility of a diagnosis at an early and curable stage of the disease has logically resulted in screening procedures aimed at reducing the high mortality related to prostate cancer. The numerous publications on prostate cancer screening provide precise information on the accuracy of available diagnostic means (PSA, DRE, TRUS, combined PSA and DRE), on the characteristics of screened tumours (stage and differentiation), and also on the population of men likely to benefit from the screening (age at beginning and end of the screening, frequency of PSA testing, identification of the men with ethnic and/or genetic predisposition). In those early diagnosed prostate cancers, the assessment of loco-regional cancer extension (extracapsular and/or, microscopic nodal involvement), remains unsatisfactory because no imaging technique (ultrasonography, CT scan, MRI,...) allows visualising the tumour itself or microscopic metastases. Nevertheless, the combination of multiple parameters such as DRE data, PSA level, biopsy data and tumour differentiation helps approaching with an increasing precision (nomograms) the true pathologic stage of the disease. Such advances allow distinguishing, among the very heterogeneous group of prostate cancers, tumours that differ from one to another in terms of disease stage, progression and prognosis, which is helpful for the determination of an adapted therapeutic strategy.

Cruciferous Vegetables and Prostate Cancer Risk

To the Editors: The recent publication by Giovannucci et al. (1) describing associations of cruciferous vegetable consumption with prostate cancer risk is an important contribution to existing literature on diet and cancer. Although cruciferous vegetables were not associated with risk in the primary analyses that included all men in the Health Professionals Follow-up Study, results of analyses among the subgroup of men who reported receiving at least one prostate-specific antigen (PSA) screening test were strikingly different. In these secondary subgroup analyses, there were statistically significant linear decreases in relative risk associated with increasing consumption of cruciferous vegetables. The authors interpret this result as evidence that cruciferous vegetables affect only early stages of prostate carcinogenesis because most cancers detected by PSA screening are organ confined. There is, however, a somewhat more parsimonious interpretation of these results, which has broad implications for current studies of risk factors for prostate cancer.PSA screening is a strong risk factor for prostate cancer. In a population-based case-control study completed in western Washington State, the age-adjusted odds ratios (95% confidence interval) for prostate cancer were 4.0 (3.1-5.3), 5.5 (3.7-7.3), and 7.1 (4.8-10.5), comparing no PSA test to 1 to 2, 3 to 4, and 5+ PSA tests in the previous 5 years (2). Thus, studies in populations not uniformly screened with PSA are subject to detection bias. In addition, if frequency of PSA testing is positively associated with an hypothesized behavioral risk factor, PSA screening may be act as a special type of confounding variable termed a distorter variable (3), which could mask a true association between behavior and prostate cancer risk (Fig. 1). Indeed, in studies examining healthful dietary behavior and prostate cancer, this is most likely the case. In a population-based survey of Washington State residents, men eating four or more servings of vegetables per day were almost three times more likely to have reported a PSA test in the previous 2 years than men eating fewer than two servings per day (4). Results from the case-control study mentioned above were consistent with this finding, as statistical control for number of PSA tests increased the magnitude of the association between cruciferous vegetable consumption and prostate cancer risk (5). Based on these arguments, we believe that epidemiologic studies of prostate cancer risk need to be controlled for PSA screening, preferably for numbers of recent PSA tests.In our experience, confounding variables that can mask true associations are rare in epidemiology. However, such confounding may be the norm in studies of environmental and behavioral risks for prostate cancer. Our interpretation of the report by Giovannucci et al. (1) is that the analyses including only men receiving PSA screening should be the primary result, which provides evidence from a large and extraordinarily well-conducted cohort study supporting an association of cruciferous vegetables with reduced prostate cancer risk.

PSA testing and digital rectal examination in New Zealand

Objective: To investigate the use of digital rectal examination and prostate specific antigen (PSA) testing in a population‐based sample of men in New Zealand.Methods: A random selection of men aged 40–74 years, weighted by age, was chosen from the general electoral roll of New Zealand. Only men with a telephone who had been married at some time were eligible. Telephone interviews were conducted using a standard questionnaire. Crude and age‐adjusted proportions were calculated. Logistic regression was used to explore associations between socio‐demographic factors and digital rectal examination or PSA testing.Results: Interviews were completed for 85% of the 1,486 eligible men and analyses were confined to the 1,225 European men. Many more men reported having a digital rectal examination (41%; 95% CI 33.8–48.2) than a PSA test (9%; 95% CI 4.2–14.2). Men in the lowest social class were significantly less likely to have had a digital rectal examination (OR 0.30; 95% CI 0.18–0.50) or PSA test (OR 0.25; 95% CI 0.11–0.60) compared with those in the highest social class. Men with vocational training or no post‐school qualifications were approximately half as likely to report a digital rectal examination or a PSA test compared with men with degrees or diplomas.Conclusions: Although current New Zealand recommendations are that population screening for prostate cancer should not be introduced, many men are still having digital rectal examinations and PSA tests in the absence of symptoms. The frequency of PSA testing is considerably lower than in Australia and appears to be largely influenced by a man's social class.

INTERVAL AFTER PROSTATE SPECIFIC ANTIGEN TESTING AND SUBSEQUENT RISK OF INCURABLE PROSTATE CANCER

Studies of the potential effect of prostate specific antigen (PSA) screening on a less than yearly basis have been limited to computer simulations using relatively small sample sets. Primary clinical data on this relationship have not been generally available. We examined the relationship of less frequent testing and the risk of nonlocalized incurable cancer. The effect of testing frequency on the risk of prostate biopsy in men ultimately diagnosed with cancer was also assessed. The study included a population based sample of 36,422 men 65 years old or older residing in 9 geographic areas with newly diagnosed prostate cancer during 1989 to 1993. The primary end point was the risk of nonlocalized cancer, as determined by logistic regression. Patient age, geographic region, year of diagnosis and race were included as covariates. In men who would be diagnosed with prostate cancer the risk of nonlocalized cancer did not differ in those tested 2 or 3 years compared with the risk in those tested 1 year before diagnosis (relative risk 1.00, 95% confidence interval 0.84 to 1.20 and 1.02, 95% confidence interval 0.74 to 1.41, respectively). However, the risk of prostate biopsy in these men was directly related to the number of PSA tests performed (test for trend p = 0.0061). Patients who choose to undergo PSA testing may be tested on a biennial instead of annual basis without an increased risks of nonlocalized cancer. Decreasing the frequency of PSA testing may lead to fewer prostate biopsies.