Cancer surveillance series: interpreting trends in prostate cancer--part III: Quantifying the link between population prostate-specific antigen testing and recent declines in prostate cancer mortality

Awareness about prostate cancer and its screening in Medina, Jeddah, and Makkah, Saudi Arabia population

Background:

Prostate cancer (PCa) is a global burden on public health; it has been ranked as the second common cancer worldwide, with 1.3 million new cases in 2018. Developed countries have a higher incidence than in developing countries. Because of the lack of studies on PCa in Saudi Arabia, our study aims to measure the awareness about PCa and knowledge of PCa screening practices among men in Medina, Jeddah, and Makkah, Saudi Arabia.

Methodology:

A cross-sectional study conducted among males in Medina, Jeddah, and Makkah, Saudi Arabia, from 2^nd to 10^th July 2020, using a validated questionnaire. The sample size was 1212 participants. Data collected through an online questionnaire. All data analyses performed using (SPSS) software, using the Chi-square test for bivariate analysis. All levels of significance were set at P < 0.05.

Results:

We collected 1212 completed surveys, with mean ages of 36 years (standard deviation ± 12.77). We found that 77% of participants heard about PCa, and 52.5% heard about PCa screening tests. This study showed that only 10.6% of all participants had good knowledge, 41.9% had fair knowledge, and 47.5% had poor knowledge. Only 3.9% of participants had experienced the prostate-specific antigen test.

Conclusion:

The study showed that the level of knowledge of PCa is low. Thus, community and individuals should collaborate to increase awareness by having more awareness campaigns, disseminating the information through the media, and encouraging men to do screening tests as indicated. In addition, including more Saudi Arabia cities in future studies is preferable to have more precise outcomes.

Prostate tumor metastasis in cecal appendix diagnosed after appendicitis in a virgin treatment patient: A case report

Involvement of cecal appendix by metastases secondary to prostate cancer is extremely rare. We have reported a case of a patient with an acute abdomen who underwent right hemicolectomy for appendicitis. Immunohistochemistry of the appendix revealed a prostate tumor metastasis. The presence of prostate cancer metastasis in the cecal appendix is rare, with less than 10 cases reported in published literature. Involvement of the cecal appendix secondary to prostate cancer must be considered as a differential diagnosis in cases of appendicitis, especially in patients who already have a diagnosis of metastatic prostate cancer.

Prostate cancer screening among family physicians in Ontario: An update on attitudes and current practice

INTRODUCTION

This study serves as an update of prostate cancer screening practices among family physicians in Ontario, Canada. Since this population was first surveyed in 2010, the Canadian Task Force on Preventive Health Care (CTFPHC) and the United States Preventive Services Task Force (USPSTF) released recommendations against prostate cancer screening.

METHODS

An online survey was developed through input from urologists and family practitioners. It was distributed via email to all members of the Ontario Medical Association's Section on General and Family practice (11 657 family physicians). A reminder email was sent at two weeks and the survey remained active for one month.

RESULTS

A total of 1880 family physicians completed surveys (response rate 16.1%). Overall, 80.4% offered prostate cancer screening compared to 91.7% when surveyed in 2010. Physicians new to practice (two years or less) were the most likely to not offer screening (24.6%). A combination of digital rectal exam (DRE) and prostate-specific antigen (PSA) remained the most common form of screening (58.3%). Following the release of the CTFPHC recommendations, 45.6% of respondents said they now screen fewer patients. Participants were less familiar with national urological society guidelines compared to task force recommendations. The majority (72.6%) of respondents feel PSA screening leads to overdiagnosis and treatment. Those surveyed remained split with respect to PSA utility.

CONCLUSIONS

Data suggest a decline in screening practices since 2010, with newer graduates less likely to offer screening. CFTPHC and USPSTF recommendations had the greatest impact on clinical practice. Those surveyed were divided with respect to PSA utility. Some additional considerations to PSA screening in the primary care setting, including patient-driven factors, were not captured by our concise survey.

Prostate Cancer Knowledge, Prevention, and Screening Behaviors in Jamaican Men

Screening is the only effective method of reducing prostate cancer mortality. Several reports have documented poor prostate cancer awareness and screening practices in Jamaican men. The Jamaica Cancer Society provides the most organized and largest form of screening in Jamaica and hosts an annual mass screening clinic on Prostate Cancer Awareness Day in September. We sought to determine the knowledge and attitudes towards screening and risks and prevention of prostate cancer. The study represented a cross-sectional analysis of 55 men presenting for screening on Prostate Cancer Awareness Day, September 2014 in Kingston, Jamaica. Information on prostate cancer knowledge and attitudes towards screening was obtained using interviewer-administered questionnaires (The Integrative Model of Prostate Cancer Disparity (PIPCaD). Prostate specific antigen (PSA) and digital rectal examination (DRE) were obtained from all patients. Mean PSA of participating men was 1.5 ± 1.48 ng/ml. Fifteen percent of men surveyed had a family history of prostate cancer. Prostate cancer knowledge was moderate, with at least 84 % of men responding correctly to 5 of 10 questions referring to prostate cancer risk and prevention. Most men had a favorable attitude towards screening. Starch formed the major portion of the diet in 68 % of men and 35 % of men engaged in no physical activity. Jamaican men surveyed have moderate prostate cancer knowledge and a positive attitude towards screening and prostate cancer prevention activities. However, the application of activities for potential prevention of modifiable risk factors is poor.

Chromatin and Aging

Recent studies from a number of model organisms have indicated chromatin structure and its remodeling as a major contributory agent for aging. Few recent experiments also demonstrate that modulation in the chromatin modifying agents also affect the life span of an organism and even in some cases the change is inherited epigenetically to subsequent generations. Hence, in the present report we discuss the chromatin organization and its changes during aging.

Cigarette Smoking and Prostate Cancer Mortality in Four US States, 1999-2010

INTRODUCTION

In the United States, prostate cancer mortality rates have declined in recent decades. Cigarette smoking, a risk factor for prostate cancer death, has also declined. It is unknown whether declines in smoking prevalence produced detectable declines in prostate cancer mortality. We examined state prostate cancer mortality rates in relation to changes in cigarette smoking.

METHODS

We studied men aged 35 years or older from California, Kentucky, Maryland, and Utah. Data on state smoking prevalence were obtained from the Behavioral Risk Factor Surveillance System. Mortality rates for prostate cancer and external causes (control condition) were obtained from the Centers for Disease Control and Prevention's Wide-Ranging Online Data for Epidemiologic Research. The average annual percentage change from 1999 through 2010 was estimated using joinpoint analysis.

RESULTS

From 1999 through 2010, smoking in California declined by 3.5% per year (-4.4% to -2.5%), and prostate cancer mortality rates declined by 2.5% per year (-2.9% to -2.2%). In Kentucky, smoking declined by 3.0% per year (-4.0% to -1.9%) and prostate cancer mortality rates declined by 3.5% per year (-4.3% to -2.7%). In Maryland, smoking declined by 3.0% per year (-7.0% to 1.2%), and prostate cancer mortality rates declined by 3.5% per year (-4.1% to -3.0%).In Utah, smoking declined by 3.5% per year (-5.6% to -1.3%) and prostate cancer mortality rates declined by 2.1% per year (-3.8% to -0.4%). No corresponding patterns were observed for external causes of death.

CONCLUSION

Declines in prostate cancer mortality rates appear to parallel declines in smoking prevalence at the population level. This study suggests that declines in prostate cancer mortality rates may be a beneficial effect of reduced smoking in the population.

Alpha-methylacyl-CoA Racemase and Hepsin as Urinary Prostate Cancer Markers

Background

Because of the numerous limitations of prostate-specific antigen (PSA), α-methylacyl-CoA racemase (AMACR) and hepsin have recently been suggested as potential biomarkers in prostate cancer (PC). This report presents a comparison study of the presence of AMACR and hepsin in urine collected before and after digital rectal examination (DRE) as a previously suggested diagnostic marker for PC.

Methods

Seventy-six urine samples (38 before and 38 after prostate massage) from patients with benign prostate hyperplasia (BPH) and 66 urine samples (33 before and 33 after prostate massage) from patients with PC were analyzed. PC was confirmed by prostate biopsy. Urinary levels of AMACR and hepsin were determined by ELISA and related to the tumor stage, Gleason score and PSA level.

Results

AMACR and hepsin levels in urine collected after prostate massage were higher only in the PC group. There were no correlations between AMACR levels, hepsin levels, tumor stage and Gleason score. AMACR and hepsin did not differentiate between BPH and PC with better true positive and false negative rates than serum PSA.

Conclusions

AMACR and hepsin were unable to diagnose PC with better true positive and false negative rates than PSA. An additional procedure combined with other markers should be applied for the reliable diagnosis of PC.

Melanoma mortality following skin cancer screening in Germany

OBJECTIVES

In 2003, a skin cancer screening campaign based on total body skin examination was launched in the federal state of Schleswig-Holstein, Germany. 20% of adults aged 20 and over were screened. In 2008, a 48% decline in melanoma mortality was reported. In the same year, skin screening was extended to the rest of Germany. We evaluated whether melanoma mortality trends decreased in Germany as compared with surrounding countries where skin screening is uncommon. We also evaluated whether the initial decreasing mortality trend observed in Schleswig-Holstein was maintained with a longer follow-up.

SETTING AND PARTICIPANTS

Regional and national melanoma mortality data from 1995 to 2013 were extracted from the GEKID database and the Federal Statistical Office. Mortality data for Germany and surrounding countries from 1980 to 2012 were extracted from the WHO mortality database.

PRIMARY AND SECONDARY OUTCOME MEASURES

Age-adjusted (European Standard Population) mortality rates were computed and joinpoint analysis performed for Schleswig-Holstein, Germany and surrounding countries.

RESULTS

In Schleswig-Holstein, melanoma mortality rates declined by 48% from 2003 to 2008, and from 2009 to 2013 returned to levels observed before screening initiation. During the 5 years of the national programme (2008-2012), melanoma mortality rates increased by 2.6% (95% CI -0.1 to 5.2) in men and 0.02% (95% CI -1.8 to 1.8) in women. No inflexion point in trends was identified after 2008 that could have suggested a decreasing melanoma mortality. Trends of cutaneous melanoma mortality in Germany from 1980 to 2012 did not differ from those observed in surrounding countries.

CONCLUSIONS

The transient decrease mortality in Schleswig-Holstein followed by return to pre-screening levels could reflect a temporal modification in the reporting of death causes. An in-depth evaluation of the screening programme is required.

Prostate cancer intervention

Cancer screening by PSA testing is widespread in the United States, and treatment recommendations encourage early therapy. Yet controversy about patient care persists because evidence demonstrating that these approaches improve the length and quality of a man's life is lacking. Physicians can assist their patients by first providing a balanced presentation of the known risks and benefits of prostate cancer detection and treatment and then incorporating patient preferences into medical decisions. Success in shared decision making may increase with use of patient education materials to convey most of the time-consuming and challenging information. At least two of the many materials developed can be easily administered with very few resources and independent of primary care encounters.

Principles of Cancer Screening

Cancer screening has long been an important component of the struggle to reduce the burden of morbidity and mortality from cancer. Notwithstanding this history, many aspects of cancer screening remain poorly understood. This article presents a summary of basic principles of cancer screening that are relevant for researchers, clinicians, and public health officials alike.

Novel prostate cancer biomarkers derived from autoantibody signatures

BACKGROUND: Due to the low specificity of the prostate-specific antigen (PSA) assay and a high false positive rate, a large number of prostate cancer (PCA) biopsies are performed unnecessarily. Consequently, there is a need for new biomarkers that can identify PCA at any stage of progression while limiting the number of false positives. The use of autoantibody signature–developed biomarkers has proven to be an effective method to solve this problem. RESULTS: Using T7 phage–peptide detection, we identified a panel of eight biomarkers for PCA on a training set. The estimated receiver-operating characteristic (ROC) curve had an area under the ROC curve of 0.69 when applied to the validation set. Spearman correlations were high, within 0.7 to 0.9, indicating that the biomarkers have a degree of inter-relatedness. The identified biomarkers play a role in processes such as androgen response regulation and cellular structural integrity and are proteins that are thought to play a role in prostate tumorigenesis. CONCLUSIONS: Autoantibodies against PCA can be developed as biomarkers for detecting PCA. The scores from the algorithm developed here can be used to indicate a relative high or low risk of PCA, particularly for patients with intermediate (4.0 to 10 ng/ml) PSA levels. Since most commercially available assays test for PSA or have a PSA component, this novel approach has the potential to improve diagnosis of PCA using a biologic measure independent of PSA.

Developing a follow-up strategy for patients with PSA ranging from 4 to 10 ng/ml via a new model to reduce unnecessary prostate biopsies

Objective

The aim of this study was to develop a follow-up strategy based on the new model to reduce unnecessary prostate biopsies in patients with prostate specific antigen (PSA) ranging from 4 to 10 ng/ml.

Methods

A total of 436 patients with PSA ranging from 4 to 10 ng/ml who had undergone transrectal ultrasound (TRUS)-guided prostate biopsy were evaluated during the first stage. Age, PSA, free PSA (fPSA), digital rectal examination (DRE) findings, ultrasonic hypoechoic mass, ultrasonic microcalcifications, prostate volume (PV) and PSA density (PSAD) were considered as predictive factors. A multiple logistic regression analysis involving a backward elimination selection procedure was applied to select independent predictors. After a comprehensive analysis of all results, we developed a new model to assess the risk of prostate cancer and an effective follow-up strategy.

Results

Age, PSA, PV, fPSA, rate of abnormal DRE findings and rate of hypoechoic masses detected by TRUS were included in our model. A significantly greater area under the receiver-operating characteristic curve was obtained in our model when compared with using PSA alone (0.782 vs. 0.566). Patients were grouped according to the value of prostate cancer risk (PCaR). In the second stage of our study, patients with PCaR>0.52 were recommended to undergo biopsies immediately while the rest of the patients continued close follow-up observation. Compared with the first stage, the detection rate of PCa in the second stage was significantly increased (33.0% vs 21.1%, p = 0.012). There was no significant difference between the two stages in distribution of the Gleason score (p = 0.808).

Conclusions

We developed a follow-up strategy based on the new model, which reduced unnecessary prostate biopsies without delaying patients’ diagnoses and treatments.

The impact of recent screening recommendations on prostate cancer screening in a large health care system

PURPOSE

The United States Preventive Services Task Force recently recommended against routine prostate cancer screening, stating that the risks of screening outweigh the benefits. We determined the impact of this recommendation on prostate cancer screening in a large health system.

MATERIALS AND METHODS

We obtained data on all screening prostate specific antigen tests performed at University Hospitals Case Medical Center and affiliated hospitals in northeastern Ohio from January 2008 to December 2012. We examined the total number of prostate specific antigen tests ordered with time and adjusted for patient volume by fitting a regression line. The overall trend was examined and stratified by location (urban, suburban or rural), patient age and provider type (primary care or urology).

RESULTS

A total of 43,498 screening prostate specific antigen tests were performed from January 2008 to December 2012. Most tests were ordered by specialists in internal medicine (64.9%), followed by family medicine (23.7%), urology (6.1%) and hematology/oncology (1.3%). Prostate specific antigen screening increased with time until March 2009, when initial screening trials were published. Prostate specific antigen testing then decreased significantly and continued to decrease after the task force recommendations. Similar patterns were noted in almost all subgroups. The greatest decrease in screening was observed by urologists and in patients in the intermediate age group (50 to 59 years).

CONCLUSIONS

United States Preventive Services Task Force recommendations appeared to have decreased prostate cancer screening. The greatest impact was seen for urologists and patients in the intermediate age group. Further study is needed to determine the long-term effects of these recommendations on the screening, diagnosis, treatment and prognosis of this prevalent malignancy.

Methods and rationale used in a matched cohort study of the incidence of new primary cancers following prostate cancer

Objectives

We describe several methodological issues that were addressed in conducting a Danish population-based matched cohort study comparing rates of new primary cancers (NPCs) in men with and without prostate cancer (PC).

Methods

We matched 30,220 men with PC to 151,100 men without PC (comparators) on age (±2 years) and PC diagnosis/index date. We focused on several methodological issues: 1) to address survival differences between the cohorts we compared rates with and without censoring comparators on the date their matched PC patient died or was censored; 2) to address diagnostic bias, we excluded men with a history of cancer from the comparator cohort; 3) to address prostate cancer immunity, we graphed the hazard of NPC in both cohorts, with and without prostate cancer as an outcome; 4) we used empirical Bayes methods to explore the effect of adjusting for multiple comparisons.

Results

After 18 months of follow-up, cumulative person-time was lower in the PC than comparator cohort due to higher mortality among PC patients. Terminating person-time in comparators at the matched PC patient’s death or loss to follow-up resulted in comparable person-time up to 30 months of follow-up and lower person-time among comparators thereafter. The hazard of NPC was lower among men with PC than comparators throughout follow-up. There was little difference in rates beyond the first four years of follow-up after removing PC as an outcome. Empirical Bayes adjustment for multiple comparisons had little effect on the estimates.

Conclusion

Addressing the issues of competing risks, treatment interference or diagnostic bias, prostate cancer immunity due to radical prostatectomy, and multiple comparisons lowered the deficit rate of NPCs among men with a history of PC compared with those without PC. However, the differing rates of NPCs may also be due to risk factor differences between the cohorts.

An examination of the dynamic changes in prostate-specific antigen occurring in a population-based cohort of men over time

OBJECTIVE

• To determine whether prostate-specific antigen velocity (PSA-V), PSA doubling time (PSA-DT), or PSA percentage change (PSA-PC) add incremental information to PSA alone for community-based men undergoing prostate cancer (PCa) screening.

PARTICIPANTS AND METHODS

• A population-based cohort of 11 872 men from Olmsted County, MN undergoing PSA screening for PCa from 1993 to 2005 was analysed for PSA, PSA-DT, PSA-PC and PSA-V and subsequent PCa. • Receiver-operating characteristics curves and logistic regression were used to calculate the area under the curve (AUC) and Aikaike's information criterion. • Reclassification analysis was performed and the net reclassification improvement and integrated discrimination improvement were measured. • The method of Begg and Greenes was used to adjust for verification bias.

RESULTS

• The single best predictor of future PCa was PSA (AUC = 0.773) with PSA-V (AUC = 0.729) and PSA-DT/PSA-PC (AUC = 0.689) performing worse. • After age adjustment, combining PSA with PSA-V (AUC = 0.773) or PSA-DT/PSA-PC (AUC = 0.773) resulted in no better predictions than PSA alone. • Reclassification analysis showed that adding PSA-V or PSA-DT/PSA-PC to PSA did not result in a meaningful amount of reclassification.

CONCLUSIONS

• PSA is a better predictor of future PCa than PSA-V, PSA-DT, or PSA-PC. • Adding PSA-V, PSA-DT, or PSA-PC to PSA does not result in clinically relevant improvements in the ability to predict future PCa.

The epigenetic promise for prostate cancer diagnosis

BACKGROUND

Prostate cancer is the most common cancer diagnosis in men and a leading cause of death. Improvements in disease management would have a significant impact and could be facilitated by the development of biomarkers, whether for diagnostic, prognostic, or predictive purposes. The blood-based prostate biomarker PSA has been part of clinical practice for over two decades, although it is surrounded by controversy. While debates of usefulness are ongoing, alternatives should be explored. Particularly with recent recommendations against routine PSA-testing, the time is ripe to explore promising biomarkers to yield a more efficient and accurate screening for detection and management of prostate cancer. Epigenetic changes, more specifically DNA methylation, are amongst the most common alterations in human cancer. These changes are associated with transcriptional silencing of genes, leading to an altered cellular biology.

METHODS

One gene in particular, GSTP1, has been widely studied in prostate cancer. Therefore a meta-analysis has been conducted to examine the role of this and other genes and the potential contribution to prostate cancer management and screening refinement.

RESULTS

More than 30 independent, peer reviewed studies have reported a consistently high sensitivity and specificity of GSTP1 hypermethylation in prostatectomy or biopsy tissue. The meta-analysis combined and compared these results.

CONCLUSIONS

GSTP1 methylation detection can serve an important role in prostate cancer managment. The meta-analysis clearly confirmed a link between tissue DNA hypermethylation of this and other genes and prostate cancer. Detection of DNA methylation in genes, including GSTP1, could serve an important role in clinical practice.

Prostate cancer screening: Attitudes and practices of family physicians in Ontario

INTRODUCTION

: The utility of prostate cancer screening is controversial. We sought to determine whether Ontario's family physicians believe it is beneficial and to characterize their screening protocols.

METHODS

: A survey was developed with input from urologists, family physicians and the Ontario Medical Association's Section on General and Family Practice. Questions covered three domains: (1) demographics, (2) beliefs about screening utility and (3) screening practices. All 7302 family physicians in Ontario were invited by email to complete the online survey.

RESULTS

: A total of 969 physicians completed the survey; 955 (52.0% male, 48.0% female) were included. Most (80.97%) use prostate-specific antigen (PSA) and digital rectal examination (DRE) for screening; 9.4% use DRE alone and 7.15% PSA. Of the respondents, 8.3% do not offer prostate cancer screening. Most physicians begin offering screening at age 50 (72.9%) and stop at ages 70 or 80 (68.4%); 17.9% offer lifelong screening. In response to the statement "screening with DRE provides a survival benefit," 37.6% and 32.6 agreed and disagreed, respectively. For "screening with PSA provides a survival benefit," 43.3% agreed and 31.0% disagreed. For the statement "the benefits of prostate cancer screening outweigh the risks," 51.4% agreed and 22.0% disagreed.

DISCUSSION

: Although 91.7% of respondents offer prostate cancer screening, they are divided over its utility. Only 51.4% were convinced that the benefits outweighed the harms. There is significant variability between physicians' screening protocols. A limitation of this study is the possibility of selection bias. Nevertheless, this is the largest sample of Ontario family physicians ever surveyed about prostate cancer screening and highlights divergent physician practices and a need for more conclusive evidence on screening utility.

The burden of prostate cancer in Asian nations

INTRODUCTION

In this review, the International Agency for Research on Cancer's cancer epidemiology databases were used to examine prostate cancer (PCa) age-standardized incidence rates (ASIR) in selected Asian nations, including Cancer Incidence in Five Continents (CI5) and GLOBOCAN databases, in an effort to determine whether ASIRs are rising in regions of the world with historically low risk of PCa development.

MATERIALS AND METHODS

Asian nations with adequate data quality were considered for this review. PCa ASIR estimates from CI5 and GLOBOCAN 2008 public use databases were examined in the four eligible countries: China, Japan, Korea and Singapore. Time trends in PCa ASIRs were examined using CI5 Volumes I-IX.

RESULTS

While PCa ASIRs remain much lower in the Asian nations examined than in North America, there is a clear trend of increasing PCa ASIRs in the four countries examined.

CONCLUSION

Efforts to systematically collect cancer incidence data in Asian nations must be expanded. Current CI5 data indicate a rise in PCa ASIR in several populous Asian countries. If these rates continue to rise, it is uncertain whether there will be sufficient resources in place, in terms of trained personnel and infrastructure for medical treatment and continuum of care, to handle the increase in PCa patient volume. The recommendation by some experts to initiate PSA screening in Asian nations could compound a resource shortfall. Obtaining accurate estimates of PCa incidence in these countries is critically important for preparing for a potential shift in the public health burden posed by this disease.

What if I don't treat my PSA-detected prostate cancer? Answers from three natural history models

BACKGROUND

Making an informed decision about treating a prostate cancer detected after a routine prostate-specific antigen (PSA) test requires knowledge about disease natural history, such as the chances that it would have been clinically diagnosed in the absence of screening and that it would metastasize or lead to death in the absence of treatment.

METHODS

We use three independently developed models of prostate cancer natural history to project risks of clinical progression events and disease-specific deaths for PSA-detected cases assuming they receive no primary treatment.

RESULTS

The three models project that 20%-33% of men have preclinical onset; of these 38%-50% would be clinically diagnosed and 12%-25% would die of the disease in the absence of screening and primary treatment. The risk that men age less than 60 at PSA detection with Gleason score 2-7 would be clinically diagnosed in the absence of screening is 67%-93% and would die of the disease in the absence of primary treatment is 23%-34%. For Gleason score 8 to 10 these risks are 90%-96% and 63%-83%.

CONCLUSIONS

Risks of disease progression among untreated PSA-detected cases can be nontrivial, particularly for younger men and men with high Gleason scores. Model projections can be useful for informing decisions about treatment.

IMPACT

This is the first study to project population-based natural history summaries in the absence of screening or primary treatment and risks of clinical progression events following PSA detection in the absence of primary treatment.

Comparison of clinical and pathologic findings of prostate cancers detected through screening versus conventional referral in Brazil

INTRODUCTION

Data regarding prostate cancer screening in Brazil are limited. We compared features of prostate cancers detected through screening versus those referred for treatment in Brazil.

PATIENTS AND METHODS

Group I included 500 of 13,754 men whose cancers were detected through screening, and Group II included 2731 men referred for treatment through the habitual public health system. We used Mann-Whitney and χ(2) tests to compare clinical and pathologic findings, considering significant any P < 0.05.

RESULTS

Median prostate-specific antigen (PSA) was lower among screened patients (5.5 ng/mL versus 10.0 ng/mL; P < 0.001). Of the screened patients, 170 (34%) had biopsy Gleason score ≥ 7, compared with 1265 (46.3%) in the referred group (P < 0.001). Lymph node metastases were suspected in 8.6% of the referred versus 3.2% of the screened men (P = 0.002). Distant metastases were more common in the referred men (9.3% vs. 3.0%; P < 0.001). Only 6.0% of the screened cancers were locally advanced at diagnosis (T3 or T4) versus 26.5% of the referred (P < 0.001). Screened patients had a higher proportion of localized tumors after surgery (67.7% vs. 54.2%; P = 0.002). Pathology Gleason scores were also lower among screened men (P < 0.01). Lymphadenectomies were performed in 166/636 men (26.1%). No nodal metastases were found in screened cancers (0/28; 0.0%), while 6/138 referred cancers (4.3%) presented nodal involvement (P = 0.3).

CONCLUSION

Clinical and pathologic characteristics of screen-detected cancers are more favorable than those of tumors diagnosed through the Brazilian health system.

Urban-rural differences in prostate cancer outcomes in Australia: what has changed?

OBJECTIVE

To update our previous analysis of trends for prostate-specific antigen (PSA) testing, prostate cancer incidence, radical prostatectomy and prostate cancer mortality to assess whether men in rural and regional areas of Australia now have more equitable access to prostate cancer services, and improved outcomes.

DESIGN, SETTING AND PARTICIPANTS

Descriptive study using population-based data for Australian men aged 50-79 years from 1982 to the 2008-09 financial year (depending on data availability for each outcome measure).

MAIN OUTCOME MEASURES

Age-standardised rates per 100,000 men and 5-year survival rates.

RESULTS

Overall, rates of PSA screening and radical prostatectomy increased, accompanied by reductions in mortality and improvements in survival throughout Australia. Incidence rates were similar for men in urban and rural areas. However, in the last year of data collection, for men in rural areas compared with urban areas, rates of PSA screening (21,267/100,000 v 24,606/100,000; P < 0.01) and radical prostatectomy (182.2/100,000 v 239.2/100,000; P < 0.01) remained lower, mortality remained higher (56.9/100,000 v 45.8/100,000; P < 0.01), and survival outcomes continued to be poorer (5-year relative survival, 87.7% v 91.4%; P < 0.01).

CONCLUSIONS

With some limitations, these ecological data demonstrate that the use of diagnostic and treatment services among men living in rural areas of Australia remains lower than among their urban counterparts, their survival and mortality outcomes are poorer, and these differentials are continuing. There is an urgent need to explore further the reasons for these differences and to implement changes so these inequalities can be reduced.

Novel diagnostic biomarkers for prostate cancer

Prostate cancer is the most frequently diagnosed malignancy in American men, and a more aggressive form of the disease is particularly prevalent among African Americans. The therapeutic success rate for prostate cancer can be tremendously improved if the disease is diagnosed early. Thus, a successful therapy for this disease depends heavily on the clinical indicators (biomarkers) for early detection of the presence and progression of the disease, as well as the prediction after the clinical intervention. However, the current clinical biomarkers for prostate cancer are not ideal as there remains a lack of reliable biomarkers that can specifically distinguish between those patients who should be treated adequately to stop the aggressive form of the disease and those who should avoid overtreatment of the indolent form.

A biomarker is a characteristic that is objectively measured and evaluated as an indicator of normal biologic processes, pathogenic processes, or pharmacologic responses to a therapeutic intervention. A biomarker reveals further information to presently existing clinical and pathological analysis. It facilitates screening and detecting the cancer, monitoring the progression of the disease, and predicting the prognosis and survival after clinical intervention. A biomarker can also be used to evaluate the process of drug development, and, optimally, to improve the efficacy and safety of cancer treatment by enabling physicians to tailor treatment for individual patients. The form of the prostate cancer biomarkers can vary from metabolites and chemical products present in body fluid to genes and proteins in the prostate tissues.

Current advances in molecular techniques have provided new tools facilitating the discovery of new biomarkers for prostate cancer. These emerging biomarkers will be beneficial and critical in developing new and clinically reliable indicators that will have a high specificity for the diagnosis and prognosis of prostate cancer. The purpose of this review is to examine the current status of prostate cancer biomarkers, with special emphasis on emerging markers, by evaluating their diagnostic and prognostic potentials. Both genes and proteins that reveal loss, mutation, or variation in expression between normal prostate and cancerous prostate tissues will be covered in this article. Along with the discovery of prostate cancer biomarkers, we will describe the criteria used when selecting potential biomarkers for further development towards clinical use. In addition, we will address how to appraise and validate candidate markers for prostate cancer and some relevant issues involved in these processes. We will also discuss the new concept of the biomarkers, existing challenges, and perspectives of biomarker development.

Impact of PSA testing and prostatic biopsy on cancer incidence and mortality: comparative study between the Republic of Ireland and Northern Ireland

OBJECTIVES

To investigate the impact of different PSA testing policies and health-care systems on prostate cancer incidence and mortality in two countries with similar populations, the Republic of Ireland (RoI) and Northern Ireland (NI).

METHODS

Population-level data on PSA tests, prostate biopsies and prostate cancer cases 1993-2005 and prostate cancer deaths 1979-2006 were compiled. Annual percentage change (APC) was estimated by joinpoint regression.

RESULTS

Prostate cancer rates were similar in both areas in 1994 but increased rapidly in RoI compared to NI. The PSA testing rate increased sharply in RoI (APC = +23.3%), and to a lesser degree in NI (APC = +9.7%) to reach 412 and 177 tests per 1,000 men in 2004, respectively. Prostatic biopsy rates rose in both countries, but were twofold higher in RoI. Cancer incidence rates rose significantly, mirroring biopsy trends, in both countries reaching 440 per 100,000 men in RoI in 2004 compared to 294 in NI. Median age at diagnosis was lower in RoI (71 years) compared to NI (73 years) (p < 0.01) and decreased significantly over time in both countries. Mortality rates declined from 1995 in both countries (APC = -1.5% in RoI, -1.3% in NI) at a time when PSA testing was not widespread.

CONCLUSIONS

Prostatic biopsy rates, rather than PSA testing per se, were the main driver of prostate cancer incidence. Because mortality decreases started before screening became widespread in RoI, and mortality remained low in NI, PSA testing is unlikely to be the explanation for declining mortality.

Empirical estimates of the lead time distribution for prostate cancer based on two independent representative cohorts of men not subject to prostate-specific antigen screening

BACKGROUND

Lead time, the estimated time by which screening advances the date of diagnosis, is used to calculate the risk of overdiagnosis. We sought to describe empirically the distribution of lead times between an elevated prostate-specific antigen (PSA) and subsequent prostate cancer diagnosis.

METHODS

We linked the Swedish cancer registry to two independent cohorts: 60-year-olds sampled in 1981-1982 and 51- to 56-year-olds sampled in 1982-1985. We used univariate kernel density estimation to characterize the lead time distribution. Linear regression was used to model the lead time as a function of baseline PSA and logistic regression was used to test for an association between lead time and either stage or grade at diagnosis.

RESULTS

Of 1,167 older men, 132 were diagnosed with prostate cancer, of which 57 had PSA>or=3 ng/mL at baseline; 495 of 4,260 younger men were diagnosed with prostate cancer, of which 116 had PSA>or=3 ng/mL at baseline. The median lead time was slightly longer in the younger men (12.8 versus 11.8 years). In both cohorts, wide variation in lead times followed an approximately normal distribution. Longer lead times were significantly associated with a lower risk of high-grade disease in older and younger men [odds ratio, 0.82 (P=0.023) and 0.77 (P<0.001)].

CONCLUSION

Our findings suggest that early changes in the natural history of the disease are associated with high-grade cancer at diagnosis.

IMPACT

The distinct differences between the observed distribution of lead times and those used in modeling studies illustrate the need to model overdiagnosis rates using empirical data.

Generational risks for cancers not related to tobacco, screening, or treatment in the United States

BACKGROUND

To assess trends in cancer, the authors evaluated the risk of 1 generation compared with that 25 years earlier (generational risk) for 3 groupings of cancers: those related to tobacco; those that reflect advances in screening or treatment; and a residual category of all other cancers.

METHODS

In individuals ages 20 years to 84 years, age-period-cohort models were used to summarize time trends in terms of generational risk and average annual percentage change for US cancer incidence (1975-2004) and mortality (1970-2004) rates associated with these 3 cancer groupings.

RESULTS

Adult white men today developed 16% fewer tobacco-related cancers and had 21% fewer deaths because of those cancers than their fathers' generation, whereas adult white women experienced increases of 28% and 19%, respectively, relative to their mothers. The incidence of commonly screened cancers rose 74% in men and 10% in women, whereas mortality fell 25% in men and 31% in women. For cancers that have not been linked chiefly to tobacco or screening, the incidence was 34% and 23% higher in white men and white women, respectively, than in their parents' generation 25 years earlier. Mortality in this residual category decreased 14% in men and 18% in women. Results among blacks were qualitatively similar to those among whites.

CONCLUSIONS

Despite declining overall cancer death rates, adults are experiencing increased incidence of cancers that are not associated with tobacco or screening relative to their parents. Future research should examine whether similar patterns are exhibited in other modern nations and should identify population-wide avoidable risks that could account for unexplained increases in these residual cancers.

Upgrading of Gleason score 6 prostate cancers on biopsy after prostatectomy in the low and intermediate tPSA range

When offering watchful waiting or active monitoring protocols to prostate cancer (PCa) patients, differentiation between Gleason scores (GS) 6 and 7 at biopsy is important. However, upgrading after prostatectomy is common. We investigated the impact of different PSA levels on misclassification in the PSA range of 2-3.9 and 4-10 ng ml(-1). A total of 448 patients with GS 6 PCa on prostate biopsy were evaluated by comparing biopsy and prostatectomy GS. Possible over diagnosis was defined as GS <7, pathological stage pT2a and negative surgical margins, and possible under diagnosis was defined as pT3a or greater, or positive surgical margins; the percentage of over- or under diagnosis was determined for correctly and upgraded tumors after prostatectomy. A match between biopsy and prostatectomy GS was found in 210 patients (46.9%). Patients in the PSA range of 2.0-3.9 and 4.0-10.0 ng ml(-1) were upgraded in 32.6 and 44.0%, respectively. Over diagnosis was more common than under diagnosis (23.2% vs 15.6%). When upgraded there was a significant increase in under diagnosis. As almost 40% of GS 6 tumors on biopsy are GS 7 or higher after surgery with a significant rise in under diagnosis there is a risk of misclassification and subsequent delayed or even insufficient treatment, when relying on favorable biopsy GS.

Bayesian Calibration of Microsimulation Models

Microsimulation models that describe disease processes synthesize information from multiple sources and can be used to estimate the effects of screening and treatment on cancer incidence and mortality at a population level. These models are characterized by simulation of individual event histories for an idealized population of interest. Microsimulation models are complex and invariably include parameters that are not well informed by existing data. Therefore, a key component of model development is the choice of parameter values. Microsimulation model parameter values are selected to reproduce expected or known results though the process of model calibration. Calibration may be done by perturbing model parameters one at a time or by using a search algorithm. As an alternative, we propose a Bayesian method to calibrate microsimulation models that uses Markov chain Monte Carlo. We show that this approach converges to the target distribution and use a simulation study to demonstrate its finite-sample performance. Although computationally intensive, this approach has several advantages over previously proposed methods, including the use of statistical criteria to select parameter values, simultaneous calibration of multiple parameters to multiple data sources, incorporation of information via prior distributions, description of parameter identifiability, and the ability to obtain interval estimates of model parameters. We develop a microsimulation model for colorectal cancer and use our proposed method to calibrate model parameters. The microsimulation model provides a good fit to the calibration data. We find evidence that some parameters are identified primarily through prior distributions. Our results underscore the need to incorporate multiple sources of variability (i.e., due to calibration data, unknown parameters, and estimated parameters and predicted values) when calibrating and applying microsimulation models.

Population-based prostate-specific antigen testing in the UK leads to a stage migration of prostate cancer

OBJECTIVE

To determine, within the UK, the stage and grade of prostate cancers that would be found through population-based prostate specific antigen (PSA) testing and biopsy.

SUBJECTS AND METHODS

In the 'Prostate Testing for Cancer and Treatment' trial (ProtecT), men aged 50-69 years were recruited from nine cities in the UK and from randomly selected practices of general practitioners. Those with a PSA level of >3 ng/mL were offered a prostate biopsy. Age, PSA, stage and grade at diagnosis of ProtecT participants with cancer were compared with contemporaneous incident cases aged 50-69 years (age-restricted Cancer Registry cases) registered with the Eastern Cancer Registration and Information Centre (ECRIC).

RESULTS

Within ProtecT, 94,427 men agreed to be tested (50% of men contacted), 8807 ( approximately 9%) had a raised PSA level and 2022 (23%) had prostate cancer; 229 ( approximately 12%) had locally advanced (T3 or T4) or metastatic cancers, the rest having clinically localized (T1c or T2) disease. Within ECRIC, 12,661 cancers were recorded over the same period; 3714 were men aged 50-69 years at diagnosis. Men in ProtecT had a lower age distribution and PSA level, and the cancers were of lower stage and grade (P < 0.001 for all comparisons). If population-based PSA testing were introduced in the UK, approximately 2660 men per 100,000 aged 50-69 years would be found to have prostate cancer, compared to current rates of approximately 130 per 100,000. If half of men accepted PSA testing, approximately 160,000 cancers would be found, compared to 30,000 diagnosed each year at present.

CONCLUSIONS

Population-based PSA testing resulted in a significant downward stage and grade migration, and most such cancers were of low stage and grade, which could lead to risks of over-treatment for some men.

Lead time and overdiagnosis in prostate-specific antigen screening: importance of methods and context

BACKGROUND

The time by which prostate-specific antigen (PSA) screening advances prostate cancer diagnosis, called the lead time, has been reported by several studies, but results have varied widely, with mean lead times ranging from 3 to 12 years. A quantity that is closely linked with the lead time is the overdiagnosis frequency, which is the fraction of screen-detected cancers that would not have been diagnosed in the absence of screening. Reported overdiagnosis estimates have also been variable, ranging from 25% to greater than 80% of screen-detected cancers.

METHODS

We used three independently developed mathematical models of prostate cancer progression and detection that were calibrated to incidence data from the Surveillance, Epidemiology, and End Results program to estimate lead times and the fraction of overdiagnosed cancers due to PSA screening among US men aged 54-80 years in 1985-2000. Lead times were estimated by use of three definitions. We also compared US and earlier estimates from the Rotterdam section of the European Randomized Study of Screening for Prostate Cancer (ERSPC) that were calculated by use of a microsimulation screening analysis (MISCAN) model.

RESULTS

The models yielded similar estimates for each definition of lead time, but estimates differed across definitions. Among screen-detected cancers that would have been diagnosed in the patients' lifetimes, the estimated mean lead time ranged from 5.4 to 6.9 years across models, and overdiagnosis ranged from 23% to 42% of all screen-detected cancers. The original MISCAN model fitted to ERSPC Rotterdam data predicted a mean lead time of 7.9 years and an overdiagnosis estimate of 66%; in the model that was calibrated to the US data, these were 6.9 years and 42%, respectively.

CONCLUSION

The precise definition and the population used to estimate lead time and overdiagnosis can be important drivers of study results and should be clearly specified.

Calibration methods used in cancer simulation models and suggested reporting guidelines

Increasingly, computer simulation models are used for economic and policy evaluation in cancer prevention and control. A model's predictions of key outcomes, such as screening effectiveness, depend on the values of unobservable natural history parameters. Calibration is the process of determining the values of unobservable parameters by constraining model output to replicate observed data. Because there are many approaches for model calibration and little consensus on best practices, we surveyed the literature to catalogue the use and reporting of these methods in cancer simulation models. We conducted a MEDLINE search (1980 through 2006) for articles on cancer-screening models and supplemented search results with articles from our personal reference databases. For each article, two authors independently abstracted pre-determined items using a standard form. Data items included cancer site, model type, methods used for determination of unobservable parameter values and description of any calibration protocol. All authors reached consensus on items of disagreement. Reviews and non-cancer models were excluded. Articles describing analytical models, which estimate parameters with statistical approaches (e.g. maximum likelihood) were catalogued separately. Models that included unobservable parameters were analysed and classified by whether calibration methods were reported and if so, the methods used. The review process yielded 154 articles that met our inclusion criteria and, of these, we concluded that 131 may have used calibration methods to determine model parameters. Although the term 'calibration' was not always used, descriptions of calibration or 'model fitting' were found in 50% (n = 66) of the articles, with an additional 16% (n = 21) providing a reference to methods. Calibration target data were identified in nearly all of these articles. Other methodological details, such as the goodness-of-fit metric, were discussed in 54% (n = 47 of 87) of the articles reporting calibration methods, while few details were provided on the algorithms used to search the parameter space. Our review shows that the use of cancer simulation modelling is increasing, although thorough descriptions of calibration procedures are rare in the published literature for these models. Calibration is a key component of model development and is central to the validity and credibility of subsequent analyses and inferences drawn from model predictions. To aid peer-review and facilitate discussion of modelling methods, we propose a standardized Calibration Reporting Checklist for model documentation.

Prostate-cancer mortality in the USA and UK in 1975-2004: an ecological study

BACKGROUND

There is no conclusive evidence that screening based on serum prostate-specific antigen (PSA) tests decreases prostate-cancer mortality. Since its introduction in the USA around 1990, uptake of PSA testing has been rapid in the USA, but much less common in the UK. Our aim was to study trends over time in prostate-cancer mortality and incidence in the USA and UK in 1975-2004, and compare these patterns with trends in screening and treatment.

METHODS

Joinpoint regression analysis of cancer-mortality statistics from Cancer Research UK (London, UK) and from the US National Cancer Institute Surveillance, Epidemiology and End Results (SEER) programme from 1975 to 2004 was used to estimate the annual percentage change in prostate-cancer mortality in both countries and the points in time when trends changed. The ratio of USA to UK age-adjusted prostate-cancer incidence was also assessed.

FINDINGS

Age-specific and age-adjusted prostate-cancer mortality peaked in the early 1990s at almost identical rates in both countries, but age-adjusted mortality in the USA subsequently declined after 1994 by -4.17% (95% CI -4.34 to -3.99) each year, four-times the rate of decline in the UK after 1992 (-1.14% [-1.44 to -0.84]). The mortality decline in the USA was greatest and most sustained in patients aged 75 years or older (-5.32% [-8.23 to -2.32]), whereas death rates had plateaued in this age group in the UK by 2000. The mean ratio of USA to UK age-adjusted prostate-cancer incidence rates in 1975-2003 was 2.5, with a pronounced peak around the time that PSA testing was introduced in the USA. Numbers needed to treat to prevent one death from prostate cancer were 33 000 in the 55-64-year age group.

INTERPRETATION

The striking decline in prostate-cancer mortality in the USA compared with the UK in 1994-2004 coincided with much higher uptake of PSA screening in the USA. Explanations for the different trends in mortality include the possibility of an early effect of initial screening rounds on men with more aggressive asymptomatic disease in the USA, different approaches to treatment in the two countries, and bias related to the misattribution of cause of death. Speculation over the role of screening will continue until evidence from randomised controlled trials is published.

Potential of magnetic resonance spectroscopic imaging in predicting absence of prostate cancer in men with serum prostate-specific antigen between 4 and 10 ng/ml: a follow-up study

OBJECTIVES

Screening for prostate cancer using serum prostate-specific antigen (PSA) determination has a positive predictive value of only 30% to 42% for a PSA level between 4 and 10 ng/mL. Magnetic resonance spectroscopic imaging (MRSI), which identifies cancer on the basis of changes in cellular metabolite levels, might be able to identify patients with noncancerous PSA elevation and help avoid unnecessary biopsies. We tested this hypothesis by evaluating the incidence of prostate cancer in men with a PSA level of 4 to 10 ng/mL and a negative MRSI study.

METHODS

A total of 155 men underwent a three-dimensional proton MRSI of the prostate before transrectal ultrasound-guided biopsy for clinical indications. MRSI was performed using an endorectal coil on a 1.5-T magnetic resonance scanner. Patients with no voxels positive for malignancy underwent standard sextant biopsy, and additional MRSI-targeted biopsies were obtained in men with suspicious or malignant voxels. Patients with a biopsy negative for cancer underwent repeat serum PSA estimation every 6 months for a minimum of 18 months.

RESULTS

Of the 155 men, 36 (mean PSA level of 6.47 ng/mL, range 4.25 to 9.9) had no malignant voxels on MRSI. None of them were positive for cancer on biopsy. Of these 36 men, 26 completed at least 18 months (mean 26.9, range 18 to 44) of follow-up. Four patients required repeat biopsies and one, with a persistently elevated PSA level was diagnosed with prostate cancer 29 months after the initial MRSI.

CONCLUSIONS

The results of our study have shown that prostate biopsy can be deferred in patients with an increased serum PSA of 4 to 10 ng/mL if their MRSI does not show any malignant voxels.

Impact of PSA screening on the incidence of advanced stage prostate cancer in the United States: a surveillance modeling approach

BACKGROUND

and objective. Both the detection and the treatment of prostate cancer have undergone important clinical advances. Simultaneously, both distant stage incidence and disease-specific mortality have fallen in the United States. A recent study suggests that if prostate-specific antigen (PSA) testing explains the decline in distant stage incidence, then it may be largely responsible for the decline in mortality. The objective was to quantify this link between PSA screening and the decline in distant stage incidence.

METHODS

A fixed-cohort simulation model of prostate cancer progression and screening was adapted to a population-based model that integrates new data on trends in testing and biopsy practices. The model was calibrated to pre-PSA incidence and then screening was superimposed, obtaining incidence projections in the absence and presence of testing. This approach permits calculation of clinically relevant measures for model validation and direct assessment of the role of testing in the distant stage incidence decline.

RESULTS

The model validated well with prior studies of natural history, and the sensitivity analysis indicated that the findings were robust to variation in model parameters. Model results indicate that PSA screening accounts for approximately 80% of the observed decline in distant stage incidence.

CONCLUSIONS

PSA screening contributed to the observed declines in distant stage incidence and mortality in the 1990s. However, additional factors, such as increasing awareness of prostate cancer and advances in treatment, have probably also played a role in these trends.

Exploring causes for declining prostate cancer mortality rates in the United States

OBJECTIVES

Prostate cancer mortality rates in the U.S.A. increased in the late 1980s and declined from 1993 until 2003. The purpose of this study is to compare declining prostate cancer mortality rates among states with independent variables that may have an association to explore causes for the decline.

METHODS AND MATERIALS

Annual rates of prostate cancer mortality for men over 50 were obtained from the National Vital Statistic System public use data file for states for individual years from 1993 to 2003. The annual rate of prostate cancer mortality decline for each state was calculated by the Joinpoint Regression Program (Statistical Research and Applications Branch of NCI). Annual rates of prostate cancer decline were cross-correlated to state levels of PSA screening, health insurance coverage, obesity, physical inactivity, diabetes, and high cholesterol for males from 45 to 64.

RESULTS

Declining prostate cancer mortality rates for white males correlated with high cholesterol levels (R = -0.42, P = 0.002) and PSA screening levels (R = -0.28, P = 0.05). Declining prostate cancer mortality rates for black males correlated with health insurance coverage (R = -0.43, P = 0.03).

CONCLUSIONS

Declining prostate cancer mortality rates are weakly associated with increased PSA screening for white males but there was no association for black males, possibly because blacks have less access to medical care. The strong inverse correlation between declining prostate cancer mortality rates and levels of white males with high cholesterol levels was unexpected but may be associated with the widespread use of cholesterol reducing medications (statins), which are hypothesized to reduce prostate cancer risk.

Secular trends in prostate cancer mortality, incidence and treatment: England and Wales, 1975-2004

OBJECTIVE

To aid the interpretation of the trends in prostate cancer mortality, which declined in the UK in the early 1990 s for unknown reasons, by investigating prostate cancer death rates, incidence and treatments in England and Wales in 1975-2004.

METHODS

Join-point regression was used to assess secular trends in mortality and incidence (source: Office of National Statistics), radical prostatectomy and orchidectomy (source: Hospital Episode Statistics database) and androgen-suppression drugs (source: Intercontinental Medical Statistics).

RESULTS

Prostate cancer mortality declined from 1992 (95% confidence interval, CI, 1990-94). The relative decline in mortality to 2004 was greater and more sustained amongst men aged 55-74 years (annual percentage mortality reduction 2.75%; 95% CI 2.33-3.18%) than amongst those aged >or=75 years (0.71%, 0.26-1.15%). The use of radical prostatectomy increased between 1991 (89 operations) and 2004 (2788) amongst men aged 55-74 years. The prescribing of androgen suppression increased between 1987 (33,000 prescriptions) and 2004 (470,000).

CONCLUSIONS

The decrease in prostate cancer mortality was greater amongst men aged 55-74 years than in those aged >or=75 years, but pre-dated the substantial use of prostate-specific antigen screening and radical prostatectomy in the UK. An increase in radical therapy amongst younger groups with localized cancers and screen-detected low-volume locally advanced disease as a result of stage migration, as well as prolonged survival from increased medical androgen suppression therapy, might partly explain recent trends.

Under diagnosis and over diagnosis of prostate cancer in a screening population with serum PSA 2 to 10 ng/ml

PURPOSE

Since the implementation of widespread serum total prostate specific antigen based screening, the risk of prostate cancer over diagnosis has become a concern. We evaluated the amount of possible over and under diagnosis of prostate cancer in an asymptomatic screening population with a total prostate specific antigen of 2.0 to 3.9 (lower range) and 4.0 to 10.0 ng/ml (higher range).

MATERIALS AND METHODS

A total of 680 patients with prostate cancer were included. Possible over diagnosis was defined as Gleason score less than 7, pathological stage pT2a and negative surgical margins. Under diagnosis was defined as pathological stage pT3 or greater, or positive surgical margins. Furthermore, insignificant tumors according to the Epstein criteria were evaluated in a small subset of patients for whom cancer volume information was available.

RESULTS

In the lower and higher total prostate specific antigen ranges there was an over diagnosis rate of 19.7% and 16.5%, and an under diagnosis rate of 18.9%* and 36.7%, respectively (p<0.05). In the prostate specific antigen range of 2.0 to 10.0 ng/ml combined the rates of over and under diagnosis were 17.6% and 30.3%, respectively. In addition, 8.7% of tumors with total prostate specific antigen 2.0 to 10.0 ng/ml met the Epstein criteria for insignificance.

CONCLUSIONS

These data show that the reported estimates of over diagnosis in the low total prostate specific antigen group are exaggerated in a screening population. Using our criteria prostate cancer under diagnosis occurs more frequently than over diagnosis in the total prostate specific antigen range of 4.0 to 10 ng/ml.

Assessing the impact of prescribed medicines on health outcomes

This paper reviews methods that can be used to assess the impact of medicine use on population health outcomes. In the absence of a gold standard, we argue that a convergence of evidence from different types of studies using multiple methods of independent imperfection provides the best bases for attributing improvements in health outcomes to the use of medicines. The major requirements are: good evidence that a safe and effective medicine is being appropriately prescribed; covariation between medicine use and improved health outcomes; and being able to discount alternative explanations of the covariation (via covariate adjustment, propensity analyses and sensitivity analyses), so that medicine use is the most plausible explanation of the improved health outcomes. The strongest possible evidence would be provided by the coherence of the following types of evidence: (1) individual linked data showing that patients are prescribed the medicine, there are reasonable levels of patient compliance, and there is a relationship between medicine use and health improvements that is not explained by other factors; (2) ecological evidence of improvements in these health outcomes in the population in which the medicine is used. Confidence in these inferences would be increased by: the replication of these results in comparable countries and consistent trends in population vital statistics in countries that have introduced the medicine; and epidemiological modelling indicating that changes observed in population health outcomes are plausible given the epidemiology of the condition being treated.

A population model of prostate cancer incidence

Introduction of screening for prostate cancer using the prostate-specific antigen (PSA) marker of the disease led to remarkable dynamics of the incidence of the disease observed in the last two decades. A statistical model is used to provide a link between dissemination of PSA and the observed transient population responses. The model is used to estimate lead time, overdiagnosis and other relevant characteristics of prostate cancer screening.

Reduction of prostate cancer mortality in Tyrol, Austria, after introduction of prostate-specific antigen testing

The objective of this study was to analyze in detail the time trend in prostate cancer mortality in the population of Tyrol, Austria. In Tyrol, prostate-specific antigen tests were introduced in 1988-1989 and, since 1993, have been offered to all men aged 45-74 years free of charge. More than three quarters of all men in this age group had at least one such test in the last decade. The authors applied the age-period-cohort model by Poisson regression to mortality data covering more than three decades, from 1970 to 2003. For Tyrol, the full model with age and period and cohort terms fit fairly well. Period terms showed a significant reduction in prostate cancer mortality in the last 5 years, with a risk ratio of 0.81 (95% confidence interval: 0.68, 0.98) for Tyrol; for Austria without Tyrol, no effect was seen, with a risk ratio of 1.00 (95% confidence interval: 0.95, 1.05). Each was compared with the mortality rate in the period 1989-1993. Although the results of randomized screening trials are not expected until 2008-2010, these findings support the evidence that prostate-specific antigen testing offered to a population free of charge can reduce prostate cancer mortality.

Trends in prostate cancer incidence, hospital utilization and surgical procedures, Canada, 1981-2000

BACKGROUND

Numbers of new prostate cancer cases in Canada continue to increase because of increasing prostate cancer incidence, population growth, aging of the population, and earlier detection methods such as PSA (prostate-specific antigen) testing. Concern has been expressed that PSA-related increases in incidence will make unaffordable demands on Canadian hospital resources. Our objective is to relate increases in prostate cancer incidence to trends in hospitalizations and in- patient treatment.

METHODS

Hospitalizations with prostate cancer as primary diagnosis were obtained from the Hospital Morbidity Database, estimates of prostate cancer day surgery from the Discharge Abstract Database, newly diagnosed cases from the Canadian Cancer Registry, and prostate cancer deaths from the Vital Statistics Mortality Databases--all for the years 1981-2000.

RESULTS

Between 1981-2000, the number of new cases rose from 7,000 to 18,500 with a transient peak, 1991-1994. Hospitalizations rose parallel to the incidence until 1991 but then fell sharply in spite of further increasing incidence. The use of radical prostatectomy (RP) increased steadily, but transurethral prostatectomy and bilateral orchiectomy decreased in the 1990s. Decreases in length of stay and in number of hospitalizations resulted in considerably decreased annual hospital days for all prostate cancer in-patient procedures except RP, which remained level since 1993.

CONCLUSIONS

A net decrease in number of in-patient days occurred, despite the increasing number of new prostate cancer cases and the increasing use of radical prostatectomy. We concluded that increases in hospital utilization due to early detection programs, such as PSA testing, are unlikely to overwhelm in-patient services of Canadian hospitals.

The Effect of Androgen Deprivation Therapy on Fasting Serum Lipid and Glucose Parameters

PURPOSE

Although prostate cancer specific mortality is decreasing, there is little effect on overall mortality in this population, suggesting the possibility of an increased risk of death from nonprostate cancer related causes. Androgen deprivation therapy could adversely affect cardiovascular health. We investigated changes in lipid and glucose during androgen deprivation therapy.

MATERIALS AND METHODS

We performed an exploratory analysis of pooled data from 3 prospective clinical trials aimed at achieving medical castration by comparing the gonadotropin releasing hormone antagonist abarelix, the gonadotropin releasing hormone agonist leuprolide acetate and leuprolide acetate plus the antiandrogen bicalutamide. Most patients were treated in the neoadjuvant setting or because of biochemical recurrence. Fasting serum lipid, glucose and hemoglobin A1C were determined in 1,102 men at baseline, and on treatment days 85 and 169. In the current study men were categorized into 3 treatment groups according to the type of androgen deprivation therapy, that is leuprolide acetate, leuprolide acetate plus bicalutamide or abarelix, and statin therapy.

RESULTS

Significant increases in total cholesterol, triglyceride and high density lipoprotein-cholesterol were observed in patients on leuprolide acetate or abarelix but not in patients on leuprolide acetate plus bicalutamide. Consistent changes in low density lipoprotein-cholesterol were not detected. Increased total cholesterol was usually due to an increase in high density lipoprotein-cholesterol. Hemoglobin A1C increased from baseline to day 85 only and there were no significant changes in fasting glucose measurements. The type of androgen deprivation therapy did not affect these parameters.

CONCLUSIONS

Short-term androgen deprivation therapy affects serum lipid and hemoglobin A1C independent of statin therapy.