Cancer surveillance series: interpreting trends in prostate cancer--part II: Cause of death misclassification and the recent rise and fall in prostate cancer mortality

Cancer incidence and mortality patterns in Europe: estimates for 40 countries in 2012

INTRODUCTION

Cancer incidence and mortality estimates for 25 cancers are presented for the 40 countries in the four United Nations-defined areas of Europe and for the European Union (EU-27) for 2012.

METHODS

We used statistical models to estimate national incidence and mortality rates in 2012 from recently-published data, predicting incidence and mortality rates for the year 2012 from recent trends, wherever possible. The estimated rates in 2012 were applied to the corresponding population estimates to obtain the estimated numbers of new cancer cases and deaths in Europe in 2012.

RESULTS

There were an estimated 3.45 million new cases of cancer (excluding non-melanoma skin cancer) and 1.75 million deaths from cancer in Europe in 2012. The most common cancer sites were cancers of the female breast (464,000 cases), followed by colorectal (447,000), prostate (417,000) and lung (410,000). These four cancers represent half of the overall burden of cancer in Europe. The most common causes of death from cancer were cancers of the lung (353,000 deaths), colorectal (215,000), breast (131,000) and stomach (107,000). In the European Union, the estimated numbers of new cases of cancer were approximately 1.4 million in males and 1.2 million in females, and around 707,000 men and 555,000 women died from cancer in the same year.

CONCLUSION

These up-to-date estimates of the cancer burden in Europe alongside the description of the varying distribution of common cancers at both the regional and country level provide a basis for establishing priorities to cancer control actions in Europe. The important role of cancer registries in disease surveillance and in planning and evaluating national cancer plans is becoming increasingly recognised, but needs to be further advocated. The estimates and software tools for further analysis (EUCAN 2012) are available online as part of the European Cancer Observatory (ECO) (http://eco.iarc.fr).

DNA methyltransferase 3b (DNMT3b), tumor tissue DNA methylation, Gleason score, and prostate cancer mortality: investigating causal relationships

PURPOSE

Aberrant DNA methylation plays a role in prostate cancer progression. We studied the relationships among DNA methyltransferase (DNMT) genotype, DNA methylation, Gleason score, and mortality in two cohorts of prostate cancer patients, previously reported with associations between DNA methylation in GSTP1, APC, and RUNX3 and prostate cancer mortality. Herein, we considered possible causal relationships between the studied variables, assuming that (1) DNMT activity affects tumor tissue methylation, (2) methylation status affects tumor morphology, and thus the Gleason score, and (3) DNA methylation affects mortality via Gleason score.

METHODS

The cohorts comprised 438 patients diagnosed at one Italian pathology ward before 1997, with DNA obtained from paraffin-embedded tumor tissues. The polymorphism rs406193 in the DNMT3b gene was assessed by allele discrimination in real-time PCR. According to the assumed causal model, we analyzed the effects of rs406193 (T carriers vs others) on the Gleason score without adjusting for gene methylation, and the effects of rs406193 on gene methylation and prostate cancer mortality without adjusting for Gleason score.

RESULTS

We found no evidence of association between T carriers and the number of methylated genes. However, T carriers had reduced risk of a Gleason score 8+ (odds ratio = 0.57, 95 % CI 0.39-0.85), and a hazard ratio of 0.81 (0.61-1.09) of dying from prostate cancer, which would have been erroneously estimated of 0.93 if adjusted for Gleason score.

CONCLUSIONS

These findings provide clues on the role of a DNMT3b SNP in prostate cancer progression and illustrate the importance of considering possible causal relationships in the analyses.

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.

Temporal trends in cause of death among Swedish and US men with prostate cancer

BACKGROUND

A growing proportion of men diagnosed with localized prostate cancer detected through prostate-specific antigen testing are dying from causes other than prostate cancer. Temporal trends in specific causes of death among prostate cancer patients have not been well described.

METHODS

We analyzed causes of death among all incident prostate cancer cases recorded in the nationwide Swedish Cancer Registry (1961-2008; n = 210 112) and in the US Surveillance, Epidemiology, and End Results Program (1973-2008; n = 490 341). We calculated the cumulative incidence of death due to seven selected causes that accounted for more than 80% of the reported deaths (including ischemic heart disease and non-prostate cancer) and analyzed mortality trends by calendar year and age at diagnosis and length of follow-up.

RESULTS

During follow-up through 2008, prostate cancer accounted for 52% of all reported deaths in Sweden and 30% of reported deaths in the United States among men with prostate cancer; however, only 35% of Swedish men and 16% of US men diagnosed with prostate cancer died from this disease. In both populations, the cumulative incidence of prostate cancer-specific death declined during follow-up, while the cumulative incidences of death from ischemic heart disease and non-prostate cancer remained constant. The 5-year cumulative incidence of death from prostate cancer among all men was 29% in Sweden and 11% in the United States.

CONCLUSIONS

In Sweden and the United States, men diagnosed with prostate cancer are less likely to die from prostate cancer than from another cause. Because many of these other causes of death are preventable through changes in lifestyle, interventions that target lifestyle factors should be integrated into prostate cancer management.

Temporal trends in long-term survival and cure rates in esophageal cancer: a SEER database analysis

PURPOSE

To assess long-term temporal trends in population-based survival and cure rates in patients with esophageal cancer and compare them over the last 3 decades in the United States.

METHODS

We identified 62,523 patients with cancer of the esophagus and the gastric cardia diagnosed between 1973 and 2007 from the Surveillance, Epidemiology, and End Results database. Long-term cancer-related survival and cure rates were calculated. Stage-by-stage disease-related survival curves of patients diagnosed in different decades were compared. Influence of available variables on survival and cure was analyzed with logistic regression.

RESULTS

Ten-year survival was 14% in all patients. Disease-related survival of esophageal cancer improved significantly since 1973. Median survival in Surveillance, Epidemiology, and End Results stages in local, regional, and metastatic cancers improved from 11, 10, and 4 months in the 1970s to 35, 15, and 6 months after 2000. Early stage, age 45 to 65 years at diagnosis and undergoing surgical therapy were independent predictors of 10-year survival. Cure rate improved in all stages during the study period and were 73%, 37%, 12%, and 2% in stages 0, 1, 2, and 4, respectively, after the year 2000. Percentage of patients undergoing surgery improved from 55% in the 1970s to 64% between 2000 and 2007. Proportion of patients diagnosed with in situ and local cancer remains below 30%.

CONCLUSION

Long-term survival with esophageal cancer is poor but survival of local esophageal cancer improved dramatically over the decades. Complete cure of nonmetastatic esophageal cancer seems possible in a growing number of patients. Early diagnosis and treatment are crucial.

Prostate cancer mortality and birth or adult residence in the southern United States

PURPOSE

Although there are few confirmed risk factors for prostate cancer (PCa), mortality rates are known to vary geographically across the United States. PCa mortality is higher among black and younger white men in a band of states spanning from Washington DC to Louisiana (the "PCa belt"). This study assessed the associations of birth and adult residence in the PCa belt with PCa mortality among black and white men and trends in these associations over time.

METHODS

PCa-specific mortality rates in 1980, 1990, and 2000 for black and white men born in the continental US, aged 40-89, were calculated by linking national mortality records with population data based on birth state, state of residence at the census, race, and age. PCa belt (Washington DC, Virginia, North Carolina, South Carolina, Georgia, Mississippi, Alabama, and Louisiana) birth was cross-classified against PCa belt adult residence.

RESULTS

Black men born in the PCa belt had elevated PCa mortality in 1980, 1990, and 2000. Associations were independent of adult residence in the PCa belt. For example, in 2000, black men aged 65-89 who were born in the PCa belt but no longer lived there in adulthood had an odds ratio of 1.19 (1.14-1.24) for PCa mortality compared to black men born and residing outside the PCa belt. The PCa belt was not associated with PCa mortality among whites.

CONCLUSIONS

Geographically patterned childhood exposures, for example, differences in social or environmental conditions, or behavioral norms, may influence PCa mortality.

Explaining racial differences in prostate cancer mortality

BACKGROUND

In the United States, black males have an annual death rate from prostate cancer that is 2.4 times that of white males. The reasons for this are poorly understood.

METHODS

Using the Surveillance, Epidemiology, and End Results-Medicare database, 77,038 black and white males aged >65 years were identified with a first primary diagnosis of prostate cancer between 1995 and 2005, as well as 49,769 controls. The racial gap in mortality was decomposed to differential incidence and stage-specific prostate cancer mortality. The importance of various clinical and socioeconomic factors to each of these components was then examined.

RESULTS

The estimated mortality gap for prostate cancer-specific mortality was 1320 more cases per 100,000 males among black than white men. This gap was due to higher prostate cancer incidence among black males (76%) and higher stage-specific mortality once diagnosed (24%). Differences in prostate-specific antigen testing, comorbidities, and income explained 29% of the difference in metastatic cancer incidence but none of the racial gap for local/regional incidence. Conditional on diagnosis, tumor characteristics explained 50% of the racial gap, comorbidities an additional 4%, choice of treatment and physician 17%, and socioeconomic factors 15%. Overall, approximately 25% of the racial gap in mortality and 86% of the gap in mortality conditional on diagnosis could be explained.

CONCLUSIONS

More frequent prostate-specific antigen testing for black and low-income males could potentially reduce the prostate cancer mortality gap through earlier diagnosis of tumors that otherwise may become metastatic. More aggressive treatment of prostate cancer, especially in poor communities, might also reduce the gap.

Modeling causes of death: an integrated approach using CODEm

BACKGROUND

Data on causes of death by age and sex are a critical input into health decision-making. Priority setting in public health should be informed not only by the current magnitude of health problems but by trends in them. However, cause of death data are often not available or are subject to substantial problems of comparability. We propose five general principles for cause of death model development, validation, and reporting.

METHODS

We detail a specific implementation of these principles that is embodied in an analytical tool - the Cause of Death Ensemble model (CODEm) - which explores a large variety of possible models to estimate trends in causes of death. Possible models are identified using a covariate selection algorithm that yields many plausible combinations of covariates, which are then run through four model classes. The model classes include mixed effects linear models and spatial-temporal Gaussian Process Regression models for cause fractions and death rates. All models for each cause of death are then assessed using out-of-sample predictive validity and combined into an ensemble with optimal out-of-sample predictive performance.

RESULTS

Ensemble models for cause of death estimation outperform any single component model in tests of root mean square error, frequency of predicting correct temporal trends, and achieving 95% coverage of the prediction interval. We present detailed results for CODEm applied to maternal mortality and summary results for several other causes of death, including cardiovascular disease and several cancers.

CONCLUSIONS

CODEm produces better estimates of cause of death trends than previous methods and is less susceptible to bias in model specification. We demonstrate the utility of CODEm for the estimation of several major causes of death.

Isotonic estimation of survival under a misattribution of cause of death

Several authors have indicated that incorrectly classified cause of death for prostate cancer survivors may have played a role in the observed recent peak and decline of prostate cancer mortality. Motivated by the suggestion we studied a competing risks model where other cause of death may be misattributed as a death of interest. We first consider a naïve approach using unconstrained nonparametric maximum likelihood estimation (NPMLE), and then present the constrained NPMLE where the survival function is forced to be monotonic. Surprising observations were made as we studied their small-sample and asymptotic properties in continuous and discrete situations. Contrary to the common belief that the non-monotonicity of a survival function NPMLE is a small-sample problem, the constrained NPMLE is asymptotically biased in the continuous setting. Other isotonic approaches, the supremum (SUP) method and the Pooled-Adjacent-Violators (PAV) algorithm, and the EM algorithm are also considered. We found that the EM algorithm is equivalent to the constrained NPMLE. Both SUP method and PAV algorithm deliver consistent and asymptotically unbiased estimator. All methods behave well asymptotically in the discrete time setting. Data from the Surveillance, Epidemiology and End Results (SEER) database are used to illustrate the proposed estimators.

Racial disparities in stage-specific colorectal cancer mortality rates from 1985 to 2008

PURPOSE

Since the early 1980s, colorectal cancer (CRC) mortality rates for whites and blacks in the United States have been diverging as a result of earlier and larger reductions in death rates for whites. We examined whether this mortality pattern varies by stage at diagnosis.

METHODS

The Incidence-Based Mortality database of the Surveillance, Epidemiology, and End Results (SEER) Program was used to examine data from the nine original SEER regions. Our main outcome measures were changes in stage-specific mortality rates by race.

RESULTS

From 1985 to 1987 to 2006 to 2008, CRC mortality rates decreased for each stage in both blacks and whites, but for every stage, the decreases were smaller for blacks, particularly for distant-stage disease. For localized stage, mortality rates decreased 30.3% in whites compared with 13.2% in blacks; for regional stage, declines were 48.5% in whites compared with 34.0% in blacks; and for distant stage, declines were 32.6% in whites compared with 4.6% in blacks. As a result, the black-white rate ratios increased from 1.17 (95% CI, 0.98 to 1.39) to 1.41 (95% CI, 1.21 to 1.63) for localized disease, from 1.03 (95% CI, 0.93 to 1.14) to 1.30 (95% CI, 1.17 to 1.44) for regional disease, and from 1.21 (95% CI, 1.10 to 1.34) to 1.72 (95% CI, 1.58 to 1.86) for distant-stage disease. In absolute terms, the disparity in distant-stage mortality rates accounted for approximately 60% of the overall black-white mortality disparity.

CONCLUSION

The black-white disparities in CRC mortality increased for each stage of the disease, but the overall disparity in overall mortality was largely driven by trends for late-stage disease. Concerted efforts to prevent or detect CRC at earlier stages in blacks could improve the worsening black- white disparities.

Age-period-cohort models in cancer surveillance research: ready for prime time?

Standard descriptive methods for the analysis of cancer surveillance data include canonical plots based on the lexis diagram, directly age-standardized rates (ASR), estimated annual percentage change (EAPC), and joinpoint regression. The age-period-cohort (APC) model has been used less often. Here, we argue that it merits much broader use. First, we describe close connections between estimable functions of the model parameters and standard quantities such as the ASR, EAPC, and joinpoints. Estimable functions have the added value of being fully adjusted for period and cohort effects, and generally more precise. Second, the APC model provides the descriptive epidemiologist with powerful new tools, including rigorous statistical methods for comparative analyses, and the ability to project the future burden of cancer. We illustrate these principles by using invasive female breast cancer incidence in the United States, but these concepts apply equally well to other cancer sites for incidence or mortality.

Comparative mortality among Department of Veterans Affairs patients prescribed methadone or long-acting morphine for chronic pain

Data on comparative safety of opioid analgesics are limited, but some reports suggest disproportionate mortality risk associated with methadone. Our objective was to compare mortality rates among patients who received prescribed methadone or long-acting morphine for pain. This is a retrospective observational cohort drawn from Department of Veterans Affairs (VA) health care databases, January 1, 2000, to December 31, 2007. We included 28,554 patients who received methadone and 79,938 who received long-acting morphine from VA pharmacies. Compared with those who received long-acting morphine, patients who received methadone were younger, less likely to have some medical comorbidities, and more likely to have psychiatric and substance use disorders. Patients were stratified into quintiles according to propensity score; the probability of receiving methadone was conditional on demographic, clinical, and VA service area variables. Overall propensity-adjusted mortality was lower for methadone than for morphine. Hazard ratios varied across propensity score quintiles; the magnitude of the between-drug difference in mortality decreased as the propensity to receive methadone increased. Mortality was significantly lower for methadone in all but the last quintile, in which there was no between-drug difference in mortality (hazard ratio=0.92, 95% confidence interval=0.74, 1.16). Multiple sensitivity analyses found either no difference in mortality between methadone and long-acting morphine or lower mortality rates among patients who received methadone. In summary, we found no evidence of excess all-cause mortality among VA patients who received methadone compared with those who received long-acting morphine. Randomized trials and prospective observational research are needed to better understand the relative safety of long-acting opioids.

Prostate cancer incidence and mortality in barbados, west indies

We describe prostate cancer incidence and mortality in Barbados, West Indies. We ascertained all histologically confirmed cases of prostate cancer during the period July 2002 to December 2008 and reviewed each death registration citing prostate cancer over a 14-year period commencing January 1995. There were 1101 new cases for an incidence rate of 160.4 (95% Confidence Interval: 151.0-170.2) per 100,000 standardized to the US population. Comparable rates in African-American and White American men were 248.2 (95% CI: 246.0-250.5) and 158.0 (95% CI: 157.5-158.6) per 100,000, respectively. Prostate cancer mortality rates in Barbados ranged from 63.2 to 101.6 per 100,000, compared to 51.1 to 78.8 per 100,000 among African Americans. Prostate cancer risks are lower in Caribbean-origin populations than previously believed, while mortality rates appeared to be higher than reported in African-American men. Studies in Caribbean populations may assist understanding of disparities among African-origin populations with shared heredity.

What we have learned from randomized trials of prostate cancer screening

The introduction of prostate-specific antigen (PSA) for prostate cancer screening in the late 1980s led to an epidemic of prostate cancer, particularly in developed countries. However, the first valid reports from randomized controlled trials on the efficacy of screening were not published until 2009. Men in the screening group in the European Randomized Study of Screening for Prostate Cancer were 20% less likely than those in the control group to die from prostate cancer. The absolute difference was only 0.7/1000, implying that over 1400 men needed to be screened to prevent one prostate cancer death. Screening was also associated with a 70% increased risk for being diagnosed with prostate cancer. The American Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial found no survival benefit for screening. Results were not conclusive because a substantial proportion of study subjects had previously undergone PSA testing, over half of the control group had PSA testing, follow-up was relatively short, and fewer than 100 subjects died from prostate cancer. Balancing the potential survival benefit from screening is the risk of overdiagnosis-finding cancers that would not otherwise cause clinical problems-and the risk of treatment complications, including urinary, sexual and bowel dysfunction. Prostate cancer screening efforts would benefit from improved biomarkers, which more readily identify clinically important cancers. Cancer control efforts might also need to include chemoprevention, though currently available agents are controversial. In the meantime, patients need to be supported in achieving informed decisions on whether to be screened for prostate cancer.

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.

Randomized trial results did not resolve controversies surrounding prostate cancer screening

PURPOSE OF REVIEW

Prostate cancer screening remains controversial. This review will address recently published results from randomized controlled screening trials as well as current practice guidelines.

RECENT FINDINGS

The Prostate Lung Colorectal and Ovarian Cancer Screening Trial found that screening did not decrease prostate cancer mortality after 7 years of follow-up. High-screening rates in the control group, the low number of deaths from prostate cancer, and the relatively short follow-up duration contributed to the negative results. The European Randomized Study of Screening for Prostate Cancer found that screening reduced prostate cancer mortality by 20% during a median 9 years of follow-up. However, the absolute benefit (0.7/1000 reduction) was small and was associated with a 70% increase in prostate cancer diagnosis. Subsequently, the American Urological Association recommended beginning screening at the age of 40 years and not relying on a specific prostate-specific antigen cutoff for biopsy referral. The United States Preventive Services Task Force and American Cancer Society have yet to issue updated guidelines.

SUMMARY

The randomized trials suggest that screening at best will have a small survival benefit but substantial potential risk for overdiagnosis and overtreatment. Patients need to understand these tradeoffs in order to make informed decisions about screening.

Incidence, Mortality and Five-year Relative Survival Ratio of Prostate Cancer among Chinese Residents in Singapore from 1968 to 2002 by Metastatic Staging

Introduction: This paper examines the incidence, mortality and survival patterns among all Chinese residents with prostate cancer reported to the Singapore Cancer Registry in Singapore from 1968 to 2002 by metastatic staging. Materials and Methods: This is a retrospective population-based study including all prostate cancer cases aged over 20 reported to the Singapore Cancer Registry (SCR) from 1968 to 2002 who are Singapore Chinese residents. Follow-up was ascertained by matching with the National Death Register until 2002. Metastatic status was obtained from the SCR. Age-standardised incidence and mortality rates, as well as the 5-year relative survival ratios (RSRs), were obtained for each 5-year period and grouped by metastatic stage. A weighted linear regression was performed on the log-transformed age-standardised incidence and mortality rates over the study period. Results: In the most recent period of 1998 to 2002, the age-standardised incidence and mortality rates (per 100,000) for prostate cancer among the Chinese were 30.9 (95% CI, 29.1 to 32.8) and 9.6 (95% CI, 8.6 to 10.7), respectively. The percentage increase in the age-standardised incidence and age-standardised mortality rates per year were 5.6% and 6.0%, respectively, for all Chinese Singapore residents. There was an improvement in the 5-year RSRs for Chinese diagnosed with non-metastatic cases from 51.3% in 1973 to 1977, to 76.1% in 1998 to 2002. However, the RSR remains poor (range, 11.1% to 49.7%) for Chinese diagnosed with metastatic prostate cancer. Conclusions: Both age-standardised incidence and mortality rates for prostate cancer among Chinese Singapore residents are still on the rise especially since the 1990s. Since the 1990s, the improvement in RSRs was substantial for the Chinese non-metastatic cases. Key words: Non-metastatic, Population-based, Registry

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.

Declining death rates reflect progress against cancer

BACKGROUND

The success of the "war on cancer" initiated in 1971 continues to be debated, with trends in cancer mortality variably presented as evidence of progress or failure. We examined temporal trends in death rates from all-cancer and the 19 most common cancers in the United States from 1970-2006.

METHODOLOGY/PRINCIPAL FINDINGS

We analyzed trends in age-standardized death rates (per 100,000) for all cancers combined, the four most common cancers, and 15 other sites from 1970-2006 in the United States using joinpoint regression model. The age-standardized death rate for all-cancers combined in men increased from 249.3 in 1970 to 279.8 in 1990, and then decreased to 221.1 in 2006, yielding a net decline of 21% and 11% from the 1990 and 1970 rates, respectively. Similarly, the all-cancer death rate in women increased from 163.0 in 1970 to 175.3 in 1991 and then decreased to 153.7 in 2006, a net decline of 12% and 6% from the 1991 and 1970 rates, respectively. These decreases since 1990/91 translate to preventing of 561,400 cancer deaths in men and 205,700 deaths in women. The decrease in death rates from all-cancers involved all ages and racial/ethnic groups. Death rates decreased for 15 of the 19 cancer sites, including the four major cancers, with lung, colorectum and prostate cancers in men and breast and colorectum cancers in women.

CONCLUSIONS/SIGNIFICANCE

Progress in reducing cancer death rates is evident whether measured against baseline rates in 1970 or in 1990. The downturn in cancer death rates since 1990 result mostly from reductions in tobacco use, increased screening allowing early detection of several cancers, and modest to large improvements in treatment for specific cancers. Continued and increased investment in cancer prevention and control, access to high quality health care, and research could accelerate this progress.

Racial differences in treatment and outcomes among patients with early stage bladder cancer

BACKGROUND

Black patients are at greater of risk of death from bladder cancer than white patients. Potential explanations for this disparity include a more aggressive phenotype and delays in diagnosis resulting in higher stage disease. Alternatively, black patients may receive a lower quality of care, which may explain this difference.

METHODS

Using Surveillance, Epidemiology, and End Results (SEER)-Medicare data for the years from 1992 through 2002, the authors identified patients with early stage bladder cancer. Multivariate models were fitted to measure relations between race and mortality, adjusting for differences in patients and treatment intensity. Next, shared-frailty proportional hazards models were fitted to evaluate whether the disparity was explained by differences in the quality of care provided.

RESULTS

Compared with white patients (n = 14,271), black patients (n = 342) were more likely to undergo restaging resection (12% vs 6.5%; P < .01) and urine cytologic evaluation (36.8% vs 29.7%; P < .01), yet they received fewer endoscopic evaluations (4 vs 5; P < .01). The use of aggressive therapies (cystectomy, systemic chemotherapy, radiation) was found to be similar among black patients and white patients (12% vs 10.2%, respectively; P = .31). Although black patients had a greater risk of death compared with white patients (hazards ratio [HR], 1.23; 95% confidence interval [95% CI], 1.07-1.42), this risk was attenuated only modestly after adjusting for differences in treatment intensity and provider effects (HR, 1.22; 95% CI, 1.06-1.42).

CONCLUSIONS

Although differences in initial treatment were evident, they did not appear to be systematic and had unclear clinical significance. Whereas black patients are at greater risk of death, this disparity did not appear to be caused by differences in the intensity or quality of care provided.

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.

Provider treatment intensity and outcomes for patients with early-stage bladder cancer

BACKGROUND

Bladder cancer is among the most prevalent and expensive to treat cancers in the United States. In the absence of high-level evidence to guide the optimal management of bladder cancer, urologists may vary widely in how aggressively they treat early-stage disease. We examined associations between initial treatment intensity and subsequent outcomes.

METHODS

We used the Surveillance, Epidemiology, and End Results-Medicare database to identify patients who were diagnosed with early-stage bladder cancer from January 1, 1992, through December 31, 2002 (n = 20 713), and the physician primarily responsible for providing care to each patient (n = 940). We ranked the providers according to the intensity of treatment they delivered to their patients (as measured by their average bladder cancer expenditures reported to Medicare in the first 2 years after a diagnosis) and then grouped them into quartiles that contained approximately equal numbers of patients. We assessed associations between treatment intensity and outcomes, including survival through December 31, 2005, and the need for subsequent major interventions by using Cox proportional hazards models. All statistical tests were two-sided.

RESULTS

The average Medicare expenditure per patient for providers in the highest quartile of treatment intensity was more than twice that for providers in the lowest quartile of treatment intensity ($7131 vs $2830, respectively). High-treatment intensity providers more commonly performed endoscopic surveillance and used more intravesical therapy and imaging studies than low-treatment intensity providers. However, the intensity of initial treatment was not associated with a lower risk of mortality (adjusted hazard ratio of death from any cause for patients of low- vs high-treatment intensity providers = 1.03, 95% confidence interval 0.97 to 1.09). Initial intensive management did not obviate the need for later interventions. In fact, a higher proportion of patients treated by high-treatment intensity providers than by low-treatment intensity providers subsequently underwent a major medical intervention (11.0% vs 6.4%, P = .02).

CONCLUSIONS

Providers vary widely in how aggressively they manage early-stage bladder cancer. Patients treated by high-treatment intensity providers do not appear to benefit in terms of survival or in avoidance of subsequent major medical interventions.

Screening, treatment, and prostate cancer mortality in the Seattle area and Connecticut: fifteen-year follow-up

BACKGROUND

Prior to introduction of the prostate-specific antigen (PSA) test, the Seattle-Puget Sound and Connecticut Surveillance, Epidemiology and End Results (SEER) areas had similar prostate cancer mortality rates. Early in the PSA era (1987-1990), men in the Seattle area were screened and treated more intensively for prostate cancer than men in Connecticut.

OBJECTIVE

We previously reported more intensive screening and treatment early in the PSA era did not lower prostate cancer mortality through 11 years and now extend follow-up to 15 years.

DESIGN

Natural experiment comparing two fixed population-based cohorts.

SUBJECTS

Male Medicare beneficiaries ages 65-79 from the Seattle (N = 94,900) and Connecticut (N = 120,621) SEER areas, followed from 1987-2001.

MEASUREMENTS

Rates of prostate cancer screening; treatment with radical prostatectomy, external beam radiotherapy, and androgen deprivation therapy; and prostate cancer-specific mortality.

MAIN RESULTS

The 15-year cumulative incidences of radical prostatectomy and radiotherapy through 2001 were 2.84% and 6.02%, respectively, for Seattle cohort members, compared to 0.56% and 5.07% for Connecticut cohort members (odds ratio 5.20, 95% confidence interval 3.22 to 8.42 for surgery and odds ratio 1.24, 95% confidence interval 0.98 to 1.58 for radiation). The cumulative incidence of androgen deprivation therapy from 1991-2001 was 4.78% for Seattle compared to 6.13% for Connecticut (odds ratio 0.77, 95% confidence interval 0.67 to 0.87). The adjusted rate ratio of prostate cancer mortality through 2001 was 1.02 (95% C.I. 0.96 to 1.09) in Seattle versus Connecticut.

CONCLUSION

Among men aged 65 or older, more intensive prostate cancer screening early in the PSA era and more intensive treatment particularly with radical prostatectomy over 15 years of follow-up were not associated with lower prostate cancer-specific mortality.

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.

Quantifying the role of PSA screening in the US prostate cancer mortality decline

OBJECTIVE

To quantify the plausible contribution of prostate-specific antigen (PSA) screening to the nearly 30% decline in the US prostate cancer mortality rate observed during the 1990s.

METHODS

Two mathematical modeling teams of the US National Cancer Institute's Cancer Intervention and Surveillance Modeling Network independently projected disease mortality in the absence and presence of PSA screening. Both teams relied on Surveillance, Epidemiology, and End Results (SEER) registry data for disease incidence, used common estimates of PSA screening rates, and assumed that screening, by shifting disease from distant to local-regional clinical stage, confers a corresponding improvement in disease-specific survival.

RESULTS

The teams projected similar mortality increases in the absence of screening and decreases in the presence of screening after 1985. By 2000, the models projected that 45% (Fred Hutchinson Cancer Research Center) to 70% (University of Michigan) of the observed decline in prostate cancer mortality could be plausibly attributed to the stage shift induced by screening.

CONCLUSIONS

PSA screening may account for much, but not all, of the observed drop in prostate cancer mortality. Other factors, such as changing treatment practices, may also have played a role in improving prostate cancer outcomes.

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.

Assessment of causes of death in a prostate cancer screening trial

Accurate assessment of the causes of death is crucial for a conclusive evaluation of the ongoing prostate cancer screening trials. Here, we report the validity of the official causes of death as compared with an independent expert review in the Finnish prostate cancer screening trial. Because nearly 80,000 men were involved, death-cause evaluation was restricted to men diagnosed for prostate cancer. Medical charts were retrieved and the cause of death was assigned by an expert review panel for all deaths among men with prostate cancer during the study period, 1996-2003. The panel decision was compared with both death certificates and the official causes of death as assigned by Statistics Finland. Of a total of 315 deaths, the review panel attributed 127 (41%) to prostate cancer and 184 (59%) to other causes, the corresponding figures in death certificates being 124 (40%) and 187 (60%). Four cases were excluded because of insufficient information. The death-certificate data were in agreement with the panel's assessment in 305 out of 311 cases (overall agreement 97.7%, kappa = 0.95). The overall agreement between the official causes of death and the panel's decision was 97.4% (304/311, kappa = 0.95). The sensitivity of the certificates in identifying prostate cancer deaths was 96.1% (panel as golden standard). Correspondingly, specificity was 98.9%. The official causes of death thus provide an accurate means for evaluating disease-specific mortality in a large population-based prostate-cancer screening trial in Finland.

Overall survival in the intervention arm of a randomized controlled screening trial for prostate cancer compared with a clinically diagnosed cohort

OBJECTIVES

This population-based study provides comparisons of prostate cancer characteristics at diagnosis of two cohorts of men from two well-defined geographical areas exposed to different intensities of prostate cancer screening. Overall survival in both cohorts was compared with that in the general population.

METHODS

A cohort of 822 men randomized to the intervention arm of a prostate cancer screening trial and subsequently diagnosed with prostate cancer was compared with a nonrandomized cohort of 947 men who were clinically diagnosed with prostate cancer in a geographically neighboring region. In both cohorts, cases were diagnosed with prostate cancer between January 1989 and December 1997. A partitioning of overall survival by variables associated with cancer onset such as age at diagnosis, stage at diagnosis, and grade at diagnosis was performed.

RESULTS

Age at diagnosis, tumor extent at diagnosis, and grade at diagnosis were significantly different between the screened and clinically diagnosed cohort. The 5- and 10-yr survival rates were higher in the screened cohort than in the clinically diagnosed cohort (88.8% vs. 52.4%, and 68.4% vs. 29.6%, respectively). Significant differences in survival were evident for all age, stage, and grade subgroups, except for metastatic disease at diagnosis.

CONCLUSIONS

Differences in overall survival favoring the screened population were observed for all baseline characteristics (age, stage, and grade of disease), and these variables may all explain differences in overall survival because screening achieves early diagnosis as well as a stage and grade shift. As observed survival rates in the screened population mirrored those within the general population, the contribution of lead time and overdiagnosis to final patient outcome is considered to be large as well.

Prostate Cancer Screening

Prostate cancer incurs a substantial incidence and mortality burden, similarly to breast cancer, and it ranks among the top ten specific causes of death in the United States. It is inherent as we maximize the detection of early prostate cancer that we increase the detection of both nonaggressive (slow growing) and aggressive (faster growing) prostate cancers. The evidence clearly supports the use of PSA screening in conjunction with DRE as a means of early detection of prostate cancer. Widespread implementation of prostate cancer screening in the United States has led to the phenomenon of stage migration with more cancers being detected at a lower stage. Such a trend has decreased the incidence of metastatic disease at diagnosis and paralleled the decrease of the mortality rate from prostate cancer. Our understanding of the natural history of prostate cancer is progressing over time, but the question of its length is unanswerable. The relatively long doubling time (on average) of early prostate cancer of 3 to 4 years or more indicates a relatively good prognosis for many men with this disease, even without early detection and treatment. Unfortunately, the poor specificity of the PSA test in men with benign prostatic hyperplasia (BPH) leads to high rates of prostate biopsy and attendant illnesses and costs. Early detection is more apt to detect a slow-growing prostate cancer than a faster growing cancer that is associated with a more rapid course of progression to metastatic disease. Hence, the launching of mass screening programs for the early detection of prostate cancer is premature. However, in the absence of solid evidence of benefit, one reasonable approach to screening at the individual level is to involve the patient in decisions about whether or not to perform a PSA test. Thus, "offering" PSA testing must be accompanied by informed discussion within the context of an ongoing patient-physician relationship. This is to be distinguished from the use of PSA testing for the purpose of "mass screening." Concepts that must be explored with the patient include: 1. The long-term ramifications of screening 2. The relatively high probability of further evaluation and biopsy with positive results 3. Potentially difficult decisions that may arise about using treatments that are associated with considerable morbidity and uncertain benefits (at the time) if cancer is discovered We should identify a future path that is evidence-based, focused on the issues that make a difference to patients, and results in better and longer lives of those with the disease and those who are at risk of getting it. If that path leads to treating fewer patients in the future, even if sometimes more aggressively, we should pursue it definitely and consequently.

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.