Age-adjusted Prostate Cancer Incidence Research Articles

Excess weight, weight gain, and prostate cancer risk and prognosis: the PROCA-life study.

Studies of excess weight and weight changes throughout adult life for prostate cancer (PCa) risk and prognosis have shown inconsistent results. In a population-based cohort, the Prostate Cancer Study throughout life (PROCA-life), 16,960 healthy men from the prospective cohort Tromsø Study (1994-2016) were included. Body mass index (BMI) and weight were measured at all four attendings, and weight change was calculated as the difference between the first and last of either Tromsø4, Tromsø5 or Tromsø6. Overall, 904 men developed PCa during 16 years of follow-up, and Poisson regression with fractional polynomials was used to investigate trends in incidence. Cox proportional hazard and logistic regression models were used to study associations between measurements of BMI and weight change and PCa risk, severity, and mortality. At study entry, 46% of the participants (median age 44 years) were overweight, and 14% were obese (BMI > 30 kg/m2). We observed a 127% increase in overall age adjusted PCa incidence in the cohort during 1995 through 2019. No overall associations between BMI or weight change and PCa risk were observed. However, in sub-group analysis, weight gain among obese men was associated with a three-fold higher PCa risk (HR 3.03, 95% CI 1.39-6.58) compared with obese men with stable weight. Overweight was associated with lower risk of metastatic cancer (OR 0.48, 95% CI 0.30-0.75) at diagnosis. Men with obesity had higher risk of PCa-specific death (HR 1.72, 95% CI 1.03-2.88), while nonsmoking obese PCa cases had two times higher PCa-specific mortality compared with normal weighted PCa cases (HR 2.10, 95% CI 1.11-3.70). In our cohort, weight gain among obese men was associated with higher risk of PCa, and obesity was associated with higher PCa-specific mortality, especially among nonsmokers. The relationship between weight and risk for PCa remains complicated, and future studies are needed to determine clinical implications.

Incidence trends in prostate cancer among men in the United States from 2000 to 2020 by race and ethnicity, age and tumor stage.

To explore whether prostate cancer incidence trends from 2000 to 2020 in the United States differed by race and ethnicity, age and tumor stage; to explore racial differences in prostate cancer incidence change due to the impact of COVID-19 pandemic lockdown in 2020; and to determine if there is any high-risk population that can be targeted for prevention. We identified 1,098,349 men who were diagnosed with incident prostate cancer at age ≥20 in 2000-2020 in 17 registries of the Surveillance, Epidemiology, and End Results (SEER) program in the United States; of whom, 778,437 were non-Hispanic whites, 155,111 non-Hispanic blacks, 4,200 American Indians and Alaska Natives (AIAN), 55,267 non-Hispanic Asians/Pacific Islanders, and 105,334 Hispanics. Age-adjusted incidence rate of prostate cancer was the highest in blacks (302.6 cases per 100,000 men), followed by whites (186.6), Hispanics (153.2), AIAN (108.5), and Asians (104.9). Age-adjusted prostate cancer incidence rates dramatically decreased from 2000 to 2013 for all ethnic men. However, age-adjusted prostate cancer incidence rates increased from 2014 to 2020, in which the increasing incidence trend looked sharper in blacks and whites, flatter in Asians, and leveled in AIAN and Hispanics. Among men with local or regional stages across all years, prostate cancer incidence rate was significantly higher in blacks, but significantly lower in Hispanics, AIAN, and Asians as compared to whites. Among men in 2007-2013, the risk of distant stage prostate cancer was statistically significantly elevated in blacks (rate-ratio: 2.22, 95% CI: 2.06-2.38) and Hispanics (1.16, 1.06-1.25), not significantly different in AIAN (1.30, 0.92-1.76), but still significantly lower in Asians (0.73, 0.66-0.82) as compared to whites. There was a drop of prostate cancer incidence from 2019 to 2020 likely due to the impact of COVID-19 pandemic lockdown on the access to medical care in 2020. Overall prostate cancer incidence rate decreased by 40.4 cases per 100,000 population from 277.4 in 2019 to 237.0 in 2020 for blacks, 20.9 from 164.2 to 143.3 for whites, 16.8 from 124.8 to 108.0 for Hispanics, 14.9 from 101.7 to 86.8 for AIAN, and 12.6 from 88.4 to 75.8 for Asians. The decreasing trend of prostate cancer incidence from 2000 to 2013 was statistically significant for all ethnic men. There was an increasing prostate cancer incidence from 2014 to 2020. Age-adjusted incidence rate of prostate cancer was the highest in blacks, followed by whites, Hispanics, AIAN, and Asians, regardless of age groups, tumor stages, and time periods. There will also be a need to monitor and investigate the prostate cancer incidence trend during and after COVID-19 pandemic season.

Prostate cancer epidemiology and prognostic factors in the United States.

Using the latest cohort study of prostate cancer patients, explore the epidemiological trend and prognostic factors, and develop a new nomogram to predict the specific survival rate of prostate cancer patients. Patients with prostate cancer diagnosed from January 1, 1975 to December 31, 2019 in the Surveillance, Epidemiology, and End Results Program (SEER) database were extracted by SEER stat software for epidemiological trend analysis. General clinical information and follow-up data were also collected from 105 135 patients with pathologically diagnosed prostate cancer from January 1, 2010 to December 1, 2019. The factors affecting patient-specific survival were analyzed by Cox regression, and the factors with the greatest influence on specific survival were selected by stepwise regression method, and nomogram was constructed. The model was evaluated by calibration plots, ROC curves, Decision Curve Analysis and C-index. There was no significant change in the age-adjusted incidence of prostate cancer from 1975 to 2019, with an average annual percentage change (AAPC) of 0.45 (95% CI:-0.87~1.80). Among the tumor grade, the most significant increase in the incidence of G2 prostate cancer was observed, with an AAPC of 2.99 (95% CI:1.47~4.54); the most significant decrease in the incidence of G4 prostate cancer was observed, with an AAPC of -10.39 (95% CI:-13.86~-6.77). Among the different tumor stages, the most significant reduction in the incidence of localized prostate cancer was observed with an AAPC of -1.83 (95% CI:-2.76~-0.90). Among different races, the incidence of prostate cancer was significantly reduced in American Indian or Alaska Native and Asian or Pacific Islander, with an AAPC of -3.40 (95% CI:-3.97~-2.82) and -2.74 (95% CI:-4.14~-1.32), respectively. Among the different age groups, the incidence rate was significantly increased in 15-54 and 55-64 age groups with AAPC of 4.03 (95% CI:2.73~5.34) and 2.50 (95% CI:0.96~4.05), respectively, and significantly decreased in ≥85 age group with AAPC of -2.50 (95% CI:-3.43~-1.57). In addition, age, tumor stage, race, PSA and gleason score were found to be independent risk factors affecting prostate cancer patient-specific survival. Age, tumor stage, PSA and gleason score were most strongly associated with prostate cancer patient-specific survival by stepwise regression screening, and nomogram prediction model was constructed using these factors. The Concordance indexes are 0.845 (95% CI:0.818~0.872) and 0.835 (95% CI:0.798~0.872) for the training and validation sets, respectively, and the area under the ROC curves (AUC) at 3, 6, and 9 years was 0.7 or more for both the training and validation set samples. The calibration plots indicated a good agreement between the predicted and actual values of the model. Although there was no significant change in the overall incidence of prostate cancer in this study, significant changes occurred in the incidence of prostate cancer with different characteristics. In addition, the nomogram prediction model of prostate cancer-specific survival rate constructed based on four factors has a high reference value, which helps physicians to correctly assess the patient-specific survival rate and provides a reference basis for patient diagnosis and prognosis evaluation.

Trends in prostate cancer incidence among Black men in the Caribbean and the United States.

Prostate cancer incidence is highest for Black men of the African diaspora in the United States and Caribbean. Recent changes in recommendations for prostate cancer screening have been shown to decrease overall prostate cancer incidence and increase the likelihood of late stage disease. However, it is unclear how trends in prostate cancer characteristics among high risk Black men differ by geographic region during the changes in screening recommendations. In this study, we used population-based prostate cancer registry data to describe age-adjusted prostate cancer incidence trends from 2008 to 2015 among Black men from six geographic regions. We obtained data on incident Black prostate cancer patients from six cancer registries (in the United States: Florida, Alabama, Pennsylvania, and New York; and in the Caribbean: Guadeloupe and Martinique). After age standardization, we used descriptive analyses to compare the demographics and tumor characteristics by cancer registry site. The Joinpoint regression program was used to compare the trends in incidence by site. A total of 59,246 men were analyzed. We found the highest incidence rates (per 100,000) for prostate cancer in the Caribbean countries (181.99 in Martinique and 176.62 in Guadeloupe) and New York state (178.74). Incidence trends decreased significantly over time at all sites except Martinique, which also showed significantly increasing rates of late stage (III/IV) and Gleason score 7+ tumors. We observed significant differences in prostate cancer incidence trends among Black men after major changes prostate screening recommendations. Future studies will examine the factors that differentially influence prostate cancer trends among the African diaspora.

Variations in Age-Adjusted Prostate Cancer Incidence Rates by Race and Ethnicity After Changes in Prostate-Specific Antigen Screening Recommendation

After publication of US Preventive Task Force Prostate-Specific Antigen (PSA) screening guidelines in 2008 and 2012, there have been documented associations with incidence and stage distributions of prostate cancer. It is unclear if these changes were temporary or differed by age or race and ethnicity. To assess the association of 2008 and 2012 PSA guidelines with prostate cancer incidence by age and race and ethnicity in the US. This cross-sectional study evaluated prostate cancer incidence from 2005 to 2018 in the US using data from the US Cancer Statistics public use database. Data were analyzed from August 2020 through June 2022. The primary outcome was the year when rates of prostate cancer incidence changed directionality by age and race and ethnicity. Age-adjusted incidence rates of prostate cancer and corresponding 95% CIs were created, followed by join point regression analysis to evaluate trends of age-adjusted incidence rates of prostate cancer by age, race, Hispanic ethnicity, and stage of diagnosis. Among 2 944 387 men with prostate cancer, 2 869 943 (97.5%) men were aged 50 years and older. Men aged 50 years and older accounted for 185 476 of 191 533 Hispanic individuals (96.8%) and 2 684 467 of 2 752 854 non-Hispanic individuals (97.5%). Men aged 50 years and older accounted for 427 016 of 447 847 African American individuals (95.4%), 12 141 of 12 470 American Indian or Alaska Native individuals (97.4%), 61 126 of 62 159 Asian or Pacific Islander individuals (98.3%), and 2 294 171 of 2 344 392 White individuals (97.9%). Men with unknown race (77 519 men) were excluded from the analysis. A decrease in age-adjusted rate of prostate cancer after the 2008 guideline change was observed in all age groups by race and ethnicity. For example, among African American men ages 65 to 74 years, 10 784 of 807 080 men (1.34%) had a prostate cancer diagnosis in 2007 vs 10 714 of 835 548 men in 2008 (1.28%). The mean annual age-adjusted incidence rates of prostate cancer per 100 000 men were 157.7 men (95% CI, 157.4-158.0 men) in 2005 to 2008 and 131.9 men (95% CI, 131.6-132.2 men) in 2009 to 2012. The number of inflections and annual percent changes (APCs) for segments separated by inflections varied by age, race, and Hispanic ethnicity. For men ages 65 to 74 years, the APC was -6.53 (95% CI, -9.28 to -3.69) for 2009 to 2014 among African American men (2 join points), -5.96 (95% CI, -6.84 to -5.07) for 2007 to 2018 among American Indian or Alaska Native men (1 join point), -6.52 (95% CI, -9.22 to -3.74) for 2007 to 2014 among Asian or Pacific Islander men (2 join points), -7.92 (95% CI, -11.36 to -4.35) for 2009 to 2014 among Hispanic men (2 join points), and -7.02 (95% CI, -9.41 to -4.57) for 2007 to 2014 among White men (2 join points).‬‬‬‬‬‬‬‬. In this study, men in different age, race, and ethnicity groups had different APC patterns after 2008 and 2012 PSA screening guideline changes. These findings may provide important data on the timing and durations of changes in cancer diagnoses that are associated with changes in PSA screening recommendations and may be valuable for targeted strategies to reduce regional- and distant-staged cancers.

Racial/Ethnic Disparities in Prostate Cancer Incidence, Distant Stage Diagnosis, and Mortality by U.S. Census Region and Age Group, 2012-2015.

We sought to characterize recent prostate cancer incidence, distant stage diagnosis, and mortality rates by region, race/ethnicity, and age group. In SEER*Stat, we examined age-specific and age-adjusted prostate cancer incidence, distant stage diagnosis, and mortality rates by race/ethnicity, census region, and age group. Incidence and mortality analyses included men diagnosed with (n = 723,269) and dying of (n = 112,116) prostate cancer between 2012 and 2015. Non-Hispanic black (NHB) and non-Hispanic Asian/Pacific Islander (NHAPI) men had the highest and lowest rates, respectively, for each indicator across regions and age groups. Hispanic men had lower incidence and mortality rates than non-Hispanic white (NHW) men in all regions except the Northeast where they had higher incidence [RR, 1.16; 95% confidence interval (CI), 1.14-1.19] and similar mortality. Hispanics had higher distant stage rates in the Northeast (RR, 1.18; 95% CI, 1.08-1.28) and South (RR, 1.22; 95% CI, 1.15-1.30), but similar rates in other regions. Non-Hispanic American Indian/Alaskan Native (NHAIAN) men had higher distant stage rates than NHWs in the West (RR, 1.38; 95% CI, 1.15-1.65). NHBs and Hispanics had higher distant stage rates than NHWs among those aged 55 to 69 years (RR, 2.91; 95% CI, 2.81-3.02 and 1.24; 95% CI, 1.18-1.31, respectively), despite lower overall incidence for Hispanics in this age group. For Hispanic and NHAIAN men, prostate cancer indicators varied by region, while NHB and NHAPI men consistently had the highest and lowest rates, respectively, across regions. Regional and age group differences in prostate cancer indicators between populations may improve understanding of prostate cancer risk and help inform screening decisions.

Evidence of prostate cancer “reverse stage migration” toward more advanced disease at diagnosis: Data from the Pennsylvania Cancer Registry

PurposeThe widespread adoption of prostate-specific antigen-based prostate cancer screening caused a stage migration toward earlier stage disease at diagnosis. We investigated whether this stage migration has persisted in a contemporary analysis of a population-based statewide cancer registry. Materials and methodsWe analyzed the Pennsylvania Cancer Registry, a statewide registry of all newly diagnosed cancers. Data were collected on prostate cancers diagnosed between 1992 and 2012. We determined age-adjusted prostate cancer incidence and mortality rates, as well as the distribution of tumor stage (localized, regional, or metastatic) at diagnosis, and assessed for changes in these variables over time using joinpoint analysis. ResultsBetween 1992 and 2012, 210,831 new cases of prostate cancer were diagnosed in Pennsylvania, and 33,948 men died of disease. Age-adjusted prostate cancer incidence rates, and specifically the incidence of localized disease, have decreased dramatically since 2007 to 2008. Due to the decreased diagnosis of localized disease, regional and metastatic tumors have made up a greater percentage of all prostate cancer diagnoses in recent years, despite a relatively stable incidence of these advanced stage tumors. ConclusionsOver the past 2 decades, age-adjusted prostate cancer incidence rates in Pennsylvania have decreased, primarily because of the decreased detection of early-stage disease. There has been a corresponding shift toward more advanced disease at diagnosis. These findings may be explained by the decreased use of prostate-specific antigen-based screening, among other factors. The 2012 United States Preventative Services Task Force recommendations against prostate cancer screening may exacerbate this concerning trend, potentially resulting in an increase in prostate cancer-specific mortality.

Prostate Cancer Incidence and Agriculture Practices in Georgia, 2000–09.

Background: Georgia has prostate cancer incidence rates consistently above the national average. A notable portion of Georgia’s economy is rooted in agricultural production, and agricultural practices have been associated with an increased risk of prostate cancer. Methods: Statistical analyses considered county age-adjusted prostate cancer incidence rates as the outcome of interest and three agricultural variables (farmland as percent of county land, dollars spent per county acre on agriculture chemicals, and dollars spent per county acre on commercial fertilizers) as exposures of interest. Multivariate linear regression models analyzed for each separately. Data were obtained from National Cancer Institute Surveillance, Epidemiology and End Results (SEER) 2000–2010, United States Department of Agriculture (USDA) 1987 Agriculture Survey, and 2010 US Census. Results: In counties with equal to or greater than Georgia counties’ median percent African-American population (27%), dollars per acre spent on agriculture chemicals was significantly associated (P50.04) and dollars spent of commercial fertilizers was moderately associated (P50.07) with elevated prostate cancer incidence rates. There was no association between percent of county farmland and prostate cancer rates. Conclusion: This study identified associations between prostate cancer incidence rates, agriculture chemical expenditure, and commercial fertilizer expenditure in Georgia counties with a population comprised of more than 27% of African Americans.

Prostate cancer incidence and agriculture practices in Georgia, 2000-2010.

Georgia has prostate cancer incidence rates consistently above the national average. A notable portion of Georgia's economy is rooted in agricultural production, and agricultural practices have been associated with an increased risk of prostate cancer. Statistical analyses considered county age-adjusted prostate cancer incidence rates as the outcome of interest and three agricultural variables (farmland as percent of county land, dollars spent per county acre on agriculture chemicals, and dollars spent per county acre on commercial fertilizers) as exposures of interest. Multivariate linear regression models analyzed for each separately. Data were obtained from National Cancer Institute Surveillance, Epidemiology and End Results (SEER) 2000-2010, United States Department of Agriculture (USDA) 1987 Agriculture Survey, and 2010 US Census. In counties with equal to or greater than Georgia counties' median percent African-American population (27%), dollars per acre spent on agriculture chemicals was significantly associated (P = 0.04) and dollars spent of commercial fertilizers was moderately associated (P = 0.07) with elevated prostate cancer incidence rates. There was no association between percent of county farmland and prostate cancer rates. This study identified associations between prostate cancer incidence rates, agriculture chemical expenditure, and commercial fertilizer expenditure in Georgia counties with a population comprised of more than 27% of African Americans.

Abstract 263: African American prostate cancer incidence rates inside and outside of zinc zones

Abstract African American males experience disproportionately higher prostate cancer incidence rates versus all other ethnic groups in the North American continent. Data indicates a decreased expression of hZIP1 zinc transporter in African American prostate tissue. Research demonstrates zinc deficiency in-vitro promotes a pro-metastatic dis-regulation of cell cycle and apoptotic processes. Research also demonstrates zinc transporter over-expression in-vitro promotes decreased pro-metastatic and anti-apoptotic activity and sensitization to ligand mediated cell death. Starting from this molecular premise, we examined the relationship between at risk populations’ proximity to zinc mines and incidence rates: hypothesizing a correlation between decreased rates within proximity to zinc mines. Data was requested from cancer registries where zinc mines were located, though only Arizona data was used. Using a combination of excel, basic image capture techniques and radius creating websites, a 100-mile radius was arbitrarily created around Ruby, Arizona where the now abandoned Montana mine is located. Counties in the state of Arizona were divided into those that fell within this radius, or outside of it. Weighted age adjusted incidence rates were then determined for each county for a given ethnic group. Averaged weighted age adjusted rates were then determined for the counties within the radius and outside. These rates were compared within each ethnic group, though one final comparison was made for all ethnicities within and outside of the radius. Maps containing additional zinc mines, locations of aquifers and main streams and the radius were super-posed to visualize the topological relationships of these elements. Our results show that every ethnic group experienced the same decrease in averaged weighted age adjusted prostate cancer incidence rates within the 100-mile radius of the zinc mine versus outside. The same result occurred when all ethnic groups were used simultaneously to compare rate differences on either side of the radius boundary. As expected, African Americans experienced the highest incidence rates within their at risk group. Asian / Pacific Islanders experienced the lowest incidence rates within their at risk group. There appears to be a correlation between the proximity of at risk populations to zinc mines and decreased prostate cancer incidence rates. The geological maps manipulated in this study provide reasonable insight into the passage of zinc from abandoned mining operations into streams and groundwater. It is from these resources that public and private wells (as well as municipal systems) draw water for human use. This basic epidemiological inquiry macroscopically mirrors the established molecular premises and leads to a holistic perspective on the subject. More rigorous statistical analyses need be performed on these data in order to properly support these conclusions. Note: This abstract was not presented at the meeting. Citation Format: Jiro D. Mckinnis, Hao Nguyen. African American prostate cancer incidence rates inside and outside of zinc zones. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 263. doi:10.1158/1538-7445.AM2014-263

Ultraviolet index and racial differences in prostate cancer incidence and mortality

Studies suggest that low levels of vitamin D may be associated with prostate cancer, and darker skin reduces the body's ability to generate vitamin D from sunshine. The impact of sunshine on racial disparities in prostate cancer incidence and mortality is unknown. Using the Surveillance, Epidemiology, and End Results program database, the authors calculated age-adjusted prostate cancer incidence rates among black and white men aged ≥ 45 years by race and county between 2000 and 2009 (N = 906,381 men). Similarly, county-level prostate cancer mortality rates were calculated from the National Vital Statistics System (N = 288,874). These data were linked with the average monthly solar ultraviolet (UV) radiation index by county and data regarding health, wellness, and demographics. Multivariable regression analysis was used to assess whether increases in the UV index (in deciles) moderated the association between black race and the incidence and mortality of prostate cancer. Compared with counties in the lowest UV index decile, prostate cancer incidence rates for white and black men were lower in counties with a higher UV index (all Ps ≤ 0.051). Incidence rates were higher for black men versus white men, but the difference by race was less for counties in the fourth to fifth UV index deciles versus those in the first decile (Ps ≤ 0.02). Mortality rates also were found to decrease with increasing UV index for white men (Ps ≤ 0.003), but increase for black men, and an unexplained increase in racial differences in mortality rates was observed with an increasing UV index. Racial disparities in the incidence of prostate cancer were larger in some areas with less sunshine. Additional research should confirm the findings of the current study and assess whether optimizing vitamin D levels among black men can reduce disparities.

Changes in case mix and treatment patterns in prostate cancer in Saskatchewan during the prostate specific antigen testing era

The prostate specific antigen (PSA) test became available in Saskatchewan in 1990 as a part of the provincial health plan. The purpose of this population-based study was to describe the changes in case mix and treatment patterns for prostate cancer following its introduction. The Saskatchewan Cancer Registry was used to identify all new cases of prostate cancer for the period 1985-2001. We reviewed over 10,000 charts to collect information on tumor characteristics, diagnostic methods, and first choice of treatment. This information was linked to the demographic and mortality data from the registry. The age-adjusted incidence of prostate cancer was influenced greatly by PSA testing volumes. Overall, the rate increased from 90.3 per 100,000 in 1985 to 151.3 per 100,000 in 2001. The increase was mostly organ-confined moderately differentiated cases. The incidence rate of metastatic disease dropped about 50% but only in the 70-79 and 80+ age groups. In 1985, 34% of cases were diagnosed by needle biopsy and 60.4% by TURP. In 2001, the values were 76.1% and 19.7%, respectively. More men now choose radical therapy as the first course of treatment, 81% during 1997-2001 compared to only 63.2% in the 1985-1989 period. Mortality rates remained stable in all age groups over these years. There have been dramatic changes in the case mix of prostate cancers diagnosed since the introduction of PSA testing in the population and significant changes in clinical management of this disease. Thus far, no changes have occurred in mortality rates in the population.

Characterizing Spatial and Environmental Determinants of Prostate Cancer Using a Geographic Information System

ISEE-652 Objective: Prostate cancer (PrCA) incidence in South Carolina (SC) exceeds the national average, particularly among African Americans (AAs). A Geographic Information System (GIS) was used to evaluate spatial and environmental determinants of PrCA in SC, a cancer for which there are few established risk factors. Materials and Methods: Age-adjusted PrCA incidence, standardized incidence ratios (SIRs), and 95% confidence intervals were calculated for census tracts using SC Central Cancer Registry data (1996–2002). Demographic data (groundwater consumption, age, race, median income, land use) were obtained from census data. Metal concentrations in groundwater and soil were obtained from existing federal and state databases to test hypotheses that zinc and selenium are protective, and that cadmium and uranium increase PrCA incidence. Census tract-specific exposure estimates included: geometric mean groundwater and soil metal concentrations, proportion of samples exceeding background, and census tract-centroid concentration obtained via spatial modeling (kriging). A GIS was used to map incidence rates, SIRs, and exposures. Statistical procedures (linear and Poisson regression) were applied with and without censoring of tracts with <50% groundwater consumption per capita (N = 173 and 854, respectively). An adjacency matrix was generated and spatial statistical models were performed using WinBUGS software, with adjustment for correlated and uncorrelated heterogeneity. Results: There were 18,091 PrCA cases; 30% AA and 69% European American. Among uncensored tracts with elevated groundwater zinc, 7 had PrCA rates below expected incidence, and this inverse relationship also was observed using linear regression (P = 0.02). There were 96 census tracts with both elevated soil selenium concentrations and reduced SIRs. Three tracts had both elevated soil cadmium and higher SIRs. Conclusions: A decreasing trend in PrCA rates was observed among SC census tracts with elevated zinc in soil or groundwater. Relationships between environmental factors and cancer incidence can be efficiently explored using GIS, spatial statistics, and existing population databases.

A case-control study of diet and prostate cancer in Japan: possible protective effect of traditional Japanese diet.

The age-adjusted incidence of prostate cancer is low in Japan, and it has been suggested that the traditional Japanese diet, which includes many soy products, plays a preventive role against prostate cancer. We performed a case-control study on dietary factors and prostate cancer in order to assess the hypothesis that the traditional Japanese diet reduces the risk of prostate cancer. Four geographical areas (Ibaraki, Fukuoka, Nara, and Hokkaido) of Japan were selected for the survey. Average daily intake of food from 5 years before the diagnosis was measured by means of a semi-quantitative food frequency questionnaire. We studied 140 cases and 140 individually age ( +/- 5 years)-matched hospital controls for analysis. Estimates of age-adjusted odds ratios (ORs) and linear trends were calculated by conditional logistic regression models with adjustment for cigarette smoking and total energy intake as confounding factors. Consumption of fish, all soybean products, tofu (bean curds), and natto (fermented soybeans) was associated with decreased risk. ORs of the fourth vs. first quartile and 95% confidence intervals (95%CIs) were 0.45 (0.20-1.02) for fish, 0.53 (0.24-1.14) for all soybean products, 0.47 (0.20-1.08) for tofu, and 0.25 (0.05-1.24) for natto. Consumption of fish and natto showed significantly decreasing linear trends for risk (P < 0.05). Consumption of meat was significantly associated with increased risk (the OR of the second vs. first quartile was 2.19, 95%CI 1.00-4.81). Consumption of milk, fruits, all vegetables, green-yellow vegetables, and tomatoes showed no association. Our results provide support to the hypothesis that the traditional Japanese diet, which is rich in soybean products and fish, might be protective against prostate cancer.

Changing Relationship Between Socioeconomic Status and Prostate Cancer Incidence

Understanding the relationship between socioeconomic status (SES) and prostate cancer incidence could identify populations that should be targeted for intervention and prevention programs. We examined this relationship within the major racial/ethnic groups during the period 1972 through 1997, which spans the introduction of prostate-specific antigen (PSA) testing. We used data from the population-based Los Angeles Cancer Surveillance Program to examine age-adjusted prostate cancer incidence rates in five SES groups over three specific calendar periods by racial/ethnic subpopulation (white, black, Asian, and Hispanic) and by stage of disease at diagnosis. Linear regression analysis was used to test for trends in the age-adjusted incidence rates that were associated with increasing levels of SES. All P values were two-sided. For men diagnosed with prostate cancer before 1987, when the test for PSA was not widely available, we found no association between SES and the incidence of prostate cancer in any of four racial/ethnic subpopulations or between SES and the stage of disease at diagnosis. In contrast, among men who were diagnosed with prostate cancer after 1987, SES was statistically significantly and positively associated with prostate cancer incidence in men from all racial/ethnic subpopulations except Asians (P =.01 for white men, P =.001 for black men, P =.02 for Hispanic men, P =.06 for Asian men, and P =.01 for all men combined). Higher SES was statistically significantly associated with cancers of earlier stage (P =.01 for localized cancer and P =.00 for regional cancer) for men who were diagnosed with prostate cancer after 1987. The association between SES and prostate cancer incidence after 1987 may reflect more prevalent PSA screening in populations with higher SES due to their greater access to health care. SES should, therefore, be considered an important factor in interpreting variations and time trends in prostate cancer incidence.

Prostate cancer in Saskatchewan Canada, before and during the PSA era.

The purpose of this study was to describe changes in the incidence of prostate cancer and in survival of diagnosed cases, as well as prostate cancer-specific mortality, during a period spanning the introduction of prostate specific antigen (PSA) testing in Saskatchewan in 1990. All cases of neoplasms of the prostate (ICD-O = C61.9) diagnosed in Saskatchewan from 1970 to 1997 inclusive, were identified in the Saskatchewan Cancer Registry. A subgroup of adenocarcinomas was defined for further study. Age-adjusted and age-specific incidence rates, and actuarial and relative survival were calculated according to time period of diagnosis. Age-adjusted and age-specific mortality rates from prostate cancer were also calculated for each time period, using Vital Statistics data. The age-adjusted incidence of prostate cancer was 60.5 per 10(5) in 1970, rising gradually to 101.5 per 10(5) in 1989. In 1990, incidence rose much more sharply, reaching a peak of 163.1 per 10(5) in 1993, after which it began to fall. This sharp increase coincided with the introduction and increasing use of the PSA test in the province. Relative survival of prostate cancer patients was stable from the late 1970s through the 1980s, then improved markedly in the 1990-94 period. After the introduction of the PSA test, the relative risk of death for prostate cancer patients was only about 60% of what it had been throughout the previous 15 years. Prostate cancer-specific death rates did not change from the early 1980s to the end of the study period. The above data are consistent with earlier diagnosis of prostate cancer due to PSA screening. Because mortality has not yet changed, it is premature to recommend widespread screening of asymptomatic men.

Trends in survival of prostate cancer in southeastern Netherlands, 1971-1989.

The increase in the incidence of prostate cancer observed over the past 2 decades is suggested to be largely due to increased detection of insignificant tumors. To explore this assumption, we investigated trends in survival of prostate cancer patients in southeastern Netherlands, an area with almost 1 million inhabitants, where the age-adjusted incidence of prostate cancer increased by 53% between 1971 and 1989, i.e., before the introduction of prostate-specific antigen testing. Survival was calculated for all patients registered in the Eindhoven Cancer Registry between 1971 and 1989 (n = 2,562). In spite of earlier diagnosis, survival barely changed during this time period. Five-year relative survival improved slightly from 53% [95% confidence interval (CI) 47%, 59%] in 1975-1979 to 56% (CI 51%, 61%) in 1985-1989. Stratified analyses suggested an improvement since 1980 for patients below 75 years with localized tumors but, despite possible stage migration, decreased survival for those with metastasized and/or poorly differentiated tumors. Patients below 75 years whose tumors were diagnosed unexpectedly during transurethral resection of the prostate (TURP) exhibited a relative survival of 85% 5 years and 68% 10 years after diagnosis. Less extensive application of TURP in The Netherlands might explain why our findings do not agree with those in Sweden and the United States. Inference from country-specific trends in survival appears not to be necessarily generalizable to other countries with a similar increase in the incidence of prostate cancer. We conclude from our results that earlier diagnosis of prostate cancer between 1971 and 1989 may be accompanied by an increased incidence of an aggressive variant.

The epidemic of prostate cancer and the medical literature: a causal association?

The diagnosis of prostate cancer has undergone an unprecedented recent increase, while mortality has increased much more slowly. We examined new prostate cancer diagnoses from 1987-1992 in a nationwide prospective cohort study of 51 529 men enrolled in the Health Professionals Follow-up Study, a population likely to be medically sophisticated and thus early to adopt medical innovations. The age-adjusted incidence of prostate cancer rose approximately 2(1/2) fold during the study period. Nearly all of the increase occurred among organ-confined tumors, with a smaller increase for regionally-advanced tumors and none for metastatic tumors. Using a Poisson regression model of newly-diagnosed cancers, we found organ-confined cancers rose abruptly by 86% (95% CI: 36-256%; P=0.0001) and regionally-advanced tumors by 73% (95% CI:12-267%; P=0.01) after March, 1991, when a study advocating screening using the prostate specific antigen (PSA) was published in the New England Journal of Medicine. The recent increase in the incidence of prostate cancer is probably due to the increased PSA screening of asymptomatic men, resulting in the diagnosis of large numbers of men with early-stage disease from 1990 onward. Despite ongoing debate over the value of PSA screening, the rate of diagnosis accelerated sharply after the publication of a well-publicized but inconclusive study advocating screening. In a context of growing disease awareness, well-publicized research reports may result in unexpectedly amplified acceptance into medical practice.