A review of African American-white differences in risk factors for cancer: prostate cancer

A Literature Review of Racial Disparities in Prostate Cancer Research

BACKGROUND

Despite recent awareness of institutional racism, there are still important racial disparities in prostate cancer medical research. We investigated the historical development of research on racial disparities and bias.

METHODS

PubMed was searched for the term 'prostate cancer race' and added key terms associated with racial disparity. As an indicator of scientific interest in the topic, we analyzed whether the number of publications increased linearly as an indicator of growing interest. The linearity is expressed as R2.

RESULTS

The general search term "prostate cancer race" yielded 4507 publications. More specific search terms with ≥12 publications showing a higher scientific interest were found after 2005. The terms with the most publications when added to the general term were "genetic" (n = 1011), "PSA" (n = 995), and "detection" (n = 861). There was a linear increase in publications for "prostate cancer race" (R2 = 0.75) since 1980. Specific terms added to the general terms with a high linear increase (R2 ≥ 0.7) were "screening" (R2 = 0.82), "detection" (R2 = 0.72), "treatment access" (R2 = 0.71), and "trial underrepresentation" (R2 = 0.71). However, only a few studies have investigated its association with sexual activity. A combination with "sexual" showed 157 publications but only two years with ≥12 publications/year.

CONCLUSION

The terms "genetic", "PSA", and "detection" have been the focus of recent research on racial differences in prostate cancer. We found that old stereotypes are still being mentioned but seem to find little interest in the current literature. Further research interest was found in "treatment access". Recently, interest in socioeconomic factors has decreased.

Recreational and occupational physical activity in relation to prostate cancer aggressiveness: the North Carolina-Louisiana Prostate Cancer Project (PCaP)

PURPOSE

To examine associations between recreational and occupational physical activity and prostate cancer aggressiveness in a population-based, case-only, incident prostate cancer study.

METHODS

Data were analyzed from the cross-sectional North Carolina-Louisiana Prostate Cancer Project of African-American (n = 1,023) and European-American (n = 1,079) men newly diagnosed with prostate cancer (CaP). High-aggressive CaP was defined as Gleason sum ≥ 8, or prostate-specific antigen > 20 ng/ml, or Gleason sum ≥ 7 and clinical stage T3-T4. Metabolic equivalent tasks (MET) were estimated from self-reported recreational physical activity in the year prior to diagnosis assessed retrospectively via a validated questionnaire and from occupational physical activity based on job titles. Associations between physical activity variables and high-aggressive prostate cancer were estimated using logistic regression to calculate odds ratios (ORs) and 95% confidence intervals (CIs), adjusting for multiple confounders.

RESULTS

There was suggestive evidence that walking for 75-150 min/week for exercise is associated with lower odds of high-aggressive prostate cancer compared to no walking (OR = 0.69, 95% CI 0.47-1.01). Physical activity at the current job was associated with 24% lower odds of high-aggressive prostate cancer (highest vs. lowest tertile OR = 0.76, 95% CI 0.56-1.04). However, total MET-h/week of recreational physical activity and accumulation of high-level physical activity at the longest-held job were not associated with high-aggressive prostate cancer. Results did not vary by race.

CONCLUSIONS

The odds of high-aggressive prostate cancer were lower among men who walk for exercise and those engaged in occupations with high activity levels.

Family history of prostate cancer and prostate tumor aggressiveness in black and non-black men;results from an equal access biopsy study

Purpose

To test for racial differences in associations between family history (FH) of prostate cancer (PC) and prostate cancer aggressiveness in a racially diverse equal access population undergoing prostate biopsy.

Subjects/patients and methods

We prospectively enrolled men undergoing prostate biopsy at the Durham Veterans Administration from 2007 to 2018 and assigned case or control status based on biopsy results. Race and FH of PC were self-reported on questionnaires. Logistic regression was used to test the association between FH and PC diagnosis overall and by tumor aggressiveness [high- (Grade Group 3–5) or low-grade (Grade Group 1–2) vs. no cancer], overall, and stratified by race. Models were adjusted for age and year of consent, race, PSA level, digital rectal exam findings, prostate volume, and previous (negative) biopsy receipt.

Results

Of 1,225 men, 323 had a FH of PC and 652 men were diagnosed with PC on biopsy. On multivariable analysis, FH was associated with increased odds of high-grade PC in black (OR 1.85, p = 0.041) and all men (OR 1.56, p = 0.057) and was unrelated to overall or low-grade PC diagnosis, overall, or stratified by race (all p ≥ 0.325). In sensitivity analyses among men without a previous biopsy, results were slightly more pronounced.

Conclusion

In this setting of equal access to care, positive FH of PC was associated with increased tumor aggressiveness in black men, but not non-black men undergoing prostate biopsy. Further research is required to tease apart the contribution of genetics from increased PC awareness potentially influencing screening and biopsy rates in men with FH.

Supplementary Information

The online version of this article (10.1007/s10552-020-01389-8) contains supplementary material, which is available to authorized users.

Prostate cancer risk by occupation in the Occupational Disease Surveillance System (ODSS) in Ontario, Canada

INTRODUCTION

Previous Canadian epidemiologic studies have identified associations between occupations and prostate cancer risk, though evidence is limited. However, there are no well-established preventable risk factors for prostate cancer, which warrants the need for further investigation into occupational factors to strengthen existing evidence. This study uses occupation and prostate cancer information from a large surveillance cohort in Ontario that linked workers' compensation claim data to administrative health databases.

METHODS

Occupations were examined using the Occupational Disease Surveillance System (ODSS). ODSS included 1 231 177 male workers for the 1983 to 2015 period, whose records were linked to the Ontario Cancer Registry (OCR) in order to identify and follow up on prostate cancer diagnoses. Cox proportional hazard models were used to calculate age-adjusted hazard ratios and 95% CI to estimate the risk of prostate cancer by occupation group.

RESULTS

A total of 34 997 prostate cancer cases were diagnosed among workers in ODSS. Overall, elevated prostate cancer risk was observed for men employed in management/ administration (HR 2.17, 95% CI = 1.98-2.38), teaching (HR 1.99, 95% CI = 1.79-2.21), transportation (HR 1.20, 95% CI = 1.16-1.24), construction (HR 1.09, 95% CI = 1.06-1.12), firefighting (HR 1.62, 95% CI = 1.47-1.78), and police work (HR 1.20, 95% CI = 1.10-1.32). Inconsistent findings were observed for clerical and farming occupations.

CONCLUSION

Associations observed in white collar, construction, transportation, and protective services occupations were consistent with previous Canadian studies. Findings emphasize the need to assess job-specific exposures, sedentary behaviour, psychological stress, and shift work. Understanding specific occupational risk factors can lead to better understanding of prostate cancer etiology and improve prevention strategies.

Development and Psychometric Properties of a Prostate Cancer Knowledge Scale for African American Men

African American men have the highest prostate cancer-related mortality nationally. In response to this disparity, targeted interventions are emerging to enhance African American men's prostate cancer (PrCA) knowledge to ensure they are equipped to make informed decisions about PrCA screening with health-care providers. African American men's PrCA knowledge has been measured inconsistently over time with limited psychometric evidence. The factor structure of this construct in African American men is relatively unknown. This study describes the development and psychometric evaluation of an 18-item Prostate Cancer Knowledge Scale among 352 African American men. Exploratory factor analysis (EFA) was conducted using weighted least square mean and variance estimation with Geomin rotation. EFA yielded three factors: PrCA Anatomy and Screening (6 items), Risk Factors (5 items), Warning Signs (7 items) with good internal consistency reliability at KR-20 = .80 for the total scale and .64, .66, and .75, respectively, for each subscale. Factor loadings ranged from .31 to .86. The standardized root mean square residual (0.08) indicated that the factor structure explained most of the correlations. The three-factor, 18-item Prostate Cancer Knowledge Scale demonstrates that PrCA knowledge is a multidimensional construct and has utility for reliably measuring PrCA knowledge among African American men. Future research is required to confirm this factor structure among socio-demographically diverse African Americans.

Placing prostate cancer disparities within a psychosocial context: challenges and opportunities for future research

Black men are more likely to be diagnosed with prostate cancer compared with White men. Despite advances in prevention and treatment strategies, disparities in prostate cancer among Black men persist. While research on the causes of higher incidence and mortality is ongoing, there is limited evidence in the existing literature that clearly speaks to the potential psychological or social factors that may contribute to disparities in prostate cancer incidence. Given the lack of attention to this issue, we review scientific evidence of the ways in which social factors, including socioeconomic status and racial segregation, as well as psychological factors, like depression and anxiety, are related to subsequent prostate cancer risk, which could occur through behavioral and biological processes. Our objective is to illuminate psychosocial factors and their context, using a racial disparity lens, which suggests opportunities for future research on the determinants of prostate cancer. Ultimately, we aim to contribute to a robust research agenda for the development of new prostate cancer prevention measures to reduce racial disparities.

Race and Time to Receipt of Androgen Deprivation Therapy Among Men With Metastatic Prostate Cancer

BACKGROUND

The Medicare Modernization Act (MMA) drastically reduced reimbursement for androgen deprivation therapy (ADT) in 2005. One unintended consequence of the MMA may be an increase in the racial disparities in receipt of ADT. Given these policy changes, it becomes increasingly important to assess racial disparities in timely receipt of ADT.

METHODS

The purpose of this study is to evaluate the associations between race and median time to receipt of ADT among men with metastatic prostate cancer before and after the passage of the MMA. A population-based retrospective cohort was created from the Surveillance, Epidemiology, and End Results-Medicare.

RESULTS

A total of 1,846 African-American and 9,462 Caucasian men diagnosed with metastatic prostate cancer from 2000 through 2011 were included. An accelerated failure time regression model was used to examine factors associated with racial differences in median time to receipt of ADT. Results indicate that African-American men had a longer median time to receipt of ADT both before the MMA (Time Ratio (TR): 1.15; 95% Confidence Interval (CI) [1.05, 1.27]) and after the MMA (TR: 1.29; 95% CI [1.10, 1.53]) as compared to Caucasian men. In addition to race, men residing in South had longer median time to receipt of ADT (TR: 1.26, 1.52; 95% CI [1.01, 1.52; 1.24, 1.87] before and after MMA, respectively) compared to the Northeast region.

CONCLUSION

Considering the palliative benefits of ADT, it is important to develop effective strategies to address racial differences in receipt of treatment for metastatic prostate cancer.

Prostate cancer risk factors in black and white men in the NIH-AARP Diet and Health Study

BACKGROUND

There are few prospective studies comparing race-specific associations between diet, nutrients, and health-related parameters, and prostate cancer risk.

METHODS

Race-specific prostate cancer risk associations were examined among men in the National Institutes of Health (NIH)-AARP Diet and Health Study. We identified 1417 cases among black men (209 advanced), and 28,845 among white men (3898 advanced). Cox proportional hazards regression models estimated hazard ratios (HRs) and 95% confidence intervals (CIs). We also evaluated the cumulative change in the HR for black race following adjustment for each factor.

RESULTS

Race-specific prostate cancer associations were similar in black and white men across disease subtypes only for history of diabetes (overall : HR = 0.77, 95% CI: 0.65-0.90 and HR = 0.72, 95% CI: 0.69-0.76, respectively; P_interaction = 0.66). By contrast, there was a positive risk association with height for white men  and  inverse for black men (P_interaction: non-advanced = 0.01; advanced = 0.04). This difference remained among men with at least 2 years of follow-up for non-advanced (P_interaction = 0.01), but not advanced disease (P_interaction = 0.24); or after adjustment for prostate cancer screening (non-advanced P_interaction = 0.53, advanced P_interaction = 0.31). The only other evidence of interaction with race was observed for dietary vitamin D intake and non-advanced disease, but only after adjustment for screening (P_interaction = 0.02). Cumulative adjustment for each factor increased the HR for black race by 32.9% for overall cancer and 12.4% for advanced disease.

CONCLUSIONS

Our data suggest few of the dietary, nutrient, and health-related factors associated with prostate cancer risk in predominantly non-Hispanic white men were associated with risk in black men, and adjustment for these factors widen the black-white difference in risk. Larger studies of black men, particularly with prospective data, are needed to help identify risk factors relevant to this population.

Comparative Effectiveness of Conservative Management Compared to Cryotherapy in Localized Prostate Cancer Patients

The high frequency of treatment-related side effects for men with localized prostate cancer creates uncertainty for treatment outcomes. This study assessed the comparative effectiveness of treatment-related side effects associated with conservative management and cryotherapy in patients with localized prostate cancer. A retrospective longitudinal cohort study was conducted, using the linked data of the Surveillance, Epidemiology, and End Results and Medicare, which included patients diagnosed from 2000 through year 2013, and their Medicare claims information from 2000 through 2014. To compare the differences in baseline characteristics and treatment-related side effects between the study cohorts, χ² tests were conducted. Multivariate logistic regression was used to assess the association between treatment selection and side effects. There were 7,998 and 3,051 patients in the conservative management and cryotherapy cohort, respectively. The likelihood of erectile dysfunction, lower urinary tract obstruction, urinary fistula, urinary incontinence, and hydronephrosis was reported to be significantly lower (53%, 35%, 69%, 65%, and 36%, respectively) in the conservative management cohort. Conservative management had a lower likelihood of treatment-related side effects compared to cryotherapy. However, further research is needed to compare other significant long-term outcomes such as costs associated with these treatment choices and quality of life.

Lifestyle and Dietary Factors and Prostate Cancer Risk: A Multicentre Case-Control Study

This study aims to explore the association between fruit and vegetable intake, high fat, body mass index (BMI) score, physical activity, and the occurrence of prostate cancer among Jordanian men. A case-control study was conducted in three large referral hospitals. The sample included 165 prostate cancer patients in the case group and 177 healthy participants in the control group. The results showed that smoking (odds ratio [OR] = 0.32; 95% confidence interval [CI] = [0.18, 0.57]), a history of prostate infection (OR = 0.21; 95% CI = [0.11, 0.38]), high-fat intake (OR = 0.44; 95% CI = [0.23, 0.85]), and increased mean of BMI (OR = 1.08; 95% CI = [1.02, 1.13]) increased the likelihood of developing prostate cancer. Healthy diet and giving up smoking are recommended, as they may contribute to a reduction in the incidence of prostate cancer. More randomized clinical trials in this area are needed to strengthen the available evidence and reduce the effects of confounding variables.

Association Between Socioeconomic Status and Tumor Grade Among Black Men with Prostate Cancer

BACKGROUND

Prostate cancer affects black men disproportionately. Black men have an increased incidence of prostate cancer diagnoses at earlier ages and higher grade as indicated by Gleason score, compared to other races. This study investigates the impact of socioeconomic status (SES) on prostate cancer tumor grade among black men.

METHODS

Black men with a prostate cancer diagnosis during 1973-2011 were examined using individual-level data from the SEER NLMS database. Logistic regression model estimated the likelihood of receiving a diagnosis of high versus low grade prostate cancer based on self-reported SES status at the time of diagnosis.

RESULTS

Men who completed high school only were statistically significantly more likely to have a higher prostate cancer grade than those with a bachelor's degree or higher. However, there was no dose-response effect across educational strata. Retirees were 30% less likely to have higher grade tumors compared to those who were employed.

CONCLUSIONS

SES differences among black men did not fully explain the high grade of prostate cancer. Further research is needed on the biology of the disease and to assess access to medical care and prostate health education, discrimination, stress exposures, and social norms that might contribute to the aggressiveness of prostate cancer among black men.

Disparities in Cancer Screening Practices among Minority and Underrepresented Populations

OBJECTIVES

To review current evidence about cancer screening challenges that lead to cancer health disparities in minority populations.

DATA SOURCES

Research reports, published journal articles, web sites, and clinical practice observations.

CONCLUSION

There are significant disparities that exist in cancer screening practices among racial and ethnic minority and underrepresented populations, resulting in disproportionately higher cancer mortality rates in these populations.

IMPLICATIONS FOR NURSING PRACTICE

Nurses are positioned to lead in educating, promoting, and bringing awareness to cancer screening recommendationsand current cancer prevention guidelines for at-risk individuals, and help them to implement these guidelines to reduce incidence and mortality.

Cancer statistics for African Americans, 2016: Progress and opportunities in reducing racial disparities

In this article, the American Cancer Society provides the estimated number of new cancer cases and deaths for blacks in the United States and the most recent data on cancer incidence, mortality, survival, screening, and risk factors for cancer. Incidence data are from the National Cancer Institute, the Centers for Disease Control and Prevention, and the North American Association of Central Cancer Registries, and mortality data are from the National Center for Health Statistics. Approximately 189,910 new cases of cancer and 69,410 cancer deaths will occur among blacks in 2016. Although blacks continue to have higher cancer death rates than whites, the disparity has narrowed for all cancers combined in men and women and for lung and prostate cancers in men. In contrast, the racial gap in death rates has widened for breast cancer in women and remained level for colorectal cancer in men. The reduction in overall cancer death rates since the early 1990s translates to the avoidance of more than 300,000 deaths among blacks. In men, incidence rates from 2003 to 2012 decreased for all cancers combined (by 2.0% per year) as well as for the top 3 cancer sites (prostate, lung, and colorectal). In women, overall rates during the corresponding time period remained unchanged, reflecting increasing trends in breast cancer combined with decreasing trends in lung and colorectal cancer rates. Five-year relative survival is lower for blacks than whites for most cancers at each stage of diagnosis. The extent to which these disparities reflect unequal access to health care versus other factors remains an active area of research. Progress in reducing cancer death rates could be accelerated by ensuring equitable access to prevention, early detection, and high-quality treatment. CA Cancer J Clin 2016;66:290-308. © 2016 American Cancer Society.

Difference in Association of Obesity With Prostate Cancer Risk Between US African American and Non-Hispanic White Men in the Selenium and Vitamin E Cancer Prevention Trial (SELECT)

IMPORTANCE

African American men have the highest rates of prostate cancer incidence and mortality in the United States. Understanding underlying reasons for this disparity could identify preventive interventions important to African American men.

OBJECTIVE

To determine whether the association of obesity with prostate cancer risk differs between African American and non-Hispanic white men and whether obesity modifies the excess risk associated with African American race.

DESIGN, SETTING, AND PARTICIPANTS

Prospective study of 3398 African American and 22,673 non-Hispanic white men who participated in the Selenium and Vitamin E Cancer Prevention Trial (2001-2011) with present analyses completed in 2014.

MAIN OUTCOMES AND MEASURES

Total, low-grade (Gleason score <7), and high-grade (Gleason score ≥7) prostate cancer incidence.

RESULTS

With a median (interquartile range) follow-up of 5.6 (1.8) years, there were 270, 148, and 88 cases of total, low-, and high-grade prostate cancers among African American men and a corresponding 1453, 898, and 441 cases in non-Hispanic white men, respectively. Although not associated with risk among non-Hispanic white men, BMI was positively associated with an increase in risk among African American men (BMI, <25 vs ≥35: hazard ratio [HR], 1.49 [95% CI, 0.95, 2.34]; P for trend = .03). Consequently, the risk associated with African American race increased from 28% (HR, 1.28 [95% CI, 0.91-1.80]) among men with BMI less than 25 to 103% (HR, 2.03 [95% CI, 1.38-2.98]) among African American men with BMI at least 35 (P for trend = .03). Body mass index was inversely associated with low-grade prostate cancer risk within non-Hispanic white men (BMI, <25 vs ≥35: HR, 0.80 [95% CI, 0.58-1.09]; P for trend = .02) but positively associated with risk within African American men (BMI, <25 vs ≥35: HR, 2.22 [95% CI, 1.17-4.21]; P for trend = .05). Body mass index was positively associated with risk of high-grade prostate cancer in both non-Hispanic white men (BMI, <25 vs ≥35: HR, 1.33 [95% CI, 0.90-1.97]; P for trend = .01) and African American men, although the increase may be larger within African American men, albeit the racial interaction was not statistically significant (BMI, <25 vs ≥35: HR, 1.81 [95% CI, 0.79-4.11]; P for trend = .02).

CONCLUSIONS AND RELEVANCE

Obesity is more strongly associated with increased prostate cancer risk among African American than non-Hispanic white men and reducing obesity among African American men could reduce the racial disparity in cancer incidence. Additional research is needed to elucidate the mechanisms underlying the differential effects of obesity in African American and non-Hispanic white men.

Incidence of prostate and urological cancers in England by ethnic group, 2001-2007: a descriptive study

Background

The aetiology of urological cancers is poorly understood and variations in incidence by ethnic group may provide insights into the relative importance of genetic and environmental risk factors. Our objective was to compare the incidence of four urological cancers (kidney, bladder, prostate and testicular) among six ‘non-White’ ethnic groups in England (Indian, Pakistani, Bangladeshi, Black African, Black Caribbean and Chinese) to each other and to Whites.

Methods

We obtained Information on ethnicity for all urological cancer registrations from 2001 to 2007 (n = 329,524) by linkage to the Hospital Episodes Statistics database. We calculated incidence rate ratios adjusted for age, sex and income, comparing the six ethnic groups (and combined ‘South Asian’ and ‘Black’ groups) to Whites and to each other.

Results

There were significant differences in the incidence of all four cancers between the ethnic groups (all p < 0.001). In general, ‘non-White’ groups had a lower incidence of urological cancers compared to Whites, except prostate cancer, which displayed a higher incidence in Blacks. (IRR 2.55) There was strong evidence of differences in risk between Indians, Pakistanis and Bangladeshis for kidney, bladder and prostate cancer (p < 0.001), and between Black Africans and Black Caribbeans for all four cancers (p < 0.001).

Conclusions

The risk of urological cancers in England varies greatly by ethnicity, including within groups that have traditionally been analysed together (South Asians and Blacks). In general, these differences are not readily explained by known risk factors, although the very high incidence of prostate cancer in both black Africans and Caribbeans suggests increased genetic susceptibility. g.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1771-2) contains supplementary material, which is available to authorized users.

Longitudinal Study of DNA Methylation of Inflammatory Genes and Cancer Risk

BACKGROUND

Chronic inflammation plays a key role in cancer etiology. DNA methylation modification, one of the epigenetic mechanisms regulating gene expression, is considered a hallmark of cancer. Human and animal models have identified numerous links between DNA methylation and inflammatory biomarkers. Our objective was to prospectively and longitudinally examine associations between methylation of four inflammatory genes and cancer risk.

METHODS

We included 795 Normative Aging Study participants with blood drawn one to four times from 1999 to 2012 (median follow-up, 10.6 years). Promoter DNA methylation of IL6, ICAM-1, IFN, and TLR2 in blood leukocytes was measured using pyrosequencing at multiple CpG sites and averaged by gene for data analysis. We used Cox regression models to examine prospective associations of baseline and time-dependent methylation with cancer risk and compared mean methylation differences over time between cancer cases and cancer-free participants.

RESULTS

Baseline IFN hypermethylation was associated with all-cancer (HR, 1.49; P = 0.04) and prostate cancer incidence (HR, 1.69; P = 0.02). Baseline ICAM-1 and IL6 hypermethylation were associated with prostate cancer incidence (HR, 1.43; P = 0.02; HR, 0.70; P = 0.03, respectively). In our time-dependent analyses, IFN hypermethylation was associated with all-cancer (HR, 1.79; P = 0.007) and prostate cancer (HR, 1.57; P = 0.03) incidence; and ICAM-1 and IL6 hypermethylation were associated with prostate cancer incidence (HR, 1.39; P = 0.02; HR, 0.69; P = 0.03, respectively). We detected significant ICAM-1 hypermethylation in cancer cases (P = 0.0003) 10 to 13 years prediagnosis.

CONCLUSION

Hypermethylation of IFN and ICAM-1 may play important roles in early carcinogenesis, particularly that of prostate cancer.

IMPACT

These methylation changes could inform the development of early detection biomarkers and potential treatments of inflammation-related carcinogenesis.

Prostate cancer mortality in Serbia, 1991-2010: a joinpoint regression analysis

BACKGROUND

The aim of this descriptive epidemiological study was to analyze the mortality trend of prostate cancer in Serbia (excluding the Kosovo and Metohia) from 1991 to 2010.

METHODS

The age-standardized prostate cancer mortality rates (per 100 000) were calculated by direct standardization, using the World Standard Population. Average annual percentage of change (AAPC) and the corresponding 95% confidence interval (CI) was computed for trend using the joinpoint regression analysis.

RESULTS

Significantly increased trend in prostate cancer mortality was recorded in Serbia continuously from 1991 to 2010 (AAPC = +2.2, 95% CI = 1.6-2.9). Mortality rates for prostate cancer showed a significant upward trend in all men aged 50 and over: AAPC (95% CI) was +1.9% (0.1-3.8) in aged 50-59 years, +1.7% (0.9-2.6) in aged 60-69 years, +2.0% (1.2-2.9) in aged 70-79 years and +3.5% (2.4-4.6) in aged 80 years and over. According to comparability test, prostate cancer mortality trends in majority of age groups were parallel (final selected model failed to reject parallelism, P > 0.05).

CONCLUSION

The increasing prostate cancer mortality trend implies the need for more effective measures of prevention, screening and early diagnosis, as well as prostate cancer treatment in Serbia.

The Most Important Causes of Death in Iranian Population; a Retrospective Cohort Study

INTRODUCTION

Health care providers and health policy managers need updated and valid information regarding causes of death (COD) for development the health care facilities, directing primary prevention, assigning funds, and promoting public health. The major causes of death and its burden have not been yet appropriately identified in Iran. Although several studies had been carried out in this area, most of them were local or performed in the past years and need to be update. Thus, the present study aimed to address the major causes of death and its burden in Iran.

METHODS

The present cross-sectional study was performed on graduate students and their families from February to March 2014. Through a two-stage random sampling procedure, data on 11315 subjects were obtained. The corresponding age of death, gender, and calendar year of death were inquired. All causes of death were categorized in nine groups including major cardiovascular disease, cancers, motor vehicle accidents, unintentional injuries, intentional injuries, stroke, lower respiratory infections, diabetes, and other reasons. Years of life lost (YLL) and person years of life lost were computed as the burden of diseases.

RESULTS

Totally, 11315 (50.4% male) subjects were studied. The results regarding death of relatives revealed that 360 deaths occurred (66.9% male). COD in 95 cases (26.4%) was cardiovascular diseases, 64 (17.8%) motor vehicle accidents, 41 (11.4%) cancers, 23 (6.4%) unintentional injuries, 22 (6.1%) intentional injuries, 10 (2.8%) stroke, 8 (2.2%) lower respiratory infections, 6 (1.8%) diabetes, and 91 (25.3%) other reasons. The average YLL due to all COD was 34.4±18.5. YLL for motor vehicle accidents and injuries (unintentional and intentional) were higher than cardiovascular diseases (p<0.001). In addition, person years of life lost for motor vehicle accidents were 2613.1 years. Cardiovascular diseases (2159.4 years), cancers (1321.0 years), and unintentional injuries (990.4 years) were in the next ranks.

CONCLUSION

Based on the findings, it seems that cardiovascular diseases, motor vehicle accidents, cancers, intentional and unintentional injuries are the major causes of death in Iranian population. Most of years of life lost were due to motor vehicle accidents, cardiovascular diseases and cancers, intentional and unintentional injuries, respectively.

Cigarette smoking and prostate cancer risk: negative results of the Seoul Male Cancer Cohort Study

We evaluated cigarette smoking as a risk factor for prostate cancer in a prospective, population-based cohort study. The subjects were 14,450 males among the participants in the Seoul Male Cancer Cohort Study who had at least 1-year follow-up. They were followed up between 1993 and 2008. During the 16-year follow-up period, 87 cases of prostate cancer occurred over the 207,326 person-years of the study. The age-adjusted relative risks of past and current smokers at entry were 0.60 (95%CI: 0.34-1.06) and 0.70 (95%CI: 0.43-1.13), respectively, suggesting that cigarette smoking may not be a risk factor for prostate cancer. The relationship between prostate cancer and other modifiable factors, such as Westernized diet, should be studied with the goal of establishing prevention programs for prostate cancer.

Folate intake and the risk of prostate cancer: a systematic review and meta-analysis

There is conflicting evidence regarding the role of folate on the risk of developing prostate cancer. We performed a systematic review and quantitative meta-analysis of folate blood levels and folate intake, and the risk of prostate cancer. Four electronic databases (Medline, PubMed, Embase and Current Contents Connect) were searched to 11 October 2013, with no language restrictions for observational studies that measured folate intake or blood levels and the risk of prostate cancer. Pooled odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated using a random effects model. The dietary folate meta-analysis comprising 11 studies with 15 336 cases and a total sample size of 146 782 found no statistically significant association with prostate cancer, with an OR of 0.97 (95% CI 0.89-1.06). The total folate meta-analysis comprising of 5 studies with 7114 cases and a total sample size of 93 781 also found no statistically significant association with prostate cancer, with an OR of 0.99 (95% CI 0.82-1.19). The blood folate meta-analysis comprising of seven studies with 6122 cases and a total sample size of 10 232 found an increased risk of prostate cancer with high blood folate levels, with an OR of 1.43 (95% CI 1.06-1.93). There was significant heterogeneity (I(2)=79.5%, P<0.01). Removal of an outlier study removed the heterogeneity (I(2)=0.0%, P=0.54) and the association remained significant with an OR of 1.14 (95% CI 1.02-1.28). Dietary and total folate intake do not appear to be significantly associated with the risk of prostate cancer. High blood folate levels are associated with an increased risk of prostate cancer. These conclusions are limited by the predominance of included studies originating from developed countries with mostly Caucasian populations. Further research in populations with a high prevalence of non-Caucasian backgrounds is needed.

Prostate cancer screening

Universal screening for prostate cancer (Pca) using prostate-specific antigen-based testing is not recommended, as the potential harms of screening (overdiagnosis and overtreatment) outweigh potential benefits. The case for Pca screening requires a paradigm shift, which emphasizes the risks of screening over the risks of undetected cancer. Physicians are encouraged to use shared decision making with patients who express an interest in Pca screening, taking into account both the patient's screening preferences and individual risk profile. New models of care informed by the Patient Protection and Affordable Care Act are intended to assist clinicians in providing recommended preventive services.

Mini-review: androgen receptor phosphorylation in prostate cancer

Androgen receptor (AR) plays an important role in the tumorigenesis and progression of prostate cancer (PCa), and is the primary therapeutic target for PCa treatment. AR activity can be regulated via phosphorylation at multiple phosphorylation sites within the protein. Modifications by phosphorylation alter AR function, including its cellular localization, stability and transcriptional activity, ultimately leading to changes in cancer cell biology and disease progression. Here we present a brief overview of AR phosphorylation sites in PCa, focusing on functional roles of phospho-AR (p-AR) species, relevance in PCa disease progression, and potential as biomarkers and/or therapeutic targets through the use of kinase inhibitors. Additionally, recent evidence has shown the important role of AR activity in the cancer associated stroma on PCa growth and progression. The phosphorylation status of epithelial and stromal AR may be distinct; however, the current data available on stromal AR phosphorylation is limited. Further research will determine global view on the synergistic effects of phosphorylation across multiple AR sites in both epithelial and stromal cells and validate whether together they can be used as prognostic markers and/or effective therapeutic targets for PCa.

Multilevel Factors Associated With Overall Mortality for Men Diagnosed With Prostate Cancer in Florida

To identify individual and contextual factors contributing to overall mortality among men diagnosed with prostate cancer in Florida, a random sample of patients (between October 1, 2001, and December 31, 2007) was taken from the Florida Cancer Data System. Patient's demographic and clinical information were obtained from the Florida Cancer Data System. Comorbidity was computed following the Elixhauser Index method. Census-tract-level socioeconomic status and farm house presence were extracted from Census 2000 and linked to patient data. The ratio of urologists and radiation oncologists to prostate cancer cases at the county level was computed. Multilevel logistic regression was conducted to identify significance of individuals and contextual factors in relation to overall mortality. A total of 18,042 patients were identified, among whom 2,363 died. No racial difference was found in our study. Being older at diagnosis, unmarried, current smoker, uninsured, diagnosed at late stage, with undifferentiated, poorly differentiated, or unknown tumor grade were significantly associated with higher odds of overall mortality. Living in a low-income area was significantly associated with higher odds of mortality (p = .0404). After adjusting for age, stage, and tumor grade, patients who received hormonal, combination of radiation with hormone therapy, and no definitive treatment had higher odds of mortality compared with those who underwent surgery only. A large number of comorbidities were associated with higher odds of mortality. Although disease-specific mortality was not examined, our findings suggest the importance of careful considerations of patient sociodemographic characteristics and their coexisting conditions in treatment decision making, which in turn affects mortality.

Cancer incidence in Morocco: report from Casablanca registry 2005-2007

INTRODUCTION

Few population-based cancer registries are in place in developing countries. In order to know the burden of cancer in Moroccan population, cancer registry initiative was put in place in the Casablanca district, the biggest city of Morocco.

METHODS

The data collected covers 3.6 millions inhabitant and included Casablanca city and the administrative region.

RESULTS

The data collected in the years 2005-07 show that the top 5 forms of cancers in women were breast (ASR: 36.4 per 100,000), cervical (15.0), thyroid (6.7), colon-rectum (5.8), and ovarian (5.3); the top 5 cancers in men were lung (25.9), prostate (13.5), bladder (8.7), colon-rectum (8.1) and non-Hodgkin lymphoma (7.2). Tumours of haematopoietic and lymphoid tissues represented 11% of all cancers (skin excluded); some presented unusual sex ratios. For breast, cervical, colorectal and thyroid cancer, respectively 57%, 42%, 28% and 60% of the cases were under 50 years of age. This was attributable to particularly low numbers of cases recorded among old people, and the young age of the general population; the observed age-specific incidences under age 50 were not higher than in western countries. Cancers at young ages were particularly common in women: 67% of the cases were under 50. Stage at diagnosis could be obtained for 82% of the breast cancer cases and was as follows: 28% local, 63% regional and 9% distant, in the absence of screening.

CONCLUSION

These first population-based data have provided an invaluable resource for the national cancer control plan of Morocco, and will be useful tool to its future evaluation.

Incidence and survival patterns of cutaneous T-cell lymphomas in the United States

Using the United States Surveillance, Epidemiology and End Results (SEER) 17 dataset, we examined incidence and survival patterns for patients with cutaneous T-cell lymphomas (CTCLs) diagnosed following institution of the World Health Organization-European Organisation for Research and Treatment of Cancer (WHO-EORTC) classification. From 2005 to 2008, 2273 cases of CTCL were diagnosed. The age-adjusted incidence rate per 100,000 person-years for mycosis fungoides (MF) was 0.55 and for Sézary syndrome (SS) was 0.01. Incidence was higher among males (MF/SS male-to-female incidence rate ratio [IRR] 1.57) and black patients (MF black-to-white IRR 1.55). Black patients with CTCL were diagnosed at a younger age and black patients with MF/SS presented with advanced stage and had worse survival than white patients. In multiple-variable Cox-regression models, age > 60 (hazard ratio [HR] 4.78, 95% confidence interval [CI] 2.97-7.70), black race (HR 2.09, 95% CI 1.29-3.37) and advanced stage (HR 6.06, 95% CI 3.66-10.05) predicted worse survival for patients with MF/SS. Additional research identifying reasons for these differences are necessary to better understand these diseases and for new strategies in the treatment of CTCL.

Reducing inequalities in cancer outcomes: what works?

Despite efforts to reduce disparities in cancer outcomes among vulnerable populations, certain subgroups do not experience the gains made in the reduction of cancer incidence and mortality. In this article, we review recent trial data reporting on patient-, physician-, and system-centered interventions to improve quality and reduce disparities in cancer care spanning patient navigation to health reform. We conclude with data from a state that implemented a multitiered approach, targeting patient and systems barriers, that serves as a guide for future endeavors.

Limited PSA testing in indigent men in South Texas: an appropriate care or missing a prevention opportunity?

BACKGROUND

No previous study has examined racial ethnic differences in prostate-specific antigen (PSA) testing and followup in primary care practices serving an indigent population.

METHODS

From electronic medical records of primary care practices affiliated with one health care system in San Antonio, we identified 9,267 men aged 50 to 74 with 2+ clinic visits from 2008 through 2010 and no prior prostate cancer diagnosis. Logistic regression was used to examine the association of race ethnicity with the use of PSA testing and, if tested, with an abnormal result (≥4 ng/mL) adjusted for demographics, health care, and clinical factors. Time to a follow-up activity after an abnormal PSA was assessed using Cox proportional models.

RESULTS

The race ethnicity of this cohort was 63% Hispanic, 27% non-Hispanic white, 7% African-American, and 3% other. In a 3-year period, 26.8% of men had at least one PSA test. Compared with African-Americans, non-Hispanic whites were less likely to be tested [OR, 0.68; 95% confidence interval (CI), 0.55-0.83] but Hispanics did not differ (OR = 0.95; 95% CI 0.79-1.15). African-Americans were more likely to have an abnormal PSA than others (12.4% vs. 5.2%, P < 0.001) and the shortest adjusted time to follow-up (P = 0.004).

CONCLUSIONS

In this 3-year indigent cohort, about one quarter had a PSA test, approximately half of the national testing rate.

IMPACT

African-Americans were more likely to be tested than non-Hispanic whites but had more abnormal results, raising concerns about missed prevention opportunities. African-Americans with high PSA results had the shortest time until follow-up, reflecting awareness of the threat of prostate cancer for African-Americans by physicians.

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.

Biomarkers in prostate cancer epidemiology

Understanding the etiology of a disease such as prostate cancer may help in identifying populations at high risk, timely intervention of the disease, and proper treatment. Biomarkers, along with exposure history and clinical data, are useful tools to achieve these goals. Individual risk and population incidence of prostate cancer result from the intervention of genetic susceptibility and exposure. Biochemical, epigenetic, genetic, and imaging biomarkers are used to identify people at high risk for developing prostate cancer. In cancer epidemiology, epigenetic biomarkers offer advantages over other types of biomarkers because they are expressed against a person's genetic background and environmental exposure, and because abnormal events occur early in cancer development, which includes several epigenetic alterations in cancer cells. This article describes different biomarkers that have potential use in studying the epidemiology of prostate cancer. We also discuss the characteristics of an ideal biomarker for prostate cancer, and technologies utilized for biomarker assays. Among epigenetic biomarkers, most reports indicate GSTP1 hypermethylation as the diagnostic marker for prostate cancer; however, NKX2-5, CLSTN1, SPOCK2, SLC16A12, DPYS, and NSE1 also have been reported to be regulated by methylation mechanisms in prostate cancer. Current challenges in utilization of biomarkers in prostate cancer diagnosis and epidemiologic studies and potential solutions also are discussed.

Interactions among genes, tumor biology and the environment in cancer health disparities: examining the evidence on a national and global scale

Cancer incidence and mortality rates show great variations across nations and between population groups. These variations are largely explained by differences in age distribution, diet and lifestyle, access to health care, cultural barriers and exposure to carcinogens and pathogens. Cancers caused by infections are significantly more common in developing than developed countries, and they overproportionally affect immigrant populations in the USA and other countries. The global pattern of cancer is not stagnant. Instead, it is dynamic because of fluctuations in the age distribution of populations, improvements in cancer prevention and early detection in affluent countries and rapid changes in diet and lifestyle in parts of the world. For example, increased smoking rates have caused tobacco-induced cancers to rise in various Asian countries, whereas reduced smoking rates have caused these cancers to plateau or even begin to decline in Western Europe and North America. Some population groups experience a disproportionally high cancer burden. In the USA and the Caribbean, cancer incidence and mortality rates are excessively high in populations of African ancestry when compared with other population groups. The causes of this disparity are multifaceted and may include tumor biological and genetic factors and their interaction with the environment. In this review, we will discuss the magnitude and causes of global cancer health disparities and will, with a focus on African-Americans and selected cancer sites, evaluate the evidence that genetic and tumor biological factors contribute to existing cancer incidence and outcome differences among population groups in the USA.