High bone density is associated with prostate cancer in older Afro-Caribbean men: Tobago prostate survey

Prostate cancer metastasis and health disparities: a systematic review

BACKGROUND

Prostate cancer (PCa), one of the most prevalent malignancies affecting men, significantly contributes to increased mortality rates worldwide. While the causative death is due to advanced metastatic disease, this occurrence disproportionately impacts men of African descent compared to men of European descent. In this review, we describe potential mechanisms underlying PCa metastases disparities and current treatments for metastatic disease among these populations, differences in treatment outcomes, and survival rates, in hopes of highlighting a need to address disparities in PCa metastases.

METHODS

We reviewed existing literature using databases such as PubMed, Google Scholar, and Science Direct using the following keywords: "prostate cancer metastases", "metastatic prostate cancer disparity", "metastatic prostate cancer diagnosis and treatment", "prostate cancer genetic differences and mechanisms", "genetic differences and prostate tumor microenvironment", and "men of African descent and access to clinical treatments". The inclusion criteria for literature usage were original research articles and review articles.

RESULTS

Studies indicate unique genetic signatures and molecular mechanisms such as Epithelial-Mesenchymal Transition (EMT), inflammation, and growth hormone signaling involved in metastatic PCa disparities. Clinical studies also demonstrate differences in treatment outcomes that are race-specific, for example, patients of African descent have a better response to enzalutamide and immunotherapy yet have less access to these drugs as compared to patients of European descent.

CONCLUSIONS

Growing evidence suggests a connection between a patient's genetic profile, the prostate tumor microenvironment, and social determinants of health that contribute to the aggressiveness of metastatic disease and treatment outcomes. With several potential pathways highlighted, the limitations in current diagnostic and therapeutic applications that target disparity in PCa metastases warrant rigorous research attention.

Bone mineral density in Nigerian men on androgen deprivation therapy for advanced prostate cancer

Background

Cancer of the prostate (CaP) is the most frequently diagnosed non-cutaneous malignancy worldwide, and it is the second leading cause of death from cancer in men. In the developing world, majority of patients with CaP present in advanced stage and often times, androgen deprivation therapy (ADT) is the only treatment option available. ADT has been reported to increase the risk of osteopenia and osteoporosis in patients with CaP in studies done predominantly among the Caucasians. There is a dearth of report of the effect of ADT on CaP in the black population most especially Nigerian population despite our high incidence of CaP. The aim of this study was to determine the effect of advanced CaP and its treatment using ADT on bone mineral density (BMD) in our patients.

Results

The age of the patients ranged from 54 to 88 years (mean 70.15 ± 6.7) and 50 to 85 years (mean 68.92 ± 8.5) for the case and control groups, respectively. The mean BMD of the control group (0.26 ± 1.5) was significantly higher than the case group pre-ADT (− 0.78 ± 1.7) (p = 0.044). Post-ADT, the BMD was significantly lower (− 1.15 ± 1.7) than pre-ADT (p = 0.001) among the case group.

Conclusion

Advanced CaP was found to be associated with a decrease in BMD, and ADT was associated with a further decline in the BMD. Therefore, prevention and treatment of skeletal-related events is vital in management of patients with advanced CaP.

Disparities in prostate cancer incidence and mortality rates: Solvable or not?

Prostate cancer (PCa) is recognized as a disease possessing not only great variation in its geographic and racial distribution but also tremendous variation in its potential to cause morbidity and death and it, therefore, ought not to be considered a homogenous disease entity. Morbidity and death from PCa are disproportionately higher in men of African ancestry (MAA) who are generally observed to have more aggressive disease and worse outcomes following treatment compared to men of European ancestry (MEA). The higher rates of PCa among MAA relative to MEA appear to be multifactorial and related to inherent differences in biological aggressiveness; a continued lack of awareness of the disease and methods of prevention; a lower prevalence of screen-detected PCa; comparatively lower access to quality healthcare as well as systemic and institutionalized disparities in the administration of optimal care to MAA in developed countries such as the United States of America where high-quality care is available. Even when access to quality healthcare is assured in equal access settings, it appears that MAA still have worse outcomes after PCa treatment stage-for-stage and grade-for-grade compared to MEA, suggesting that, inherent racial, ethnic and biological differences are paramount in predicting poor outcomes. This review has explored the different contributing factors to the current disparities in PCa incidence and mortality rates with emphasis on the incongruence in how research has been conducted in understanding the disease towards developing therapies.

Cancer-bone microenvironmental interactions promotes STAT3 signaling

Prostate cancer (PCa) patients' mortality is mainly attributed to complications caused by metastasis of the tumor cells to organs critical for survival, such as bone. We hypothesized that PCa cell-bone interactions would promote paracrine signaling. A panel of PCa cell lines were cocultured with hydroxyapatite ([HA]; inorganic component of bone) of different densities. Conditioned media (CM) was collected and analyzed for calcium levels and effect on paracrine signaling, cell migration, and viability in vitro and in vivo. Our results showed that calcium levels were elevated in CM from cancer cell-bone cocultures, compared to media or cancer cells alone, and this could be antagonized by ethylene glycol-bis(2-aminoethyl ether)N,N,N',N'-tetraacetic acid (EGTA), a calcium chelator, or knockdown of Snail protein. We also observed increased signal transducer and activator of transcription 3 (STAT3) phosphorylation and paracrine cell proliferation and migration in LNCaP cells incubated with CM from various cell lines; this phosphorylation and cell migration could be antagonized by Snail knockdown or various inhibitors including EGTA, STAT3 inhibitor (WP1066) or cathepsin L inhibitor (Z-FY-CHO). In vivo, higher HA bone density increased tumorigenicity and migration of tumor cells to HA implant. Our study shows that cancer-bone microenvironment interactions lead to calcium-STAT3 signaling, which may present an area for therapeutic targeting of metastatic PCa.

Global Trends and Prostate Cancer: A Review of Incidence, Detection, and Mortality as Influenced by Race, Ethnicity, and Geographic Location

Although research has reported that prostate cancer (PCa) incidence and mortality rates are among the highest for African Americans, the data is inconclusive regarding PCa rates in native African men, Black men residing in other countries, and men in Asia, Europe, and the Americas. Data reveals that prostate-specific antigen (PSA) testing and disease incidence have risen significantly in developing and Asian countries, and PCa has become one of the leading male cancers in many of those nations. The objective of this study was to review published peer-reviewed studies that address PCa in different regions of the world to get a better understanding of how PCa incidence, prevalence, detection, and mortality are influenced by race, ethnicity, and geography. A secondary goal was to compare PCa data from various world regions to contextualize how disproportionate the incidence and mortality rates are among men from the African diaspora versus men of European, Hispanic, and Asian descent, as well as to highlight the need for more robust screening and treatment guidelines in developing countries. There are differences in incidence and mortality rates between men of African, Asian, Hispanic, and European ancestry, confirming the involvement of genetic factors. However, differences between men of the same race and ethnicity who live in different countries suggest that environmental factors may also be implicated. Availability and access to diagnostic and health-care services as well as recommendations regarding PCa testing vary from country to country and contribute to the variability in incidence and mortality rates.

Cancer risk in patients with osteoporosis: a population-based cohort study

BACKGROUND

Osteoporosis has been associated with cancer development. We conducted a nationwide population-based cohort study in Taiwan to evaluate this possible association of osteoporosis with subsequent cancer development.

METHODS

A total of 35,979 patients diagnosed with osteoporosis between 2000 and 2010 identified from the National Health Insurance Research Database comprised the osteoporosis cohort, and each patient was randomly frequency matched with one individual from the general population (without osteoporosis) based on age, sex, and year of osteoporosis diagnosis to form the non-osteoporosis (control) cohort. Cox proportional hazard regression analysis was used to calculate adjusted hazard ratios and 95% confidence intervals and determine the effect of osteoporosis on cancer risk.

RESULTS

Patients with osteoporosis showed a significantly higher risk of developing liver and thyroid cancers and lower risk of colorectal cancer than did individuals without osteoporosis. Male patients with osteoporosis had a significantly increased risk for liver cancer, whereas female patients with osteoporosis had a significantly increased risk for thyroid cancer, but a significantly decreased risk for overall and colorectal cancers. In addition, more significant findings were observed when age ≤64 years or the follow-up duration was ≤5 years; however, a significantly lower risk for colorectal cancer was observed when follow-up duration was >5 years. Study limits including lack of data for some health-related behaviors, inclusion criteria of osteoporosis and potential selection bias have been discussed.

CONCLUSION

Patients with osteoporosis showed a higher risk for liver and thyroid cancers and a lower risk for colorectal cancer than did control individuals. Stratified analyses by sex, age, and follow-up duration showed various patterns in different cancers.

Bone mineral content and prostate cancer risk: data from the Baltimore Longitudinal Study of Aging

STUDY TYPE

Aetiology (inception cohort) Level of Evidence 2b.

OBJECTIVE

To determine whether there might be differences in bone mineral content (BMC) between men who develop life-threatening prostate cancer and those who do not, as bone is a common site of prostate cancer metastases.

SUBJECTS AND METHODS

From 1973 to 1984, BMC was serially measured in 519 participants (778 observations) as part of a longitudinal study of ageing. We examined the association between serial BMC measurements with the development of overall and high-risk prostate cancer over the next one to three decades. For all prostate cancer cases, BMC was censored at the time of diagnosis.

RESULTS

During a median (range) overall follow-up of 21.1 (0.2-35.0) years after the last BMC measurement, 76 (14.6%) men were later diagnosed with prostate cancer (18 high-risk and 58 not high-risk). BMC declined with age to a greater extent in healthy controls than among men diagnosed with prostate cancer (P = 0.018, likelihood ratio test), and tended to decline less in high-risk than non-high-risk cases.

CONCLUSION

The distribution of BMC was significantly different between men who did and did not develop prostate cancer, over an extended follow-up. Specifically, BMC appeared to decline to a greater extent with age among healthy controls than in men with prostate cancer, especially high-risk disease. The biology underlying the lesser decline in BMC among men with prostate cancer remains unclear, but suggests that host factors in the bony milieu might be associated with prostate cancer development and progression.

The association of bone mineral density with prostate cancer risk in the Osteoporotic Fractures in Men (MrOS) Study

We investigated the association of bone mineral density (BMD) measures with prostate cancer (PCa) risk in older men enrolled in the Osteoporotic Fractures in Men Study. We hypothesized that men with higher BMD, a marker of exposure to endogenous sex hormones, would have an increased incidence of PCa. The cohort included 4,597 men (89% White, 65 years or older) with no prior history of PCa. Baseline total body, total hip, and spine BMD were assessed using dual energy X-ray absorptiometry. Prostate cancer was confirmed by review of medical records. Cox regression was used to assess the association of BMD quartiles with incident PCa, adjusting for age, body mass index, and other covariates. During an average follow-up of 5.2 years, 5.6% (n = 255) of men developed PCa. Total body BMD was inversely associated with incident PCa, with a significant trend for decreasing PCa risk with increasing BMD quartiles (P(trend) = 0.007). Men in the highest total body BMD quartile had a 41% reduced risk for PCa (hazard ratio, 0.59; 95% confidence interval, 0.40-0.86), compared with men in the lowest quartile. Total hip and spine BMD did not exhibit significant relationships with PCa. Associations of BMD measures differed for low-grade (Gleason sum, 2-6) versus high-grade tumors (Gleason sum, >or=7). Significant inverse relationships with high-grade disease were noted at the total body and total hip sites. However, no associations were observed with low-grade disease. Our results provide support for an inverse association between BMD and PCa risk. Possible pathophyisological mechanisms linking BMD and PCa should be elucidated.

Functional characterization of genetic variation in the Frizzled 1 (FZD1) promoter and association with bone phenotypes: more to the LRP5 story?

WNT signaling is an important determinant of bone formation. The WNT co-receptor, Frizzled homolog 1 (FZD1), initiates WNT signal transduction. To study the influence of FZD1 genetic variation on measures of bone health, we first sequenced a 6.8-kb region surrounding FZD1 in 48 samples of African ancestry. We genotyped all common polymorphisms and performed association analysis with bone phenotypes in a larger sample. Only 3 of 35 SNPs identified were present in >or=5% of the sample and assayed further in 1084 men of African ancestry. Two of these SNPs were in the FZD1 promoter (rs2232157, rs2232158) and were associated with femoral neck areal BMD (p = 0.041 and 0.009, respectively). The minor alleles of these two SNPs were also associated with larger bone size at the radius (p < 0.05 for both), and rs2232158 was associated with greater strength-strain index, an indicator of bone's ability to withstand torsion. Functional experiments were completed to assess the influence of the rs2232158 promoter polymorphism on transcriptional regulation of FZD1. The minor C allele in rs2232158 creates a binding site for the transcription factor Egr1, has higher Egr1 binding affinity, and has greater FZD1 promoter activity in MG63 and SaOS-2 cells, providing a plausible molecular mechanism for the population associations. This study indicates that a cis-regulatory polymorphism in the FZD1 promoter region may have a functional role in determining bone structural geometry.

Risks of cancer among a cohort of 23,935 men and women with osteoporosis

Low hormone levels among persons with osteoporosis may decrease risk of some cancers. Other osteoporosis risk factors, such as smoking and alcohol consumption, however, may increase risk. As these deleterious factors are more often associated with osteoporosis diagnosed prior to age 70 years, cancer risk may be higher in these younger persons than in the general population. To examine this hypothesis, a cohort study of 23,935 persons with osteoporosis was conducted in Denmark. Patients hospitalized with osteoporosis between 1978 and 1993 were identified in the Danish Inpatient Register. Linkage to the Danish Cancer Registry identified all cancer outcomes through 2003. Standardized incidence ratios (SIR) and 95% confidence intervals (95%CI) were calculated to compare cancer incidence in the cohort with that in the general population. Persons diagnosed prior to age 70 years were at increased cancer risk (women: SIR = 1.11, 95%CI = 1.04-1.19; men: SIR = 1.31, 95%CI = 1.13-1.50) due, in part, to increased risks of cancers of the buccal cavity, esophagus, liver, pancreas and lung. Persons diagnosed at ages 70 and older were at decreased risk (women: SIR = 0.91, 95%CI = 0.87-0.96; men: SIR = 0.89, 0.77-1.01) due, in part, to decreased risks of breast, endometrial, colon, rectal and brain cancers in women and prostate cancer in men. These results suggest that risk factors associated with earlier onset osteoporosis may be associated with increased risk of cancer. Conversely, factors associated with later onset osteoporosis may be related to a decreased risk of cancer.

African-Caribbean cancer consortium for the study of viral, genetic and environmental cancer risk factors

This is a short summary of a meeting of the "African-Caribbean Cancer Consortium", jointly organized by the University of Pittsburgh, Department of Epidemiology and the University of Pittsburgh Cancer Institute, held in Montego Bay, Jamaica as a satellite meeting at the Caribbean Health Research Council, 52^nd Annual Council and Scientific meeting on May 4, 2007.