Bone mass and the risk of prostate cancer: the Framingham Study

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.

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.

Fracture risk in men with prostate cancer: a population-based study

Fractures are increased among men with prostate cancer, especially those on androgen-deprivation therapy (ADT), but few data are available on men with localized prostate cancer. The purpose of this investigation was to estimate fracture risk among unselected community men with prostate cancer and systematically assess associations with ADT and other risk factors for fracture. In a population-based retrospective cohort study, 742 Olmsted County, MN, men with prostate cancer first diagnosed in 1990-1999 (mean age 68.2 ± 8.9 years) were followed for 6821 person-years. We estimated cumulative fracture incidence, assessed relative risk by standardized incidence ratios, and evaluated risk factors in time-to-fracture regression models. All together, 482 fractures were observed in 258 men (71 per 1000 person-years). Overall fracture risk was elevated 1.9-fold, with an absolute increase in risk of 9%. Relative to rates among community men generally, fracture risk was increased even among men not on ADT but was elevated a further 1.7-fold among ADT-treated compared with untreated men with prostate cancer. The increased risk following various forms of ADT was accounted for mainly by associations with pathologic fractures (14% of all fractures). Among men not on ADT (62% of the cohort), more traditional osteoporosis risk factors were implicated. In both groups, underlying clinical characteristics prompting different treatments (indication bias) may have been partially responsible for the associations seen with specific therapies. To the extent that advanced-stage disease and pathologic fractures account for the excess risk, the effectiveness of fracture prevention among men with prostate cancer may be limited.

How pleiotropic genetics of the musculoskeletal system can inform genomics and phenomics of aging

Genetic study can provide insight into the biologic mechanisms underlying inter-individual differences in susceptibility to (or resistance to) organisms' aging. Recent advances in molecular genetics and genetic epidemiology provide the necessary tools to perform a study of the genetic sources of biological aging. However, to be successful, the genetic study of a complex condition requires a heritable phenotype to be developed and validated. Genome-wide association studies offer an unbiased approach to identify new candidate genes for human diseases. It is hypothesized that convergent results from multiple aging-related traits will point out the genes responsible for the general aging of the organism. This perspective focuses on the musculoskeletal aging as an example of an approach to identify a downstream common pathway that summarizes aging processes. Since the musculoskeletal traits are linked to the state of many vital functions, disability, and ultimately survival rates, we postulate that there is significance in studying musculoskeletal aging. Construction of an integrated phenotype of aging can be achieved based on shared genetics among multiple musculoskeletal biomarkers. Valid biomarkers from other systems of the organism should be similarly explored. The new composite aging score needs to be validated by determining whether it predicts all-cause mortality, incidences of major chronic diseases, and disability late in life. Comprehensive databases on biomarkers of musculoskeletal aging in multiple large cohort studies, along with information on various health outcomes, are needed to validate the proposed measure of biological aging.

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.

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.

Fine mapping of familial prostate cancer families narrows the interval for a susceptibility locus on chromosome 22q12.3 to 1.36 Mb

Genetic studies suggest that hereditary prostate cancer is a genetically heterogeneous disease with multiple contributing loci. Studies of high-risk prostate cancer families selected for aggressive disease, analysis of large multigenerational families, and a meta-analysis from the International Consortium for Prostate Cancer Genetics (ICPCG), all highlight chromosome 22q12.3 as a susceptibility locus with strong statistical significance. Recently, two publications have narrowed the 22q12.3 locus to a 2.18 Mb interval using 54 high-risk families from the ICPCG collaboration, as defined by three recombination events on either side of the locus. In this paper, we present the results from fine mapping studies at 22q12.3 using both haplotype and recombination data from 42 high-risk families contributed from the Mayo Clinic and the Prostate Cancer Genetic Research Study (PROGRESS) mapping studies. No clear consensus interval is present when all families are used. However, in the subset of 14 families with >/=5 affected men per family, a 2.53-Mb shared consensus segment that overlaps with the previously published interval is identified. Combining these results with data from the earlier ICPCG study reduces the three-recombination interval at 22q12.3 to approximately 1.36 Mb.

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

OBJECTIVE

To test the hypothesis that bone mineral density (BMD), a possible surrogate of lifetime exposure to hormone/growth factor/vitamin D/calcium exposure, is higher in prostate cancer cases than controls.

METHODS

Hip BMD was measured by dual X-ray absorptiometry in 222 Afro-Caribbean screening-detected prostate cancer cases and 1,503 screened non-cases, aged 45-79, in the population-based Tobago Prostate Survey. Because possible skeletal metastases may modulate BMD, men with prostate specific antigen >20 ng/ml or highly undifferentiated tumors (Gleason score > or = 8) were excluded. Mean BMD, adjusted for age and body mass index, was compared in cases and non-cases by analysis of variance. Risk across age group-specific BMD quartiles was compared using logistic regression.

RESULTS

Overall, adjusted mean hip BMD was higher in cases (1.157 g/cm2) than non-cases (1.134 g/cm2) (p = 0.02). In men aged 60-79, prostate cancer risk was two-fold higher (OR, 2.12; 95% CI: 1.21-3.71) in the highest BMD quartile compared to the lowest. There was no association in younger men (interaction, p = 0.055).

CONCLUSIONS

High bone density is associated with prostate cancer among older men, consistent with an etiological role for lifetime exposure to factors which modulate bone density. However, other etiologies may dominate prostate cancer risk among younger men.

A prospective study of calcium intake and incident and fatal prostate cancer

Prostate cancer is the most common incident cancer and the second leading cause of cancer mortality in U.S. males. Higher milk intake has been relatively consistently associated with an increased risk of prostate cancer, especially advanced prostate cancer. Some data suggest that high intake of calcium might account for this association, but this relationship remains controversial. We hypothesized that high calcium intake, possibly by lowering 1,25(OH)2 vitamin D levels, is associated with poorer differentiation in prostate cancer and thereby with fatal prostate cancer. We examined calcium intake in relation to prostate cancer risk using data from the Health Professionals Follow-up Study, a prospective cohort study of 47,750 male health professionals with no history of cancer other than nonmelanoma skin cancer at baseline. We assessed total, dietary, and supplementary calcium intake in 1986, 1990, 1994, and 1998, using a validated food frequency questionnaire. We calculated the multivariable relative risk (RR) and 95% confidence intervals (95% CI) using Cox proportional hazards regression. Over 16 years of follow-up, we identified 3,544 total cases of prostate cancer, 523 advanced (extraprostatic) cases, and 312 fatal cases. Higher calcium intake was not appreciably associated with total or nonadvanced prostate cancer but was associated with a higher risk of advanced and fatal prostate cancer [for fatal prostate cancer, compared with men whose long-term calcium intake was 500-749 mg/d (excluding supplement use of <5 years); those with intakes of 1,500-1,999 mg/d had a RR, 1.87; 95% CI, 1.17-3.01; and those with > or = 2,000 mg/d had a RR, 2.43; 95% CI, 1.32-4.48; P(trend) = 0.003]. Dietary calcium and supplementary calcium were independently associated with an increased risk. For high-grade prostate cancer (Gleason > or = 7), an association was observed for high versus low calcium intake (RR, 1.89; 95% CI, 1.32-2.71; P(trend) = 0.005), but a nonsignificant, inverse association was observed for organ-confined, low-grade prostate cancer (RR, 0.79; 95% CI, 0.50-1.25; P(trend) = 0.09). In a sample of this cohort, higher calcium intake was associated with lower circulating 1,25(OH)2 vitamin D levels. Our findings suggest that calcium intakes exceeding 1,500 mg/d may be associated with a decrease in differentiation in prostate cancer and ultimately with a higher risk of advanced and fatal prostate cancer but not with well-differentiated, organ-confined cancers.

Hand workload and the metacarpal cortical index. a study of middle-aged teachers and dentists

We studied load-related predictors (handedness, occupation and workload history) of cortical bone mass as estimated by the metacarpal cortical index (MCI). After being randomly selected from trade-union registers, 295 female dentists and 248 teachers, aged 45-63 years (mean 54 years), participated in the study. The MCI was defined from the second metacarpal of both hands by analogue radiographs. Data regarding anthropometric measures, handedness, occupational exposure, number of pregnancies, hormonal therapy and contraceptive use, the presence of chronic diseases, dietary factors, smoking and leisure time physical activity were collected by questionnaire. Weight was measured. The dentists' workload was assessed in detail in 10-year periods. Multivariate methods were used in the statistical analysis. The metacarpal index averaged 0.62 in the right hand and 0.61 in the left hand (P = 0.02) among the right-handed subjects, while no differences by hand were observed among the left-handed or mixed-handed. The MCI of the teachers and dentists did not differ from each other, when we controlled for potential confounders. The MCI decreased similarly by age in both occupational groups. Among the dentists, workload history was inversely associated with the MCI in multivariate analyses by age group. Computer use was a positive predictor for MCI among dentists aged 55-63 years. Occupational factors seem to have contradictory effects on the MCI. Too heavy or one-sided manual work may be deleterious for cortical bone mass.

Diet and cancer prevention

Dietary effects are presumed to underlie many of the large international differences in incidence seen for most cancers. Apart from alcohol and a few micronutrients, however, the role of specific nutritional factors remains ill-defined. The evidence for a role of energy balance, physical inactivity, and obesity has strengthened, while for dietary fat it has weakened. Phytochemicals such as folate, lycopene and flavonoids are still the subject of active research. As the mechanisms underlying human carcinogenesis are better understood, dietary research will focus increasingly on intermediate markers such as the insulin-like growth factors and potentially carcinogenic metabolites.

High levels of circulating insulin-like growth factor-I increase prostate cancer risk: a prospective study in a population-based nonscreened cohort

PURPOSE

Insulin-like growth factor-I (IGF-I) stimulates proliferation and inhibits apoptosis in prostate cancer cells, and IGF-I has been associated with increased prostate cancer risk in some, but not all, epidemiologic studies.

SUBJECTS AND METHODS

We extended our previous case-control study nested in the Northern Sweden Health and Disease Cohort, a population-based cohort from a region where little prostate specific antigen (PSA) screening is done. Levels of IGF-I and IGF binding protein-3 (IGFBP-3) were measured in prediagnostic blood samples from a total of 281 men who were subsequently diagnosed with prostate cancer after recruitment (median, 5 years after blood collection) and from 560 matched controls.

RESULTS

Logistic regression analyses showed increases in prostate cancer risk with increasing plasma peptide levels, up to an odds ratio (OR) for top versus bottom quartile of IGF-I of 1.67 (95% CI, 1.02 to 2.71; Ptrend = .05), which was attenuated after adjustment for IGFBP-3 to an OR of 1.47 (95% CI, 0.81 to 2.64; P (trend) =.32). For men younger than 59 years at recruitment, OR for top versus bottom quartile of IGF-I was 4.12 (95% CI, 1.01 to 16.70; Ptrend = .002), which was significantly stronger than for men older than 59 years (P (interaction) = .006). For men with advanced cancer, OR for top versus bottom quartile of IGF-I was 2.87 (95% CI, 1.01 to 8.12; Ptrend = .10).

CONCLUSION

Our data add further support for IGF-I as an etiologic factor in prostate cancer and indicate that circulating IGF-I levels measured at a comparatively young age may be most strongly associated with prostate cancer risk.

A Multicountry Ecologic Study of Risk and Risk Reduction Factors for Prostate Cancer Mortality

OBJECTIVE

The objective of this research is to identify and determine the relative importance of dietary and environmental risk and risk reduction factors for prostate cancer mortality.

MATERIALS AND METHODS

A multicountry ecologic approach was used in multivariate regression analyses with prostate cancer mortality rates and dietary factors and solar ultraviolet-B (UV-B) radiation. Prostate cancer mortality rates for 32 predominantly Caucasian countries for the late 1990s were obtained from the World Health Organization. Dietary supply data were obtained from the Food and Agriculture Organization. Annual solar UV-B dose data were obtained from European ground stations and used to estimate values elsewhere. Linear and multiple linear regression analyses were conducted for all 32 countries as well as the 20 European countries.

RESULTS

The strongest risk factor for prostate cancer mortality was animal products, with the nonfat portion of milk and alcohol being somewhat weaker; the strongest risk reduction factors were onions, other protective vegetable products (excluding alcohol, oils, and sweeteners), and solar UV-B radiation. Dietary data for 1979-81 yielded the highest correlations.

CONCLUSIONS

These results are consistent with insulin-like growth factor-I (IGF-I), being an important risk factor for prostate cancer, with alcohol and calcium being less important risk factors, and with allium family vegetables, and, to a lesser extent, vitamin D being important risk reduction factors. These results should provide guidance for additional studies on dietary and environmental links to prostate cancer.

Epidemiology of prostate cancer

Prostate cancer incidence and mortality rates vary worldwide. In the United States, prostate cancer is the most common malignancy affecting men and is the second-leading cause of cancer death. Risk of developing prostate cancer is associated with advancing age, African American ethnicity, and a positive family history, and may be influenced by diet and other factors. The incidence of prostate cancer increased sharply after the introduction of widespread screening for prostate-specific antigen (PSA), although rates have now returned to levels seen before that time. PSA screening has been associated with a shift toward diagnosis of earlier-stage disease, but this has not been accompanied by a shift toward a lower histologic grade. Although overall prostate cancer mortality rates decreased during the 1990s, it was largely because of reductions in deaths among men diagnosed with distant disease. In contrast, mortality rates for men diagnosed with localized or regional disease increased gradually during most of the 1990s before decreasing slightly among white men and reaching plateaus among African Americans.