An analysis of the association between prostate cancer risk loci, PSA levels, disease aggressiveness and disease-specific mortality

BACKGROUND

Genome-wide association studies have identified multiple single-nucleotide polymorphsims (SNPs) associated with prostate cancer (PCa). Although these SNPs have been clearly associated with disease risk, their relationship with clinical outcomes is less clear. Our aim was to assess the frequency of known PCa susceptibility alleles within a single institution ascertainment and to correlate risk alleles with disease-specific outcomes.

METHODS

We genotyped 1354 individuals treated for localised PCa between June 1988 and December 2007. Blood samples were prospectively collected and de-identified before being genotyped and matched to phenotypic data. We investigated associations between 61 SNPs and disease-specific end points using multivariable analysis and also determined if SNPs were associated with PSA at diagnosis.

RESULTS

Seven SNPs showed associations on multivariable analysis (P<0.05), rs13385191 with both biochemical recurrence (BR) and castrate metastasis (CM), rs339331 (BR), rs1894292, rs17178655 and rs11067228 (CM), and rs11902236 and rs4857841 PCa-specific mortality. After applying a Bonferroni correction for number of SNPs (P<0.0008), the only persistent significant association was between rs17632542 (KLK3) and PSA levels at diagnosis (P=1.4 × 10(-5)).

CONCLUSIONS

We confirmed that rs17632542 in KLK3 is associated with PSA at diagnosis. No significant association was seen between loci and disease-specific end points when accounting for multiple testing. This provides further evidence that known PCa risk SNPs do not predict likelihood of disease progression.

Disseminating results: community response and input on Kisumu breastfeeding study

Communicating findings to study participants and their communities is a practice that often gets overlooked or receives low prioritization by research investigators, but is crucially important. The purpose of this study was to describe the process and community response to the dissemination of results from the Kisumu Breastfeeding Study (KiBS), specifically in terms of (1) community research knowledge and expectations and (2) impressions of result dissemination efforts. A qualitative evaluation was completed for 10 result dissemination events using focus group discussions (FGDs) (n = 10; total number of participants = 98). An inductive, thematic qualitative data analysis was completed in NVivo 8.0. Overall, FGD participants expressed great appreciation for being given information on the study results. Participants had a good understanding of what research entails and had specific expectations for the process, including that the community receive information about the study, not only at the end of the study but also at regular intervals throughout the study's conduct. They also wanted to receive the communications from a credible source, the principal investigator preferably. Other expectations centered on better community and research interactions and development and the use of community collaborators. Impressions of KiBS result dissemination events were positive, but suggestions for the future included having the event in a larger area, inviting more people, having more written materials, and putting the information in an entertaining format such as skits or movies. Sharing study findings with local community members is essential and beneficial to the researchers' long-term engagement with communities and importantly, the successful implementation of study findings when appropriate. It is imperative that dissemination of results be embedded as an integral part of research project planning and development.

Aspirin therapy is associated with less compact fibrin networks and enhanced fibrinolysis in patients with abdominal aortic aneurysm

OBJECTIVE

Thrombotic changes in fibrin networks contribute to increased cardiovascular risk in patients with abdominal aortic aneurysm (AAA). Given that aspirin modulates the fibrin network, we aimed to determine if aspirin therapy is associated with changes in ex-vivo fibrin clot characteristics in AAA patients and also conducted an exploratory analysis of 5-year mortality in these individuals.

METHODS

We recruited 145 male patients, divided into controls (aortic diameter < 3 cm, n = 49), AAA not taking aspirin (AAA-Asp, n = 50) and AAA on 75 mg day(-1) aspirin (AAA+Asp, n = 46), matched for aneurysm size. Characteristics of clots made from plasma and plasma-purified fibrinogen were investigated using turbidimetric analysis, permeation studies, and confocal and electron microscopy. Plasma fibrinogen, D-dimer and inflammatory marker levels were also measured.

RESULTS

Maximum absorbance (MA) of plasma clots from controls was lower than that of AAA patients not on aspirin (AAA-Asp) at 0.30 ± 0.01 and 0.38 ± 0.02 au, respectively (P = 0.002), whereas aspirin-treated subjects had MA similar to controls (0.31 ± 0.02 P = 0.9). Plasma clot lysis time displayed an identical pattern at 482 ± 15, 597 ± 24 and 517 ± 27 s for control, AAA-Asp and AAA+Asp (P = 0.001 and P = 0.8). The lysis time of clots made from purified fibrinogen of AAA-Asp was longer than that of AAA+Asp patients (756 ± 47 and 592 ± 52 s, respectively; P = 0.041). Permeation studies and confocal and electron microscopy showed increased clot density in AAA-Asp compared with the AAA+Asp group. Mortality in AAA-Asp and AAA+Asp was similar, despite increased cardiovascular risk in the latter group, and both exhibited higher mortality than controls.

CONCLUSION

Aspirin improves fibrin clot characteristics in patients with AAA, which may have important clinical implications.

HOSPEX in the antipodes

The Australian Army recently adopted the British concept of hospital exercise (HOSPEX) as a means of evaluating the capabilities of its deployable NATO Role 2E hospital, the 2nd General Health Battalion. The Australian approach to HOSPEX differs from the original UK model. This article describes the reasons why the Australian Army needed to adopt the HOSPEX concept, how it was adapted to suit local circumstances and how the concept may evolve to meet the needs of the wider Australian Defence Force and our allies.

Abstract 5578: Breast cancer cell growth regulatory mechanisms of tamoxifen metabolites

The proliferation of estrogen receptor alpha (ERalpha)-positive breast cancer cells is stimulated by estradiol. Tamoxifen [(Z)-2-[4-(1,2-diphenylbut-1-enyl)phenoxy]-N,N-dimethylethanamine] is the most commonly used endocrine treatment for ERalpha-positive breast cancer in pre- and post-menopausal women. Tamoxifen is metabolized to 4-hydroxytamoxifen and endoxifen. ICI 182780 (Faslodex or Fulvestrant) is a pure antiestrogen targeted to the ERalpha. We investigated the effects of endoxifen and 4-hydroxytamoxifen on ERalpha-positive MCF-7 breast cancer cells using cell growth assay, oncogene expression and polyamine regulatory pathways. Polyamines are ubiquitous cellular components and are essential for cell growth and differentiation. Treatment of cells for 1-5 days with 4 nM estradiol increased cells number, whereas the addition of endoxifen, 4-hydroxytamoxifen or ICI 182780 in combination with estradiol suppressed cell growth in a concentration- and time-dependent manner. Real time quantitative polymerase chain reaction (RT-qPCR) experiments showed that the addition of 4 nM estradiol to MCF-7 cells increased the expression of c-myc, c-fos and Tiff1 genes significantly, while the addition endoxifen, 4-hydroxytamoxifen, or ICI 182780 suppressed estradiol-mediated increase in gene expression. Polyamine biosynthetic enzymes were also affected by tamoxifen metabolites. Estradiol increased the activities of the polyamine biosynthetic enzyme, ornithine decarboxlase (ODC) and S-adenosylmethionine decarboxlase (AdoMetDC), whereas the antiestrogens suppressed ODC and AdoMetDC activities in a concentration- and time-dependent manner. However, these agents had little effect on the activity of the polyamine catabolic enzyme, spermidine/spermine N1-acetyl transferase (SSAT). The change in biosynthetic enzyme activities was reflected in polyamine pools, as decreased putrescine and spermidine levels. There was no significant change in spermine level. These results suggest that the mechanism of action of tamoxifen metabolites involves multiple cell growth regulatory pathways. In addition, endoxifen can act as an antiestrogen and suppress cell growth stimulatory effects of estradiol on ERalpha-positive breast cancer cells in a manner similar to that of ICI 182780.

Note: This abstract was not presented at the meeting.

Citation Format: T. Thomas, Huichen Hsu, PingAr Yang, Mervi T. Hyvonen, Tuomo A. Keinanen. Breast cancer cell growth regulatory mechanisms of tamoxifen metabolites. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5578. doi:10.1158/1538-7445.AM2014-5578

Cost-effectiveness analysis of hip fracture prevention with vitamin D supplementation: a Markov micro-simulation model applied to the French population over 65 years old without previous hip fracture

We performed a cost-effectiveness analysis of four vitamin D supplementation strategies for primary prevention of hip fracture among the elderly population and found that the most cost-effective strategy was screening for vitamin D insufficiency followed by adequate treatment to attain a minimum 25(OH) serum level.

INTRODUCTION

Vitamin D supplementation has a demonstrated ability to reduce the incidence of hip fractures. The efficiency of lifetime supplementation has not yet been assessed in the population over 65 years without previous hip fracture. The objective was to analyze the efficiency of various vitamin D supplementation strategies for that population.

METHODS

A Markov micro-simulation model was built with data extracted from published studies and from the French reimbursement schedule. Four vitamin D supplementation strategies were evaluated on our study population: (1) no treatment, (2) supplementation without any serum level check; (3) supplementation with a serum level check 3 months after initiation and subsequent treatment adaptation; (4) population screening for vitamin D insufficiency followed by treatment based on the vitamin D serum level.

RESULTS

"Treat, then check" and "screen and treat" were two cost-effective strategies and dominated "treat without check" with incremental cost-effectiveness ratios of €5,219/quality-adjusted life-years (QALY) and €9,104/QALY, respectively. The acceptability curves showed that over €6,000/QALY, the "screen and treat" strategy had the greatest probability of being cost-effective, and the "no treatment" strategy would never be cost-effective if society were willing to spend over €8,000/QALY. The sensitivity analysis showed that among all parameters varying within realistic ranges, the cost of vitamin D treatment had the greatest effect and yet remained below the WHO cost-effectiveness thresholds.

CONCLUSIONS

Population screening for vitamin D insufficiency followed by treatment based on the vitamin D serum level is the most cost-effective strategy for preventing hip fracture occurrence in the population over 65 years old.

Maintaining a way of life for São Miguel Island (the Azores archipelago, Portugal): an assessment of coastal processes and protection

Traditional hard engineering structures and recently emerging soft engineering alternatives have been employed to protect vulnerable coastlines. Despite negative publicity, they have ensured community survival where socio-economic benefits outweigh adverse impacts. This is especially true for Small Islands (SI) where increasing sea levels and storm intensities threaten already limited land availability. This paper presents coastal vulnerability in São Miguel Island (the Azores SI archipelago) and considers SI issues with regard to coastal land loss. Regional wave statistics using 1998 to 2011 wind record showed: periods ranging from 7 to 13s (circa 83%); wave heights between 1 and 3m (circa 60%); and increasing trends in westerly (p=0.473), easterly (p=0.632) and southeasterly (p=0.932) waves. Sea level analyses between 1978 and 2007 indicated a statistically significant rising trend (2.5 ± 0.4 mm yr(-1); p=0.000), while between 1996 and 2007 it was 3.3 ± 1.5 mm yr(-1) (p=0.025), agreeing with other global sea level studies. Based on 2001 and 2008 population data and using zonal statistics, circa 60% of the Island's population was found to reside within 1 km of the sea and the percentage of total population was linearly correlated with distance from the shoreline (r(2)=99%). Three case studies show hard coastal engineering solutions preserved Azorean coastal lifestyle and had little or no observed negative impacts on their environs. Although hard engineering is likely to remain a valuable and feasible coastal protection option, an inventory of São Miguel's population distribution, surf breaks, bathymetry and coastal erosion rates showed the potential of using multifunctional artificial reefs as a soft engineering solution. These offshore submerged breakwaters offer coastal protection while providing additional benefits such as surfing amenity and beach widening. Consequently, findings of this work can inform other SI communities.