Abstract P3-10-02: Circulating miRNA Signature: Potential Screening and Prognostic Tool for Breast Cancer

Introduction: Genetic profiling of breast tumors revolutionized the classification of breast cancer and unravelled the complexity of this phenotypically diverse disease. However there appears to be discordance between the various mRNA-based single sample predictors which stratify tumors into subgroups. Clinical decision making based on a tumor's mRNA expression is therefore concerning. The potential of mi(cro) RNAs as novel tumor markers has been the focus of recent scrutiny due to their tissue specificity, stability and superiority to mRNA in tumor classification. Additionally, the ability to quantify tumor-associated miRNAs in the circulation and their correlations with clinicopathologic variables, highlights their potential to improve upon existing breast tumor classification methods. Systemic miR-195 and let-7a have been shown to hold properties as breast tumor markers. The aim of this study was to identify a larger panel of miRNAs which augment the sensitivity and specificity of circulating miRNAs as diagnostic and prognostic markers for breast cancer.

Methods: The expression levels of 9 miRNAs were evaluated in 345 preoperative cancer patients including 265 breast cancers and 80 non-breast malignancies, and 63 age-matched disease-free controls using RQ-PCR. MiRNA quantification was also performed on tumor tissue from 83 age and stage matched breast cancer patients. Advanced QBase Plus software and SPSS were used for biostatistical analysis of the data and correlation with clinicopathologic variables.

Results: This study confirmed significantly deranged expression levels of systemic miR-195 and let-7a in an independent validation cohort of breast cancer patients (p < 0.001 and p < 0.001 respectively). In addition miR-181c and miR-342 were identified as breast cancer specific biomarkers. Elevated levels of this 4-miRNA signature in breast cancer patients, including those with in-situ carcinoma, increased the discriminatory power of this test for breast cancer (all types) to 94% (P<0.001).

Circulating levels of these 4 miRNAs correlated with tumor miRNA expression, and decreased to basal levels by 2 weeks following curative tumor resection. Additionally circulating miRNA levels correlated with clinicopathological variables such as tumor size and hormone receptor status. A subset of 2 systemic miRNAs was predictive of the Luminal A subtype of breast cancer (ER/PR positive, Her2/neu negative) with 91% accuracy.

Conclusion: This study validates the recent novel finding of dysregulated tumor-specific miRNAs in the circulation of breast cancer patients. Considering that the sensitivity of mammography is 75-90%, this circulating miRNA signature could improve upon existing breast cancer screening methods, given that it was significantly altered even in patients with in-situ carcinoma. These results indicate that circulating miRNA analysis holds immense potential in the future individualized management of breast cancer patients.

A splice variant of ADAMTS13 is expressed in human hepatic stellate cells and cancerous tissues

Although ADAMTS13, the von Willebrand factor (VWF)-cleaving protease, is expressed in a range of tissues, the physiological significance of tissue-specific ADAMTS13 alternative splicing isoforms have yet to be clarified. Screening a panel of human tissues and cell lines revealed a spliced ADAMTS13 transcript in hepatic stellate cells and a hepatoma cell line that retains the 25th intron. A nonsense codon within the intron truncates the protease, which gains 64 novel amino acids in lieu of both CUB domains. This isoform, while retaining VWF-cleaving capability, accumulates intracellularly and its biological inaccessibility may prevent its participation in regulating haemostasis and other physiologic functions.

Characterisation of 17q12-21 – Identification of Novel Therapeutic Targets

Introduction: Over-expression of the HER2/neu oncogene is associated with poorer clinical outcome in breast cancer. Notwithstanding the success achieved with Trastuzumab in treating HER2/neu positive patients, numerous questions remain. In particular, there are concerns regarding accurate identification of HER2/neu positivity and the correct management of these patients in terms of the dosage, timing and optimal combination of Trastzumab with chemotherapeutic regimens. One approach to answering these questions has been to focus on the area of chromosome 17 in which HER2/neu is located in order to identify other genes in the vicinity. As potential therapeutic targets, we examined the amplification and expression patterns of co-localised cancer-associated genes at the HER2/neu amplicon on chromosome 17.Aims: The primary objective of this study was to examine amplification and expression patterns of co-localised genes at 17q12-21. In doing so, we aimed to establish their relationship with HER2/neu positivity, and then to quantify their relative importance in developing a gene panel predictive of HER2/neu status.Methods: Breast tissue from a cohort of patients with HER2/neu positive (n=48) and negative (n=48) tumours was retrieved at time of surgery. Protein and gene expression levels were determined using immunohistochemistry and RQ-PCR, respectively. Results were analysed to detect patterns of amplification among the genes, namely HER2/neu, STARD3, GRB7, TOP2A, TUBG1, RPL19, LASP1, RARA, and ER Alpha, and to identify associations between expression levels and clinical data. A binary logistic approach and classification tree analysis was employed to determine whether the expression levels of our target genes were useful predictors of HER2/neu status.Results: Strong correlation was noted between expression levels of HER2/neu and multiple cancer-associated genes at 17q12-21, including the novel genes LASP1 (p=0.000) and RPL19 (p=0.000). A significant relationship was also noted between TOP2A and the previously unexplored TUBG1 (p=0.000). Analysis of gene expression patterns according to clinicopathological variables revealed significant associations across intrinsic breast cancer subtypes.Conclusion: This study reaffirms the correlation between HER2/neu and its co-localised genes at 17q12-21, including novel candidate genes LASP1 and RPL19. We have also identified a novel relationship between TOP2A and TUBG1. Furthermore, our work represents a tentative step in the development of more accurate means of characterising HER2/neu status. As such, this work has again indicated the central role which this amplicon may play in selection of patients for treatment, not alone for Herceptin and anthracyclines, but also for taxane-based therapies, and as such, has revealed novel pathways for us to follow as we move towards our goal of individually tailored therapy.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3137.

Bilateral Breast Cancer: Analysis of Incidence, Characteristics and Outcome of the Disease

Background: Despite the widespread adoption of breast conservation therapy in breast cancer, there is a dramatic increase in the rate of bilateral mastectomy in USA. The aim of this study was to address the incidence of bilateral breast cancer (BBC) and to investigate its characteristics, survival and outcome compared to unilateral breast cancer.Methods: Data was acquired from the prospectively maintained NUI Galway breast cancer database between 1988 and 2008. BBC were then categorized as synchronous (within 12 months) or metachronous cancer (after 12 months of first tumour). SPSS was used for data analysis.Results: The incidence of bilateral breast cancer in our population was 4.4% (112 of 2524). Of those 2.1% were synchronous while 2.3% were metachronous. Compared to unilateral cases, bilateral cancer patients were younger (0=0.021) and had smaller size (p=0.001) and earlier stage (p<0.001) tumours at diagnosis. There were no differences in histological type (p=0.630) and grade (p=0.054)). While there was no significant difference in survival for patients with bilateral compared to unilateral tumour (p>0.05), the synchronous bilateral tumour was associated with poor overall survival (p=0.010) and disease free survival (p=0.013) in comparison to metachronous bilateral tumour.Conclusion: We observed significant differences in bilateral tumour characteristics compared to unilateral disease. Although bilateral synchronous tumour was associated with poor outcome and overall survival, patients with metachronous disease do as well as patients with unilateral tumour. The increasing practice of bilateral mastectomy is not supported by this large single centre experience.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5033.

Effect of tailored practice and patient care plans on secondary prevention of heart disease in general practice: cluster randomised controlled trial

OBJECTIVE

To test the effectiveness of a complex intervention designed, within a theoretical framework, to improve outcomes for patients with coronary heart disease.

DESIGN

Cluster randomised controlled multicentre trial.

SETTING

General practices in Northern Ireland and the Republic of Ireland, regions with different healthcare systems.

PARTICIPANTS

903 patients with established coronary heart disease registered with one of 48 practices.

INTERVENTION

Tailored care plans for practices (practice based training in prescribing and behaviour change, administrative support, quarterly newsletter), and tailored care plans for patients (motivational interviewing, goal identification, and target setting for lifestyle change) with reviews every four months at the practices. Control practices provided usual care.

MAIN OUTCOME MEASURES

The proportion of patients at 18 month follow-up above target levels for blood pressure and total cholesterol concentration, and those admitted to hospital, and changes in physical and mental health status (SF-12).

RESULTS

At baseline the numbers (proportions) of patients above the recommended limits were: systolic blood pressure greater than 140 mm Hg (305/899; 33.9%, 95% confidence interval 30.8% to 33.9%), diastolic blood pressure greater than 90 mm Hg (111/901; 12.3%, 10.2% to 14.5%), and total cholesterol concentration greater than 5 mmol/l (188/860; 20.8%, 19.1% to 24.6%). At the 18 month follow-up there were no significant differences between intervention and control groups in the numbers (proportions) of patients above the recommended limits: systolic blood pressure, intervention 98/360 (27.2%) v control, 133/405 (32.8%), odds ratio 1.51 (95% confidence interval 0.99 to 2.30; P=0.06); diastolic blood pressure, intervention 32/360 (8.9%) v control, 40/405 (9.9%), 1.40 (0.75 to 2.64; P=0.29); and total cholesterol concentration, intervention 52/342 (15.2%) v control, 64/391 (16.4%), 1.13 (0.63 to 2.03; P=0.65). The number of patients admitted to hospital over the 18 month study period significantly decreased in the intervention group compared with the control group: 107/415 (25.8%) v 148/435 (34.0%), 1.56 (1.53 to 2.60; P=0.03).

CONCLUSIONS

Admissions to hospital were significantly reduced after an intensive 18 month intervention to improve outcomes for patients with coronary heart disease, but no other clinical benefits were shown, possibly because of a ceiling effect related to improved management of the disease.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN24081411.

Fluid and electrolyte balance in elite gaelic football players

The aim of this study was to investigate fluid and electrolyte balance in elite Gaelic Football players (n=20) during a typical training session in a warm environment (16 to 18 degrees C, 82-88% humidity). Pre-training urine samples were used to determine hydration status. Sweat sodium concentration was collected from four body site locations using absorbent patches. The mean sweat rate per hour was 1.39 l x h(-1) and mean body mass loss was 1.1%. Mean sweat sodium concentrations were 35 mmol x l(-1) (range 19-52 mmol x l(-1)). On average, players did not drink enough fluid to match their sweat rates (p<0.001) and this fluid deficit was not related to pre-training hydration status (p= 0.67). A single hydration strategy based on published guidelines may not be suitable for an entire team due to variations in individual sweat rates. Maximising player performance could be better achieved by accurate quantification of individual fluid and electrolyte losses.

Developing services for the carers of young adults with early-onset psychosis - implementing evidence-based practice on psycho-educational family intervention

This paper describes a series of practice and service development initiatives to incorporate the family-inclusive approach into the newly established Early Intervention in Psychosis Service in Berkshire, England. Following a local study on carers' experiences and needs from those who cared for a young adult with a first-episode psychosis (FEP), a series of flexible services for this group of carers has been developed incorporating the much-researched psycho-educational family interventions. The findings of our local phenomenological study on the carers for young adults with FEP clearly specified the unique needs of this group of carers and that well-established approaches in family work and carers support facilities may have to be adapted to meet such needs. This paper reports the service development process through which a series of specially designed carers' services were set up for carers caring for a young adult with FEP. These services were developed to address carers' needs for knowledge, skills and support to cope with their caring roles and situation, from the stressful beginning of a potentially long caring journey.

Effects of sequential changes from conventional ventilation to high-frequency oscillatory ventilation at increasing mean airway pressures in an ovine model of combined lung and head injury

BACKGROUND

The objective of this study was to determine the intracranial, cardiovascular and respiratory changes induced by conversion to high-frequency oscillator ventilation from conventional mechanical ventilation at increasing airway pressures.

METHODS

In this study, 11 anaesthetized sheep had invasive cardiovascular and intracranial monitors placed. Lung injury was induced by saline lavage and head injury was induced by inflation of an intracranial balloon catheter. All animals were sequentially converted from conventional mechanical ventilation to high-frequency oscillator ventilation at target mean airway pressures of 16, 22, 28, 34 and 40 cm H(2)O. The mean airway pressure was achieved by adjusting positive end expiratory pressure while on conventional mechanical ventilation, and continuous distending pressures while on high-frequency oscillator ventilation. Cerebral lactate production, oxygen consumption and venous oximetry were measured and analysed in relation to changes in transcranial Doppler flow velocity. Transcranial Doppler profiles together with other physiological parameters were measured at each airway pressure.

RESULTS

Cerebral perfusion pressure was significantly lower during high-frequency oscillator ventilation than during conventional mechanical ventilation (CMV: 45, 34, 22, 6, 9 mmHg vs. HFOV: 33, 20, 19, 5, 5 mmHg at airway pressures mentioned above, P = 0.02). Intracranial pressure and cerebrovascular resistance increased with increasing intrathoracic pressures (P = 0.001). Cerebral metabolic indices demonstrated an initial increase in anaerobic metabolism followed by a decrease in cerebral oxygen consumption progressing to cerebral infarction as intrathoracic pressures were further increased in a stepwise fashion. Arterial PaCO(2) increased significantly after converting from conventional mechanical ventilation to high-frequency oscillator ventilation (P = 0.001). However, no difference was observed between conventional mechanical ventilation and high-frequency oscillator ventilation when intracranial pressure, metabolic and transcranial Doppler indices were compared at equivalent mean airway pressures.

CONCLUSIONS

The use of high positive end expiratory pressure with conventional mechanical ventilation or high continuous distending pressure with high-frequency oscillator ventilation increased intracranial pressure and adversely affected cerebral metabolic indices in this ovine model. Transcranial Doppler is a useful adjunct to intracranial pressure and intracranial venous saturation monitoring when major changes in ventilation strategy are adopted.

Incidence of injury in elite Gaelic footballers

The purpose of this study was to undertake a comprehensive prospective epidemiological study of injuries sustained by elite Gaelic Football players over one season. The pattern of injury is strikingly similar across all teams with 47% of all injuries occurring in the final quarter of games and training. Injuries to the lower limb, particularly the hamstrings muscles accounted for the majority of injuries. 65% of players were unable to participate fully in Gaelic Football activity for between one and three weeks as a result of injury. The high incidence of injury especially hamstrings injuries in the latter stages of training and games warrants further investigation.

Using functional data analysis to summarise and interpret lactate curves

John Tukey used the term exploratory data analysis (EDA) to describe a philosophy for analyzing data where graphical and numerical summaries are used to uncover interesting structures. The applied statistician today has a much more sophisticated set of methods to use when applying the EDA philosophy. One such collection of methods is functional data analysis (FDA), which was used to explore the structure of lactate curves. A principal components analysis and plots of the second derivatives provide new intuitive endurance markers which correlates highly with other numerical summaries of lactate curves that have been suggested in the literature.

Survival ratio plots with permutation envelopes in survival data problems

A new method is proposed, based on a simple ratio plot, which is useful for identifying time intervals or regions in which survival prospects differ between two distinct populations or treatments. In order to investigate whether any observed difference or trend is due to sampling variation or is due to a possible real effect, resampling techniques are used to generate permutation envelopes as reference bands. The method is applicable to the comparison of survival in two populations for both independent and paired survival problems and also to the assessment of the symmetry of a bivariate survival function.

The effect of health status on patients' satisfaction with out-of-hours care provided by a family doctor co-operative

BACKGROUND

Systems for providing primary care outside normal hours have changed significantly in Europe over the last 20 years. The impetus for this change has come almost entirely from the medical profession, and it is important to consider the patients' perspective. Although patient's satisfaction with out-of-hours care has been studied extensively, the effect of patient's health status on satisfaction level has not been examined previously.

OBJECTIVES

The primary objective of this study was to investigate whether health status has an influence on patient satisfaction with out-of-hours care provided by a family doctor co-operative. The secondary objective of this study was to investigate the impact of age, gender, socio-economic status and call outcome on patients' satisfaction with out-of-hours care.

METHODS

All patients contacting the service over a designated 24 day period were forwarded a postal questionnaire. Health status was recorded using the Short Form-12 (SF-12) health survey. Patients' satisfaction was measured by using a version of the McKinley questionnaire.

RESULTS

The response rate was 55% (531 out of 966). Overall satisfaction levels were high, with 88% of patients rating the service as either excellent or good. Logistic regression, modelling for the simultaneous effects of age, gender, socio-economic status, call outcome and health status on overall satisfaction, found that patients with lower physical and mental health status scores were significantly less likely to be satisfied with their out-of-hours care [odds ratio (OR) 1.04, 95% confidence interval (CI) 1.01-1.07, P = 0.017; and 1.03, 95% CI 1.00-1.06, P = 0.046, respectively]. Patients with higher socio-economic status were also significantly less likely to be satisfied (OR 0.25, 95% CI 0.11-0.55, P = 0.001). Patient's age and gender, and call outcome did not significantly affect overall satisfaction levels.

CONCLUSION

Family doctor co-operatives have significantly altered the way out-of-hours care is delivered. Patients with lower health status are significantly less likely to be satisfied with this new form of out-of-hours care. This finding has important implications for the future planning of out-of-hours primary care services.

Reproducibility of the blood lactate threshold, 4 mmol.l(-1) marker, heart rate and ratings of perceived exertion during incremental treadmill exercise in humans

The aim of this study was to investigate the reproducibility of blood lactate measurements, heart rate (HR) and ratings of perceived exertion (RPE) during treadmill exercise at speeds corresponding to the lactate threshold ( v(Th,la)-) and a fixed blood lactate concentration of 4 mmol.l(-1)( v(la)-(,4)). Possible differences in reproducibility related to fitness levels were also investigated. A group of 20 men [mean (SD)] [age 20.5 (1.4) years] and 16 women [age 21.2 (0.9) years] took part in the study. The subjects performed two identical incremental exercise tests consisting of at least six 4 min stages. Blood lactate concentrations, HR and RPE were recorded at the end of each stage. Limits of agreement (LoA), correlation coefficients and 95% confidence intervals for the mean difference between tests were employed to investigate the level of agreement and reproducibility of blood lactate concentration, HR and RPE. For the group as a whole, the sample correlation coefficient for speed at v(Th,la)- was r=0.88, and was r=0.92 for the speed at v(la)-(,4). At v(Th,la) -, the correlation coefficients for the moderately fit and unfit were r=0.94 and r=0.36, respectively, and at v(la)-(,4) r=0.93 and r=0.68, respectively. The LoA for the moderately fit group indicated that a change of 1.62 km.h(-1) in v(Th,la)- would be necessary to be considered a change in training status. For HR and RPE, relationships between the tests were generally poor. The LoA suggested that changes in scores must be unacceptably large. These findings cast doubt on the sensitivity of testing for change of blood lactate concentration, HR and RPE in this population.